This is not an actual common mistake, meaning that the term is not “wrong” in its own terminology, but it leads to people thinking science actually “proves” things. The terminology is not wrong when the one using it knows that all science has, everything that it gives us, are theories and no more. In that case we know that it is not equivalent to actual “proving”, but rather a highly reliable theory, or at its highest strength a scientific fact (which are the most established theories that science has to offer).
Why science does not prove? The reason is related to scientific method of its discoveries. No method based on scientific tests exists that can give us absolute certainty about a scientific theory or statement.
This is usually called Hume’s problem, he clearly showed that logically we cannot derive a general statement from a limited number of observations, no matter how big that number is. History of science also shows the same pattern, things that we had tested and thought were true turned out to be not true at all. I personally like to use “shows” instead of proves.
That brings me to my other point: There are statements that turn out to be ridiculous by the measure of the people saying them. The following typical conversation happened in my head:
- Evolution is just a theory, it has not been proven yet!
- Oh really? would you care to explain what part of science isn’t “just a theory”? And in that case “The earth is a globe” is also just a theory. But wait, you believe in that, don’t you?
- No! I’m am a member of flat earth society!
I don’t think that I can guess how that conversation would end!