Mr Trump, as many will know, is very fond of walls. He promised, to build a glorious wall that one day would be named after him on the border with Mexico. He promised that Mexico would even pay for it. He has since back-pedalled on the fundamental aspects of that promise. He’s also quite sketchy on science and its importance. His lack of understanding of science is revealed whenever he tries to talk about it. Whether that’s when he thought that Bill Gates could shut down the internet, or when he thought that global warming was a Chinese hoax.
So why am I mentioning these two things? It’s because I’d like to highlight the importance of walls in science. You see, when a scientist forms a new hypothesis (something that Mr Trump will call “Just a theory folks, just a theory“), they aren’t taken at their word at all. No matter how respected the person who came up with the hypothesis, it remains just that until proven. So how do we prove our hypotheses correct as scientists? We put our hypotheses to the test and compare them with the factual data. If the hypotheses produce accurate predictions, we can call them a theory. Point to note: the word theory has a very different meaning to a scientist than to the average person.
But we don’t stop there. You see, even a very accurate and reliable theory may still be just an approximation of the facts and it may still be “mostly right, but not all right”. So we need our wall. As scientists, we put our theory into the largest and most powerful cannon we can find, and then we fire it and the strongest, most sturdy wall we can find. After the dust settles, we walk over and see what is left. If the theory is still intact and the wall is in pieces, we can continue to trust the theory. If the wall still stands and there are pieces of the theory scattered all around, then it is time to go back in search of a better theory. Critics will say “See, if the theory is broken, you have to change. Science is changing all the time, so we can’t even be sure it’s correct about the issues now.” Strictly speaking, this is true. Pragmatically speaking though, doubting science for these reasons akin to saying “Science tells us that there’s only a 99.9% chance that this delicious drink is poisonous. They can’t be sure. Why should we trust them? They admit they don’t know for certain. We should keep on drinking it cause the scientists don’t know for sure. They could be wrong.”