Why Neil deGrasse Tyson thinks science is true

I titled my medical misinformation podcast 'Follow the Science,' because it was a popular catchphrase and because science is the best method humanity has found for sorting reliable knowledge from misinformation. But following science is no easy feat when there is so much contention among professionals. 

Political views are constantly getting mixed up with scientific opinions, and there is so much pseudoscience that ends up looking like the real thing. What should people trust and what should we question?

Astrophysicist and science communicator Neil deGrasse Tyson leans toward questioning. He advises people not to dismiss things out of hand because they sound weird, or accept things out of trust because they're coming from an expert.

He is co-author of a new book, 'A Brief Welcome to the Universe,' and he was my guest for episode 42 of my podcast — a number that was, coincidentally, made famous by Douglas Adams as the answer to the deepest question about Life, The Universe and Everything.

And so we talk about how to deploy questions to sort real science from misinformation in a conversation that spans life, the universe and everything else  — from vaccines to UFOs. This excerpt of our conversation has been lightly edited for length and clarity.

Faye Flam: First, let us talk about the science of alien life. Scientists obviously have not found any aliens yet, but they are finding habitable zones beyond our planet. What are scientists observing and what is reasonable to infer about alien life?

Neil deGrasse Tyson: Let me split your comment into two paths. One of them is the search for life at all, and this would be microbes — anything self-replicating with a metabolism. There is a whole branch of modern astrophysics doing just that, looking for life on Mars, beneath its surface, the icy moons of the outer planets, Jupiter and Saturn.

Then, there is SETI, the search for extraterrestrial intelligence. That uses different tactics that assume that someone out there is intelligent, has technology and wants to communicate.

Faye: Right. It is a long shot, but, hey, it would be crazy not to try it.

Neil: It might be crazy not to! It is a very high return on what could be a trifling investment of funds.

Tyson then brings up something known as the Drake equation, which has been used to estimate the number of civilisations in the galaxy. Some terms, such as the number of planets, are backed by data. But there are a few final terms regarding the abundance of intelligence and civilisation, where we have to resort to guessing.

Neil: We have more than 4,000 exoplanets in the catalogue, and 25 years ago that number was zero. But when we get to those last few terms, we have to ask ourselves: What are the chances that an intelligent civilisation will actually have the technology and want to communicate? They have to have this level of curiosity. 

We have to estimate that somehow. How are we even going to do that? Is our conduct inevitable? By the way, if it is, then that means that species risks annihilating itself, as we have done many times in the last century — risked annihilating ourselves.

Who defined us as intelligent? Oh, we did! So, maybe on the scale of the universe, we are drooling, blithering idiots compared to an actual prevailing intelligence that aliens might have! And so the audacity of us to say, "Let us find other intelligent creatures just like us," and then we discover a life form where we, to them, look like worms to us.

Faye: Those aliens might have more interesting other aliens to study. We might be low on the totem pole.

Neil: So now, given all of this, we can ask: Have we been visited by aliens?

That is a stretch, for many reasons. The best evidence you have is the monochromatic fuzzy video from Navy pilots flying in restricted airspace? That is your best evidence? We have 3 billion high-resolution video cameras in people's smartphones who walk the earth every day. We have unwittingly crowd-sourced any possible thing that could be visiting us. Where is that footage? It is nowhere!

Do you remember, in the 1970s, there were all these accounts of people getting abducted? Well, you have got a video camera now, everybody does. You do not have to tell the alien, "Wait until I go home and get my camera and come back..."

Faye: That would totally go viral.

Neil: Yes. Look at the crap that goes viral that has nowhere near that interest. Plus, you could live-stream it. So I am just not impressed with what people have put forth as evidence for being visited by intelligent extraterrestrials.

That does not mean there are no UFOs – that just means you do not know what it is, and it is flying and it is some kind of object. Sure. And here is something that some journalists have not figured out yet— the newspaper headline "UFOs Are Real!" has no meaning.

Faye: How do we recognise real science and pseudoscience? So much real science sounds weird to people – including some ideas put forth in your latest book. For example, you and your co-authors write that scientists have inferred that our so-called observable universe might be just one bubble in a vast sea of other universes, the multiverse.

Neil: The multiverse is a natural consequence of applying theories of the universe that have already been demonstrated to work into regimes that will possibly guide the future of exploration. So we did not pull the multiverse out of our ass. It came out of equations that work in other contexts that make predictable, testable, statements about our world. 

Now we can say, will we ever be able to detect the multiverse? I do not know. That may await another generation to think about access points in our current experiments.

Faye: I think that is the best, most concise explanation of why the multiverse is a part of legitimate science. Segueing into vaccine hesitancy, there is a connection between that and the multiverse — people need to be asking the same kinds of questions, whether they are concerned about vaccines, aliens or alternative universes.

Neil: Now, we get to vaccines that have been tested. We have people, for example, in the Black community, who remember the Tuskegee experiments and the very ugly history of medicine. That is a very ugly legacy that is very hard to overcome. But to say, "I'm not going to take it because of the history of this against Black people," you realise most of the people who have had their vaccine are White people, OK?

Not enough people are asking those kinds of questions about what it is that they believe. And part of that is to recognise, what is true and what is not, is not to believe it outright because an expert tells you. 

You might do that because it is easier, but, if you want your own brain to participate, it should participate in the way of asking questions. But if you do not know how to ask questions about it, you can chase yourself down a rabbit hole and never come out again, and think things like the earth is flat, that vaccines have chips in them because you are looking at sources that somehow feed your fears, and you want to believe them as an excuse for not following sane science.

Faye: You hit on something really important, which is the ability to ask questions. Because we often hear conflicting information, and it is not always clear who is right. So you cannot count on trust alone.

Neil: Take the UFO case, for example. If you are going to hear startled Navy pilots looking at something they do not understand, and you want to use that as evidence that we have been visited, why not ask other questions? Why is the best visual of this fuzzy?

You would think somebody would have an iPhone video out their window of a trailing flying saucer, and we do not.

So maybe we are being visited by aliens. I have just not been convinced yet and people get angry with me when I say that. They say, "you are off not being a scientist, you are not being open." But I am saying, keep gathering data. And the day you bring an alien forth, you will not need me to agree with you because it will be clear and present to everyone who sees it.

Neil deGrasse Tyson. Photo: Reuters

Faye: You have sometimes said that science is true whether or not you believe it. I would love to hear you talk about what you mean by that.

Neil: In fact, I tweeted that long ago and people said, yeah, that is cool. Thanks, and then it ended up on T-shirts and things. I tweeted it again a few years later, and fights broke out. So it is interesting to watch the ground shift.

Science is exquisitely constructed to determine what is and is not objectively true in this world. And by objective truth, I mean things that are true, whether or not you believe in them. So E=mc2, which comes from Einstein's Theory of Relativity, is true whether or not you believe in it. 

We make bombs out of it! You cannot say "I do not believe that," meanwhile you have just been incinerated by a hydrogen bomb. You do not have the option to not believe in something that is objectively true.

How does science establish truth? By repeated measurements and observations that show the same result.

Faye: I think a lot of the problem is that people are seeing studies get retracted, or debunked, but that is actually the way the system is supposed to work. People try to replicate things and then it does not work and the conclusion gets thrown out.  A single study is not the same thing as a scientific fact.

Neil: Journalists have the urge to break a story that is brand-new or controversial. And the story will be based on one study that shows that all the other studies might be wrong. Well, that study is not true unless other studies affirm it…. And so the public is thinking, scientists have no clue what they are doing. Is cholesterol good for you or is it bad for you? Is it bad? Is it not?

When something is affirmed by multiple studies and multiple observations, it is not later shown to be false. It could be embedded in a larger truth like Newton's laws of gravity and motion — got us to the moon, by the way — but we learned that for very high speeds and very high gravity which fall outside of the experimental sphere of his laws. 

We needed relativity to figure out the more correct answer, and do you know something? If you take Einstein's equations and put them in low speeds and low gravity, they become Newton's equations, right? 

So we did not discard Newton because we found new results that conflicted with it; we broadened our understanding because of it. And Newton's laws are now a subset of a deeper, larger truth that we came to realise.

If someone wants to sell you special healing crystals, you can say, oh, that is BS. I am not going to do it. We can say, I will buy them. Well, each of those steps is equally intellectually lazy. In the first one, you're just denying it, and in the second one, you're completely accepting it. 

It is harder to probe the question than to probe the claim. And that is really what we're missing in our educational background. So you say, oh, what are the crystals made of? Uh, in what ways do they work? What do people say that it heals? What is the evidence of this? You just start asking these questions, and then the person walks away because they will not have the answers.

Faye: Or they will have an anecdote. They will say, well, my friend used this crystal, and, you know, she had this terrible backache and then she wore the crystal around her neck.

Neil: And the biggest problem in our brain, and advertisers exploit this,  is we are more likely to believe eyewitness testimony than we are to believe cold data.

Faye: Do you think the flat earthers really believe the Earth is flat? Or are they just putting us on because it is funny to talk about the Earth being flat?

Neil: I want to believe that they are just putting us on. But you see other stuff people believe in the world, and flat earth is not the most extreme of what people think.

Faye: Do you think the questioning scientific mindset can be taught, or do you think that some people are born to be questioners and others to be believers?

Neil: I think curiosity is something built into us as a species and is manifested in us very early as children. Oh, what is under the rock? What is behind the leaf? What does this bug look like?

Everybody's curious, that is all science is. We are just kids that never grew up. And so I do not think you even have to teach it. 

You just have to make sure it remains within you through school when it might otherwise get, not beaten out of you, but certainly exhausted out of you. When the learning no longer becomes fun.

Faye Flam. Illustration: TBS

Faye Flam is a Bloomberg Opinion columnist and host of the podcast "Follow the Science."

Disclaimer: This article first appeared on Bloomberg, and is published by special syndication arrangement.