The world is a fascinating place, filled with natural wonders and manmade marvels. It challenges us to want to learn all about it. How do things work? What’s the answer to this old mystery? Is this new thing good for me or bad for me? But there’s a lot of pseudoscience out there. Marketers make dubious claims to sell us their products. People believe weird things. TV documentaries blur the line between fact and fiction in the name of entertainment. And in the midst of all this, we’re all making life decisions based on questionable knowledge. How do we learn to separate what’s real from what’s not; what works from what doesn’t; the dependable from the fallible? How do we keep our curiosity from leading us to the wrong conclusion? It can be done, and this is your guide.
I’m Brian Dunning. I’m a science writer, and I’ve spent the last 10 years writing and podcasting about urban legends, paranormal phenomena, ancient mysteries, and the world’s biggest science discoveries, sharing what I’ve learned about what’s real and what’s not. One thing I can say for sure is that we’re all curious about this kind of stuff, and the more amazing something is, the more we want it to be true. Right now I’m in Death Valley, California. I’m on my way to see a surprising phenomenon that I learned about in college; a mystery that nobody had ever solved. It was so astonishing to me that it changed the course of my life, and led me to become a science writer. We’ll be there pretty soon. Lots of us get captivated by provocative stories, just like I did. The other day I sat down with some friends to see what kinds of things they’d heard that really intrigued them. I’m here with my friends Tamara, Heather, and Dan, and we’re talking about things we’ve seen on TV that seem amazing or surprising.
Yeah, you know I watch these documentaries on TV about different subjects, and I’m like wow, is this really a thing? Yeah, like the historical mysteries, or ancient aliens, or the unexplained files. Yeah, I hear these things and I ask, is this really unexplained? Well what about these reality shows where they investigate mysterious phenomena? Yeah, like the ghost hunting shows, where something weird always seems to happen. Yeah and it’s like, is something weird actually happening, or is it just special effects or editing or whatever. I want it to be real because it’s exciting, but at the same time, I don’t want to be fooled into believing something that’s not true. Well, definitely, television is a source of information that we all have to figure out how to process on our own. That can be a daunting task, because TV shows aren’t there to educate and inform — they’re there to entertain; even the ones that bill themselves as science or history networks.
How could that be? How could an education channel mislead us? We tend to forget that TV networks are for-profit businesses, not public services. Their motivation is to attract eyeball share and generate revenue for their advertisers. Whether the science or history that they present is real or not, simply isn’t part of that equation. The easiest way for them to make a program fascinating is to go for cheap sensationalism. Create the appearance of mystery, the appearance of controversy. Present things as being “unsolved” or “baffling to scientists”.
Present fringe cranks with oddball theories as if they’re real experts. That’s not true. Sometimes we’ll often show a real scientist to give the “conventional” view. It’s great that you’ll often present good information, but when you show it alongside bad information, as if they’re equally valid, that’s what we call “false balance”, and it’s a terrible way to inform. Why is it a terrible idea to give both sides of a story? Audiences are smart enough to decide for themselves. Giving two conflicting stories and saying “You decide” produces a confused viewer. Presenting what we actually know and how we know it produces an educated viewer.
We’re all products of the information we’re given. You’re just saying you want to be the arbiter of what’s true and what’s not. Why are your experts any more valid than ours? We work really hard to find the best people we can, people who have worked their whole careers, and you just want to shoot them down… (Argue, argue, argue…) The fact is, science communicators and TV producers have different motivations.
When those motivations align, we get great programming; but when they don’t… …what we see onscreen might be make-believe. But even television isn’t the biggest pipeline of unreliable information flowing straight into our brains. To find out what that is, let’s go ask some more people. Here we are with a couple of friends now, Ron and Tyson. So where does most bad information come from these days? The Internet. The Internet. That seems to be where most of us get our news. But you have to go out of your way to find something reputable. Yeah, the stuff that comes through your social media feed, you don’t know what the source is. If two of my friends on social media are debating something, they’ll each send out a link to an article, the articles will say exactly the opposite thing.
Which one’s true? Everything is on the Internet, the true stuff, the false stuff. The thing is, I can guarantee no matter how crazy something seems, I can go on the Internet and find a source to support it. It sounds like using the Internet to figure out what’s true can be pretty frustrating. This is a data center filled with web servers, where the Internet actually lives. It’s got good websites, and garbage websites.
But even with reputable news sites, the system for reporting science to the general public actually does favor lower quality information. That’s right: any given science article on a consumer-focused website that describes the latest research is very likely misleading. And here’s why: This line is the history of research in some scientific field. These circles are studies that were done over time. The big circles are larger, well designed studies, that have really good data, and probably give us the most reliable results. That’s why most of these are along the line, which represents the true facts in this scientific field. Basic facts that get reinforced every time we take a second look. The better a study is, the more likely its results are to reflect the real science. Now, the smaller circles are smaller studies, less rigorous, and more susceptible to anomalous data. So we see some of these give us crazy results, farther away from what most of the best research has found. Now let’s say you’re the editor of a TV news program, looking for something interesting to report.
Are you going to choose one of these here in the middle? Gravity still makes things fall, water is still wet? No, you’re going to choose one of these outliers, because it seems to tell us something surprising, something interesting, something that really shakes things up. And sometimes, the PR departments of research institutions actually make this problem worse. Because they’re trying to draw attention and funding to their institution. You don’t do that with “Water is still wet”, you do that with “One pill will cure all disease!” and “Invisibility cloaks are real!” so that’s what they put in their press releases.
The result? Many of the new science discoveries you hear about on the TV news, or read on a consumer-focused website, really are — more than likely — wrong. That can really blow your mind. We start to realize, wow, we really do get fed a lot of bad information, which shouldn’t surprise anyone whose main source of news is Facebook. I feel like I need a trusted friend to help me navigate the fog. Because we can always rely on what our friends tell us, right? Well let’s see about that. This is Lisa and Phil, we’re talking about the kinds of things we learn from our friends. Last night, half of my friends were talking about this cleansing diet that they’re all doing. With “amazing medical benefits”? I don’t remember my doctor ever suggesting that I do anything like that. Did they tell you to eat this superfood, or to avoid that bad food? Well I had another friend tell me that I should do acupuncture for literally everything.
But friends don’t try to steer each other wrong. I trust my friends, and I know they won’t intentionally give me bad advice, but sometimes you got to wonder if you’re doing something just because everybody’s doing it. How do I know whether something is true or not? Oh, thanks. My pleasure. Every weird thing you can think of, people do it. And a lot of them claim to be magically easy solutions to difficult problems.
Purify your body, some new mental technique, lose weight really fast, all with this really simple new thing that promises to be a lot easier than the hard work you used to have to do. Sounds seductive, doesn’t it? And I bet that the last time you went out with friends, you heard that at least one of them is doing at least one of those. Magically easy solutions to difficult problems. Everyone wants them, so they’re very easy to sell, and we all want to believe in them.
Unfortunately the facts aren’t always so magical. Difficult problems are difficult because they’re hard to solve. Losing weight is really hard. Aging is a painful reality. Getting rich is unlikely. And most of us are never going to look like movie stars because that’s controlled a lot more by genetics than by behavior. The data shows that we can improve ourselves in many of these areas, but never as much as we wish, and only through a lot of really hard work. That’s why it’s such a snap for marketers to sell magically easy solutions, and why so many of our friends become deeply invested in them psychologically.
I love that curiosity is one of our basic, instinctive characteristics. I love how it’s taken us from making stone tools all the way to… landing humans on the surface of the moon. That’s the power of curiosity. But the flip side is that it can get the better of us. We get mesmerized by sales pitches and buy things we don’t need, we treat ourselves with alternative remedies that promise miracles but do nothing, and we devote time and energy believing all kinds of things that aren’t true, all because we often fail to temper our curiosity with critical thinking. In my work as a science writer, I focus on separating science from pseudoscience. My job is to research the facts and find out what we really know. To help me do this, I’ve developed a set of principles I call the three C’s: Challenge, Consider, and Conclude. To show you how these work, let’s apply them to my favorite mystery, back in Death Valley. Well here we are, Racetrack Playa.
It’s a dry lake, 4 kilometers long, …and it’s famous for rocks that move across its surface, all by themselves. We see the trails that they leave, but so far nobody’s ever seen them move. They’re called the sailing stones. So here’s one of them. And you can see the trail that it left. And this is absolutely real, we’ve tracked their positions and we know for a fact that these rocks do move. This rock really did start off way down there, and it slid across the surface, all by itself to here. For 100 years, people had no idea what caused these stones to move. The closest thing to a science-based explanation anyone came up with was that strong winds would push the rocks when the mud was wet and slippery, something that’s never been observed anywhere on Earth; the physics just don’t make that possible.
Some people were so confounded by it that they came up with some really far-out ideas. Somehow magnetic fields were involved, or gravity would shift, or aliens and UFOs were responsible, or people would even just throw out random words like “energy vortex” and hoped that that would somehow provide the explanation. The simple fact is that nobody had a clue. So let’s apply our principles and see if we can understand this mystery. Step one, the first of our three C’s, CHALLENGE the concept that we’re curious about. Like, before it makes sense to ask about magnetic fields and telekinesis and aliens moving the rocks, let’s first make sure about something. Are the rocks actually moving at all? You see, that’s a question that we often fail to ask. Your friend is drinking a detox juice cleanse to remove toxins from her body; how often do we fail to ask whether these mysterious toxins are actually there to begin with? They’re not. Or, a TV documentary gives us a new explanation for the disappearances in the Bermuda Triangle; how often do we fail to ask whether there actually are an unusual number of disappearances there? There aren’t.
There’s a great maxim attributed to psychologist Ray Hyman: “Do not try to explain something until you’re sure there is something to be explained.” Let’s try this out. Let’s see if we can find something that makes a really popular, really compelling claim, and see if we can challenge it at this most basic level. Before trying to explain it, can we first verify whether it exists at all? Here’s a good one. A lot of products promise to boost your immune system. And that’s compelling, we’d all love to have a super-powered immune system and never get sick. We might be curious enough about this to ask how it works. But when we look into this, we quickly find out a disturbing fact. There’s no such thing as boosting your immune system. Medically, the words are meaningless. Your immune system is a delicate balance. We want it to attack things like viruses and bacteria, but we don’t want it so active that it attacks our own healthy tissue.
When it does, that’s called an autoimmune disease, and a lot of people suffer from them. Lupus and Rheumatoid Arthritis are just two of the more than 80 different “boosted immune systems”, aka autoimmune diseases. They are not something you want. Fortunately, these aren’t going to do anything. If you see a product like this, put it back. We challenged it, and it failed. Medically, there’s no such thing as immune system boosting, so there’s nothing here for us to have to explain. But when we challenged the story of the sailing stones from Racetrack Playa, we found out there is something to explain. They are moving. People have tracked them on GPS. It was important to wonder if these trails might have been created some other way, but no, we do have a real thing here.
The sailing stones survived our initial challenge, so now it makes sense to proceed and try to figure out what’s going on. The next step in doing that is the second of our three C’s: CONSIDER alternate explanations. I want to find out everything I can about what work people have already done to solve this. Some of it might be a little odd, but the wider I can cast my net, the more likely I am to find the best work done by the smartest people. How does the average person on the street, who may not have any special knowledge, learn what the latest research says on a given topic? Well, no matter what question you’re pondering, you can almost always come up with a few explanations to consider, just by starting somewhere obvious like Wikipedia.
Often, your choices boil down to two. These are usually a boring science-based explanation, and an exciting alternate explanation, promoted by a small number of personalities, often non-scientists, but who might be on TV or writing books. For example, the Apollo 11 astronauts saw something following them when they flew to the moon. The science-based explanation is that they soon realized it was one of four adapter panels that fit between the S-IVB third stage and the lunar module. The exciting alternate explanation is that it must have been an alien spacecraft. That’s two possible explanations for us to consider. How does the average person know which one to trust? There’s one piece of advice I always give. Go with the experts, the real working scientists, who have studied this their entire careers, and have worked closely with other researchers in the same field worldwide, and developed a pretty strong knowledge base.
Aliens did not follow the Apollo astronauts to the moon. Sometimes this advice means depending on what some government agency says, or some other establishment that you might be inclined to distrust. That’s true, and that can be a valid concern. But remember what we’re trying to do here: we’re collecting ideas to consider. We’d be foolish to dismiss the one that most professional experts in the field agree on. Distrust of authority goes back throughout history. The Roman statesman Cicero said “There is nothing so absurd that some philosopher has not already said it.” Even the Royal Society’s motto is “Nullius in verba” meaning “Don’t take anybody’s word for anything.” So there’s a popular notion that trusting an authoritative source is automatically a logical fallacy called the Appeal to Authority. Being in a position of authority doesn’t automatically make you right. But the logical fallacy refers to false authorities: Celebrity spokespeople, or snake oil salesmen who pose wearing authoritative-looking white labcoats, when they’re not actually doctors. But real experts in any field truly do represent the core of our knowledge in that field.
We landed humans on the moon because the scientists and engineers spent years working together with the best knowledge we had. When we need heart surgery we go to a real cardiovascular surgeon who went to a real medical school. When we take a trip on a plane we want a real pilot with a legitimate pilot’s license. So when we ask a science question, it is not irrational to go to a science expert. I always advise the average person to go with the experts, instead of the media personalities. Maybe you won’t always be right, but you will be right far more often than you’re wrong.
For another example, let’s look at one subject where pop culture is filled with misinformation: food! Specifically, genetically engineered crops, like these sugar beets. Demonizing modern agriculture has become a tremendously profitable food fad, and as a result, non-food-scientists pressure us with misinformation from a bewildering number of angles. Packaging experts use labels that suggest GMOs should be avoided; Bookstores are full of bestsellers by dieting or cooking gurus cashing in on the fad; Restaurants proudly display signage that they won’t serve these foods either. Here’s where you find yourself having to make a choice. There’s a huge amount of noise coming from self-proclaimed pop foodie experts, promoting the idea that genetically engineered crops are dangerous to us or to the environment. Yet, those products remain a staple of our food supply. Farmers keep growing them, food producers keep using them, and virtually every product found in the supermarket contains some GMO ingredient.
Hundreds of billions of GMO meals have been served over the past 50 years, and not a single health problem — not one — has ever been traced to the crop’s genome. It would seem there’s a huge amount of evidence that all this non-expert advice might be driven less by real science, and more by marketing and sensationalism. So let’s see what the real experts have to say: the farmers, the regulators, the testers, the agriculturalists. All the world’s most experienced experts at figuring out how to best feed the world. Turns out some of the tools are new, like gene splicing with CRISPR-Cas9, but the basic techniques have been a staple of agriculture for thousands of years. Apples, bananas, melons, even sugar; they’re all products of genetic engineering at some level. You wouldn’t even recognize kale if you saw what it looked like 2000 years ago, before we started cross-pollinating it to make it palatable. It does stand to reason that graduate school, years in the field, years in the lab, years of working with the best minds, is going to produce a better informed expert.
If you want to be right more often than wrong, go with what the real experts say. So the expert opinion on the sailing stones? Well, geologists had published a bit, but nobody had ever managed to collect any direct evidence. The best guess was that strong winds would push the rocks hard enough to unstick them and slide them across the wet mud. It wasn’t very persuasive; we just never had enough data to come up with anything better.
I wanted to see if I could learn anything new. So I came here with some friends way back in 2001, and luckily, I found something. This is the video I took. It was winter, when water from snow melt and rain formed a shallow lake at the south end of the playa. The morning wind was strong and ice cold. The whole lake was actually being pushed along by the wind at almost walking speed. It’s not really visible in this low-quality video, but we could see great sheets of thin ice out on the lake. The sun had been on us for an hour and it was above freezing, but think how it must have been just before dawn with that wind screaming. Wind alone might not be able to move a rock that’s planted in mud, but what if something solid pushes it? The rock is in the shallow water, and so are these great sheets of ice.
When the wind gets that ice moving, that’s a lot of momentum. The solid ice takes hold of those rocks, and it’s the mud that gives way. The rocks drag across the playa, leaving tracks wherever those meandering ice sheets take them. One lucky morning, and I found myself with a new alternate explanation in hand. I’d challenged and I’d considered, and now it was time for the final C: to CONCLUDE which explanation fits best. Could it be the ice sheets that I saw? Is it magnetic fields moving these non-magnetic rocks around? Was the wind unsticking them from the mud and sliding them across the ground? All of these explanations — except the ice sheets — have one very important thing wrong with them, and it makes it easy to cross them off the list.
They’d all require some tweak to our understanding of the world to make them work. If aliens were moving the stones, we’d need to change our model of the world to include visiting aliens. If energy vortexes were doing it, we’d need to live in a world where there’s such a thing as… well, whatever an “energy vortex” is supposed to be. What’s a good way to assess these kinds of explanations? If only there was some tool… You may have heard of Occam’s razor, named for the Franciscan philosopher William of Ockham. It’s a tool that can help us decide which of several possibilities is most likely true. It’s been stated in a number of different ways, but the one I like best is “Among competing hypotheses, the one with the fewest assumptions should be selected.” An “assumption” refers to some condition that’s required to make the hypothesis possible. If we see some strange light in the sky, one option is that it’s an alien spaceship.
For this to be possible, we’d first need to accept the assumption that alien spaceships visit us — a pretty big change from what we currently understand. The other option, that the light is simply something we don’t personally recognize, requires no new assumptions about the world, and is therefore most likely correct. In short, Occam’s razor tells us that ideas which only work if some magical new thing is added to the world, are probably wrong. Here’s another example. We’ve all seen photographs like these. These circles weren’t visible when the picture was taken, but here they are now. There are two competing hypotheses for what these are. Some people think they represent ghostly presences, and they call them orbs, or spirit orbs. Others think they’re simply particles of dust, lit up by the camera flash, and appear as large circles simply because they’re out of focus.
Occam’s razor can help us determine which hypothesis is more likely true. The ghost explanation requires us to assume that ghosts are a known thing. Unfortunately, we don’t know that. We’ve never caught one. We don’t know what properties they might have. We don’t even have a theory that might support the possibility of their existence. So to accept the ghost explanation of orb photos, we’d have to make a new assumption. But the dust theory relies only on things that are well known to exist. Dust does get illuminated by a camera flash, which we can simulate with this light here. Dust does appear to be a large circle when it’s out of focus, and brightly illuminated. Since we don’t need to introduce any new assumptions, Occam’s razor tells us the dust theory is probably the better explanation for orb photos. So, did space aliens move these rocks? Just think of all the new assumptions that would call for. No, it wasn’t aliens. Occam’s razor also tells us that it probably wasn’t psychic energies or vortexes or other powers that would require us to overhaul our understanding of nature.
But we already know for a fact that ice forms here, and that wind blows those ice sheets around. Those conditions are real, they’re not new assumptions. We also know that ice moves rocks; if icebound rocks can carve Yosemite Valley, they can certainly drag a trail in some mud. The ice sheet hypothesis dovetails perfectly with facts about the world that we already know are true. Sure enough, in 2014, a group of scientists proved that this is, in fact, exactly what causes the sailing stones to move. They installed time-lapse cameras and a remote weather station right up there on that hillside.
They placed fifteen GPS-equipped stones on the playa surface, then collected data for two years. Finally they caught the stones in action, as sheets of ice pushed the rocks around, and were captured in these time-lapse photos. Finding out that my solution was the true one was exciting. Solving a mystery, and getting it right, is pretty fun. It’s also empowering, and inspires you to want to know more. I had the very best tool: I knew the basic principles to follow. They really do work. You may not be right every time, but you will be right most of the time. The Principles of Curiosity are basically the scientific method.
Some of you watching might have recognized it. We challenge and falsify until we have a reliable observation, for which we can then form provisional explanations. We consider and test those explanations, and finally we conclude which one fits best. And that conclusion is always in motion. We might get better data tomorrow, it might allow us to improve our conclusion. Our ability to understand things is driven, at its core, by our basic curiosity. The scientific method is a way to steer our curiosity, and keep it on course to the best of our limited, human ability. A lot of times people will ask me why. Why shouldn’t I believe in ghosts, or psychic powers, or miracle foods, or alternative medicine? What’s the harm if I enjoy these things and they bring me comfort? After all, such things bring meaning and comfort to a lot of people.
But happiness and enlightenment are all around us in our world; you don’t have to turn to pseudoscience to find them. Searching for meaning in reality is far more likely to yield results. Test your beliefs. Subject them to scrutiny. Immunizing yourself against misinformation is more important than many of us ever stop to think. We make important life decisions based on what we think we know. Making the right decisions is how humanity advances. The tools of science have served us pretty well in this regard. We’ve learned a lot, and improved our lives immeasurably. Think of how much more we can do when we can better judge what’s real from what’s not. Longer life, happiness, a cleaner planet, technology, and peace are driven by the engine of science, and fired by the fuel of our curiosity.
What makes a rocket ship fly? How far are those lights in the sky? Isn’t there some way That I could go up there too? Things I can touch must be real But what about feelings I feel? So many mysteries Conceal secrets I want to know. A new idea, a new technique Threaten to turn me into a geek Love the old stories so full of mystique Tempting me to learn. Open up, let me in, let me see The wonders you’re hiding from me I’ve got a little curiosity And possibly you’ve got some too. I’ve got a little curiosity And possibly you’ve got some too. .