When a scientific topic is covered in the media or talked about extensively, words like “proven” are often used. This word is often accompanied by a grandiose claim that seeks to impress people. Either this miraculous medicine is proven to work, or this diet is proven to be more effective. Everywhere we look in science communication, the word “proven” is there.
Unfortunately, while scientists and those who are familiar with the scientific process understand what we implicitly mean by the word “proven”, it is a completely different reality for those who are merely passive receptors to scientific information from the world at large. To them, the word “proven” means certainty, as in 100% certainty. When a scientist or science communicator says that something is “proven”, the idea they get is that the scientific concept or hypothesis has been validated and will be correct forever.
This is at odds with the enterprise of science. As every student in a scientific discipline finds out during their education, science is self-correcting and always updating its beliefs through experimentation. No idea is set in stone, except for perhaps the idea of how science should be conducted (as mentioned above). Everything else is fair game for updating, improving, or renovating.
However, it’s inconvenient for scientists to talk with all these uncertainties surrounding their experiments. Therefore, the more colloquial language of hypotheses being “proven” is used, simply because it’s easier. Make no mistake though: the implicit assumption is always there. Science as a principle cannot know that something is 100% true. We can be very, very, very certain of it, but never fully.
If you were fully certain something had been proved, then there would be no way to change your mind about the topic. Therefore, no more experimentation would be needed, and the information would never be updated. Your view on this particular topic would be static, never changing. As such, the scientific process would be useless. Incidentally, the information you believe would basically become the stuff of religious beliefs.
This is why I dislike the term “proven”. Despite what some people may believe, science is not the same thing as mathematics, and only the latter can definitively prove something. The former always has a certain degree of uncertainty surrounding it.
Consequently, I favour a different way of looking at which scientific theories are accepted and beat out competing ones. Instead of thinking about a scientific hypothesis as the best fit for the data, I like to think of it as a game of survivor. There are a bunch of candidates looking to explain a certain phenomenon, and the first thing that occurs is that the data invalidates certain hypotheses. As the data is analyzed further, more hypotheses are crossed off the list because they don’t adhere to the data until only one remains. This final hypothesis isn’t necessarily proven. Instead, it simply hasn’t been disproven. Therefore, it becomes the survivor and the accepted theory.
This process much better illustrates the process of science. It’s about constantly pruning out hypotheses that don’t fit the data, and keeping the one that survives the trimming. By thinking about the process in this way, we can get a better idea of what a scientist really means when they say an idea is “proven”.