PBS Space Time

31 Episodes
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By: PBS

Space Time explores the outer reaches of space, the craziness of astrophysics, the possibilities of sci-fi, and anything else you can think of beyond Planet Earth with our astrophysicist host: Matthew O’Dowd. For all business inquiries and sponsorship opportunities please reach out to: pbsspacetime@lighthouseagents.com Matt O'Dowd spends his time studying the universe, especially really far-away things like quasars, super-massive black holes, and evolving galaxies. He uses telescopes in space to do it. Matt completed his Ph.D. at NASA's Space Telescope Science Institute, followed by work at the University of Melbourne and Columbia University. He's now a pr...

The NEW Ultimate Energy Limit of the Universe
Today at 8:00 AM

Remove your personal information from the web at https://joindeleteme.com/SPACETIME and use code SPACETIME for 20% off DeleteMe international Plans: https://international.joindeleteme.com Is there a limit to how much energy you can cram into, or pull out of one patch of space? Well, we thought so, but the James Webb Space Telescope has found a quasar that simultaneously breaks a century-old theoretical limit and may explain the conundrum of gigantic black holes in the early universe. Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime 15% Off the Entire Merch...


What Does An Electron ACTUALLY Look Like?
Yesterday at 2:30 PM

Enjoy 10% OFF on all Hoverpens and free shipping to most countries with code PBS: North America / UK / Australia / International: https://bit.ly/pbs_novium EU: https://bit.ly/pbs_noviumeu Take the PBS Annual Survey Here: https://to.pbs.org/2024SurveyST What does an electron really look like? I mean, if we zoom in all the way. Is it a sizeless speck of charge? Is it a multidimensional vortex of quantum strangeness? Is it the boundary of a tiny universe with universe-electrons of its own? Let’s find out. 15% off the Space Time Merch Store all December!!! https://www.pbsspacetime.co...


Does Infinity - Infinity = an Electron?
Last Saturday at 9:00 PM

Thanks to Radiacode for sponsoring this video. Use the promo code "PBS" to get an exclusive 10% discount at: https://103.radiacode.com/PBS What do you get if you take something that’s infinitely massive and combining with something else that’s negative infinitely massive? You get a single electron, at least that’s what it looks like in our most precise way of describing the quantum world. 15% Off The Entire Merch Store https://www.pbsspacetime.com/shop Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Sign up for the mailing list to get...


How Many Black Holes Are In The Solar System?
Last Saturday at 3:30 AM

Learn More About Anydesk: https://anydesk.com/spacetime Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Dark matter has eluded us for many decades. Even our most advanced particle colliders and sophisticated underground detectors have come up short. But it may be that we can finally solve this mystery with a much simpler experiment, involving a ray of light, a good clock, and the planet Mars. Check out the Space Time Merch Store https://www.pbsspacetime.com/shop Sign up for the mailing list to get episode notifications and hear special...


Why Time Flows Differently Between Galaxies
Last Friday at 10:00 AM

Thanks to Radiacode for sponsoring this video. Use the promo code "PBS" to get an exclusive 10% discount at: https://103.radiacode.com/PBS The universe is expanding and that expansion is accelerating under the power of dark energy and eventually all matter and energy will be dispersed over such unthinkable distances that nothing can stop space from blowing up infinitely. Unless of course cosmologists blundered and dark energy doesn't even exist. Then it's back to the drawing board. Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch...


The Crisis in Physics: Why the Higgs Boson Should NOT Exist!
Last Thursday at 4:30 PM

Learn More About Anydesk: https://anydesk.com/spacetime According to quantum physics, the universe should have collapsed on itself in the instant after the Big Bang due to all particles being 100 million billion times heavier. Recent observations of the universe existing suggest that this may not have happened. Even more recent experiments at the Large Hardron Collider have failed to find out why. In particular, why the Higgs boson is light enough to allow the universe to exist. This is part of something known as the hierarchy problem, and some consider it to be the most important unsolved problem in...


The Final Barrier to (Nearly) Infinite Energy
Last Wednesday at 11:00 PM

Thanks to Radiacode for sponsoring this video. Use the promo code "PBS" to get an exclusive 10% discount at: https://103.radiacode.com/PBS They say fusion is 50 years away, no matter when you ask. Then why are billions suddenly being pumped into fusion startups? Yes to train LLMs, but there's a reason the technobrats are bullish on fusion in particular. The fact is, the technological challenges have been chipped away and in many cases solved over the past decades, and there's really no one deal-breaker difficulty remaining. One of the final challenges is deciding on the physical vessel to contain our...


Will The Big Bang Happen AGAIN (and Again)?
Last Wednesday at 5:30 AM

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime How did the universe begin? How can something come from nothing? One way to “solve” this most difficult of philosophical conundrums is to avoid it altogether. Maybe the universe didn’t begin. Maybe the Big Bang was just one in an endless cycle. Check out the Space Time Merch Store https://www.pbsspacetime.com/shop PBS Member Stations rely on viewers like you. To support your local station, go to:http://to.pbs.org/DonateSPACE Sign up for the mailing list to get episod...


Your DNA's Codes Are (Probably) From Outer Space
Last Tuesday at 12:00 PM

Thank you to Cyber GhostVPN for Supporting PBS. Learn More About Cyber GhostVPN: https://www.cyberghostvpn.com/PBSSpaceTime Did you know that many of us have up to 4% neanderthal DNA? And that 100% of your DNA may come from outer space? No joke. The biochemistry that defined the coding system of your DNA may have happened off-world, and perhaps even long before Earth existed. Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime PBS Member Stations rely on viewers like you. To support your local station, go to:http://to.pbs.org/DonateSPACE ...


How Astrophysics Can (LITERALLY) Save the World
03/23/2026

Remove your personal information from the web at https://joindeleteme.com/SPACETIME Giant space rocks are definitely going to hit the Earth again. We actually do know how to deflect them, but only if we find them and correctly assess their risk. But the solar system is a chaotic place. How is it even possible to tell if a space rock will one day collide with the Earth? Check out the Space Time Merch Store https://www.pbsspacetime.com/shop Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Sign up for...


NEW EVIDENCE: Earth Had Rings (and Might Regain Them)
03/23/2026

Check Out All PBS Earth Episodes: https://www.youtube.com/playlist?list=PLnNZYWyBGJ1F8ofFm4H9UTrHxqU8zngK4 Planet Earth is the jewel of the solar system—the shimmery blue oceans, the verdant green forests, the wispy whimsical cloud formations. Saturn is the only competitor for most gorgeous planet with that giant ring system. Hmm… what if we could put the jewel of the Earth in its own ring? Then no contest. Well, there’s an extremely good chance that Earth once DID have a ring system. At least, that’s the proposal by a recent study that has evidence that a m...


How a One-in-a-Billion Mistake Made the Universe Possible
03/22/2026

Huge thanks to KiwiCo for sponsoring today’s video! Go to https://www.kiwico.com/spacetime and use code SPACETIME for 50% off your first monthly crate Check Out Reactions on the Earth Month Playlist https://www.youtube.com/watch?v=fJFMP0_fhLQ&list=PLnNZYWyBGJ1F8ofFm4H9UTrHxqU8zngK4&index=2 At one-one-thousandth of a second after the Big Bang, the great annihilation event should have wiped out all matter, leaving a universe of only radiation. Why still don't know why any matter survived. Well, a new finding from the LHC brings us one step closer to understanding why there's something ra...


Quantum Energy Teleportation is REAL!
03/21/2026

Remove your personal information from the web at https://joindeleteme.com/SPACETIME The vacuum of space is a chaotic sea of quantum fluctuations. Some have said that this vacuum energy can be harvested to build our future starship engines, or manipulated to build warp drives. It can't. But it is technically possible to move real energy through the quantum vacuum without it passing through intervening space. Quantum energy teleportation may be as close as we get to transporter beams. But how close is that? Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com...


Is There A Simple Solution To The Fermi Paradox?
03/20/2026

Use code PBS to get 15% off all Hoverpens and free shipping to most countries for the first 48 hours, 10% off after that. North America / UK / Australia / International: https://bit.ly/pbs_novium EU: https://bit.ly/pbs_noviumeu Around 2 billion years ago, life had plateaued in complexity, ruined the atmosphere, and was on the verge of self-annihilation. But then something strange and potentially extremely lucky happened that enabled endless new evolutionary paths. The first eukaryote cell was born. This may also explain why there are no aliens. Patreon Interview with Dr. Matt Caplan https://youtu.be/hN1I01ZGzJc?feature=shared ...


Is Our Model of Dark Energy WRONG? | New 4.2σ Results
03/20/2026

Learn More About Anydesk: https://anydesk.com/spacetime The biggest news in cosmology in recent years is that the mysterious universe-accelerating entity we call dark energy may be fading away. The evidence for this is now strong enough that enormous effort is going into confirming this result. So what’s it going to take, and when are we going to know? Sign Up on Patreon to get access to the Patreon Livestream with Looking Glass Universe! https://www.patreon.com/pbsspacetime https://www.youtube.com/lookingglassuniverse Check out the Space Time Merch Store https://www.pbsspacetime.com/shop Sign up fo...


The Crisis In Physics: Are We Missing 17 Layers of Reality?
03/19/2026

Remove your personal information from the web at https://joindeleteme.com/SPACETIME Big things are made of smaller things, and those smaller things are made of smaller things still. That’s reductionism in a nutshell, and digging our way to the smallest layer has been one of the primary goals of physics for ever. But what if, just before we reach the bottom, we find out that reductionism fails? Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://www.pbsspacetime.com/shop Sign up fo...


Are The Fundamental Constants Finely Tuned? | The Naturalness Problem
03/18/2026

Learn More About Anydesk: https://anydesk.com/spacetime Did God have any choice in creating the world? So asked Albert Einstein. He was being poetic. What he really meant, was whether the universe could have been any other way. Could it have had different laws of physics, driven by different fundamental constants. Or is this one vast and complex universe the inevitable result of an inevitable and unique underlying principle, perhaps expressible as a supremely elegant Theory of Everything. It certainly seems that Einstein thought this should be the case … that God had no choice in whether or how to cr...


Why Is All DNA Right Handed?
03/17/2026

PBS Member Stations rely on viewers like you. To support your local station, go to:http://to.pbs.org/DonateSPACE The molecular basis of all life is mysteriously asymmetric, only using molecules on one side of what should be the equivalent mirrored pairs. The universe has a similar mirror asymmetry, and it may be that our very DNA inherited its twist from the underlying handedness of reality. Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://www.pbsspacetime.com/shop Sign up for the...


Why The Multiverse Could Be Real
03/17/2026

Thanks to Displate for sponsoring the video. Use code SPACETIME at checkout for exclusive discounts on your order at https://displate.com/@spacetime 25% off for 1 Displate, 32% off for 2 to 3, 37% off for 4 and more. Valid on Textra. Not valid on Limited Edition & Lumino. The multiverse pops out of quite a few theories in physics, and has been proposed as a solution to certain vexing problems. But it’s also been argued that the very idea of a multiverse is just bad science. That it’s unfalsifiable and a dead-end to inquiry and as bad a violation of Occam’s razor as you co...


Is There Evidence For a Vast Multiverse?
03/16/2026

Learn More About Anydesk: https://anydesk.com/spacetime In 1987, Steven Weinberg wrote a cute little paper entitled “Anthropic Bound on the Cosmological Constant”. I say cute little paper because it feels minor in comparison to, say, electroweak unification theory that won him the Nobel Prize. Weinberg was foundational in establishing the standard model of particle physics, and represented an enormous leap in understanding how this universe works. But his little 1987 paper, though more obscure, may tell us something about how the multiverse works, and can even be thought of as evidence for the existence of an enormous number of other univ...


The Most Important Satellite You’ve (Probably) Never Heard Of
03/15/2026

Remove your personal information from the web at https://joindeleteme.com/SPACETIME One of the most important reasons we go to space is to know our own planet better. Today I'm going to tell you about an orbiting facility that literally watches Earth's biosphere breath and grow and die with incredible resolution. I'll talk about its profound existential and economic importance, and about why it's in danger of being lost. 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...


At What Point Does Spacetime Become Quantum?
03/15/2026

Learn More About Anydesk: https://anydesk.com/spacetime To observe the quantum nature of gravity and of spacetime itself, we need a particle collider the size of the solar system. Or we could just physics smarter and build one on a lab bench. Here’s how. Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://www.pbsspacetime.com/shop Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime PBS Member Stations re...


Why Life on Mars Will DOOM Humanity
03/14/2026

Click this link: https://www.boot.dev/?promo=spacetime and use my code SPACETIME to get 25% off your first payment for boot.dev Recent findings have brought us closer than we’ve ever been to confirming life beyond the Earth. As we wait for confirmation or otherwise, let’s think about what this will tell us about life everywhere, and also about our own imminent destruction. Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://www.pbsspacetime.com/shop Sign up for the mailing list...


We Were WRONG About the Quantum Eraser! ft. @LookingGlassUniverse
03/13/2026

Thank you to Cyber GhostVPN for Supporting PBS. Learn More About Cyber GhostVPN: https://cyberghostvpn.com/PBSSpaceTime Does quantum mechanics allow the future to retroactively influence the past, as in the infamous delayed choice quantum eraser experiment? How about we get an actual quantum physicist--who many of you already know--to show us how to do this experiment at home, and hopefully set this matter to rest. Check Out Looking Glass Universe: https://www.youtube.com/@LookingGlassUniverse And Check Out Matt’s Conversation with Mithuna https://youtu.be/QPuVtvIOYcM?si=TQovlQ6kW_6PPxKy Sign Up on Patreon to get access to th...


Why Antimatter Engines Could Launch In Your Lifetime
03/12/2026

Thanks to Displate for sponsoring the video. Get a great Displate deal using my link https://displate.com/l/spacetime or my discount code spacetime Discounts: 1-2 Displate: 33%off 3+ Displates: 38% off Valid on Textra Not valid on Lumino and Limited Edition Antimatter drives sound like science fiction, but they may not be as far as you think. There’s a version that could, just maybe, launch within your lifetime. Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://www.pbsspacetime.com/shop Sign up fo...


The Gravity Particle Should Exist. So Where Is It?
03/12/2026

Head to https://brilliant.org/Spacetime/ to start learning for free. Plus, our viewers get 20% off an annual Premium subscription for unlimited daily access to everything Brilliant has to offer Physics is this close to understanding the entire universe. And what lives in this gap? Many physicists think it’s the elusive graviton—the quantum particle of gravity—whose discovery will finally allow us to stitch together our two great theories of nature into a single master theory. But what is the graviton, and does it even exist? Help us determine the future of Space Time with the PBS Annual Survey...


Do We Live in the Rarest Solar System In The Universe? We're about to find out!
03/11/2026

To learn more visit: https://hensonshaving.com/pbs and use code spacetime to get 100 blades for free with your purchase of a Henson Razor. Add both products to your cart for the code to take effect! There are lots of reasons to search for planets around other stars—exoplanets. A big one is to find other places in the universe that might harbor life. We only know of one such planet so far: Earth. And so we get particularly excited when we find Earth-mass planets at the right distance from their star to sustain liquid water—also critical for life as w...


Heisenberg Made a Discovery in 1925. We Still Can't Explain It
03/10/2026

For 72 hours, enjoy 15% OFF on all Hoverpens with code PBS, or click on the link https://noviumdesign.shop/PBS - Free shipping to most countries. Also on Amazon: https://noviumdesign.shop/crQH4A 2025 is … was the international year of quantum science and technology. Yes because quantum tech is increasingly important, but especially because quantum mechanics was invented 100 years ago this year. In 1925, our strangest true theory went from being a peculiar set of ideas to describe some funny results from experiments, to a full-blown theoretical framework that overturned how we think reality really works. So today, as the centenary year ap...


Black Holes. Explained. For 1.5 Hours.
03/09/2026

Black holes are not just the strangest objects in the universe, they're the sharpest test we have of how reality actually works. This episode explores how these extreme cosmic laboratories force general relativity and quantum physics into direct confrontation. We look back through a decade of content to understand their formation and the theoretical diagrams that describe them, offering a journey through the profound implications of these celestial objects for our understanding of space time and astrophysics. Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch...


The Universe Itself Might Be Hiding the Gravity Particle From Us
03/09/2026

Head to https://brilliant.org/Spacetime/ to start learning for free for 30 days. Plus, our viewers get 20% off an annual Premium subscription for unlimited daily access to everything Brilliant has to offer. To progress to the next level in understanding reality, we need to combine quantum mechanics and Einstein’s general relativity. And to do that, most physicists believe we need a theory of quantum gravity .. which means we need gravitons. But it also seems like the laws of physics make it impossible to ever detect this quantum particle of gravity. Almost like the universe is set up to keep th...


The Universe Itself Might Be Hiding the Gravity Particle From Us
03/08/2026

Head to https://brilliant.org/Spacetime/ to start learning for free for 30 days. Plus, our viewers get 20% off an annual Premium subscription for unlimited daily access to everything Brilliant has to offer. To progress to the next level in understanding reality, we need to combine quantum mechanics and Einstein’s general relativity. And to do that, most physicists believe we need a theory of quantum gravity .. which means we need gravitons. But it also seems like the laws of physics make it impossible to ever detect this quantum particle of gravity. Almost like the universe is set up to keep th...