# Science questions answered for laymen



## It's Snake Pliskin (15 July 2009)

This thread can be for science questions we laymen might have regarding science.

First question:

*In the vacuum of space* that would be encountered in an Earth orbit would:

*a*. a water bubble or oxygen bubble (gas bubble) move in an undirected way without evident force?
*b*. a water bubble or oxygen bubble (gas bubble) move in a direction evident as though it had force propelling it?

This scenario could be applied to, say a space walk or inside a vehicle capable of carrying man. Even these guys:alien2:


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## jonojpsg (15 July 2009)

It's Snake Pliskin said:


> This thread can be for science questions we laymen might have regarding science.
> 
> First question:
> 
> ...




I like it - a science nerds thread

I would have thought that the Brownian motion of the water molecules inside the droplet *may* impart some motion on the droplet, BUT the net force of the molecules hitting the inside surface may in fact be zero.  

A great video of water in zero g -

http://www.youtube.com/watch?v=cXsvy2tBJlU

PS How do I embed a video in a post?


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## skyQuake (15 July 2009)

It's Snake Pliskin said:


> This thread can be for science questions we laymen might have regarding science.
> 
> First question:
> 
> ...




Ok I'll bite:

First of all there would be no such bubble, the vacuum of space would make it explode.
Excluding centrifugal force, I don't think theres any force propelling it in any specific direction. (assuming it doesnt fall out of orbit)


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## Naked shorts (15 July 2009)

That comes under Newtons first law of motion,

1. A body at rest remains at rest and a body in linear motion remains in motion with constant velocity until and unless an external force is applied on it.

http://en.wikipedia.org/wiki/Newton's_laws_of_motion


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## It's Snake Pliskin (15 July 2009)

skyQuake said:


> Ok I'll bite:
> 
> First of all there would be no such bubble, the vacuum of space would make it explode.
> Excluding centrifugal force, I don't think theres any force propelling it in any specific direction. (assuming it doesnt fall out of orbit)



Thanks skyquake. So a gas bubble would burst or a water bubble would burst or both? Wouldn't the water bubble just float like in the video posted aboove by jonojsp? Thanks jono.


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## It's Snake Pliskin (15 July 2009)

Naked shorts said:


> That comes under Newtons first law of motion,
> 
> 1. A body at rest remains at rest and a body in linear motion remains in motion with constant velocity until and unless an external force is applied on it.
> 
> http://en.wikipedia.org/wiki/Newton's_laws_of_motion




Thanks Naked shorts. So on Earth an oxygen bubble in water that rises rather quickly is propelled by what force?


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## spooly74 (15 July 2009)

It's Snake Pliskin said:


> This thread can be for science questions we laymen might have regarding science.
> 
> First question:
> 
> ...




If it's in Earth orbit it would have a force acting on it, Gravity. How long it stays in orbit depends on its speed.



> So on Earth an oxygen bubble in water that rises rather quickly is propelled by what force?



Air is lighter than water.


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## Buddy (15 July 2009)

It's Snake Pliskin said:


> Thanks Naked shorts. So on Earth an oxygen bubble in water that rises rather quickly is propelled by what force?




If I understand your question correctly........ the answer is buoyancy as explained by Archimedes Principle, which is in summary caused by the differential pressure forces (due to the water) at the top and bottom of the bubble.


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## It's Snake Pliskin (15 July 2009)

spooly74 said:


> If it's in Earth orbit it would have a force acting on it, *Gravity*. How long it stays in orbit depends on its speed.
> 
> Air is lighter than water.



Thanks Spooly. Is there gravity in the vacuum of space? 

For example:

An air bubble comes from the helmet of a cosmonaught as he is doing a space walk. *Would that bubble explode? *or *move because of the gravity force of the Earth due to being in orbit? *

And more importantly what would become of that cosmonaught?



> If I understand your question correctly........ the answer is buoyancy as explained by Archimedes Principle, which is in summary caused by the differential pressure forces (due to the water) at the top and bottom of the bubble.



Thanks Buddy.


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## Naked shorts (15 July 2009)

It's Snake Pliskin said:


> Thanks Naked shorts. So on Earth an oxygen bubble in water that rises rather quickly is propelled by what force?




Gravity.


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## Naked shorts (15 July 2009)

It's Snake Pliskin said:


> Thanks skyquake. So a gas bubble would burst or a water bubble would burst or both? Wouldn't the water bubble just float like in the video posted aboove by jonojsp? Thanks jono.




The bubble of liquid water would turn into a gas if exposed to the vacuum of space. This is because there is no pressure forcing the molecules together.


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## It's Snake Pliskin (15 July 2009)

Naked shorts said:


> Gravity.






> The bubble of liquid water would turn into a gas if exposed to the vacuum of space. This is because there is no pressure forcing the molecules together.




Thanks for your input.


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## Buddy (15 July 2009)

It's Snake Pliskin said:


> Thanks Spooly. Is there gravity in the vacuum of space?




Aah, gravity. It's everywhere, it's everywhere!



> An air bubble comes from the helmet of a cosmonaught as he is doing a space walk. Would that bubble explode? or move because of the gravity force of the Earth due to being in orbit?




It wouldn't really "explode", more like disperse into the vacuum of space. The "air" is subject to exactly the same gravitational forces as the guy with the helmet.



> And more importantly what would become of that cosmonaught?



Gotta watch those peskie Russian cosmonauts. If the "air bubble" is under significant pressure, the Ruskie might find himself going backwards at a significant rate of travel. Newton's laws and all that.


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## happytown (15 July 2009)

It's Snake Pliskin said:


> Is there gravity in the vacuum of space?




galaxies 'collide' and merge courtesy of gravity, eg NGC 5257 & NGC 5258 (currently in the early stages of a cosmic meet 'n greet)

cheers


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## Gillie (15 July 2009)

Naked shorts said:


> The bubble of liquid water would turn into a gas if exposed to the vacuum of space. This is because there is no pressure forcing the molecules together.




Would've thought that the bubble of liquid water would freeze before it had time to turn into gas and escape into the vacuum of space, as long as there were no sunlight, hence there is a force holding the molecular chains together. The real temperature in space is about 3 °K (-270 °C or three degrees Celsius above Absolute Zero). Absolute zero is the temperature in outer space without any sunlight. In sunlight the temperature can rise to 120 °C/ 250 °F (So typically the liquid water bubble would be turned gaseous). There are still molecules in space just very few of them.


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## skyQuake (15 July 2009)

Gillie said:


> Would've thought that the bubble of liquid water would freeze before it had time to turn into gas and escape into the vacuum of space, as long as there were no sunlight. The real temperature in space is about 3 °K (-270 °C or three degrees Celsius above Absolute Zero). Absolute zero is the temperature in outer space without any sunlight. In sunlight the temperature can rise to 120 °C/ 250 °F (So typically the liquid water bubble would be turned gaseous). There are still molecules in space just very few of them.




A ball of ice exploding?

Depends how the ball of water got up there in the first place.
Hollywood has imprinted too much floating globs of water in space stereotype


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## Gillie (15 July 2009)

skyQuake said:


> A ball of ice exploding?
> 
> Depends how the ball of water got up there in the first place.
> Hollywood has imprinted too much floating globs of water in space stereotype




Well, if you think of it, comets are exploding balls of dirt and ice. The coma and tail of the comet is the ice evaporating into space when heated by the sun on it's approach.


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## jono1887 (15 July 2009)

How about a new question... if you were to travel at the speed of light, is it possible to travel back in time?


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## Gillie (15 July 2009)

jono1887 said:


> How about a new question... if you were to travel at the speed of light, is it possible to travel back in time?




Not according to relativity.


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## skyQuake (15 July 2009)

Gillie said:


> Well, if you think of it, comets are exploding balls of dirt and ice. The coma and tail of the comet is the ice evaporating into space when heated by the sun on it's approach.




Yup, that water was already attracted to the comet by gravity and was already frozen.

However if you magically get a 'ball' of water into space, would it freeze first or dissipate or explode?


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## Buddy (15 July 2009)

jono1887 said:


> How about a new question... if you were to travel at the speed of light, is it possible to travel back in time?




No. According to the special theory of relativity you would in fact "go forward" in time faster ("apparently") than those you last saw. Although there are new theories under development that may supersede the special theory.

Of course you can always apply a paradox to say No. ...... if reverse time travel is possible, how come we have not seen any time travellers from the future? Another paradox is that future time travellers would impact the past, which impacts the future. My head spins in circles thinking about that.

On the other hand, maybe it's because we are too boring to visit.


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## Naked shorts (15 July 2009)

jono1887 said:


> How about a new question... if you were to travel at the speed of light, is it possible to travel back in time?




No, you travel forward in time (relative to people not moving as fast).


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## Naked shorts (15 July 2009)

Buddy said:


> Of course you can always apply a paradox to say No. ...... if reverse time travel is possible, how come we have not seen any time travellers from the future? Another paradox is that future time travellers would impact the past, which impacts the future. My head spins in circles thinking about that.
> 
> On the other hand, maybe it's because we are too boring to visit.




No, you can only go back in time to when the time machine was created. We have no time machine today so thats why we havent been visited yet.


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## Buddy (15 July 2009)

Naked shorts said:


> No, you can only go back in time to when the time machine was created. We have no time machine today so thats why we havent been visited yet.




That sounds like another paradox to me. I prefer the "too boring" line, if in fact it were/is/will be possible. Which it isn't/wasn't/willn't. Eh?


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## mayk (15 July 2009)

jono1887 said:


> How about a new question... if you were to travel at the speed of light, is it possible to travel back in time?



No. Forward travel is possible, because of relative time. Backward is impossible. Existence precedes essence and what not!


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## Gillie (15 July 2009)

skyQuake said:


> Yup, that water was already attracted to the comet by gravity and was already frozen.
> 
> However if you magically get a 'ball' of water into space, would it freeze first or dissipate or explode?




None of the above - it's called desublimation. water boils violently and then forms ice crystals immediately from the gas.


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## Naked shorts (15 July 2009)

Buddy said:


> That sounds like another paradox to me. I prefer the "too boring" line, if in fact it were/is/will be possible. Which it isn't/wasn't/willn't. Eh?




There is talk that it is possible. Plenty of information on the web about ways it can be done.


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## Gillie (15 July 2009)

mayk said:


> No. Forward travel is possible, because of relative time. Backward is impossible. Existence precedes essence and what not!




True, but i wouldn't really call it time travel because those travelling at the speed of light would effectively perceive time as being standard. Whereas here on earth time would be faster. Take for example a communications satellite in orbit above the earth, it has to adjust its internal clock by 1/4 of a sec a day down travelling at 30,000 km/hr.


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## Gillie (15 July 2009)

Naked shorts said:


> There is talk that it is possible. Plenty of information on the web about ways it can be done.




Then why has no one actually done it?


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## Naked shorts (15 July 2009)

Gillie said:


> Then why has no one actually done it?




Lack of technology.


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## Buddy (15 July 2009)

Gillie said:


> Then why has no one actually done it?




Take your pick:-
(a) Impossible
(b) Too hard 
(c) Don't know how to


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## Naked shorts (15 July 2009)

If i might add, they have done it with quantum entanglement (or tunneling, i forget). I heard Dr Karl describing an experiment that happened recently where they managed to teleport a photon of light, thing is, it went faster then the speed of light...the teleportation happened instantly. By logical deduction, in the frame of the receiver, the photon was received before it was sent.... meaning it traveled back in time. So yes, time travel is possible and its been done. Just not with anything substantial in size.

The universe is crazy.


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## Buddy (15 July 2009)

Naked shorts said:


> The universe is crazy.




Yes. And......... So what about string theory - everything is held together by "string".   And "dark matter" and "gravitational waves". Both of which have only been hypothesised but not proven.

I would say wrt time travel, that I was only basing my answer on current theory (eg special relativity).  Who knows what the "future" will bring. We have only just scratched the surface so far. The paradoxes are hard to overcome though.


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## It's Snake Pliskin (17 July 2009)

Buddy said:


> It wouldn't really "explode", *more like disperse into the vacuum of space.* The "air" is subject to exactly the same gravitational forces as the guy with the helmet.
> 
> If the "air bubble" is under significant pressure, the Ruskie might find himself going backwards at a significant rate of travel. Newton's laws and all that.



Thanks for that Buddy. 
So in conclusion an air leak in space would be catastrophic. And an air bubble would not rise in one direction like it would under water on Earth. This is helping answer some questions I had.  
Thanks.


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## moses (17 July 2009)

skyQuake said:


> Yup, that water was already attracted to the comet by gravity and was already frozen.
> 
> However if you magically get a 'ball' of water into space, would it freeze first or dissipate or explode?




Explode. 

Liquid needs pressure, so in the absence of pressure the ball water would turn to vapour and effectively explode. Any water vapour subsequently contacting a very cold surface might freeze on that surface.


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## moses (17 July 2009)

It's Snake Pliskin said:


> Thanks for that Buddy.
> So in conclusion an air leak in space would be catastrophic. And an air bubble would not rise in one direction like it would under water on Earth. This is helping answer some questions I had.
> Thanks.




Yes. The air would dissipate so quickly it may as well not exist. The average speed of a molecule of air from a space suit or capsule at room temperature is about 1000km/h, and in space there are effectively no other molecules to confine or deflect its movement. So once it escapes it is gone, there would be no bubbles.


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## It's Snake Pliskin (17 July 2009)

moses said:


> Yes. The air would dissipate so quickly it may as well not exist. The average speed of a molecule of air from a space suit or capsule at room temperature is about 1000km/h, and in space there are effectively no other molecules to confine or deflect its movement. So once it escapes it is gone, *there would be no bubbles.*




Thanks Moses for your contribution.


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## spooly74 (17 July 2009)

moses said:


> Explode.
> 
> *Liquid needs pressure*, so in the absence of pressure the ball water would turn to vapour and effectively explode. Any water vapour subsequently contacting a very cold surface might freeze on that surface.




The pressure wouldn't effect the temp of the water directly, as it's not a gas. But, as the pressure drops below the point where water boils at room temperature, it would start to boil, as Gillie suggested earlier. However, as there is not sufficent energy in the water to continue completly boiling because it requires 2,270 kJ/kg to vapourise, it would start to freeze.
Its proximity to the Sun would determine how the remainder behaves.


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## Gillie (17 July 2009)

Naked shorts said:


> If i might add, they have done it with quantum entanglement (or tunneling, i forget). I heard Dr Karl describing an experiment that happened recently where they managed to teleport a photon of light, thing is, it went faster then the speed of light...the teleportation happened instantly. By logical deduction, in the frame of the receiver, the photon was received before it was sent.... meaning it traveled back in time. So yes, time travel is possible and its been done. Just not with anything substantial in size.
> 
> The universe is crazy.




Think you might have you wires a bit crossed here (sorry for the pun). Quantum entanglement is more like creating a facsimilie of the counterpart. Whereas, quantum tunnelling is more to do with passing through objects in a solid state and uses the heisenberg uncertainty principle(essentially all your particals in your body are still solid but not solid at the same time, eg they are out of phase - many a sci fi tv show has used this concept.)

I agree with your last quote, the universe is a crazy place and it has alot to answer for!


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## The_Bman (17 July 2009)

I have a question Google has failed in answering thus far:

Is there a Thermocouple or Thermopile which only cools when electricity is applied?

*Note:*- The cooling effect cannot be offset by an equal heating effect e.g. Peltier.


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## It's Snake Pliskin (18 July 2009)

It's Snake Pliskin said:


> Thanks for that Buddy.
> So in conclusion an air leak in space would be catastrophic. And an air bubble would not rise in one direction like it would under water on Earth. This is helping answer some questions I had.
> Thanks.






> Yes. The air would dissipate so quickly it may as well not exist. The average speed of a molecule of air from a space suit or capsule at room temperature is about 1000km/h, and in space there are effectively no other molecules to confine or deflect its movement. So once it escapes it is gone, *there would be no bubbles.*



Once again thankyou moses.

Considering the answers to my initial questions on this thread and that of the above could someone explain how these guys have air bubbles floating upwards whilst doing a spacewalk? (more like a spacehanging on)


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## spooly74 (19 July 2009)

It's Snake Pliskin said:


> Once again thankyou moses.
> 
> Considering the answers to my initial questions on this thread and that of the above could someone explain how these guys have air bubbles floating upwards whilst doing a spacewalk? (more like a spacehanging on)



Are they definitely air bubbles


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## It's Snake Pliskin (19 July 2009)

spooly74 said:


> Are they definitely air bubbles



Spooly,
Looks like it to me. We are led to believe that it is debris after opening the hatch but the part of the walk is minutes after the opening so all debris would have been ejected in the first few seconds. Considering it comes from the guy in the suit why does it rise? Why not just float near him if it is debris. _*It rises quickly.*_ Suspect to say the least.


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## Aurum (19 July 2009)

Why are there spiral galaxies?

Stars further from the center move slower and so this would explain how the spiral forms. However, after a few turns wouldn't it be jumbled up and no longer a spiral.

Mike.


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## Chris45 (19 July 2009)

Re the discussion of space walks: I wonder if anyone remembers the “space walk” sequence from Kubrick’s “2001: A Space Odyssey” when Dave is locked out of the spaceship in his spacepod but without his helmet by Hal and Dave then enters the ship manually through the emergency air lock?

I have always thought that that was a glaring impossibility because as soon as Dave was ejected into the vacuum of space, the sudden total decompression would surely cause his blood to boil throughout his body causing instant death. Even if he didn’t die instantly, I figured the mass of bubbles that would form in the blood vessels in his brain would so severely interfere with his brain function he would be incapable of any coordinated activity like searching for and turning a handle.

Then I discovered this: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.html

Well, whaddaya know!


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## xyzedarteerf (19 July 2009)

if i travel too far into the future i would eventually see myself?
if i have telescope that can see so far i would eventually see the back of my head?


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## Chris45 (19 July 2009)

xyzedarteerf said:


> if i travel too far into the future i would eventually see myself?



You can't travel into the future. It hasn't yet happened.



xyzedarteerf said:


> if i have telescope that can see so far i would eventually see the back of my head?



If light is bent by gravity and circles around the universe, and if you lived long enough, that might be possible but you would see the back of your head as it was a zillion years ago.


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## Chris45 (19 July 2009)

Have you ever wondered why an electric jug makes so much noise when it's heating up and then becomes quieter when it gets to the boil?


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## 2020hindsight (19 July 2009)

Chris45 said:


> ..If light is bent by gravity and circles around the universe, and if you lived long enough, that might be possible but you would see the back of your head as it was a zillion years ago.



ok - suppose you're bald by then, and the back of your head is real shiny  - 

Would you see your own image? 
When would the image appear?
How old would the face of the image be?

(PS "Real old" is not an acceptable answer - but it's the only one I'm prepared to guess - either that or "real young") 

PS As they say (I think), when we see a new star/ solar system say 230- 65 mill light years ago, and if it was in phase with earth in time / development - then presumably you'd get to see dinosaurs (?)



Chris45 said:


> Have you ever wondered why an electric jug makes so much noise when it's heating up and then becomes quieter when it gets to the boil?




hey Chris - is it because the jug turns itself off when it boils ?


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## 2020hindsight (19 July 2009)

If a golf ball goes further because of the dimples ...
does that mean that a car with hail damage goes faster ?


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## trainspotter (19 July 2009)

When I start my Quantum Wave Particle Generator up it tends to throw the rest of the electronics in the house into chaos. Would I be better off shielding the entire room with lead or just turn off the electronics prior to experimenting on sub atomic particles?


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## 2020hindsight (20 July 2009)

trainspotter said:


> When I start my Quantum Wave Particle Generator up it tends to throw the rest of the electronics in the house into chaos. Would I be better off shielding the entire room with lead or just turn off the electronics prior to experimenting on sub atomic particles?



I just take mine up the back paddock a coupla hundred metres.
Mind you, it sends the bludy roos into a right tizzy.


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## Happy (20 July 2009)

Chris45 said:


> Have you ever wondered why an electric jug makes so much noise when it's heating up and then becomes quieter when it gets to the boil?





Electric element in current kettles is about or above 2000 W and it is concealed below bottom, which boils water right at the bottom before it has chance to go toward surface due to lowered density. But layer immediately above is much colder, which caused created bubbles to collapse in a process called cavitation and this is responsible for so much noise.

Sold as 'Whisper quiet kettle' electric jugs have this process reduced to so some extent, by having perforated plate placed about 2 or 3 mm above the bottom.

Best solution would be to go back to 1200W or 1500W kettle with not concealed but submerged element, which allows better circulation of water.

Noisy kettle can be made little bit quieter by throwing towel over it and covering spigot with spoon, but surely this will affect the way family and friends perceive you.


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## Ardyne (20 July 2009)

i think the golf ball flies straighter not further


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## bassmanpete (20 July 2009)

> solar system say 230- 65 mill light years ago




As a light year is a unit of distance that should be away not ago.[/pedant mode]


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## 2020hindsight (20 July 2009)

bassmanpete said:


> ... should be away not ago.[/pedant mode]



way to go mate 
btw, I think the moon is a lightsecond away from memory (?) - so when we watched the Armstrong walk, if you were watching his step start, then you'd already missed it because it finished (almost) a second ago (plus the other transmission delays) 


Ardyne said:


> i think the golf ball flies straighter not further



thanks ardnye
remind me never to hit an undimpled golf ball.


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## trainspotter (20 July 2009)

Ardyne said:


> i think the golf ball flies straighter not further




Not when I hit it !


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## Chris45 (20 July 2009)

2020hindsight said:


> ok - suppose you're bald by then, and the back of your head is real shiny  -
> 
> Would you see your own image?
> When would the image appear?
> How old would the face of the image be?



ROFL ... Good questions!!! OK, so if light takes a zillion years to circle the universe, then:
1 zillion for the light reflected from your face now, to circle round to the back of your then zillion year old shiny bald head;
1 zillion for the reflection of your current face to come back to your then 2 zillion year old eyes.
However, you probably wouldn't be there to see it because you would have long ago lost interest staring into the telescope waiting for it to appear and would have gone off to watch the latest incarnation of "Biggest Loser" instead. (That's unless the light took a shortcut via a wormhole, in which case, it's anyone's guess.) 



2020hindsight said:


> PS As they say (I think), when we see a new star/ solar system say 230- 65 mill light years ago, and if it was in phase with earth in time / development - then presumably you'd get to see dinosaurs (?)




Why does everyone assume that life has to exist elsewhere in the universe? Every invention has to have a prototype and I think we're probably the "prototype" of life in our universe. When you throw a stone into a pond, there's always a first ripple. We're it. If life is so easily created, why haven't our best and brightest been able to whip up a microbe, or two, in the lab from the basic starting materials?

If we fail, and somehow wipe ourselves out or get wiped out by some cataclysmic natural event, then assuming that all life here is not completely destroyed, the next version of "us" should be an improvement just as we are an improvement on the dinosaurs that ruled before us.

However, to answer your question, yes. Assuming life is ubiquitous in our universe and in phase with Earth's development, if you could see a very distant planet with an environment identical to ours, you might just see dinosaurs etc.

Whether or not there's life in the parallel universe immediately adjacent to ours is another question. What do you think?



2020hindsight said:


> hey Chris - is it because the jug turns itself off when it boils ?



 Aaaahhh of course! Why didn't I think of that???


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## white_crane (20 July 2009)

If you want to look back in time, all you have to do is open your eyes?  As light takes an amount of time to reflect off an object and travel to your eyes and into your brain to where it is perceived aren't we in fact always looking at the past?  e.g.  If we look through a telescope at a star that is 5 light years away, we are seeing the star as it was 5 years ago.

Also,
If a point in space was bent by gravity so much that the space/time continuum folded back upon itself, could we then travel instantaneously from one place to another many light years away - and thus travel faster than the speed of light?


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## Chris45 (20 July 2009)

Happy said:


> Electric element in current kettles is about or above 2000 W and it is concealed below bottom, which boils water right at the bottom before it has chance to go toward surface due to lowered density. But layer immediately above is much colder, which caused created bubbles to collapse in a process called cavitation and this is responsible for so much noise.



That's what I thought too. Just looking for confirmation.



Happy said:


> Sold as 'Whisper quiet kettle' electric jugs have this process reduced to so some extent, by having perforated plate placed about 2 or 3 mm above the bottom.



I didn't know about those. My $10 cheapy jug sounds like a Space Shuttle launch every time I make a cup of coffee and I have to turn my TV up to full volume. The neighbours always know what I'm watching.



Happy said:


> Best solution would be to go back to 1200W or 1500W kettle with not concealed but submerged element, which allows better circulation of water.



Yes I used to have one. So simple to use, but took a bit of planning. Add 1 cup of cold water and switch on. Go and do the weekly shopping and the water would just be coming to the boil when I got back.



Happy said:


> Noisy kettle can be made little bit quieter by throwing towel over it and covering spigot with spoon, but surely this will affect the way family and friends perceive you.



Not me. Everyone already perceives me as "different".


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## Chris45 (20 July 2009)

white_crane said:


> If a point in space was bent by gravity so much that the space/time continuum folded back upon itself, could we then travel instantaneously from one place to another many light years away - and thus travel faster than the speed of light?



I think that's what those wormholes are; "shortcuts" in the space/time continuum. So if you could find the door to a wormhole, it would be like someone taking a shortcut via a tunnel through a mountain compared with another taking the long way around the mountain. You would travel faster than the light that took the normal route but not faster than the light that accompanied you through the wormhole.

What condition you'd be in when you came out of the wormhole is another question.


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## bassmanpete (20 July 2009)

> i think the golf ball flies straighter not further




The ball goes farther because the dimples reduce drag. The backspin produced by the loft of the club face produces lift which also adds to the distance a ball can travel.

Sidespin is imparted to the ball when the club face isn't perpendicular to the line of the swing, thus causing a hook or a slice. As I know only too well, the dimples accentuate this effect


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## 2020hindsight (20 July 2009)

Chris45 said:


> 1. ... However, you probably wouldn't be there to see it because you would have long ago lost interest staring into the telescope waiting for it to appear and would have gone off to watch the latest incarnation of "Biggest Loser" instead.
> 
> 2. Why does everyone assume that life has to exist elsewhere in the universe? Every invention has to have a prototype and I think we're probably the "prototype" of life in our universe.
> 
> 3. If we fail, and somehow wipe ourselves out or get wiped out by some cataclysmic natural event, then assuming that all life here is not completely destroyed, the next version of "us" should be an improvement just as we are an improvement on the dinosaurs that ruled before us.




howdy Chris
1. yep -  and I bet, when you'd finished watching for a zillion years, and there was finally a brief gap in the clouds and/or cosmic dust through which you're presumably peering - that you saw just the telescope, because you're off at the pub for a quick beer.  

2.   Sagan on the Drake Eqn  - he comes up with 10 civilisations out there capable of communicating with us - now, today   - here's the link to a previous post...
https://www.aussiestockforums.com/forums/showthread.php?p=307212

3. No question we will go the way of  hundreds / thousands / whatever of planets before us that had life.  - For a start the sun will burn out "one of these days"   ;  - and with that  -  here's mud in your eye!

....And Yep, it was just a fluke that an asteroid hit and the dinosaurs died leaving the "evolutionary space" for us to develop - no asteroid, there would have been no us - we are indeed a fluke of the universe   - cheers. 

PS Heres' a poem on Einstein etc :-
https://www.aussiestockforums.com/forums/showthread.php?p=88164 
PPS Something eerie about whitecrane talking about the universe lol.  I feel I'm back watching StarWars 8.


----------



## 2020hindsight (20 July 2009)

hey Chris, speaking of which ...

Why do they call it an as-teroid when it's outside the hemisphere,

... but call it a hemorrhoid when it's in your butt?


----------



## kincella (20 July 2009)

why do 40% more men die from cancer....I just heard my 95 year old neighbour has bowel cancer.......and last year a friend of a friend died aged 41....he knew for 12 months before and never told anyone....
are men too afraid to go to the doctor...???
ps if this is the wrong thread.....sorry....

http://www.nursingtimes.net/whats-n...to-die-from-cancer-than-women/5002936.article


----------



## Chris45 (20 July 2009)

Chris45 said:


> However, you probably wouldn't be there to see it because you would have long ago lost interest staring into the telescope waiting for it to appear and would have gone off to watch the latest incarnation of "Biggest Loser" instead.



Hi 2020hindsight,
Damn! I just reread that. I hope you didn't take that as an insult because it certainly wasn't meant to be. Just my weak attempt at humour.  Cheers.


----------



## 2020hindsight (20 July 2009)

Chris45 said:


> Hi 2020hindsight,
> Damn! I just reread that.



jeez, lol, no need to apologise.  I watch only a few TV shows, but the rest of the family seem to make up for it - screams of excitement last night for instance because someone cooked a plate of bludy chicken stir fry or something lol  
  "So WHO will be crowned the first Master Chef? -   pregnant pause.......  another pause, even more pregnant ...... .  "You'll find out after this set of 18 advertisements" ...


----------



## 2020hindsight (20 July 2009)

Quote by someone I forget ...
"As for the challenge of making life in a laboratory ?   - dead simple, with a sufficiently attractive lab assistant"


----------



## Chris45 (20 July 2009)

2020hindsight said:


> 2.   Sagan on the Drake Eqn  - he comes up with 10 civilisations out there capable of communicating with us - now, today   - here's the link to a previous post...
> https://www.aussiestockforums.com/forums/showthread.php?p=307212




I haven't read through the whole thread but I've just watched the Sagan video. Some fancy mathematics there but too many wild estimates and assumptions for my liking. (fl=0.5???) I know many people want us to believe that we're not alone (maybe their continued funding depends on it) but the fact that we haven't yet discovered any solid evidence of extraterrestrial life, despite a pretty good effort by some, leads me to think that maybe there is none to find and that we are the prototype. 

Whatever happened to those fossilized microbes they were supposed to have found on Mars?

I will remain a skeptic until either solid evidence is found or someone can demonstrate that "the molecules of life spontaneously self-assemble", as Sagan claims. Until then, all options remain on the table IMHO.

Re Master Chef: I think I'm in synch with you there. I watched the semifinal with my sister (she LOVES all those programs). I nearly threw something at the TV with all those pathetic pregnant pauses and suspense music. 

I'll contact my constipated mathematician mate and we'll work on that hemorrhoid question. BTW, don't you mean *ass*-teroid??? And the ones that women get, are they "shemorrhoids"? 



2020hindsight said:


> Quote by someone I forget ...
> "As for the challenge of making life in a laboratory? - dead simple, with a sufficiently attractive lab assistant"



Brilliant!!! 
 ... Cheers.


----------



## tech/a (20 July 2009)

Son is a Doctor of Physics.
Ive pointed him to this thread but he cant be bothered. Plus hes pretty damned busy.
Pity have had some amazing discussions with him.
I cant believe what science actually knows.


----------



## bassmanpete (20 July 2009)

> I haven't read through the whole thread but I've just watched the Sagan video. Some fancy mathematics there but too many wild estimates and assumptions for my liking. (fl=0.5???) I know many people want us to believe that we're not alone (maybe their continued funding depends on it) but the fact that we haven't yet discovered any solid evidence of extraterrestrial life, despite a pretty good effort by some, leads me to think that maybe there is none to find and that we are the prototype.




Hi Chris45. Much as I would like to believe that there is other "intelligent" life in the Universe, I agree with you that the Drake equation has too many numbers plucked out of thin air. When you consider that there are more galaxies in the Universe than there are stars in the Milky Way, I think that there probably are other life forms somewhere out there. Whether any have reached or surpassed our level of civilisation is another matter, and if any have, are any of them around at the same time as we are? I think maybe George Lucas had the same thoughts when he started the Star Wars movies with "A long time ago, in a galaxy far, far away..."

I used the quotes around the word intelligent because I think that the vast majority of humans are really only smarter or more cunning than other species on the planet. If they were REALLY intelligent they wouldn't be stuffing up their future prospects of survival the way they are.


----------



## tech/a (20 July 2009)

Would you really like to be discovered by intelligent life that could travel through Galaxy's.

What if they saw Humans as a delicacy like a lobster?
Were so powerful we were just rounded up like cattle without even a notion towards OUR values in life.

Be quiet very very quiet.


----------



## 2020hindsight (20 July 2009)

bmp said:
			
		

> 1. Drake equation has too many numbers plucked out of thin air
> 
> 2.When you consider that there are more galaxies in the Universe than there are stars in the Milky Way, I think that there probably are other life forms somewhere out there




Two opposing views there bassman 
PS - no biggie  

Just looking at that point that Sagan only considers the Milky Way ( with 400 billion stars 400E9 assumed   - and they now believe there's a total number of stars in the observed universe of 'heaps"! - Ive seen estimates of 1E23 or 100000E18.  or 250E9 times as many as Milky Way. 

So if there are 10 civilisations in the milky way capable of extra terrestrial communication,  *then there are 250 billion in the observable universe*.  (E&OE) (oops 10x250 billion!) 

And the entire universe could be 1000 times larger again !!...



> According to the theory of cosmic inflation and its founder, Alan Guth, the entire universe could be (at least) 1023 to 1026 times as large in volume as the observable universe. For comparison: assuming a factor of 1024, then *the observable universe in comparison with the entire universe would be about the same as .... an orange in comparison with the earth*.




Moving on....
I ran across this quote lol - what a ripper -  there is a chance you'll count the same stars twice - because the light is going round and round  

http://en.wikipedia.org/wiki/Observable_universe



> It is also possible that the universe is smaller than the observable universe. In this case, *what we take to be very distant galaxies may actually be duplicate images of nearby galaxies, formed by light that has circumnavigated the universe. It is difficult to test this hypothesis experimentally because different images of a galaxy would show different eras in its history, and consequently might appear quite different*.


----------



## Chris45 (20 July 2009)

bassmanpete said:


> I used the quotes around the word intelligent because I think that the vast majority of humans are really only smarter or more cunning than other species on the planet. If they were REALLY intelligent they wouldn't be stuffing up their future prospects of survival the way they are.



Yes, I agree that it's really a relative term. I heard a while ago about a lonely old guy who suffered a stroke and was lying paralyzed on the floor and his dog got a piece of clothing, dunked it in the toilet bowl and carried it to him and placed it on his mouth so he could suck the moisture out of it. I thought that was an amazing example of intelligence for a dog.



tech/a said:


> Would you really like to be discovered by intelligent life that could travel through Galaxy's.
> What if they saw Humans as a delicacy like a lobster?
> Were so powerful we were just rounded up like cattle without even a notion towards OUR values in life.
> Be quiet very very quiet.



I definitely agree with that! Friendly cuddly ETs - no way!


----------



## bassmanpete (20 July 2009)

> two opposing views there bassman.




I don't think they're opposing. There could very well be life out there. Whether any of it takes the form of something we could have a conversation with is something else entirely!


----------



## 2020hindsight (20 July 2009)

tech].... Were so powerful we were just rounded up like cattle without even a notion towards OUR values in life.
Be quiet very very quiet.[/QUOTE]

M8 said:


> PS.  Here's one of the priests of my religion
> 
> http://au.youtube.com/watch?v=p86BPM1GV8M
> Carl Sagan: Pale Blue Dot
> ...





PS bassman - I withdraw that comment about two opposing views - sorry. no offence intended.


----------



## trainspotter (20 July 2009)

You are all too late. They already walk among us. Have you not seen MIB and Transformers?  I personally know some people who are DEFINITLEY NOT of this earth. I have witnessed them at a dinner party. Alien life forms.


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## 2020hindsight (20 July 2009)

trainspotter said:


> .. I have witnessed them at a dinner party. Alien life forms.



At the risk of being accused of personal abuse lol - 
I'm guessing there was alcohol at said dinner party trainspotter.


----------



## Chris45 (21 July 2009)

tech/a said:


> Would you really like to be discovered by intelligent life that could travel through Galaxy's.
> What if they saw Humans as a delicacy like a lobster?
> Were so powerful we were just rounded up like cattle without even a notion towards OUR values in life.
> Be quiet very very quiet.



Probably too late for that now tech. Don't forget we've been broadcasting our existence to the universe since the days of Morse Code. I bet there are a couple of giant trawlercrafts heading our way right now, racing to see who can be the first to bring this succulent new delicacy to the universal food market. No doubt their excitement is escalating as they start to receive the first images of Biggest Loser.


----------



## 2020hindsight (21 July 2009)

Chris45 said:


> ...racing to see who can be the first to bring this succulent new delicacy to the universal food market.



:topic
Reminds me of this Larson (Far Side)


----------



## Beej (21 July 2009)

Chris45 said:


> Probably too late for that now tech. Don't forget we've been broadcasting our existence to the universe since the days of Morse Code. I bet there are a couple of giant trawlercrafts heading our way right now, racing to see who can be the first to bring this succulent new delicacy to the universal food market. No doubt their excitement is escalating as they start to receive the first images of Biggest Loser.




This is basically the plot to Peter Jacksons (of Lord of The Rings fame) first movie - a spectacturaly funny ultra-low budget kiwi flick called "Bad Taste"! A must see fillum.... 

A memorable quote goes something like: "It's amazing how little space a whole town full of people take up if you cut off the fat and shove them in a bunch of cardboard boxes!" 

Cheers,

Beej


----------



## tech/a (21 July 2009)

Which leads me to the question.

There are 6,000,000,000 on this planet.
If I had a box big enough how big would it
have to be to stack everyone in the box like Sardines?


----------



## derty (21 July 2009)

I can give you a rubbery answer to a rubbery question.

You need to know the average density of a human, the average weights of humans by age and gender and the global %'s of these age groups.

The desity of a human is close enough to water  = 1kg/litre

Average weight/mass. Male = 70kg, female = 61kg and child a rubbery 25kg.
http://hypertextbook.com/facts/2003/AlexSchlessingerman.shtml

The % distribution of ages is 0-14 = 27.3% 15+ 72.7% (assume 50-50 male to female).
http://www.indexmundi.com/world/demographics_profile.html

If you do the maths that gives a total global human mass of 326,661,000 tonnes. Now at a density of 1 a tonne takes up one cubic metre. 

So if you blend the human race up you could fit them into a box that is the cube root of 326,661,000. That cube would have sides 688.7m long. 

Have attached a .xls for the maths  feel free to correct me if i'm wrong.


----------



## Timmy (21 July 2009)

derty said:


> So *if you blend the human race up* you could fit them into a box that is ....
> 
> feel free to correct me if i'm wrong.




Oh yes, 

You are soooo wrong derty LOL


----------



## tech/a (21 July 2009)

derty said:


> I can give you a rubbery answer to a rubbery question.
> 
> You need to know the average density of a human, the average weights of humans by age and gender and the global %'s of these age groups.
> 
> ...





Pretty good.

Allowing for a bit of space 1 cubic kilometer.
I found that quite amazing.
So few can stuff up so much.


----------



## Gillie (21 July 2009)

tech/a said:


> Pretty good.
> 
> Allowing for a bit of space 1 cubic kilometer.
> I found that quite amazing.
> So few can stuff up so much.




Considering that the estimated population is currently 6.7 bln we will need the extra 300 cubic metres sooner rather than later.

Hope they bring a cargo container big enough.... LOL


----------



## derty (21 July 2009)

tech/a said:


> Pretty good.
> 
> Allowing for a bit of space 1 cubic kilometer.
> I found that quite amazing.
> So few can stuff up so much.



Those extra few hundred metres make a big difference to the volume of a cube. You could fit over 18 billion blended humans into a cubic km


----------



## beamstas (21 July 2009)

what does fire do in zero gravity


----------



## nunthewiser (21 July 2009)

ok .........

why does the water swirl in different directions when one emptys the sink? ie in oz it swirls one way ....... in the uk it swirls the opposite way


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## 2020hindsight (21 July 2009)

derty said:


> So if you blend the human race up you could fit them into a box that is the cube root of 326,661,000.[cubic metres]



Jeez, we were planning to have stir fry tonight too.  

Btw, would the last bloke have to turn the blender off - or would you set it on auto-timer?

PS The Sydney Harbour Bridge under deck is 50m wide x 50m high (off the water) x 500m between the springing points of the arch . 
So the volume under the deck is approx 50x50x500 - subtract the bits of the arch under the deck at the ends = 1,000,000 cubic metres.  
= 1,000,000 tonnes of water. (or "mousse blend"). (= 1 gL.)

The volume of Sydney Harbour - 520 gL from memory. = 520,000,000 cubic metres. 
Hence the entire "blend" wouldn't even fill Sydney Harbour.  (E&OE).


----------



## 2020hindsight (21 July 2009)

nunthewiser said:


> ok .........
> 
> why does the water swirl in different directions when one emptys the sink? ie in oz it swirls one way ....... in the uk it swirls the opposite way



or (similarly) why do cyclones (Sth Hemi) swirl clockwise, whilst the Typhoons, Tornadoes etc  (Nth Hemi) swirl anticlockwise?
(I'm guessing in the case of Tornadoes).

What would happen if they collided at the equator?


----------



## 2020hindsight (21 July 2009)

PS Further to the gL under the deck...

And if you extrude that shape (effectively 400m mean width x 50m high) from the heads to Parramatta ( very very roughly 26km) then you have 520gL = 1 Syd Harbour.


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## Chris45 (21 July 2009)

2020hindsight said:


> Btw, would the last bloke have to turn the blender off - or would you set it on auto-timer?



The last bloke would have to get used to having sausages every night for the rest of his life.  ..... OK, OK, OK I hear you. I'll shutup.


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## Chris45 (21 July 2009)

2020hindsight said:


> or (similarly) why do cyclones (Sth Hemi) swirl clockwise, whilst the Typhoons, Tornadoes etc  (Nth Hemi) swirl anticlockwise?
> (I'm guessing in the case of Tornadoes).
> What would happen if they collided at the equator?



It's called the Coriolis effect and is due to the Earth's rotation.
http://en.wikipedia.org/wiki/Coriolis_effect


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## 2020hindsight (21 July 2009)

Chris45 said:


> It's called the Coriolis effect and is due to the Earth's rotation.
> http://en.wikipedia.org/wiki/Coriolis_effect




ahh I tried explaining it to my mate, and he said "ahh so the Earth rotates Clockwise in the Sth Hemisphere, and Anticlockwise in the Nth.?"

I guess when you think about it - when you view down on the pole, (Arctic or Antarctic) - either way, the cyclone spins in the same direction as the Equator (west to east) 

Here's another question.
How many times does the Earth rotate (relative to a distant star, say Aries) in a year. ?


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## 2020hindsight (21 July 2009)

If a scuba diver drew in 1/2 of a lungful of air whilst at say 10m using
a) a tank and a regulator, or
b) a length of hose to the surface, 
and then came to the surface without exhaling,
would there be any difference in the outcome (i.e. between a) and b)) ?
(Never thought of it before, - but either way he starts with 1/2 a lungful of air  )


----------



## Buddy (21 July 2009)

2020hindsight said:


> If a scuba diver drew in 1/2 of a lungful of air whilst at say 10m using
> a) a tank and a regulator, or
> b) a length of hose to the surface,
> and then came to the surface without exhaling,
> ...




Boyles Law...... PV=k.
I suggest exhaling would be a really good idea.


----------



## Chris45 (21 July 2009)

beamstas said:


> what does fire do in zero gravity



Now that's a good question! 
I assume you're talking about an oxygenated atmosphere in zero gravity, like in a spaceship?
Explosions are easy - they just swirl outwards equally in all directions, but a fire say, like a candle flame ... ??? Hmmm!
I'm guessing here that since a flame relies on convection to feed it with oxygen (the ot hair rises), and convection relies ultimately on gravity, in zero gravity there would be no convection hence no new oxygen coming in to feed the flame so the wick would be surrounded by CO2 and would extinguish very quickly, ... that's if it ever got started.
And that's probably why NASA discourages smokers from trying to become astronauts and astronauts having candlelit dinners on board.


----------



## Buddy (21 July 2009)

P.S. No difference between (a) & (b), as in both cases he is "breathing in" at a pressure of 10m water.


----------



## Chris45 (21 July 2009)

2020hindsight said:


> Here's another question.
> How many times does the Earth rotate (relative to a distant star, say Aries) in a year. ?



365 1/4?


----------



## 2020hindsight (21 July 2009)

I'd probably agree with you buddy. 
But then again, with a hose, the moment he closes his mouth, the air is at the same pressure as at the surface = 1 bar.  (hence it should be the same volume as at the surface. (PV etc).  

Must be something to do with the ribcage   Like I say, I've never thought of it before.  

If surface = 1 bar (absolute),
and 10m = 2 bar
then I'm guessing when he comes to the surface, his ribcage expands, and the airpressure in his lungs is around 0.5 bar  - or 0.6 maybe (?)

PS. As for Chris45's answer ( next post - but why duplicate - I almost used 5m instead of 10m for that reason - but same principle)

*PS lol - Think I see my error - the moment he closes his mouth and relaxes, he only has 1/4 lungful of air *


----------



## Chris45 (21 July 2009)

Buddy said:


> Boyles Law...... PV=k.
> I suggest exhaling would be a really good idea.



True, but maybe not essential. Isn't 1 atmosphere = 10m water?
So, wouldn't 1/2 of a lungful of air at 10m expand to 1 lungful at the surface?

And, unless in b) the air was being pumped down to you, you wouldn't be able to inhale at 10m. Didn't Leonardo or someone try that at one stage?


----------



## 2020hindsight (21 July 2009)

Chris45 said:


> 365 1/4?




Turns out to be 365.24+1 = 366.24 
The earth actually rotates 360 degrees (wrt stars) once every 23 hours 56 mins 



> The stars, however, ....return to their highest point in a sidereal day. A sidereal day is almost 4 minutes shorter than a mean solar day.




http://en.wikipedia.org/wiki/Sidereal_time


> Another way to see this difference is to notice that, relative to the stars, the Sun appears to move around the Earth once per year. Therefore, there is one less solar day per year than there are sidereal days. This makes a sidereal day approximately 365.24⁄366.24 times the length of the 24-hour solar day, giving approximately 23 hours, 56 minutes, 4.1 seconds (86,164.1 seconds


----------



## Chris45 (21 July 2009)

2020hindsight said:


> PS. As for Chris45's answer ( next post - but why duplicate - I almost used 5m instead of 10m for that reason - but same principle)



Sheesh it's hard work keeping up with you 2020! You're too quick for me! OK, ya got me on the rotation one.



2020hindsight said:


> But then again, with a hose, the moment he closes his mouth, the air is at the same pressure as at the surface = 1 bar.



Don't think so. The air pressure would immediately jump to surrounding water pressure, 2 atm. But anyway you can't inhale through a snorkel much below about half a metre because our lungs & rib muscles aren't strong enough to expand against the surrounding water pressure.


----------



## Chris45 (21 July 2009)

Bit off-topic because this is not a science question, but a variation of an old brain teaser which might keep you thinking for a few minutes:

An explorer sets out from his campsite and follows directions to walk exactly 1km due south then exactly 1km due west then exactly 1km due north, and he arrives back at his campsite.
(a)	(easy) Where’s the obvious location of his campsite?
(b)	(difficult) Apart from the obvious location, there’s an infinite number of other locations on the Earth’s surface where he can follow the same set of instructions and arrive back at his campsite. Where are these?


----------



## 2020hindsight (21 July 2009)

Chris45 said:


> Bit off-topic because this is not a science question, but a variation of an old brain teaser which might keep you thinking for a few minutes:
> 
> An explorer sets out from his campsite and follows directions to walk exactly 1km due south then exactly 1km due west then exactly 1km due north, and he arrives back at his campsite.
> (a)	(easy) Where’s the obvious location of his campsite?
> (b)	(difficult) Apart from the obvious location, there’s an infinite number of other locations on the Earth’s surface where he can follow the same set of instructions and arrive back at his campsite. Where are these?




a) campsite at the north pole 
b) campsite exactly 1km from south pole ?  (not that I'm at all certain which direction he 's going in after he's gone 1km west, and he then turns north lol)

Rider:-  I'm gonna take your words to mean as follows:-
"where he *can* follow the same set of instructions and arrive back "
= "*where it is possible to*"  etcetc .. 

PS Which side of Antarctica is called East ?


----------



## 2020hindsight (21 July 2009)

ok a mummy is found in a cave in ?? Eden ? - the cryptologist (?) uncloths it, and immediately declares that this is Adam , (as in Adam and Eve) .  How did he know?


----------



## bassmanpete (21 July 2009)

> An explorer sets out from his campsite and follows directions to walk exactly 1km due south then exactly 1km due west then exactly 1km due north, and he arrives back at his campsite.
> (a) (easy) Where’s the obvious location of his campsite?
> (b) (difficult) Apart from the obvious location, there’s an infinite number of other locations on the Earth’s surface where he can follow the same set of instructions and arrive back at his campsite. Where are these?




(a) The North Pole

(b) I don't have enough space to enter an infinite number of locations


----------



## 2020hindsight (21 July 2009)

> PS Which side of Antarctica is called East ?



...


----------



## Chris45 (22 July 2009)

2020hindsight said:


> a) campsite at the north pole
> b) campsite exactly 1km from south pole?






bassmanpete said:


> (a) The North Pole
> (b) I don't have enough space to enter an infinite number of locations



Both correct with (a)
Neither correct with (b)

Might add this is NOT a trick question - no "wormholes" etc involved. AFAIK you can actually "walk the walk" but to keep it simple you may assume that the Earth's surface is smooth (no jagged mountains etc).


----------



## Chris45 (22 July 2009)

2020hindsight said:


> ok a mummy is found in a cave in ?? Eden ? - the cryptologist (?) uncloths it, and immediately declares that this is Adam , (as in Adam and Eve) .  How did he know?



<thinks> I knew it would be a mistake to stray from the science thread </thinks>
<rethinks> Then again, maybe this is a science question - biology??? </rethinks>

OK, let's see. Assuming Eden existed (somewhere in Iraq I think? - certainly not there now LOL) would A&E's kids have known how to mummify their bodies??? Probably not, but anyway, a "cryptologist" is someone skilled in the analysis of codes and cryptograms so maybe there was an inscription somewhere, but I don't think so - you probably meant "archaeologist" ???

(a) Maybe Adam's huge dick survived mummification?
(b) Females are supposed to have bigger hips than males.
(c) Both males and females usually have 12 pairs of ribs but Adam was supposed to have lost one when Eve was created so maybe he counted the ribs and found only 11 pairs.

You said the guy declares the mummy not just a male but specifically as "Adam", so .... I think I'll go with (c)


----------



## 2020hindsight (22 July 2009)

no navel 
sorry - I give up on the campsite one. 
cheesr


----------



## Chris45 (22 July 2009)

2020hindsight said:


> no navel



(Slaps forehead) *DOH!!!* 



2020hindsight said:


> sorry - I give up on the campsite one.
> cheesr



You nearly had it!!!!!
Bit more lateral thinking required. Instead of a triangle, think of the male & female symbols.
Answer: 1.159km (+/- a metre) from south pole.

When you're standing at the south pole, there's only one direction you can go ... north. Move a bit away from the s. pole and you now have east and west.

Ok, back to science questions.


----------



## 2020hindsight (22 July 2009)

Chris45 said:


> Answer: 1.159km (+/- a metre) from south pole.



ahh very clever.  Bet you've made a few bob on that one in pub bets over the years.  cheers


----------



## Chris45 (22 July 2009)

2020hindsight said:


> PS Which side of Antarctica is called East ?



http://geology.com/world/antarctica-map.jpg


----------



## 2020hindsight (22 July 2009)

Chris45]there’s an infinite number of other locations on the Earth’s surface where he [B][U]can[/U][/B] follow the same set of instructions and arrive back at his campsite. Where are these[/QUOTE]

[QUOTE=Chris45 said:


> You nearly had it!!!!!
> Bit more lateral thinking required. Instead of a triangle, think of the male & female symbols.
> Answer: 1.159km (+/- a metre) from south pole.



Hey Chris !! lol
just thinking some more as I was drivin home...
Not sure I'd hand over the money if that was a bet. 
because of the "picket fence" effect, viz:-

1159m +/- 1m assumes he walks one complete circle yes?  Other options are a series viz :-
1080m +/- 1m if he walks around two circles
1053m +/- 1m for three circles 
......
1016m +/- 1m for 10 circles
...
1002m +/- 1m for 100 circles
...
1000.16m +/- 1m for 1000 circles.
 etc

Hence (with your specified tolerance of +/- 1m  ) 1000m north of the South Pole is also an acceptable answer yes?

(we could go on to talk limits as n (= number of circles) approaches infinity lol,  but let's not bother. 

cheers - and thanks for getting the grey matter working.

PS Wish I hadn't said 'exactly' 1km north of sth pole.  Still if you're allowed a tolerance, then so arguably am i lol.


----------



## moses (22 July 2009)

Aurum said:


> Why are there spiral galaxies?
> 
> Stars further from the center move slower and so this would explain how the spiral forms. However, after a few turns wouldn't it be jumbled up and no longer a spiral.
> 
> Mike.



The observation that galaxies rotate rather more like plates than they should led to the "Dark Matter" theory, that there is a vast amount of unseen matter in a galaxy that crudely speaking gravitationally binds it all together.

http://en.wikipedia.org/wiki/Dark_matter


----------



## 2020hindsight (23 July 2009)

Chris45 said:


> [east side of Antarctica]



maybe I should have asked , which landmass surrounded by water only has a northern coastline, without a southern one? - dead simple , move on as they say.


----------



## Chris45 (23 July 2009)

2020hindsight said:


> Hence (with your specified tolerance of +/- 1m  ) 1000m north of the South Pole is also an acceptable answer yes?
> PS Wish I hadn't said 'exactly' 1km north of sth pole.  Still if you're allowed a tolerance, then so arguably am i lol.



Hmmm, wish I hadn't said (+/- a metre)  Anyway, that's a very good extension to the teaser. You get the credit for that bit. (Thinks: Can you die of dizziness???)

Does that mean I have to give you back that 2c now?



2020hindsight said:


> maybe I should have asked , which landmass surrounded by water only has a northern coastline, without a southern one? - dead simple , move on as they say.



Had similar thoughts when you asked the question.

There's another old teaser (ho hum ...) that goes:
An explorer builds a hut with each side having a southerly aspect. He looks out a window and sees a big bear approaching. What colour is the bear?

(Ducks hail of projectiles.)

BTW Loved the Larson cartoon!!!


----------



## 2020hindsight (25 July 2009)

wow - anyone see mythbusters tonight?  Best of their shows ever by a country mile. - bludy brilliant. 

They ripped apart the conspiracy theory(ies) that the photos of man's landing on the moon were doctored and/or never happened and/or were taken on Earth.  (and of course some go on to say the US never went to the moon). :silly:

- the flag waves for a few seconds because it's a vacuum, and the momentum of planting the flag goes back and forth for a while

- the skippy-run impersonation was replicated "exactly" in a NASA plane at 1/6th gravity. (they were each carrying suits and incidentals weighing 180 lbs = 80kg - sheesh !) 

- the footprint was formed without requiring moisture because the sand was angular (rather than round / weathered as it is here)

- the feather and hammer landed simultaneously in a vacuum chamber (as Galileo predicted they would)

- the reflection from the moon's surface's albedo (7 - 10%, maybe even 12% ?) is enough to highlight the photo with Armstrong / Aldrin? despite the fact he's in shadow. 

Finally they send a laser from Earth (several gigawatts) and get a reflection from one of the reflectors left there by a later Apollo mission.  QED   (It's great when idiot conspiracy theories are trashed imo).

You can allegedly rewatch at sbs.com.au,   I'm guessing here (but not sure) :-
http://www.sbs.com.au/shop/product/category/DVDs/360/Mythbusters-Season-1

But this is what they're up against lol


> http://www.sbs.com.au/news/article/1049327/Moon-conspiracy-theories-die-hard#
> 2001 : Fox TV aired a program called "Conspiracy Theory: Did We Land on the Moon?"
> 
> The show portrayed NASA as little more than "a blundering movie producer," wrote Dr Tony Phillips on the Science@NASA website.
> ...


----------



## It's Snake Pliskin (26 July 2009)

2020hindsight said:


> wow - anyone see mythbusters tonight?  Best of their shows ever by a country mile. - bludy brilliant.
> 
> They ripped apart the conspiracy theory(ies) that the photos of man's landing on the moon were doctored and/or never happened and/or were taken on Earth.  (and of course some go on to say the US never went to the moon). :silly:
> 
> ...




Is that all they focussed on or did they cover any other relevant points that you may have not noted here?


----------



## 2020hindsight (26 July 2009)

It's Snake Pliskin said:


> Is that all they focussed on or did they cover any other relevant points that you may have not noted here?



there there snake - If I posted any more, you'd accuse me of making too long a post. 

BUT in summary - you'll see I make reference to QED concerning the laser beam reflection.  Herewith the meaning ...


> Q.E.D. is an abbreviation of the Latin phrase quod erat demonstrandum, which literally means "which was to be demonstrated". The phrase is written in its abbreviated form at the end of a mathematical proof or philosophical argument to signify that the last statement deduced was the one to be demonstrated; *the abbreviation thus signals the completion of the proof*.



http://en.wikipedia.org/wiki/Q.E.D.


----------



## 2020hindsight (26 July 2009)

tell you what, that Mythbuster show would have cost a heap to make - even using NASA's reduced gravity planes - doing parabolic arcs across the sky with this pair of idiots inside trying to imitate Armstrong and Aldrin.  

I can't find where you get a replay of the show on sbs.com.su (other than the "shop")- well it's not obvious let's say.


----------



## CapnBirdseye (26 July 2009)

This might be what you are looking for.

http://player.sbs.com.au/programs#/...laylist/Mythbusters-Ep-112-Moon-Landing-Hoax/

I'll watch it once I get past the feature length Macquarie ad.


----------



## 2020hindsight (26 July 2009)

CapnBirdseye said:


> This might be what you are looking for.
> 
> http://player.sbs.com.au/programs#/...laylist/Mythbusters-Ep-112-Moon-Landing-Hoax/



spot on 
thanks capn


----------



## 2020hindsight (26 July 2009)

Anyone remember Julius Sumner Miller?
http://www.abc.net.au/science/features/whyisitso/
I met him at Sydney Airport once.  Introduced myself as a fan of his - he immediately hit me with a question - "see the red velvet chord there to channel the people like sheep - now what shape would you say that is ?"
I actually said the answer I believe, but he was a bit deaf and said " that my young man is a "CAT-in-Airy"  - his prononciation was quite amusing. 

Looking back 30-40 years, they now appear pretty tame  by today's standards.

But one there (Episode 8) about making an electromagnet  reminds me of a science experiment - My son came home from infant school saying he had to whip up a science experiment - so I wired him up with a "solar powered lie detector".    - put the current from a solar cell across a patch of skin - and measured the resistance  - which (theoretically) changes when he told a lie lol.   It was totally unreliable of course ( given the other variables), but sure had him wide-eyed to think that the truth could be measured   I wish I was at school the next day during show-and-tell,  when he explained to the class how the invention worked.  :eek3:


----------



## MrBurns (26 July 2009)

> Anyone remember Julius Sumner Miller?




I do, they dont make them like that any more, sigh...........

NOW - why are planets and moons round ?

There's no stmosphere out there, there's no air so why aren't some of them odd shapes ?

A shiny new donkey for the best answer.


----------



## 2020hindsight (26 July 2009)

don' know Mr B, and here's a similar one which I also don't know (only a coupla hours to happy hour ok?) ... plus some cut and paste from another forum (ABC) 



> From: AMY 11/02/00 11:31:01
> Subject: Square Wombat Droppings post id: 37195
> I have heard that a certain type of wombat has square shaped droppings, and even remember seeing a photo of the leftovers. Can anyone please explain how this is done?





> From: Mac 11/02/00 11:53:44
> Subject: re: Square Wombat Droppings post id: 37209
> Don't know why but I can confirm it. I wondered the same thing when on numerous occasions I came across the cubed landmines whilst walking all over Tassie. Very strange.





> From: Cam 11/02/00 13:37:39
> Subject: re: Square Wombat Droppings post id: 37242
> Yep, Tassie is knee-deep in cubes of wombat droppings. Well, maybe not knee-deep, but there are plenty to be found in the bush.
> 
> ... my theory is that they have square bums, but that only explains 4 sides of the cube. To get 6 sides they must snip off the square extrusion with a sudden closure of the aperture, and re-open just as suddenly for the next one. On a still night in the bush you can sometimes hear a faint "clap... clap". That's the wombat bums snapping shut.



Importantly :-


> This forum is un-moderated.  The views and opinions expressed are those of the individual poster and not the ABC.



more reading here:-
https://www.aussiestockforums.com/forums/showthread.php?p=465726


----------



## Stan 101 (26 July 2009)

planets are basically spherical due to the distance from centre to crust being uniform at any particular point. Gravitational forces are basically equal and keep it all in check.


----------



## MrBurns (26 July 2009)

Stan 101 said:


> planets are basically spherical due to the distance from centre to crust being uniform at any particular point. Gravitational forces are basically equal and keep it all in check.




Ahh yes gravitly thanks Stan.......


----------



## 2020hindsight (26 July 2009)

More of a riddle / trick this one - 
 but how do they balance this can on its edge ?  

http://www.youtube.com/watch?v=Z1N17Sh0j2Q


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## Stan 101 (26 July 2009)

2020hindsight said:


> More of a riddle / trick this one -
> but how do they balance this can on its edge ?
> 
> http://www.youtube.com/watch?v=Z1N17Sh0j2Q




I'd say a ball bearing with a mass greater than the can is rolling around in there.


cheers,


----------



## MrBurns (26 July 2009)

Stan 101 said:


> I'd say a ball bearing with a mass greater than the can is rolling around in there.
> cheers,




He picks it up and there's no rolling aound noise so my guess is they melted some lead and poured it in there.


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## 2020hindsight (26 July 2009)

howdy sq  how's the diving going. 

You could well be right -that's one way to get the CG in the correct place  - but I don't think it's a ball bearing ...  (as Mr B says, no sound of  a ball bearing) 

Actually it's dead simple... answer is here :- (mind you, there must be a blob of epoxy or some such in the previous example with the Canada Dry can - no sound of water etc -  to get the centre of gravity at the correct position (between the twin edges)

http://www.youtube.com/watch?v=eeNgzCPahUE
How to Balance a soda can on its edge!

Here's another experiment btw - try it on soda, (win a bet maybe?) but I'm guessing it's a waste of time on beer - certainly it is with a stubbie, lol - I just tried it (sheesh only 2.50pm too.  )

"'Strictly scientific research dear, - just need to check it one more time' - as I just explained to the missus opening the last of the sixpack "  sorta thing.  


http://www.youtube.com/watch?v=l5xbgNTxApo
Soda Can Shake-Up - Cool Science Experiment


----------



## 2020hindsight (26 July 2009)

PS I'm thinking you could win a few beers balancing a can on the bar like that


----------



## 2020hindsight (26 July 2009)

OK - you're in some outpost somewhere, and there are no matches or lighters at the store - and you're trying to buy a reliable and quick way to start a fire when you get back to camp.  What do you buy?

Answer:-  according to this mob, fine steel wool and a 9V battery (?) 

http://www.youtube.com/watch?v=Iha9vQvnWMU
How to make fire without matches or a lighter


----------



## 2020hindsight (26 July 2009)

wow, these posters are clever...
how about this one ...  win a bet that you'll change the matches to a star - without even touching them  -  personally I'd say "without touching more than 4 (say)" - then, when they give in, say " well in fact I won't touch any" 

http://www.youtube.com/watch?v=Ju5sF3YUseU&NR=1

(PS I haven't actually tried it ok? lol - don't blame me if it don't work, and you lose yuor house)


----------



## It's Snake Pliskin (26 July 2009)

*Re: Did they cover everything?*



2020hindsight said:


> there there snake - If I posted any more, you'd accuse me of making too long a post.
> 
> BUT in summary - you'll see I make reference to QED concerning the laser beam reflection.  Herewith the meaning ...
> 
> http://en.wikipedia.org/wiki/Q.E.D.



Hindsight I'm not interested in petty arguments. All I wanted to know was if they covered _everything_ concerned with the cosnpiracy. It is common to see lots of rebuttals but some important things are missing - most don't know about them. 

As far as the laser reflecting device:

These guys sure have an attitude:http://www.youtube.com/watch?v=VmVxSFnjYCA
Perhaps they should unbias the debate and include more credible background.

There is no doubt that man made equipment has been to the moon, but what about this:source: http://www.newscientist.com/article/mg20327162.300-apollo-special-mirrors-on-the-moon.html


> EACH clear night when the moon is high in the sky, a group of astronomers in New Mexico take aim at our celestial neighbour and blast it repeatedly with pulses of light from a powerful laser. They target suitcase-sized reflectors left on the lunar surface by the Apollo 11, 14 and 15 missions, as well as by two Russian landers.




Source: http://www.einsteins-theory-of-relativity-4engineers.com/apollo.html


> Neil Armstrong and Buzz Aldrin of Apollo 11 fame sparked off the lunar laser ranging experiments in 1969 when they installed a corner-cube prism (or retro-reflector) array on the surface of the Moon. Later, Apollo 14 and 15 installed two more retro-reflectors on different areas of the Moon. The Russian missions Luna 17 and 21 also ‘parked’ retro-reflectors on the Moon as part of the unmanned Lunokhod rovers.




Unmanned Russian equipment did what some think only Appollo could have done. The Russians were the first to the moon in 1959 unmanned.


----------



## 2020hindsight (27 July 2009)

Yes that is the relevant excerpt from the 30 minute show. 
http://www.youtube.com/watch?v=VmVxSFnjYCA

Well this is my understanding of that youtube.  They firstly zoom in visually on the area where Apollo 15 set up its reflector.  And where we have footage of them setting it up.  And they shoot a 1 GW laser beam.  And they get the reflection predicted, albeit faint.

Would you accept that it's a high probability that they actually set it up as claimed?

Incidentally, today (US time) is the 36th anniversay of their 12 day stay on the moon (26 July to 7 Aug) .   

An Aside :- Must be something about this time of year ( no hurricanes maybe?) - Apollo 11 landed "last week" viz.. 


> On July 20, 1969, Armstrong and Aldrin [Apollo 11] became the first humans to land on the Moon, while Collins orbited above.[






> Apollo 15 was the ninth manned mission in the Apollo program and the fourth mission to land on the Moon. It was the first of what were termed "J missions", long duration stays on the Moon with a greater focus on science than had been possible on previous missions. The mission began on July 26, 1971, and concluded on August 7. NASA called it the most successful manned flight ever achieved.[2]



THey continue to measure the distance to the moon - including use of the Apollo 11 reflector...  


> The ongoing Lunar Laser Ranging Experiment measures the distance between the Earth and the Moon using laser ranging. Lasers on Earth are aimed at retroreflectors previously planted on the Moon and the time delay for the reflected light to return is determined. Since the speed of light is known with very high accuracy, the distance to the moon can be calculated. This distance has been measured with increasing accuracy for more than 35 years.
> 
> The distance continually changes for a number of reasons, but averages about 384,467 kilometers (238,897 miles).
> 
> *The experiment was first made possible by a retroreflector array installed on July 21, 1969, by the crew of the Apollo 11*. Two more retroreflector arrays left by the Apollo 14 and Apollo 15 missions have contributed to the experiment.




Incidentally, the soviet ones are not as reliable - what else would you expect the US to say 


> The unmanned Soviet Lunokhod 1 and Lunokhod 2 rovers carried smaller arrays. Reflected signals were initially received from Lunokhod 1, but no return signals have been detected since 1971, at least in part due to some uncertainty in its location on the Moon. Lunokhod 2's array continues to return signals to Earth.[1]




PS as for exactly what's on the 30 minute original footage - why not watch it and see?.  That's all I recall, but I was doing other things at the time myself.  Importantly, they obviously can't cover all the conspiracy theories in 30 minutes ! including zero / reduced gravity flights etc and many pretty tricky experiments in vacuum chambers .  Incidentally, as for their attitude, they are enthusiatic yes, - especially the red headed dude - what else would you expect from a redhead - probably Irish ancestry - but not sure you or I could fault em? or could we?

Surely you'll agree that they trounce some of the bigger theories - and show up the theorists theories as just "wild guessing".  
http://en.wikipedia.org/wiki/Lunar_Laser_Ranging_Experiment
http://en.wikipedia.org/wiki/Mons_Hadley
http://en.wikipedia.org/wiki/Apollo_15
http://en.wikipedia.org/wiki/Apollo_11


----------



## 2020hindsight (27 July 2009)

PS I don't recall the show mentioning this one, (probably because the show was madein 2008 prior to this) but it's something else to chew over ...
http://en.wikipedia.org/wiki/Apollo_11


----------



## 2020hindsight (27 July 2009)

Incidentally, 
If there are so many craters on the *near* side of the moon - (pictures of 30 major ones here :- http://en.wikipedia.org/wiki/Lunar_crater_locations )
and these were caused by asteroid collisions -  and the moon is massively smaller than the Earth - then how close must those asteroids have come to Earth 

especially Plinius - see jpeg below. - sheesh that one must have just clipped someone's ear on the way past.   (unless relative positions have changed with time I guess )


Another bit of history:- but on November it will be 400 years since Galileo looked at the Moon for the first time (with a telescope that is). 


> The word crater was adopted by Galileo from the Latin word for cup. Galileo built his first telescope in late 1609, and turned it to the Moon for the first time on November 30, 1609. He discovered that, contrary to general opinion at that time, the Moon was not a perfect sphere, but had both mountains and cup-like depressions, the latter of which he gave the name craters.
> 
> Scientific opinion as to the origin of craters swung back and forth over the ensuing centuries. The competing theories were (a) volcanic eruptions blasting holes in the Moon, (b) meteoric impact, (c) a strange theory known as the Welteislehre developed in Germany between the two World Wars which suggested glacial action creating the craters.
> 
> Evidence collected during the Apollo Project and from unmanned spacecraft of the same period proved conclusively that meteoric impact, or impact by asteroids for larger craters, was the origin of almost all lunar craters...


----------



## It's Snake Pliskin (29 July 2009)

> 2020hindsight
> Would you accept that it's a high probability that they actually set it up as claimed?



We know they are there but cannot be sure as to how they got there:

1. we believe what is officially claimed, or
2. we believe they got there just like the soviet ones' did. 

It's a choice for one to make on the information one has.



> Incidentally, the soviet ones are not as reliable - what else would you expect the US to say



Naturally.



> Surely you'll agree that they trounce some of the bigger theories - and show up the theorists theories as just "wild guessing".



The easier ones.


----------



## It's Snake Pliskin (29 July 2009)

Here's a question for the experts:

_If the sun and Earth are viewed from the moon which would appear bigger and why?_


----------



## Chris45 (29 July 2009)

It's Snake Pliskin said:


> Here's a question for the experts:
> 
> _If the sun and Earth are viewed from the moon which would appear bigger and why?_



Well, during a lunar eclipse (Earth between Sun and Moon) I understand that the Moon is totally in the Earth's shadow so I guess that would mean that the Earth would appear bigger than the Sun. Could use trig to prove it I suppose but I'll leave that up to the mathematicians.


----------



## It's Snake Pliskin (29 July 2009)

Chris45 said:


> Well, during a lunar eclipse (Earth between Sun and Moon) I understand that the Moon is totally in the Earth's shadow so I guess that would mean that the Earth would appear bigger than the Sun. Could use trig to prove it I suppose but I'll leave that up to the mathematicians.



That's what I thought. The moon blocks the sun so the Earth should block the sun too. 
Thanks.


----------



## 2020hindsight (29 July 2009)

which is bigger (angle subtended at the eye)? - your little fingernail when your arm is extended - of a full moon?


----------



## wayneL (29 July 2009)

2020hindsight said:


> which is bigger (angle subtended at the eye)? - your little fingernail when your arm is extended - of a full moon?




Depends how long your arm is I guess.


----------



## 2020hindsight (29 July 2009)

or whether you've recently cut your fingernail for that matter.


----------



## 2020hindsight (29 July 2009)

Chris45 said:


> Well, during a lunar eclipse (Earth between Sun and Moon) I understand that the Moon is totally in the Earth's shadow so I guess that would mean that the Earth would appear bigger than the Sun. Could use trig to prove it I suppose but I'll leave that up to the mathematicians.




makes sense to me m8.

Interesting that during a solar eclipse ( moon between earth and sun) , sun and moon are almost identical in diameter. 

But that's partly because yuo are just one "driver" on the "vehicle" earth - 
bit like that one "if you can't see my mirrors then I can't see you".  
(PS i.e. where the sun in the prime mover, and the moon is the trailer  - whatever, not important lol)


> http://en.wikipedia.org/wiki/Lunar_eclipse
> As viewed from Earth, the Earth’s shadow can be imagined as two concentric circles. As the diagram illustrates, the type of lunar eclipse is defined by the path taken by the Moon as it passes through Earth’s shadow. If the Moon passes through the outer circle but does not reach the inner circle, it is a penumbral eclipse; if only a portion of the Moon passes through the inner circle, it is a partial eclipse; and if entire Moon passes through the inner circle at some point, it is a total eclipse.




PS here's that trig you were talking about ... (jpegs below - lunar and solar eclipses)


----------



## queenslander55 (29 July 2009)

jonojpsg said:


> I like it - a science nerds thread
> 
> I would have thought that the Brownian motion of the water molecules inside the droplet *may* impart some motion on the droplet...




...and at what juncture does the infinite improbability drive kick in?:ald:


----------



## MrBurns (29 July 2009)

Cant see any reference to it here but it mist be here somewhere but did anyone see the show on SBS (I think) where they explained that the moon landing footage was actually pre taped because they thought they would not be able to get a picture from the Moon and it was important that they showed the world that they landed ?

They had interviews with Donand Rumsfeld and Henry Kissinger among athers and it all appeared to be on the level.

Stanley Kubrick helped because they helped him with the filming of Space Odyssey 2001 - the actors they used were given new identities and disbursed far and wide but Richard Nixon got paranoid the truth would get out and ordered their elimination.

All the interviews with so many credible people made it seem true.


----------



## xyzedarteerf (29 July 2009)

is there an edge to the visible universe, if so does this mean our universe is finite?
so if i drive my starship on the edge i will fall off right.


----------



## derty (29 July 2009)

xyzedarteerf said:


> is there an edge to the visible universe, if so does this mean our universe is finite?
> so if i drive my starship on the edge i will fall off right.



So are you asking if the universe is essentially flat?


----------



## spooly74 (29 July 2009)

MrBurns said:


> Cant see any reference to it here but it mist be here somewhere but did anyone see the show on SBS (I think) where they explained that the moon landing footage was actually pre taped because they thought they would not be able to get a picture from the Moon and it was important that they showed the world that they landed ?
> 
> They had interviews with Donand Rumsfeld and Henry Kissinger among athers and it all appeared to be on the level.
> 
> ...




Yep, saw that the other night.

It was a spoof documentary to show the unimaginable lengths they would have needed to through to fake it.


----------



## MrBurns (29 July 2009)

Infinity in all directions is a great concept if you can get your head around it.

How can it end ? what would be after that ?


----------



## MrBurns (29 July 2009)

spooly74 said:


> Yep, saw that the other night.
> 
> It was a spoof documentary to show the unimaginable lengths they would have needed to through to fake it.




Geez thanks for clearing that up I thought it must have been real or I dreamt it or something.

I must have missed the intro.


----------



## 2020hindsight (29 July 2009)

xyzedarteerf said:


> is there an edge to the visible universe, if so does this mean our universe is finite?
> so if i drive my starship on the edge i will fall off right.



like , the observable universe is (presumably) expanding at the speed of light (c) in all directions (ignoring count-ing stars more than once because the light has been round more than once - and other riddles that only weird old professors with grey afros understand) ...

Furthermore you'll never catch up to the "edge" because it's likewise expanding at the same speed. and we can't go faster than speed of light. 

Hey - does that mean that's just as far as we can "c". ?


----------



## xyzedarteerf (29 July 2009)

2020hindsight said:


> Hey - does that mean that's just as far as we can "c". ?




i always liked this photo from hubble deep field makes me feel significant :.

Galaxies Billions of Light-Years Away


----------



## xyzedarteerf (29 July 2009)

derty said:


> So are you asking if the universe is essentially flat?




not necessarily flat but an end.


----------



## xyzedarteerf (29 July 2009)

MrBurns said:


> Infinity in all directions is a great concept if you can get your head around it.




i like this concept, as everything that was does end and gets reborn again in a different form making it a never ending cycle which is how i see the universe and existence itself a never ending cycle.


----------



## Happy (29 July 2009)

spooly74 said:


> Yep, saw that the other night.
> 
> It was a spoof documentary to show the unimaginable lengths they would have needed to through to fake it.




That's what I heard too, but for conspiracy pushers this was for real and even this week somebody told me that Moon landing was not for real, so might say it worked on some brains well.


----------



## Happy (29 July 2009)

xyzedarteerf said:


> i like this concept, as everything that was does end and gets reborn again in a different form making it a never ending cycle which is how i see the universe and existence itself a never ending cycle.




One of the S/F books worked along the lines that all the galaxies and stars with orbiting bodies is part of the large organism or was it large object and comparison was drawn that even Hydogen atom is between 99% and 100% empty, as it is orbiting electron that makes it appear larger. 

Similar proportions apply to any atom.


----------



## 2020hindsight (29 July 2009)

xyzedarteerf said:


> ... as everything that was does end and gets reborn again in a different form making it a never ending cycle...



:topic
Seem to recall a bumper sticker ... "Born perfectly ok the first time thanks" ...
- but maybe that's for the religious thread.  

PS I believe that Hubble Deep Field shot is the one that lest em calculate that there are (at least!) 123 million million million stars - or if you prefer 123 billion billion.

Anyways it's a bludy big number.  
try the number of hairs (where hairsbreadth = 0.1mm) placed side by side 1 billion times around the world (at Cape of Good Hope).  

https://www.aussiestockforums.com/forums/showthread.php?p=165559

there's also a youtube there on the topic (ignore the idiot at the 2 min mark - brief only) - but I've misplaced where they calculate 123 x 10^18 stars ( and I believe it's probably more like 1000 x 10^18 etc - not that I'm an astronomer - just facinated by these numbers):-
http://www.youtube.com/watch?v=mcBV-cXVWFw


----------



## 2020hindsight (29 July 2009)

http://en.allexperts.com/q/Astronomy-1360/apparent-size-moon.htm


> The diameter of the full moon is just about half a degree, and assuming you want to fill both the night and day skies, the sky is 360 degrees.  So it would take 720 moons just to make a single, moon-wide band around the sky. And another 719 to a similar band to cross it.  That's 1439, and we have only covered a tiny fraction of the surface of the sky. Of course, to cover those bands completely, you would need to fill in the spaces where the disks of the moon aren't touching.  ... etc etc
> 
> ... answer ... you get:  206611 moons in both the night and day skies = full sphere




If it takes 206,000 moons to fill the entire sphere (- or 103,000 to fill one hemisphere)
Then just dividing ... you have 123E18 / 206E3 = *600 million million* stars JUST BEHIND THE (FULL) MOON lol. - and statistically,  thousands if not millions of associated planets probably have life (so said the likes of Sagan)


----------



## Chris45 (29 July 2009)

It's Snake Pliskin said:


> That's what I thought. The moon blocks the sun so the Earth should block the sun too.
> Thanks.






2020hindsight said:


> Interesting that during a solar eclipse ( moon between earth and sun) , sun and moon are almost identical in diameter.
> 
> PS here's that trig you were talking about ... (jpegs below - lunar and solar eclipses)



Nice set of images! Illustrate the answer perfectly. 

A question for the mathematical geniuses (Snake, 2020??? ):
Looking at that 1999 total eclipse pic got me wondering, what is the probability that a moon would have the same periods of rotation and revolution AND subtend the same angle on the planet's surface as the sun around which they both revolve? I'd better be careful about quoting tolerances this time but at a guess, the angles would have to be +/- 1 sec or less, but the periods? Anyone's guess.

So, how many other moons would there be elsewhere in the universe with the same set of properties as our Moon?

I'm thinking our Moon must be unique.


----------



## Chris45 (29 July 2009)

spooly74 said:


> Yep, saw that the other night.
> 
> It was a spoof documentary to show the unimaginable lengths they would have needed to through to fake it.



Do you recall the name of the program? You're not talking about that recent Mythbusters episode are you?


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## spooly74 (29 July 2009)

Chris45 said:


> Do you recall the name of the program? You're not talking about that recent Mythbusters episode are you?



Found it 
The Dark Side Of The Moon

This spoof documentary plays on the conspiracy theory that the moon landing in 1969 never took place, but was pre-produced by Stanley Kubrick. The story is told by Kubrick's widow, Christiane, and interviews pieced together with among others Donald Rumsfeld, Henry Kissinger and former CIA Director Vernon Walters. They appear to be putting forward the idea that President Richard Nixon asked for fake footage to be shot at the MGM studios in England, with CIA agents acting the parts of the astronauts. (From France, in English and French, English subtitles) (Entertainment) (Rpt) PG CC 

http://www.sbs.com.au/schedule/SBSONE/2009-07-27/SBS Sydney#


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## 2020hindsight (29 July 2009)

well now we know where the Chinese got the idea to prerecord the Olympics opening


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## derty (29 July 2009)

2020hindsight said:


> Incidentally,
> If there are so many craters on the *near* side of the moon - (pictures of 30 major ones here :- http://en.wikipedia.org/wiki/Lunar_crater_locations )
> and these were caused by asteroid collisions -  and the moon is massively smaller than the Earth - then how close must those asteroids have come to Earth




A lot more would have hit the Earth than hit the Moon. The Moon may have shielded us from a few of them but as we have a larger gravity well Earth would have been the main target. 

The Moon has no active tectonics, no atmosphere so therefore no weathering and erosion. Earths impacts get worn down and filled up over short geological periods and, dependant on where they are, over longer periods they will also get buried, squashed, folded up and cooked. On the Moon they just stay there, only to be modified by the effects of successive impacts.


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## 2020hindsight (29 July 2009)

derty said:


> A lot more would have hit the Earth than hit the Moon. The Moon may have shielded us from a few of them but as we have a larger gravity well Earth would have been the main target...



brilliant m8 - no argument from me ...
(and I'm sure the Earth's gravity probably attracted a heap of those "front on" craters- as you say - no comparison between Earth and Moon in that score).

 and don't it make you worry lol
(I'm wearing a helmet tomorrow).

:topic 
PS .  Remember when Dick Smith offered a massive life insurance to anyone hit by part of the spacelab debris while shopping in his stores?  

PS Still not convinced that a big life insurance payout would compensate for debris from a typical asteroid / meteorite however.

I read that typically one of those impacts would splatter debris over an area equal to all of NSW.   (to say nothing of the "nuclear winter" that followed.)

Or this one ( jpeg attached) - 300 km diameter would take out Sydney Newcastle and Wollongong - and some.    - 

One "Sydney Harbour" would suddenly become a bit bigger than 520 GL  !!


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## Chris45 (30 July 2009)

spooly74 said:


> Found it
> The Dark Side Of The Moon



Thanks. Found it on Google videos. Watching it now.


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## Savoy Special (30 July 2009)

What is the meaning of life?

Don't say 42!(ref. hitch hikers guide to the galaxy)


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## 2020hindsight (30 July 2009)

Savoy Special said:


> What is the meaning of life?
> 
> Don't say 42!(ref. hitch hikers guide to the galaxy)



Don't have it handy, but an old Wizard of Id cartoon went as follows :-

Spook (wistfully looking as if into the distance, in fact at the bars of his cell): "What's the meaning of life"?

Turnkey : - "A custodial sentence where you get to eat swill till we carry you out"  (something like that anyways)


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## MrBurns (30 July 2009)

2020hindsight said:


> Don't have it handy, but an old Wizard of Id cartoon went as follows :-
> 
> Spook (wistfully looking as if into the distance, in fact at the bars of his cell): "What's the meaning of life"?
> 
> Turnkey : - "A custodial sentence where you get to eat swill till we carry you out"  (something like that anyways)




The answer was - *there's no time off for good behaviour*


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## 2020hindsight (30 July 2009)

yep - quite right thanks 
Also found this one ...
People are DNA’s way of making more DNA

Then there's the serious stuff lol :-  http://en.wikipedia.org/wiki/Meaning_of_life


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## basilio (30 July 2009)

The Dark Side of the Moon was a beautiful piece of work. It did manage to create a sense of authenticity with the co-operation of Rumsfeld, Kissinger ect in the spoof.

I remember when I first saw it I thought I had entered another universe. Of course the story unfolds at the end when you see these obviously fake North Vietnamese peasants and other characters.

But just a brilliant piece of theatre (Shame that many people actually took it at face value..!)


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## Mr J (30 July 2009)

2020hindsight said:


> Or this one ( jpeg attached) - 300 km diameter would take out Sydney Newcastle and Wollongong - and some.    -




Doesn't really matter, as it would kill most organisms on the planet.


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## 2020hindsight (30 July 2009)

Mr J said:


> Doesn't really matter, as it would kill most organisms on the planet.



too true Mr J (nuclear winter etc).
would sure solve the global warming problem, if a bit drastic  

Alternatively it could hit the ocean - Sheesh what sort of a tsunami would it create !! 

How many craters would you expect to find on earth?
Well the moon is apparently "saturated with craters" of all sizes.
If we only consider the monsters, = "Impact Basins" (i.e. greater than 300km)

1. there are 40 off on the moon greater than 300km diam. 

2. The area of the moon is 37.9E6 km^2 (= 37.9 x 10^6)
say one every 1 million sq km. 

3. The area of the earth is 510E6 km^2  (= 510 x 10^6)
Hence probably 500 such craters on earth.

4. The area of the Australia is 7.62 million km^2  (7.62E6)
Hence 7 or 8 have probably hit us. 

5. Or say one per state.  (possibly Victoria  and Tassie shared one - width of Bass straight only 240km at its maximum)  

PS I'm sure it's possible that the Earth's crust is a bit stronger than the Moon's - hence possibly less than 300km diam.  Still, it would be "a very significant event", lol.


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## 2020hindsight (30 July 2009)

Then again the earth has been around longer etc 
and the moon is made of debris from one such impact in any case (apparently) 

http://www.psi.edu/projects/moon/moon.html



> At the time Earth formed 4.5 billion years ago, other smaller planetary bodies were also growing. One of these hit earth late in Earth's growth process, blowing out rocky debris. A fraction of that debris went into orbit around the Earth and aggregated into the moon
> 
> Why this is a good hypothesis:
> 
> ...


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## Mr J (30 July 2009)

Maybe a bit higher due to gravitational pull. We could go much smaller than 300km to get an event of worldwide devastation, i.e. we don't survive. I think 10km is more than enough, tried to wiki a number but couldn't find it. 

This is pretty cool:



> In 2004, a newly discovered 320 m asteroid, 99942 Apophis (previously called 2004 MN4), achieved the highest impact probability of any potentially dangerous object. The probability of collision on April 13, 2029 is estimated to be as high as 1 in 17 by Steve Chesley of NASA's Jet Propulsion Laboratory, though the previously published figure was the slightly lower odds of 1 in 37, calculated in December 2004. Later observations showed that the asteroid will miss the earth by 25,600 km (within the orbits of communications satellites) in 2029, but its orbit will be altered unpredictably in a way which does not rule out a collision on April 13 or 14, 2036 or later in the century. These possible future dates have a cumulative probability of 1 in 45,000 for an impact in the 21st century.






> On May 19, 1996 a 300–500 m asteroid, 1996 JA1, passed within 450,000 km of Earth; *it had been detected a few days before*.


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## 2020hindsight (30 July 2009)

FAR OUT lol.  scarey stuff there m8.
A few day's notice?  Just time to say "a few words of unfinished prayer" as they say 

Heck even the asteroid which (possibly/ one theory) caused the extinction of dinosaurs ( permitting man to evolve) was possibly only 15km in diameter. !!
(But I think its crater is much bigger??) 

http://www.enchantedlearning.com/subjects/dinosaurs/extinction/Asteroid.html


> THE ALVAREZ ASTEROID IMPACT THEORY
> There are a lot of theories about why this K-T (Cretaceous-Tertiary) extinction occurred, but a widely accepted theory (proposed in 1980 by physicist Luis Alvarez and his son Walter Alvarez, a geologist), *is that an asteroid 4-9 miles (6-15 km) in diameter hit the Earth  about 65 million years ago*.
> 
> The impact would have penetrated the Earth's crust, scattering dust and debris into the atmosphere, and causing
> ...




Then again this theory is challenged :-
http://www.eurekalert.org/pub_releases/2009-04/nsf-nbf042009.php


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## 2020hindsight (31 July 2009)

Mr J said:


> .. We could go much smaller than 300km to get an event of worldwide devastation, i.e. we don't survive.



Mr J ...
thought for the day ...
how long would you have to hide out in one of those (previously ?) compulsory Swiss bomb shelters to survive such an event - 
a) assuming an asteroid the size of that one predicted (2036, 13 Apr etc) , 1 chance in 17 whatever.  
b) assuming a smaller one 

i.e. before you could crawl out and go buy a couple of dozen lottery tickets ... etc

being realistic / less alarmist, lol - I like the sound of "a cumulative probability of 1 in 45,000" -  sounds much better.  Still that's a lot higher than winning the lottery  

Mind you "assuming a smaller one" makes it more like winning one of the minor prizes in lottery - and even I've won one of them once or twice. 



> In 2004, a newly discovered 320 m asteroid, 99942 Apophis (previously called 2004 MN4), achieved the highest impact probability of any potentially dangerous object. The probability of collision on April 13, 2029 is estimated to be as high as 1 in 17 by Steve Chesley of NASA's Jet Propulsion Laboratory, though the previously published figure was the slightly lower odds of 1 in 37, calculated in December 2004.
> 
> Later observations showed that the asteroid will miss the earth by 25,600 km (within the orbits of communications satellites) in 2029, but its orbit will be altered unpredictably in a way which does not rule out a collision on *April 13 or 14, 2036* or later in the century. *These possible future dates have a cumulative probability of 1 in 45,000 for an impact in the 21st century*.


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## 2020hindsight (1 August 2009)

then there's the "twin paradox", but gotta feeling that we've already covered that.


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## 2020hindsight (1 August 2009)

http://en.wikipedia.org/wiki/Twin_paradox


> Specific example
> Consider a space ship traveling from Earth to the nearest star system outside of our solar system: a distance d = 4.45 light years away, at a speed v = 0.866c (i.e., 86.6 percent of the speed of light). The Earth-based mission control reasons about the journey this way (for convenience in this thought experiment the ship is assumed to immediately attain its full speed upon departure): the round trip will take t = 2d / v = 10.28 years in Earth time (i.e. everybody on earth will be 10.28 years older when the ship returns). The amount of time as measured on the ship's clocks and the aging of the travelers during their trip will be reduced by the factor , the reciprocal of the Lorentz factor. In this case  and the travelers will have aged only 0.500Ã—10.28 = 5.14 years when they return.




personally, I don't believe it lol.
I'd be calling it a reductio ad absurdum and looking for the error. 
(eg when he turns the corner, or when he decellerates to land etc. )

Other explanations given on that website make more sense , at least to my eyes..
eg the Minkowski diagram or Lewinski diagram whatever it's called ...


> In the spacetime diagram on the right, drawn for the reference frame of the stay-at-home twin, that twin's world line coincides with the vertical axis (his position is constant in space, moving only in time). On the first leg of the trip, the second twin moves to the right (black sloped line); and on the second leg, back to the left. Blue lines show the planes of simultaneity for the traveling twin during the first leg of the journey; red lines, during the second leg. Just before turnover, the traveling twin calculates the age of the resting twin by measuring the interval along the vertical axis from the origin to the upper blue line. Just after turnover, if he recalculates, he'll measure the interval from the origin to the lower red line. In a sense, during the U-turn the plane of simultaneity jumps from blue to red and very quickly sweeps over a large segment of the world line of the resting twin. The traveling twin reckons that there has been a jump discontinuity in the age of the resting twin.



perhaps it's a bit like flying over the dateline at midnight lol. (that's a jest btw)


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## 2020hindsight (1 August 2009)

Basically , like there's this dude - he's the go-getter twin, and he leaves the stay-at-home twin behind, and screams off at 0.86 times the speed of light.

well then he chucks a u-ey, and comes back   - but when he does the gear-shift-handbrake turn - throw in a dougnut maybe -  well then his stay-at-home brother goes from red shift to blue shift. 

Like, not only does he suddenly get old man,  but he changes flaming colour !!
sick as.

E&OE lol


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## wayneL (2 August 2009)

The theory of everything?

http://www.telegraph.co.uk/science/...uns-physicists-with-theory-of-everything.html



> An impoverished surfer has drawn up a new theory of the universe, seen by some as the Holy Grail of physics, which has received rave reviews from scientists..........


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## 2020hindsight (2 August 2009)

Just a PS on that twin paradox ... 
best explanation of all (for me) is to just consider doppler... 

If an image is coming towards you it is faster "moving" (in the motion sense - not in the speed of light sense), and that also goes for the frequency of it's light.  i.e. it gets bluer. 

Going away gets slower and  redder etc  (red shift).  That's how they calculate the speed of and distance to stars after all. 



> The asymmetry between the earth and the space ship is manifested in this diagram by the fact that more blue-shifted (fast aging) images are received by the Ship.
> 
> Put another way, the space ship sees the image change from a red-shift (slower aging of the image) to a blue-shift (faster aging of the image) at the mid-point of its trip (at the turnaround, 2.57 years after departure); the Earth sees the image of the ship change from red-shift to blue shift after 9.59 years (almost at the end of the period that the ship is absent).
> 
> In the next section, one will see another asymmetry in the images: the Earth twin sees the ship twin age by the same amount in the red and blue shifted images; the ship twin sees the Earth twin age by different amounts in the red and blue shifted images.



End of the day, they are both standing together back home on earth, same age etc .


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## 2020hindsight (2 August 2009)

ok- Dame Kiri Te Kanawa gives a blast (wide cone of sound) at High C - some distance from a cliff in a canyon, and (no wind), she hears an echo 5 seconds later.

a) What if the wind is blowing on her back?
b) on her face?
c) on the side of her face (parallel to the cliff)?.

What would happen to the pitch? 

What if she then drives towards the cliff in an open convertible and repeated the exercise(s)?  times, pitch.?

(PS I don't know the answers - might need a bit of meditation lol)

http://www.youtube.com/watch?v=TuoEtFgfLmM
Opera  in  the  Outback


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## wayneL (2 August 2009)

I'd be more interested if it were Anna Netrebko.


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## 2020hindsight (2 August 2009)

ok the follow up question is would it make any difference if it were Anna Netrebko ? 

or maybe with Luciano Pavarotti ?  - maybe with more "timbre" in his voice, the branches would interfere with the echoes 

(not that I ever really understood the term ) 



> http://en.wikipedia.org/wiki/Timbre
> Timbre is also known .. as tone quality or tone color.
> For example, timbre is what, with a little practice, people use to distinguish the saxophone from the trumpet in a jazz group, even if both instruments are playing notes at the same pitch and loudness. Timbre has been called "the ... multidimensional wastebasket category for everything that cannot be qualified as pitch or loudness"



Sounds like harmonics to me .  (or associated frequencies - which fair enough is the "frequency spectrum" or "frequency signature" and just a complicated way to say timbre lol



> *"Timbre" is actually the color or tone of your voice*, not what part you sing. Timbre can play a role in finding what specific fach you belong into, but for now you should just find a general range.
> 
> *"Fach" is a method of classifying singers, primarily opera singers, by the range, weight, and color of their voices.* (dictionary definition) Look at http://en.wikipedia.org/wiki/Fach




"The show isn't over till the lady with the heavy fach nails on the horny helmet" etc.


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## 2020hindsight (2 August 2009)

Speaking of ( and researching) that timbre ....

http://www.uwec.edu/walkerjs/media/38228[1].pdf

Couple of comparisons :-
1. Piano  (E above middle C = 660 Hz) vs a "Pure" note (at middle C = 440Hz) - graphs vs time and also in "the frequency domain".  Audible range is 20 Hz to 20 kHz from memory. 

PS I'm guessing that it's probably fair enough that exciting the E string of the piano, 660Hz, would also trigger some vibration at 440Hz (middle C) , since they are both multiples of 220Hz (??)

2. Also Piano vs Flute. (references to sounding different depending on how you "attack" the instrument )


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## It's Snake Pliskin (5 August 2009)

> Originally Posted by It's Snake Pliskin
> Thanks for that Buddy.
> So in conclusion an air leak in space would be catastrophic. And an air bubble would not rise in one direction like it would under water on Earth. This is helping answer some questions I had.
> Thanks.






> Quote:
> Yes. The air would dissipate so quickly it may as well not exist. The average speed of a molecule of air from a space suit or capsule at room temperature is about 1000km/h, and in space there are effectively no other molecules to confine or deflect its movement. So once it escapes it is gone, *there would be no bubbles*.







It's Snake Pliskin said:


> Once again thankyou moses.
> 
> Considering the answers to my initial questions on this thread and that of the above could someone explain how these guys have air bubbles floating upwards whilst doing a spacewalk? (more like a spacehanging on)




And no responses to this? 

The Earth moves strangely, no sign of the sun, waving flag upwards, and perfect on land type of radio transmission?


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## 2020hindsight (5 August 2009)

It's Snake Pliskin said:


> And no responses to this?
> 
> The Earth moves strangely, no sign of the sun, waving flag upwards, and perfect on land type of radio transmission?



I give up snake...
what's the answer?

as for the bubbles rising up...
is it because they landed in the sea of tranquility?

PS fascinating to read back through those posts of yours, and discover it was a game of musical chairs


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## 2020hindsight (5 August 2009)

one for you snake..
what trajectory (talking earth now) would a droplet of spittal make if, say, Buzz Aldrin hit someone calling him a liar in the mouth ...  assuming 45 degree initial elevation upwards to the left?. 

look carefully  - there's a lill drop of spittal - 
answer :- a parabola 
http://www.youtube.com/watch?v=ZOo6aHSY8hU
 Buzz Aldrin punch


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## spooly74 (5 August 2009)

It's Snake Pliskin said:


> And no responses to this?
> 
> The Earth moves strangely (in what way?), no sign of the sun (why is this an issue?), waving flag upwards (how is it predicted to move?), and perfect on land type of radio transmission?(that's good thing)




I responded, and wanted to know how you knew they were air bubbles.

Whats propelling them? I can't be buyoancy as they seem to move in different directions.

And as for the object that moves towards the camera and seems to speed up. Can you find similar underwater video footage of a air bubble moving towards the surface, towards the camera? There may be some points of difference. 
2020 has provided a clue.


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## It's Snake Pliskin (5 August 2009)

2020hindsight said:


> one for you snake..
> what trajectory (talking earth now) would a droplet of spittal make if, say, Buzz Aldrin hit someone calling him a liar in the mouth ...  assuming 45 degree initial elevation upwards to the left?.
> 
> look carefully  - there's a lill drop of spittal -
> ...




Will you get away from me! Just to borrow the ole Buzz words.


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## It's Snake Pliskin (5 August 2009)

spooly74 said:


> I responded, and wanted to know how you knew they were air bubbles.
> 
> Whats propelling them? I can't be buyoancy as they seem to move in different directions.
> 
> ...



Because they act and look like air bubbles in water.  Perhaps a scientist could show they are not. Notice how they rise and even blow back down in the top corner of the clip. Things don't blow around in space and oranges are orange.


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## spooly74 (5 August 2009)

It's Snake Pliskin said:


> Because they act and look like air bubbles in water.  Perhaps a scientist could show they are not. Notice how they rise and even blow back down in the top corner of the clip. Things don't blow around in space and oranges are orange.



Where have they gone in the clip below then?


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## It's Snake Pliskin (5 August 2009)

spooly74 said:


> Where have they gone in the clip below then?





Ah you are expecting lots of bubbles just like a diver would goive off. It is possible that they have masked the bubbles by refunneling them into a tank or something. Note how their backpacks seem to hug their helmets? 

The air bubbles I refer to are the escaping ones - not a continuous stream.


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## Tysonboss1 (5 August 2009)

I have a question,

I know that satilites eventually return to earth after so many years of orbit, and that the lower they are the less time they have before their orbit declines and they re-enter the atmosphere.

My question is Does everything orbiting the earth eventually re-enter the atmosphere, or do some thing just stay up there for ever, and will the moon eventually have it's orbit decline, and will earths orbit eventually move closer to the sun.


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## bassmanpete (5 August 2009)

> My question is Does everything orbiting the earth eventually re-enter the atmosphere, or do some thing just stay up there for ever, and will the moon eventually have it's orbit decline, and will earths orbit eventually move closer to the sun.




Anything in low Earth orbit will eventually crash back to Earth as there are still molecules of gases going out several hundred kilometres. Although only tiny the cumulative effect over many years will gradually slow any satellites.

The Moon is gradually moving away from Earth, so in the days of the dinosaurs it would have appeared larger than it does today and total solar eclipses wouldn't have shown the sun's corona the way todays do. In the distant future the Moon will have an apparent size less than the Sun so there will never be any total, only annular, eclipses.

Currently the Sun and Moon have the same apparent size as seen from Earth (mostly, because the Moon's distance from Earth varies). You can read into that what you will.


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## It's Snake Pliskin (5 August 2009)

bassmanpete said:


> The Moon is gradually moving away from Earth, so in the days of the dinosaurs it would have appeared larger than it does today and total solar eclipses wouldn't have shown the sun's corona the way todays do. In the distant future the Moon will have an apparent size less than the Sun so there will never be any total, only annular, eclipses.
> 
> *Currently the Sun and Moon have the same apparent size as seen from Earth* (mostly, because the Moon's distance from Earth varies). You can read into that what you will.



Given the above why did the moon missions find a large sun?
http://www.aulis.com/sunsize.htm Sourced quote below:


> A convex (an outwardly curved surface) always considerably reduces the size of whatever is being reflected. If this large bright reflection was the Sun, given its distance from the Moon, it would be barely visible in a visor – nothing more than a tiny pinprick of light.


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## spooly74 (6 August 2009)

It's Snake Pliskin said:


> Given the above why did the moon missions find a large sun?
> http://www.aulis.com/sunsize.htm Sourced quote below:




hmmmm in that photo, I'd say lens flare. Can you imagine taking a photo of the Sun without an atmosphere?

A question to you Mr. Snake.
How could they fake moon rocks?

Rocks from the moon must mean someone brought them back, no?


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## It's Snake Pliskin (8 August 2009)

spooly74 said:


> hmmmm in that photo, I'd say lens flare. Can you imagine taking a photo of the Sun without an atmosphere?
> 
> A question to you Mr. Snake.
> How could they fake moon rocks?
> ...



I believe there are true moon rocks collected. The Russians have moon samples too. There are moon rocks in antarctica too which can be found still to this day which I have read about.

There are other photos of the sun in space. Check them out.


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## spooly74 (8 August 2009)

It's Snake Pliskin said:


> I believe there are true moon rocks collected. The Russians have moon samples too. There are moon rocks in antarctica too which can be found still to this day which I have read about.



Yes, the Russians managed to collect about 300 grams, a fine effort.
The US collected nearly 400 kilograms.

How do you explain such a big difference?


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## It's Snake Pliskin (16 August 2009)

spooly74 said:


> Yes, the Russians managed to collect about 300 grams, a fine effort.
> The US collected nearly 400 kilograms.
> 
> How do you explain such a big difference?



First point, I don't explain. I drink alcohol. 
Second point, there is no way to verify or critique it. 
Just drink beer is the answer. Vodka is th ebest but not always available and ot n tap.


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## Knobby22 (16 August 2009)

There are moon rocks on Earth.
They occur when the moon is hit by a meteor and due to the weak gravity of the moon and the large impact of the collision there is enough energy to escape the moons gravity field and fall into the earth.

Nothing will convince some people we landed on the moon except putting the particualr doubter in space and getting them to land next to the moonlander.
Of course they wouldn't go because they would expect it was a conspiracy to keep them quiet and they would die in space.


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## spooly74 (16 August 2009)

Knobby22 said:


> There are moon rocks on Earth.
> They occur when the moon is hit by a meteor and due to the weak gravity of the moon and the large impact of the collision there is enough energy to escape the moons gravity field and fall into the earth.



That's true. I was just wondering if Snake had an idea how the US managed to get that quantity of perfectly preserved moon rocks (not burnt up through the atmosphere), without landing on the moon.
Alas, he's hit the bottle.

Think I'll join him.


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## tech/a (16 August 2009)

> Think I'll join him.




Snakes actually the other gender.


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## Tisme (5 October 2018)

Wow who wooda thunk it!!


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## SirRumpole (5 October 2018)

Tisme said:


> Wow who wooda thunk it!!
> 
> View attachment 89612




Works for me.


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## PZ99 (5 October 2018)

Wouldn't it work for every year? Everyones' age + birth year will add up to the current year.


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## SirRumpole (5 October 2018)

PZ99 said:


> Wouldn't it work for every year? Everyones' age + birth year will add up to the current year.




Geez I hate smart@rses.


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## tech/a (5 October 2018)

PZ99 said:


> Wouldn't it work for every year? Everyones' age + birth year will add up to the current year.




Can’t wait until next year!


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## bellenuit (5 October 2018)

PZ99 said:


> Wouldn't it work for every year? Everyones' age + birth year will add up to the current year.




Actually it is wrong when it says “Today”. 

It only applies if you have already celebrated your birthday this year. If not, it doesn’t compute.


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## tech/a (5 October 2018)

2017 born 1960 + age 57 = year
2018 born 1960 + age 58 = year
2019 born 1960 + age 59 = year

etc.


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## bellenuit (5 October 2018)

tech/a said:


> 2017 born 1960 + age 57 = year
> 2018 born 1960 + age 58 = year
> 2019 born 1960 + age 59 = year
> 
> etc.




Today 5 Oct 2018. Born 10 Sep 1960 so age is 58. Therefore 1960 + 58 = 2018
Today 5 Oct 2018. Born 10 Oct 1960 so age is still 57. 1960 + 57 = 2017

As I said, the use of the word "Today" is wrong as it won't work for those whose birthday falls between tomorrow and year end.


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## tech/a (5 October 2018)

Stand Corrected


----------

