PBS Space Time

Science and Nature Series / 11 Seasons

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. Host Matt O'Dowd breaks down both the basic and incredibly complex sides of space and time.

5m 57s

Do We Need a New Dark Matter Model?

S9 E21 / 16m 21s

We have no idea what dark matter is, other than it’s some source of gravity that is completely invisible but exerts way more pull that all of the regular matter. Dark matter constitutes 80% or so of the mass in the universe, which means we should really try to figure out what it actually is.

Did JWST Discover Dark Matter Stars?

S9 E22 / 11m 49s

No one was expecting that JWST would find a completely new type of star—one mostly made of and powered by dark matter and shining as bright as an entire galaxy. Which, by the way, might help us explain those pesky giant galaxies.

What If Space is Not Empty?

S9 E23 / 14m 59s

Spacetime on its smallest scales is a seething ocean of black holes and wormholes flickering into and out of existence—or so many physicists think has to be the case. But why should we take this spacetime foam seriously if we’ve never seen any evidence of it?

What New Science Would We Discover with a Moon Telescope?

S9 E24 / 20m 39s

There’s nowhere on the earth, or even orbiting the Earth, that’s far enough to hear to the faint radio hum from the time before stars. In fact, we may need to build a giant radio telescope in the quietest place in the solar system—the far side of the moon.

Are Room Temperature Superconductors Impossible?

S9 E25 / 18m

The broader use of superconductors is limited because they need to be cooled to extremely low temperatures to work. But what if we could produce superconductivity at room temperature? It would change the world.

Are Many Worlds & Pilot Wave The Same Theory?

S9 E26 / 17m 24s

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.

JWST Discovered The Farthest Star Ever Seen!

S9 E27 / 15m 59s

With the James Webb Space Telescope we’re starting to be able to see the first galaxies. If only we could see the individual stars in those galaxies we could learn so much more. Well, now using this one weird trick we can do exactly that. Or at least we have one lonely star at the end of the universe. But it won’t be lonely for long.

Why Did Attosecond Physics Win the Nobel Prize?

S9 E28 / 12m 5s

The 2023 Nobel prize in physics has been awarded to three physicists for opening a new window in physics—but it's not a window to a new size scale or a new mode of seeing—-it’s for a new window in time. It’s for attosecond physics—the billionth of a billionth of a second that represents the timescale of the insides of atoms. This year’s Nobel in physics is for a microscope in time.

How Will We (Most Likely) Discover Alien Life?

S9 E29 / 18m 32s

The first discovery of extraterrestrial life will almost certainly NOT be when it visits us, nor when we visit it. 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 probably not aliens, and why there’s a tiny chance that it still might not not be aliens.

What If Gravity is Not Quantum?

S9 E30 / 18m 32s

The holy grail of theoretical physics is to come up with a quantum theory of gravity. But after a century of trying we really have no idea how close we are, or it it's even possible. But we shouldn't feel bad because it turns out that the universe is doing everything it its power to make this as difficult as possible. Or it's telling us that it isn't. Should we take the hint?

Does Many Worlds Explain Quantum Probabilities?

S9 E31 / 19m 3s

The mystery of what happens when we go from a superposition to a definite state is known as the Measurement Problem. The different interpretations of quantum mechanics are really about solving the measurement problem. But Many Worlds offers one thing that the other interpretations do not: there’s no collapse of the wavefunction - which might be the key to solving the measurement problem?

What if Humans Are Not Earth's First Civilization?

S9 E32 / 19m 19s

We’re almost certainly the first technological civilization on Earth. But what if we’re not? We are. Although how sure are we, really? The Silurian hypothesis, which asks whether pre-human industrial civilizations might have existed.

What If There's A Black Hole Inside The Sun?

S9 E33 / 17m 53s

A fun nightmare sci-fi scenario is the sun being consumed by a black hole. Fortunately the chance of a black hole randomly wandering into our solar system is pretty tiny. That’s good news. But what if it’s already here, hiding in the core of the Sun and slowly eating it from the inside out?

Can The Crisis in Cosmology Be Solved With Cosmic Voids?

S9 E34 / 14m 29s

Two of the greatest mysteries in cosmology are the nature of dark energy and the apparent conflict in our measurements of the expansion rate of the early versus the modern universe that even dark energy can’t account for. Could both of these be explained by looking to a part of the universe that we’ve largely ignored so far? Could cosmic voids be driving the universe?

Does Antimatter Create Anti-Gravity?

S9 E35 / 16m 30s

For many years, physicists have wondered whether a certain well-known exotic material may experience gravitational repulsion from the Earth. That material is antimatter, and physicists at CERN have just completed a very long and very difficult experiment to answer a seemingly simple question: does antimatter fall down, or does it fall up?

Did JWST Solve The Mystery of Supermassive Black Hole Origin

S9 E36 / 14m 33s

We’ve just observed the most distant black hole we’ve semi-directly detected. That’s cool enough on its own, but as an added bonus this one smudge may have solved the mystery of the origin of the supermassive black holes in our universe.

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