Of course it hasn’t. In fact, it is impossible for science to prove anything, because science is based on experiments and observations, both of which can be flawed. Often, those flaws don’t become apparent to the scientific community for quite some time. Flawed experiments and observations, of course, lead to flawed conclusions, so even the most secure scientific statements have never been proven. There might be gobs and gobs of evidence for them, but they have not been proven.
Karl Popper probably wrote the most important book related to this concept, which was titled The Logic of Scientific Discovery. Interestingly enough, he originally wrote it in German and then rewrote it in English. As a result, it is one of the few books that is published in two different languages but was never translated. The author wrote both versions. In this book, he argues that science should follow a methodology based on falsification. He shows quite clearly that while science cannot prove anything, it can falsify ideas that are currently thought to be true. He therefore argues that the test of any real scientific theory is whether or not it can be falsified. If not, then it is not truly a scientific theory.
There are a lot of scientists who disagree with Popper that falsification is the key to whether or not a theory is scientific. However, few would argue with his point that science cannot prove anything. Indeed, the journal Science seemed to forget this fact for a moment, but an astute reader chastised the editor, who admitted he was wrong.
