[acqq]

> A fact is generally considered to be a proposition that is true.

Where do you get that idea? A fact has to be "established." As in the trial, in front of a jury.

Now in science, the jury are qualified scientists. Others simply aren't qualified. Even unqualified people can invalidate something that is believed to be a fact. But they can't do by just being loud. The jury has to acknowledge that that unqualified guy is not speaking nonsense.

Read about the testing of EmDrive as an example. The guy who made it and can't explain it will still be accepted to be the discoverer, if his claimed effect gets to be really proved. The jury was skeptical, but they will still accept the results, if the measurements demonstrate it "beyond any doubt." At the moment, what was measured is far from that.

Another example: global warming is a scientific fact. There are some loud persons claiming that it isn't so, but what they bring to support their claims is truly and utterly worthless. Who says that: the climate scientists, all in the world. How do we know it's true? Because that's how science works, the specialists are trained the whole life to recognize the valid claims. The valid claims would become a new facts. The deniers don't have them.