PBS_SpaceTime

Hawking Radiation12m00s

Hawking Radiation

It’s the most famous prediction of perhaps the most famous genius of our time ... Stephen Hawking's theory of Hawking Radiation.

How Gaia Changed Astronomy Forever8m47s

How Gaia Changed Astronomy Forever

The great advances in any science tend to come in sudden leaps. April 25th of 2018 marks the beginning of just such a leap for much of astronomy. In the early hours of the morning, the Gaia mission’s second data release dropped. Our understanding of our own galaxy will never be the same again.

Noether's Theorem and The Symmetries of Reality9m38s

Noether's Theorem and The Symmetries of Reality

Conservation laws are among the most important tools in physics. They feel as fundamental as you can get. And yet they’re wrong - or at least they’re only right sometimes. These laws are consequences of a much deeper, more fundamental principle: Noether’s theorem.

Why Quantum Information is Never Destroyed10m06s

Why Quantum Information is Never Destroyed

If you have perfect knowledge of every single particle in the universe, can you use the laws of physics to rewind all the way back to the Big Bang? Is the entire history of the universe perfectly knowable? Or has information somehow lost along the way?

What Survives Inside A Black Hole?11m03s

What Survives Inside A Black Hole?

Black holes are the result of absolute gravitational collapse of a massive body: a point of hypothetical infinite density surrounded by an event horizon. At that horizon time is frozen and the fabric of space itself cascades inwards at the speed of light. Nothing can travel faster than light, and so nothing can escape from below the event horizon- not matter, not light, not even information.

The Black Hole Information Paradox11m37s

The Black Hole Information Paradox

Black holes are the result of absolute gravitational collapse of a massive body: a point of hypothetical infinite density surrounded by an event horizon. At that horizon time is frozen and the fabric of space itself cascades inwards at the speed of light. Nothing can travel faster than light, and so nothing can escape from below the event horizon- not matter, not light, not even information.

Citizen Science10m02s

Citizen Science

The professional astronomer or astrophysicist is a pretty recent phenomenon. In the past, astronomy was often performed by nobility and extremely enthusiastic amateurs. Although it seems like the scientific exploration of our universe is now in the hands of full-time career astro-professionals, a ton of really valuable science is still done by people with proper day jobs.

The Unruh Effect10m52s

The Unruh Effect

Worried about black holes? Consider this: Every time you accelerate - you generate an event horizon behind you. The more you accelerate away from it the closer it gets. Don’t worry, it can never catch up to you, but the Unruh radiation it generates sure can.

Using Stars to See Gravitational Waves8m36s

Using Stars to See Gravitational Waves

Now that gravitational waves are definitely a thing, it’s time to think about some of the crazy things we can figure out with them. In some cases we’re going to need a gravitational wave observatory - in fact, we've already built one.

Black Hole Swarms8m33s

Black Hole Swarms

It’s been conjectured that the center of the Milky Way is swarming with tens of thousands of black holes. And now we’ve actually seen them.

The Star at the End of Time8m55s

The Star at the End of Time

If we, or any conscious being is around to witness the very distant future our galaxy, what will they see? How long will life persist as the stars begin to die?

The Vacuum Catastrophe9m17s

The Vacuum Catastrophe

If vacuum energy really does have the enormous value predicted by quantum field theory then our gently expanding, geometrically flat universe shouldn’t exist. This is the vacuum catastrophe.

Horizon Radiation12m03s

Horizon Radiation

Learn about Horizon radiation and why it's essential for us to understand as we continue our journey towards the Unruh Effect and Hawking Radiation.