No, this is not about the origins of Christianity. The Paul in the title is not the Apostle, but Sir Paul McCartney, former Beatle. Back 1969, rumors on some American college campuses that Paul McCartney had died in a car crash began to spread. Radio DJs and talk-show hosts expanded and elaborated the hoax. The details can be found here. For years, very serious, thoughtful people compiled and presented “evidence” that Paul was dead. Such evidence included clues one could hear by playing some of the Beatles records backwards and the fact that Paul is not wearing shoes in one of the album cover photos. At the time I was a science student, and several friends wondered why I was skeptical about the story. “You are a scientist,” they said. “You must believe in evidence.”.

This story is a good way to illustrate what science is not. Science is not about amassing evidence to prove a point. That’s what lawyers do. That’s what advocates do, and scientists are not supposed to be advocates. One can always find evidence for or against anything. As a counter to this rumor, I began to accumulate a great deal of evidence that the Beatle John was really a woman. I even convinced a couple of poor souls.

I once watched a crazy lady on the news holding up evidence for yet another “Paul is dead” story. This was the one about President Obama being a fraud and a liar (her words) and that he was born outside of the US. Oh yes, she (and other people) presented a lot of evidence. Did that make it true? No. I have seen tons of evidence that US intelligence and/or the Israeli military blew up the Twin Towers on 9/11. There is evidence that vaccines cause autism, that GMOs make you sick, that the Holocaust never happened, that Elvis lives, that we never landed on the moon, that fluoride kills, that AIDS is caused by drug abuse, and so on.

And of course, when I say that I don’t believe it, the believers always counter, “look at the evidence”.

So let me say this. Evidence is cheap. You can find evidence to support or refute any statement. Evidence is not the way to establish the truth. Evidence is important, but by itself is useless. Now I can hear the computer keys clicking away. “SCIENCE IS BASED ON EVIDENCE. YOU ARE ANTI-SCIENCE!!”

Actually, that is a common misconception. Science is not based on what you might call evidence. Scientists are not juries. They do not reach a conclusion about truth by hearing arguments from many sides, and weighing the evidence. The scientific process is quite different from what people generally think. For most tough scientific questions, where there is evidence pointing to different answers, scientists will usually say “We don’t know yet. I favor this answer, but it could be the other one.” Eventually, as more data comes in, one answer becomes obviously correct to everyone (sometimes with exceptions).  That can take years or decades.

Experimental science is not set up to answer big questions, but very small ones. No scientist goes into a lab ready to prove that evolution is true or false or to cure cancer, or to learn how life began. No experiment or observation could do that. What they do is set up an experiment to measure the enzymatic activity of an extract of one species of yeast cells by determining the rate of disappearance of a particular metabolite labelled with radioactive phosphate. And 9 times out of 10, the experiment doesn’t work: the controls show the wrong values, the replicates give wildly different answers, nothing makes sense. After several months, usable data finally comes out. It’s usually not very impressive or interesting. The measured enzymatic activity is pretty much zero, which means either that this yeast species doesn’t degrade the metabolite, or the extract didn’t have the enzyme in it, or there is no such enzyme, or who the hell knows. That is what really happens in science labs, folks.

Sometimes we get lucky and we make a real finding. Something that can be published. Something that might mean something interesting. But proof? Truth? Sorry, no. At best we have an experimental result or an observation that is factually true (because we did the experiment according to the rules). But that fact by itself could mean any number of things. Scientifically defined evidence for a hypothesis, especially for a major important hypothesis, comes very slowly and from many different approaches.

This is why I am not interested in evidence for or against the reality of God or Jesus Christ. LaPlace famously said “I have no need of that hypothesis” when asked about God – well, I have no need of that evidence, because I know that “that hypothesis” cannot be tested by any manner of experiment, and that evidence can be presented by both sides ad infinitum.

Some people still think that the original Paul McCartney is dead. During the height of the hysteria, one addled reporter challenged Paul to prove he was the real deal. Of course, he couldn’t. How would you go about proving you are really you, and not a very clever impersonator who has learned all of the life story of the real actual you? How do we prove that Shakespeare wrote his own plays? Obama showed his birth certificate and Trump declared it a forgery. Christians point to historical documents, and skeptics say they were forged or not early enough. None of this is science, people. It’s politics, and its fake.