Category Archives: Astronomy

Thank you to Wren for supporting PBS. To learn more, go to https://wren.co/start/spacetime. PBS Member Stations rely on viewers like you. To support your local station, go to:http://to.pbs.org/DonateSPACE ***** Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime We routinely simulate the universe on all of its scales, from planets to […]

PBS Member Stations rely on viewers like you. To support your local station, go to:http://to.pbs.org/DonateSPACE ***** Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime If you used every particle in the observable universe to do a full quantum simulation, how big would that simulation be? At best a large molecule. […]

PBS Member Stations rely on viewers like you. To support your local station, go to:http://to.pbs.org/DonateSPACE ***** Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime On our search for alien lifeforms we scan for primitive biosignatures, and wait and hope for their errant signals to happen by the Earth. But that […]

Check Out Above The Noise: https://youtu.be/GKS3ph3G2jc The possibility that a black hole could actually impact Earth may seem straight out of science fiction, but the reality is that microscopic primordial black holes could actually hit Earth. If one did, it wouldn’t just impact like an asteroid, it’d pass straight through the entire Earth and exit […]

Learn More about Brilliant: https://brilliant.org/SpaceTime/ Take the PBS Digital Studios audience survey: https://to.pbs.org/2021survey Black holes are a paradox. They are paradoxical because they simultaneously must exist but can’t, and so they break physics as we know it. Many physicists will tell you that the best way to fix broken physics is with string. String theory, […]

Thank you to CuriosityStream for supporting PBS. For more information go to https://curiositystream.thld.co/PBSSPACETIME Check Out @PBSVitals here: https://youtu.be/FOL0Hs8UcNs What if there is no such thing as dark matter? What if our understanding of gravity is just wrong? New work is taking another shot at that Einstein guy. Let’s see if we’ve finally scored a hit […]

Learn More About NordVPN at: https://nordvpn.com/spacetime It’s about time we discussed an obscure concept in physics that may be more fundamental than energy and entropy and perhaps time itself. That’s right – the time has come for Action. Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space […]

Check Out American Voices: Keep it Close: https://youtu.be/LMJqb5A51_Y The people behind the greatest leaps in physics – Einstein, Newton, Heisenberg, all had the uncanny ability to see the fundamentals – see the deepest, underlying facts about the world, and from simple statements about reality they built up their incredible theories. Well what if we all […]

Learn More about Brilliant: https://brilliant.org/SpaceTime/ Paradoxically, the most promising prospects for moving matter around faster than light may be to put a metaphorical brick wall in its way. New efforts in quantum tunneling – both theory and experiment – show that superluminal motion may be possible, while still managing to avoid the paradox of superluminal […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime What happens if you cut a bar magnetic in half? We get two magnets, each with their own North and South poles. But what happens if you keep on cutting, into fourths and eighths and sixteenths and so on? Will we ever […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Today I’m going to explain why you’re not falling through your chair right now using one simple fact, and one object. The fact is that all electrons are the same as each other, and the object is a structurally critical item of […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime We’ve traveled to lots of weird places on this show – from the interiors of black holes to the time before the big bang. But today I want to take you on a journey to what has got to be the weirdest […]

Thank you to Blinkist for supporting PBS. For more information and trial go to http://www.blinkist.com/PBSSpacetime How do you see the unseeable – how do you explore the inescapable? Our cleverest astronomers have figured out ways to catch light that skims the very edge of black holes. Let’s find out what they learned. A few weeks […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime The universe is going to end. But of all the possible ends of the universe vacuum decay would have to be the most thorough – because it could totally rewrite the laws of physics. Today I hope to help you understand exactly […]

Check Out Megawow on PBS Kids: https://youtu.be/meU4f31gqYI In the Many Worlds interpretation of quantum mechanics, the universal wavefunction is the reality, encompassing all possible histories and futures and all exist. But we are only sensitive to a slice of the wavefunction corresponding to our “world”, and due to the superposition principle our world can happily […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime A new white dwarf has been discovered (poetically named: ZTF J1901+1458) that’s doing some stuff that no white dwarf should ever be able to do. In fact, it has multiple properties that are so extreme that it almost certainly did NOT form […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Many Worlds interpretation of quantum mechanics proposes that every time a quantum event gets decided, the universe splits so that every possible outcome really does occur. But where exactly are those worlds, and can we ever see them? Check out the Space […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Many Worlds interpretation of quantum mechanics proposes that every time a quantum event gets decided, the universe splits so that every possible outcome really does occur. But where exactly are those worlds, and can we ever see them? Check out the Space […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Quantum mechanics has a lot of weird stuff – but there’s thing that everyone agrees that no one understands. I’m talking about quantum spin. Let’s find out how chasing this elusive little behavior of the electron led us to some of the […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Entropy is surely one of the most perplexing concepts in physics. It’s variously described as a measure of a system’s disorder – or as the amount of useful work that you can get from it – or as the information hidden by […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime How many times can I half the distance between my hands? Assume perfect coordination and the ability to localize my palms to the quantum level. 15 halvings gets them to within a cell’s width. 33 to within a single atom, 50 and […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime While recent news about the Chinese Long March 5 Rocket made a lot of people very nervous because a 22-ton rocket was going to fall out of the sky, this sort of thing happens all the time. Boosters, dead satellites, and sometimes […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime It’s fair to say that black holes may be the scariest objects in the universe. Happily for us, the nearest is probably many light-years away. Unless of course, Planck relics are a thing – in which case they might be literally everywhere. […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Quantum mechanics forbids us from measuring the universe beyond a certain level of precision. But that doesn’t stop us from trying. And in some cases succeeding, by squeezing the Heisenberg uncertainty principle to its breaking point. Check out the Space Time Merch […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime There’s one rule on Space Time: It’s never Aliens. But every rule has an exception and this rule is no exception because: It’s never aliens, until it is. So is it aliens yet? And on today’s Space Time we’re going to examine […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime That Einstein guy was a real bummer for our hopes of a star-hopping, science-fiction-y future. His whole “nothing travels faster than light” rule seems to ensure that exploration of even the local part of our galaxy will be an excruciating slow. But […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime​ It may be that for every star in the universe there are billions of microscopic black holes streaming through the solar system, the planet, even our bodies every second. Sounds horrible – but hey, at least we’d have explained dark matter. Want […]

Support Us On https://www.patreon.com/pbsspacetime When a theory makes a prediction that disagrees with an experimental test, sometimes it means we should throw the theory away. But what if that theory has otherwise produced the most successful predictions in all of physics? Then, that little glitch may be pointing the way to layers of physics deeper […]

To learn more, check out: https://www.TheGreatCoursesPlus.com/spacetimepbs Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime “A moving arrow is at rest.” This is obviously a nonsensical contradiction. But Zeno, a Greek philosopher famous for his metaphysical trolling, devised a paradox whose conclusion is just this. Here’s how it goes: if you […]

https://www.patreon.com/pbsspacetime I have good news and bad news. Bad news first: two years ago we reported on the Crisis in Cosmology. Since then, it’s only gotten worse. And actually, the good news is also that the crisis in cosmology has actually gotten worse, which means we may be onto something! The most exciting thing for […]

https://www.patreon.com/pbsspacetime​ We know that gravity exerts its pull on light, and we have an explanation for why. Actually, we have multiple explanations that all predict the same thing. And at first glance, these explanations seem to describe completely different causes. So what is the true connection between light and gravity, or is truth, in fact, […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime​ We know that gravity must cause clocks to run slow on the basis of logical consistency. And we know that gravity DOES cause clocks to run slow based on many brilliant experiments. But I never explained WHY or HOW gravity causes the […]

Check Out Overview on PBS Terra: https://youtu.be/Pgj95EntvW0 Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime​ It was pretty impressive when LIGO detected gravitational waves from colliding black holes. Well we’ve just taken that to the next level with a galaxy-spanning gravitational wave detector that may have detected a foundational element […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime There’s a deep connection between gravity and time – gravitational fields seem to slow the pace of time in what we call gravitational time dilation. And today we’ll explore the origin of this effect. And ultimately, we’ll use what we learn to […]

Check out Weathered on PBS Terra: https://youtu.be/q1hj9RCWuH0 Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime By the time you’ve read this, a billion billion dark matter particles may have streamed through your body like ghosts. The particle or particles of the dark sector make up the vast majority of the […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Today we’re going to delve into a couple of the most famous paradoxes of special relativity: the Twin Paradox, The Ladder Paradox (aka the Barn-Pole Paradox), and a paradox suggested by our very own viewers, which asks whether a spaceship could wrap […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Since the very beginning of quantum mechanics, a debate has raged about how to interpret its bizarre predictions. And at the heart and origin of that debate is the quantum jump or quantum leap – the seemingly miraculous and instantaneous transitions of […]

Check Out Weathered on PBS Terra Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime We often think of quantum mechanics as only affecting only the smallest scales of reality, with classical reality taking over at some intermediate level. But in his 1944 book, What is Life?, the quantum physicist Erwin […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Good news everyone: it looks like the universe is going to end with a series of catastrophic explosions. The very, very long story short is that the universe ends in heat death, as it approaches maximum entropy, and its eternal exponential expansion […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime The laws of physics don’t specify an arrow of time – they don’t distinguish the past from the future. The equations we use to describe how things evolve forward in time also perfectly describe their evolution backwards in time. So the brain […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Ever wish you could travel backward in time and do things differently? Good news: the laws of physics seem to say traveling backward in time is the same as traveling forwards. So why do we seem to be stuck in this inexorable […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Physicists have a long history of sticking our noses where they don’t belong – and one of our favorite places to step beyond our expertise is the question of consciousness and free will. Sometimes our musings are insightful, sometimes incoherent, and usually […]

Our universe seems pretty complicated. We have a weird zoo of elementary particles, which interact through very different fundamental forces. But some extremely subtle clues in nature have led us to believe that the forces of nature were once unified, ruled by a single, grand symmetry. But how does one force separate into multiple? And […]

The Nobel prize in physics this year went to black holes. Generally speaking. Specifically, it was shared by the astronomers who revealed to us the Milky Way’s central black hole and by Roger Penrose, who proved that in general relativity, every black hole contains a place of infinite gravity – a singularity. But the true […]