Examples:
If you accept that we know things, such as the bottom of the ocean has volcanoes, the speed of light can be calculated, and that the right type of matter as big as your fist can destroy a city, then you have a basis for justified true belief. Put another way, if you did not know, there would be way to show you it was true.
We do not need to be subject experts to "know" things because we have a reasoned basis for trusting people that are trained to tell us the truth about what they learn.
You seem to have completely missed the point that "authority" has lost credibility over time so far as many are concerned.
Here's a current news item:
https://www.abc.net.au/news/2019-10...-traces-asbestos-found/11619958?section=world
I've linked the ABC version but for the record News Corp and Fairfax are both running the same story. This a current news item.
So what we have is a long established and supposedly reputable manufacturer of consumer products with asbestos in baby powder. Can't get much worse than that really, a proven and widely known carcinogen in a product specifically marketed for use on babies.
Now there's few points of relevance to the point I've made:
1. Yet another reminder to consumers that even "reputable" businesses aren't to be trusted. Not the first such incident with the same product after all and the dangers of asbestos are common knowledge.
2. Yet another reminder to consumers that government regulators also are not to be trusted. Took them how many decades to get onto this one?
Now that's just one incident with one consumer product but it's one among many. As the years go by ordinary consumers keep getting these little reminders to not simply take as accurate what those in authority say.
A few decades ago sure, if an expert in whatever said something then people tended to trust that as being true. Doctors and universities were beyond doubt but even big businesses were held in reasonably high regard that they'd provide factually correct information and steer consumers in the right direction.
Those days are long gone and the reality is that the general public is aware that if they can't prove it themselves then caution is warranted. Too many false alarms, too many denials and so on have lead to that.
Get any saucepan, fill it with cold tap water, place it on a hotplate and turn it on. Result is it gets steadily warmer until it boils. This is easily proven at home since practically everyone has access to at least one cooking pot of some sort and a gas, electric or other heat source indeed most people have boiled water on numerous occasions.
Now if I tell you that the internet works then you can prove this yourself with any device connected to it. If I tell you
how it works then unless you have technical expertise we are now in the realm of
belief. You cannot readily prove to yourself exactly how it works - either you believe the explanation of myself or others or you don't believe it but regardless of what you conclude, it will be a
belief for anyone who isn't themselves technically knowledgeable. There are facts available yes, but they are not easily proven by demonstration such that a person's understanding becomes a belief in practice - a belief that someone else correctly understands it and has correctly communicated that information without bias or omission.
Now if we go onto subjects like religion (any of them) or climate change then those things are well and truly beyond the ability of most people to prove or disprove indeed religion is beyond outright proof period. As such, an individual's understanding in relation to these matters is a belief that they are being told the truth by someone else in an environment where absolutely opposing views are commonly aired.
My personal belief on the question of religion is that the entire thing is fictitious. That is however a belief and I cannot prove it one way or the other.
My personal belief on the climate issue is that the problem exists but that humans probably don't understand every detail of it. I say that having read an abundance of work on the subject by others, having looked at weather data sources I know to be accurate and so on. It seems to be correct but I cannot personally prove this and as such my understanding of the issue is a belief.
Religion and climate are not like the pot on the stove where I can repeatedly demonstrate it with the exact same results thus removing all reasonable doubt. I can't go to heaven, have a look around and verify the whole thing. Can't go to hell and do that either. Also can't actually prove that they don't exist and are works of fiction. Much the same with the climate - I can read a report of someone else's work and
assume that the report is factually correct but I can't muck about with the earth's atmosphere and watch the temperature go up and down to prove it.
So we're back to beliefs and authority at a time when authority is increasingly distrusted.