
The biggest scientific mysteries remain unsolved. Explore what science knows—and doesn't know—with Michael Brooks.
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There are some mysteries that science has solved beautifully. And then there are the ones that stubbornly refuse to give up their secrets from strange phenomena and unexplained discoveries to questions that have challenged brilliant minds for decades. These are the puzzles that continue to fascinate scientists and the rest of us. Which is why today's Sysk trending topic is Mysteries that Science can't Expl. Today, we'll explore some of the most intriguing mysteries that still don't have satisfying answers. My guest is science writer Michael Brooks, whose work dives into the fascinating intersection of what we know, what we think we know, and what remains completely unexplained. It is a fascinating conversation that will leave you wondering just how much there is still to discover, and we'll dig into it right after this Something I've noticed over the last year or so is that Quince is quietly taking over my closet. It wasn't intentional. I bought a couple things a while ago. A cashmere sweater, a polo, some pants. Recently I ordered some jeans. Now I've got over 20 things in my closet from Quince and my wife started ordering clothes and my son. Now every time one of us is wearing something we really like, the other one will ask, is that from Quince? And most of the time it's from Quince. What surprised me most is these aren't clothes you save for special occasions. They're the ones you reach for all the time. The fit is great, the quality is outstanding, and well, they just hold up. And then you find out why the prices are so reasonable. You see, Quince works directly with ethical factories and cuts out the middlemen. So you're paying for premium materials instead of expensive brand markups. That's why they can offer everything from organic cotton tees to premium denim and Mongolian cashmere at prices that really surprised me. Upgrade your everyday download the Quint's app for app exclusive offers or go to quince.com sysk get free shipping on your order and 365 day returns. Now available in Canada and the UK too. That's Q U-I-N-C-E.com sysk. Science is good at explaining a lot of things, but there are plenty of things science can't explain, not with our current technology. It's really fascinating to look at some of the things that we know exist that are there, but there's no explanation for why or how. Michael Brooks is a science writer who has a pretty good reputation for explaining complicated things so people like me can understand them. One of his books is called 13 Things that Don't make sense. The most baffling scientific mysteries of our time. Hi, Michael. Welcome. So tell me one of these baffling mysteries.
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One of the things is that 96% of the universe is missing, and that scientists don't know what most of the universe is made of.
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What do you mean it's missing?
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They know that there's something out there that has mass, but they can't see it. So when you gather up all the information about stars and planets and all the stuff that's made out of ordinary stuff, it turns out that that can only account for about 4% of the universe. And the rest of it seems to be in some form of invisible matter that we just call dark matter. And there's some kind of energy in the universe that we can't see, can't get our heads around and find out anything about, and that's known to scientists as dark energy.
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Well, that concerns me a little bit.
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It's a big subject, actually, in cosmology at the moment. People who study the universe Are just scratching their heads about this, and they think the dark matter must be out there. The dark energy is more of a puzzle in that it's causing the universe to expand faster and faster, but nobody really knows what this stuff is that's causing this to happen.
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So to call it dark energy, I mean, that name is like a placeholder. Until you figure out what it is exactly, we'll just call it dark energy.
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Well, that's right. Somebody has suggested that you might as well call dark matter pink space blancmange, because it's just so completely out there that nobody has an idea what it is at all.
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But in human experience, if you have something that 96% of it is missing, well, the missing part could be anything. So maybe all this universe that they can't see, I mean, it could be anything.
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It could be anything. And one of the things that it might be Is an optical illusion or the equivalent of an optical illusion. It may be that scientists have actually got their equations wrong and have just kind of missed something about the sort of fundamental nature of the universe, and that can't be ruled out. And the longer we fail to find this stuff that's missing, Then the better that assumption becomes that somehow there's just something that we need to fundamentally readdress.
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But I wonder if it could just be that it's something beyond human comprehension. Like, when we talk about the universe expanding, well, what could it possibly be expanding into? We can't conceive that Maybe we can't conceive this.
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That's a very good point. It's very possible that we will never know the answer to these things, which is what's so frustrating when you're a scientist who studies this and studies the universe and realizes that almost all of it could be completely beyond our understanding.
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So let's pick something a little more down to earth and closer to home, the placebo effect, which you say really can't.
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There are people who study the placebo effect and can induce the placebo effect, but there are other people who say that when they look through all the scientific literature, they can't see any evidence that the placebo effect actually has any effect whatsoever. So, again, it's one of these things that seems to be there, but scientists can't agree on whether it actually is there. The funny thing is, I went to one of these groups that researches the placebo effect. I actually had them induce it in me. They gave me a series of electric shocks and managed to make me think that the shocks were actually very mild when actually they were quite severe. So for me, it seems there is something there, but scientists can't really get a grip on it at all.
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But doesn't it seem as if you should be able to test the placebo effect pretty accurately, that you give one group sugar pills and tell them it does something, and you give another group sugar pills and tell them it doesn't do anything else and see what happens? I mean, it seems like there ought to be some way to definitively determine if there really is something there.
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Yeah, it seems that way, except that the only place where you see placebo effects is actually when people are reporting their own state of mind, if you like. So if you have somebody in pain, you can give them a pill and they'll say, oh, that's better. It's not hurting so much anymore. But you can equally give them a sugar pill. And they might say that you can give them a real pill that might do that. And we like to think of the drugs and pharmaceuticals that we take as actually producing chemical effects in our bodies and helping us. But it turns out that it may just all be an illusion in our minds. And you can do tests that actually show that some of these chemicals don't work unless people know that they're taking them. There's a classic study of diazepam, which is Valium, that shows that it doesn't reduce your anxiety level unless you actually know you're taking it. When people get it in a hidden dose, they say they're still just as anxious as they were.
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But what about more physical diseases like cancer and lung disease? What about the placebo effect and those.
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If the placebo effect is real and it works on things like pain, it doesn't seem to have any effect on things like lung disease or cancer. The power of positive thinking in that respect doesn't seem to be able to help you. So if you're given a pill that you're told will help your cancer, it just won't.
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Well, I think that comes as a surprise to a lot of people because there is this idea that attitude and positive outlook will help with those physical diseases. But you're saying that the belief that a pill is working if it doesn't, doesn't do anything.
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But there are plenty of other ways that if the placebo effect is real and we can get a handle on it, that we will be able to help people. I mean, American doctors are already using this quite considerably, actually. There's something like 45% of doctors are saying that they kind of give people pills that aren't necessarily going to work exactly for the condition they've got, but they will help the patient to feel better and they will get better because of it. So it's not like we can't use it, but we know so little about it at the moment that we're really struggling to learn how to use it properly.
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There has to be, though, some theory underlying theory or belief as to how this works, that the placebo effect in some cases does seem to work. And when it does seem to work, I mean, it's not magic.
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So what is seems to be that the placebo effect seems to kind of help your body to help itself in some ways. It's like you raise your hopes and you raise your expectations and something chemical goes on that in some cases seems to have a positive medical effect. I guess our bodies have learned how to fight lots of things and maybe given a little help with a bit of hope, then they fight even better.
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But it sounds like you're saying two opposite things, that it works, but it doesn't work.
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Well, that's because there's a kind of split in scientific opinion on this, but that there's very strong evidence that shows no effect of placebo whatsoever when you look at all the scientific literature. And yet on an individual case by case basis, there does seem to be a lot of evidence that placebo, or the idea of helping somebody kind of feel more positive actually does have an effect.
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Yeah, it's kind of like those studies that say that sugar has no effect on hyperactivity in kids, but you ask any mother and they'll tell you you're crazy.
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That's absolutely right. And I've seen those studies on sugar. And I've also carried out my own studies on my own children, and I think sugar has an effect.
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I'm speaking with Michael Brooks. He's a science writer, and the book we're talking about is 13 things that don't Make Sense. The Most Baffling Scientific Mysteries of Our Time. One thing I discovered after shopping on Wayfair is that it's almost impossible to stop at just one thing. I went there thinking, well, I might order a thing or two for the house, and instead I just kept finding things that we actually need. I replaced the old cover on my gas grill that's been sitting out in the California sun for years and looked horrible. I picked up some new cutting boards for the kitchen because the old ones looked horrible. And my son found a new nightstand for his room. I even grabbed some new grilling tools. None of it was anything I went there looking for. I just kept scrolling and thinking, you know, oh, we could use that. What impressed me was the quality. The products feel solid and everything arrived quickly and I can see why. Wayfair has Wayfair Verified where products are hand vetted for quality before they make the cut. Plus, with millions of verified customer reviews, it's easy to shop with confidence and if you join Wayfair Rewards, you get 5% back on every purchase. Honestly, it was such a fun shopping experience you gotta try it. Join Wayfair Rewards today to get 5% back on every purchase and start saving on your next home Upgrade. Head to Wayfair.com to shop all things home. That's W-A-Y-F-A-I-R.com Wayfair Every Style Every Home
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so, Michael, what's another mystery that baffles science?
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Free will, the idea that you make your own decisions and that your body is under your control is actually not the view of science, even though it's the view of us every day. The idea is that we have free will, that we can choose what to do. And we're making decisions all the time. Neuroscientists are saying that actually, really we're just brain machines. Our brains are kind of making these decisions well before we're conscious of any intention to do something. So if you perform a measurement on somebody's brain to see when the arm is about to start moving or something like that, and compare that to when the person said, I'm going to move my arm, you find that the brain has already started the movement well before the person has made the conscious decision to move, which is quite a scary concept.
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But how is that possible? How can your arm start to move before you've made the decision to move it?
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Well, it seems that the brain and the guy, interestingly, the guy who did this experiment first, a guy called Benjamin Libet, he hated the result that he got so much that he spent the rest of his life trying to find ways out of it. But it seems that our conscious will and our conscious intention of something is kind of almost like a trick our body pulls on us. And it kind of gives us the illusion that we're in control. But actually, we just seem to be working as machines controlled by something going on in our brain that isn't necessarily our conscious will. I can't explain it, and it goes against every kind of everyday experience that we have. But actually a scientific finding like that, and there was a more recent study that found that up to seven seconds could occur between the brain starting a movement and the person becoming aware of it. So it seems there's a lot to explore there in terms of are we responsible for our actions?
A
Well, now, wait a minute. Wait. Let's say I have an itch, and my inclination would be to reach over and scratch the itch. But let's say I consciously decide not to scratch the itch. But if what you say is true, then maybe seven seconds before the something decided that I should scratch the itch and I stopped it. I didn't scratch the itch. Is that free will?
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Well, there's two explanations for that. One of them is what this guy Benjamin Libet came up with, which was he called the power of veto. In that, okay, your brain has started these things, but your conscious will can stop them. The other argument around this is actually invoking your own will to prove that you have free will is actually another sign that you don't have free will in that you're using your conscious will just as a kind of. Just to be difficult and prove that you don't have. Prove that you do have free will. But actually, maybe that's something that your brain is kind of already doing.
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So what do you think? I mean, you've looked at the research closer than most. Do you think we have free will?
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I don't believe we do. I don't think you can defend the idea of free will scientifically. And one of the examples that was given in the 18th century, in fact, was when you get out of bed in the morning, and you could be lying there under your duvet and kind of trying to get yourself out of bed, but actually what happens is you just tell yourself, oh, I don't really want to get out of bed. And then you'll find. And try this tomorrow morning. You'll find that somehow you actually have got up and you didn't really. You're not really aware of having issued a command to get up, but actually you're on your feet and you're up. And this was kind of used as the first example of our lack of free will. That actually there's something going on that kind of bypasses our conscious decision making. And although we have this general kind of feeling that we should get up, the fact that when we do get up, it can almost take us by surprise is a show that our bodies are kind of a bit more out of our control than we'd like.
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But we've all been told since as early as we can remember that we're responsible for our choices. We are the ones who choose to do what we do. We can choose a life of crime, or we can become a Priest or these are our choices to make.
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This is why this subject is actually becoming quite important now, because neuroscience is finding these things about people's choices and intentions. And some of them are being asked to. Some neuroscientists are being asked to testify in court that somebody couldn't have chosen to do anything else. You know, they effectively didn't choose to do whatever it is that landed them in court. And it's becoming a very difficult area. I think this is one thing, and this is what I describe in the book as my only conclusion about any of these anomalies that we should ignore, really, is that our society is kind of set up to deal, as you say, with people who make their own choices. And people have to be held accountable and responsible for their choices. And even if neuroscience is telling us that they're not really accountable, then I don't think we can afford as a society to take that too literally.
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But it may not be all or nothing. It may not be all our decisions are free will, or none of our decisions are free will. Maybe we make some of them, and maybe other decisions are made in some other way.
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I think there must be some that we do make. I find it so hard to believe that we're not making any choices. The question we have to ask is, which choices are we making? And there was a famous case of a man who had a tumor in the front of his brain, and he actually found that all of a sudden, he had sexual feelings towards younger children, inappropriate sexual feelings. And when this tumor was cut out of his brain, that went away completely. Now, that suggests that something in his brain chemistry or the physical sort of shape of his brain with this tumor actually changed everything to do with his personality. And then we're getting into the science of are we making choices, or are we just a function of what our brains do to us?
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Another one of the unexplained mysteries you talk about is the wow. Signal. What is that?
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This was a signal that was received by a telescope in Ohio in 1977. And it looks exactly like a signal that we were expecting from aliens. In the 1950s, scientists worked out what an alien signal might look like and how they might communicate, as in what kind of frequency of radio signal and how long it would last and all the aspects like that. And this signal that we received in 1977 turned out to be exactly that. And so, because it's been the only signal of its kind that nothing else like it has ever been found or seen, we might have this one contact with aliens unfortunately, we've never had another one. And we don't know what to make of this. But it seems that, you know, the wow. Signal, and it was called the wow Signal because the guy who saw it on the printout wrote wow Beside it because he was so amazed at what he'd seen. And this has never been resolved. And people have looked for all kinds of other explanations. Maybe it was reflections of our own radio signals that we're broadcasting from Earth or something, from space rocks or space debris or spacecraft or aircraft. And nobody's ever been able to find any other explanation other than it came from some alien civilization.
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So what do you think? Do you think this was aliens? Do you think there are aliens?
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Do I believe that? That's a good question. I don't see any reason why there shouldn't be something else living somewhere in the universe. I find it hard to believe that we're the only thing in the whole universe that's kind of conscious and intelligent. Arthur C. Clarke once said either that we're alone in the universe or. Or we're not. And either way, it's staggering. So if you think that we're alone, then that seems inexplicable that there should just be this one planet in the whole universe that's inhabited by intelligent beings. On the other hand, if you think there are other intelligent beings out there, wouldn't it be the greatest thing in human history to make contact with them? For me, I think there must be other civilizations out there somewhere. The universe is a vast place, and I find it hard to believe that the conditions for life, an intelligent life, has only occurred here on Earth.
A
Well, but those are two different arguments. There may well be other intelligent life somewhere in the universe, but that doesn't necessarily mean they've tried to contact us.
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It doesn't, but it may mean. I mean, we have sent signals out from the Arecibo telescope in Puerto Rico, for instance. We sent a signal out into space hoping that somebody might intercept it. And it may be that another race has done the same thing. And to be honest, we wouldn't know if anyone has intercepted our signal, just as this other civilization might not know whether we intercepted theirs. It's a possibility. One of the most important things is for science, contact with another civilization in the universe would actually prove to us a lot about the nature of life and what it means to be alive and whether there's life on other planets. So it would be an enormous thing to be able to say we have made contact with another civilization.
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Well, most of the time on this podcast, we try to answer questions and explain things, but you've answered no questions and explain nothing. You've just raised more questions. But they're really interesting ones. Michael Brooks has been my guest. He is a science writer and his book, one of several he's written, is 13 things that don't Make Sense, the Most Baffling Scientific Mysteries of Our Time. There's a link to his book in the show notes. Thank you, Michael. And that's it for this Sysk trending episode. I'm Mike Carruthers. Thanks for listening to something you should know.
Host: Mike Carruthers
Guest: Michael Brooks (science writer, author of "13 Things that Don’t Make Sense")
Episode: SYSK TRENDING – Mysteries That Science Can’t Explain
Date: August 4, 2026
This episode delves into scientific mysteries that baffle even the brightest minds. Host Mike Carruthers interviews Michael Brooks, who shares insights from his book about unresolved questions at the frontiers of science. They discuss everything from the missing matter in the universe, the placebo effect, and the possibility of free will, to the famous "Wow! Signal"—inviting listeners to consider just how much is still left unknown.
(05:49) The placebo effect remains controversial. Some scientists can induce and measure it, while others, reviewing literature, find little evidence it exists.
(07:01) Placebo effects primarily occur in subjective areas (pain, mood), not in objective diseases (cancer, lung disease).
(09:29) The working hypothesis is that placebo boosts the body's self-healing through expectations and hope.
Host Mike Carruthers maintains a tone of curiosity and fascination, frequently drawing analogies and probing for practical implications. Brooks’s style is thoughtful, sometimes skeptical, with a willingness to embrace ambiguity and uncertainty. Their exchanges are engaging and accessible, often using vivid examples to clarify difficult concepts.
You can find Michael Brooks’s book, “13 Things That Don’t Make Sense: The Most Baffling Scientific Mysteries of Our Time,” through the link in the show notes.
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