It’s a common situation that I run into frequently: two people are debating about some scientific concept, and one of them is arguing for the mainstream view and supporting their arguments with the relevant literature. Meanwhile, the other one is “supporting” their arguments with blogs, personal anecdotes, and discredited papers. The debate eventually reaches a point where the anti-scientist realizes that a mountain of evidence and a strong scientific consensus opposes them, but rather than admitting the problems with their view, they instead invoke either Galileo or Columbus with arguments like, “well everyone thought that Galileo was crazy, but he turned out to be right” or “in Columbus’s day, every ‘knew’ that the earth was flat, but they were wrong, so why should I trust what scientists ‘know’ today?” Politicians have also been known to use these faulty arguments to support their non-sense. For example, in an attempt to defend the fact that he denies the science of climate change, presidential hopeful Ted Cruz said,

“Today, the global warming alarmists are the equivalent of the flat-Earthers. It used to be [that] it is accepted scientific wisdom the Earth is flat, and this heretic named Galileo was branded a denier.”

At their core, these arguments are just a variation of the fundamentally flawed argument that scientists shouldn’t be trusted because they have been wrong in the past (debunked here). Nevertheless, I want to look more closely at these examples, because not only do they not work, but they actually strongly oppose anti-science positions.

Columbus challenged the size of the earth, not it’s shape

Let’s start with Columbus. The common trope which we are all familiar with is that everyone in Columbus’s day thought that the earth was flat and Columbus would simply fall off of the edge if he tried to sail around it, but he thought that the earth was round and you could sail from one side to the other. That story is, however, nothing more than a wonderful fairly tale. No one in Columbus’s day thought that the earth was flat. The idea that the earth is round dates all the way back to the Greek philosophers, and it was nearly universally accepted well before Columbus set sail. So the debate in Columbus’s day was over the size of the earth, not its shape. You see, the most widely accepted estimate of earth’s circumference in Columbus’s time was 40,250 to 45,900 kilometers (25,000 to 28,500 miles), but Columbus thought that it was much smaller, only about 30,200 kilometers (18765 miles). So the debate was not about whether or not Columbus would fall off the edge of the earth. Rather, the debate was about whether or not he could survive such a long voyage. The ships of that day could not carry enough supplies to make it all the way to the other side of the planet if it was actually 40,250 kilometers in circumference. So people thought that his voyage was fool-hardy because they thought that he would run out of supplies part way.

Now, here is the really important part: Columbus was wrong! The actual circumference of the earth is 40,074 kilometers (24,901 miles), which is remarkably close to the well-accepted estimate in Columbus’s day, and way off from the number that Columbus had calculated. If it hadn’t been for the existence of North America and the Caribbean islands (which were previously unknown to most Europeans), Columbus and his crews would most likely have died.

In short, yes, Columbus was ridiculed, and people did think that he was crazy, but their derision was completely justified! Just like the modern anti-scientists, he ignored the well-established science and plowed forward, blindly following his own ignorance with reckless abandon. So, to any science deniers reading this, by all means compare yourself to Columbus, because you actually have a lot in common with him. You both have “done your own research,” you both defiantly ignore experts and the scientific consensus, you both allow your biases to cloud your judgment and drive you to make dangerous decisions, and you are both dead wrong.

No one thought that Galileo was crazy

Let’s get a couple of things straight about Galileo. First, he got in trouble for claiming that the earth moved around the sun, not that the earth was round. As explained above, everyone knew that the earth was round long before Galileo.

Second, no one accused him of being crazy. There were people who thought he was wrong, but he was never viewed as a raving lunatic. Further, he had support from many of his fellow astronomers. A large number of his colleagues thought that he was right. The people who disagreed with him were, in many cases, disagreeing because of religious reasons, not scientific reasons. In other words, they did not like the implication that the literal interpretations of certain Biblical passages (such as Joshua) were wrong; therefore, they insisted that Galileo must be incorrect. Let me describe this another way. One one side, you had Galileo with hard facts, careful observations, and rigorous calculations. On the other side, you had religious fanatics who were blindly rejecting Galileo’s facts because those facts didn’t agree with their preconceived biases. To be clear, there were also astronomers who disagreed with him, but it was the religious implications that really got him in trouble. Also, the astronomers who disagreed with him weren’t doing so because they had strong evidence that said he was wrong. Rather, they were disagreeing with him because he was proposing a fundamental shift in how we view the world (i.e., a rejection of Aristotle’s views of matter and motion). In other words, they were disagreeing with him because he was arguing against their biases and preconceptions, not because they had opposing evidence.

Now, let’s apply that to the modern anti-science movement. If you are arguing against climate change, vaccines, evolution, etc. you do not get to invoke Galileo because in any accurate analogy, you are the religious fanatics (or the astronomers who blindly clung to Aristotle). For example, when it comes to climate change, on one side we have scientists who have collected an enormous mountain of data and published thousands of studies, and on the other side, we have the deniers who have no data and rely instead on personal biases and logically invalid arguments like, “well it changed naturally in the past, so it must be a natural change now.” Similarly, we have thousands of studies which show that vaccines are safe and effective, yet those studies are opposed with anecdotes, “mommy instincts,” and fear-mongering.

In short, the idea that Galileo was a ridiculed rogue who dared to defy the consensus and turned out to be right is completely inaccurate. He certainly challenged the views of his day, but he did so with actual evidence, and many scientists realized that he was right. That is completely and totally different from claiming that the studies showing that vaccines don’t cause autism must be wrong because you know someone who was vaccinated and got autism, or that some “miracle cure” must work because you’ve done “thousands of hours of research” and the internet has assured you that it is legitimate. If you have numerous properly conducted, carefully controlled, peer-reviewed studies, with large sample sizes that have been replicated by other independent scientists and show that homeopathy works, GMOs are dangerous, acupuncture is effective, evolution isn’t true, etc. then you get to be Galileo. Until then, you are the religious fanatics who are opposing progress because of your own biases and misconceptions.