I don't know if I've talked about this or not, but I have been thinking about it a lot recently. Most people believe a scientific fact is something that has been proven true, but that's not really the case. It might be true. Or it might not be.

What it really means is this: given the scientific evidence we have to date, we believe it to be true. Further experiments might show that it is, in fact, not true.

That does not mean "anything goes," that is, that anything we believe to be true might be true. No, it must be backed up by rigorous and reproducible scientific experimentation.

Now, a theory is a postulation, what we think might be true. And that is where the problem arises: in trying to determine the nature of reality, for example, or the nature of matter, it is possible that theory after theory will fall by the wayside as evidence emerges. (Indeed, that is what seems to be happening in both of these cases.)

We assume that eventually we will determine the answers to these, and other, fundamental questions. But why must that be the case? Isn't it possible that multiple theories could be put forward that fit all available scientific evidence, and that this will always be the case?

And if that is true we are not getting nearer to our goal of reaching the truth. We are merely going around in circles.