PBS Space Time

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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...

Episodes(40 episodes)

We Had It WRONG About the Quantum Eraser! ft. @LookingGlassUniverse

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...

Published: Sep 10, 2026Duration: 32m 11s

Secrets of the Cosmic Microwave Background

You can learn more about CuriosityStream at https://curiositystream.com/spacetime PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE Check out the new Space Time Merch Store! https://pbsspacetime.com/ Support Space Time on Patreon https://www.patreon.com/pbsspacetime Hook up an old antenna to your TV and scan between channels. The static buzz you hear is mostly due to the ambient radio produced by our noisy pre-galactic civilization. But around one percent of that buzz is something very different – it’s the cosmic microwave background radiation – the re...

Published: Sep 10, 2026Duration: 22m 55s

Thorium and the Future of Nuclear Energy

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ Check out the new Space Time Merch Store! https://pbsspacetime.com/ Support Space Time on Patreon https://www.patreon.com/pbsspacetime Energy too cheap to meter - that was the promise of nuclear power in the 1950s, at least according to Lewis Strauss chairman of the Atomic Energy Commission. That promise has not come to pass - but with some incredible new technologies, perhaps it still could. The question is - should it? Hosted by Matt O'Dowd Writ...

Published: Sep 10, 2026Duration: 24m 26s

How Do Quantum States Manifest In The Classical World?

Thank you for The Great Courses Plus for supporting PBS. To learn more click http://ow.ly/oSus30qpmwX 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 Sign up for the mailing list to get episode notifications and hear special announcements! https://tinyurl.com/yx9cusk5 Check out the Space Time Merch Store https://pbsspacetime.com/ This episode of space time is brought to you by the information flowing through an...

Published: Sep 10, 2026Duration: 25m 11s

Venus May Have Life!

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ Check Out Overview of PBS Terra: https://bit.ly/33otrUn If you rank the most habitable places in our solar system Venus lands pretty low, with surface temperatures hot enough to melt lead and sulphuric acid rain. And yet it may have just jumped to the front of the pack. In fact, we may have detected the signature of alien life - Venusian life -for the first time. Sign Up on Patreon to get access to the Spac...

Published: Sep 10, 2026Duration: 20m 42s

Are Many Worlds & Pilot Wave THE SAME Interpretation?

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 It’s hard to interpret the strange results of quantum mechanics, though many have tried. Interpretations range from the outlandish—like the multiple universes of Many Worlds, to the almost mundane, like the very mechanical Pilot Wave Theory. But perhaps we’re converging on an answer, because some are arguing that these two interpretations are really the same thing. Check out the Space Time M...

Published: Sep 10, 2026Duration: 23m 9s

Theory of Everything Controversies: Livestream

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ The second in our two event series about Theories of Everything! Watch the first one: https://www.youtube.com/watch?v=_izocEgArtQ Please subscribe to Brian Keating's YouTube Channel to watch one-on-one interviews with the guest speakers and more: https://www.youtube.com/DrBrianKeating Existing Theories of Everything have not yet produced experimental evidence that solves the fundamental challenges facing physics. That lack of progress has opened up a sea of controversy, from disagreements about the very nece...

Published: Sep 10, 2026Duration: 1h 30m 12s

What If Gravity Isn't Quantum? New Experiments Examine

👉 Head to https://brilliant.org/spacetime/ for a 30-day free trial + 20% off your annual subscription Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime If we discover how to connect quantum mechanics with general relativity we’ll pretty much win physics. There are multiple theories that claim to do this, but it’s notoriously difficult to test them. They seem to require absurd experiments like a particle collider the size of a galaxy. Or we could try to physics smarter, instead of physicsing harder. Let’s talk about some ideas for quantum gravity e...

Published: Sep 10, 2026Duration: 24m 4s

Why Is 1/137 One of the Biggest Unsolved Mysteries In Physics?

Thank you to Squarespace for supporting PBS. Go to https://www.squarespace.com/pbs for a free trial, and when you are ready to launch, go to Squarespace.com/PBS to save 10% off your first purchase of a website or domain. 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 The Fine Structure Constant is one the strangest numbers in all of physics. It’s the job of physicists to worry about numb...

Published: Sep 10, 2026Duration: 20m 22s

Loop Quantum Gravity Explained

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ 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://pbsspacetime.com/ It’s time we talked about loop quantum gravity. What exactly is it? What are the loops? And can it really defeat string theory in our quest for a Theory of Everything? Hosted by Matt O'Dowd Written by Graeme Gossel & Matt O'Dowd Graphics by Leonardo Scholzer Directed by: Andrew Kornhaber Execut...

Published: Sep 10, 2026Duration: 23m 17s

Can Viruses Travel Between Planets?

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ 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://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime With the global pandemic of Covid 19 still encompassing the world, we are generally not big fans of viruses right now. But we sure are thinking about them a lot...

Published: Sep 10, 2026Duration: 22m 54s

What Happened Before the Big Bang?

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ Check out the new Space Time Merch Store! https://pbsspacetime.com/ Support Space Time on Patreon https://www.patreon.com/pbsspacetime We actually have a pretty good idea of what might have happened before the Big Bang. That is, as long as we define the Big Bang as the extremely hot, dense, rapidly expanding universe that is described by Einstein’s equations. That picture of the universe is very solid down to about a trillionth of a second...

Published: Sep 10, 2026Duration: 18m 35s

Is Time Travel Impossible?

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ 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://pbsspacetime.com/ Invitation to Time Travelers: https://www.youtube.com/post/UgzeIA0O00-bVioxU4t4AaABCQ Time travel stories are cool because both the past and future are somehow more interesting that the present and because everyone wants a redo. But so far it appears we’re doomed to live consumed by regret...

Published: Sep 10, 2026Duration: 17m 45s

Did Life on Earth Come from Space?

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ Check out the new Space Time Merch Store! https://pbsspacetime.com/ How did life on Earth get started? Did life on Earth originate on another planet? Either Mars, or in a distant solar system? Could Earth life have spread to have seeded life elsewhere? Let’s see what modern science has to say about the plausibility of panspermia. You can further support us on Patreon at https://www.patreon.com/pbsspacetime Tweet at us! @pbsspacetime Facebook: facebook.com/pb...

Published: Sep 10, 2026Duration: 24m 18s

Electrons DO NOT Spin

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 deepest insights into the nature of the quantum world. Spin Renderings by the Incredible Jason Hise http://entropygames.net/ Check out the Space Time Merch Store https://www.pbsspacetime.com/shop Sign up for the mailing list to get ep...

Published: Sep 10, 2026Duration: 23m 54s

Why The Multiverse Might Actually Be Real

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...

Published: Sep 10, 2026Duration: 26m 3s

What Occurs Within a Proton?

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 we ever want to simulate a universe, we should probably learn to simulate even a single atomic nucleus. But it’s taken some of the most incredible ingenuity of the past half-century to figure out how that out. All so that today I can teach you how to simulate a very very small universe. Check out the Space Time Merch Store https://ww...

Published: Sep 10, 2026Duration: 26m 0s

How Will We (Most Probably) Discover Extraterrestrial Life?

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 The first discovery of extraterrestrial life will almost certainly NOT be when it visits us, nor when we visit it. It won’t be when we see it’s stray TV signals. It’ll be in the excruciatingly faint changes in the color of alien sunsets glimpsed hundreds of light years away. Today we’re going to talk about the first such hint, why it's...

Published: Sep 10, 2026Duration: 24m 40s

Can We Break the Universe?

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ 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 around the universe & destroy itself. We’ll explore these paradoxes and see why, against our intuition, the universe...

Published: Sep 10, 2026Duration: 21m 27s

The Doomsday Argument

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ 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 episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Since the dawn of humanity around 100 billion people have lived. How many will live in the future of our species? We might hope for a trillion times that if w...

Published: Sep 10, 2026Duration: 23m 34s