PBS_SpaceTime

When you look in mirror, and see what you think is a perfect reflection, you might be looking at universe whose laws are fundamentally different.

Let’s talk about the mysterious zero-point energy and what it really can, and really can’t do.

Let’s take a moment to remember the selfless sacrifices made by some amazing robotic explorers.

Energy is the most powerful and useful concept in all of physics, but what exactly is it?

What exactly will happen when the sun dies?

Will the future of space exploration be guided by public or private entities? Which is better?

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

What do the first stars in the universe, dark matter, and superior siege engines have in common?

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.

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.

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?

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.

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 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.

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.

Our universe is prone to increasing disorder and chaos. So how did it generate the extreme complexity we see in life? Actually, the laws of physics themselves may demand it.

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.

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.

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?

For years, astronomers have been unable to find up to half of the baryonic matter in the universe. We may just have solved this problem.

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.

Sometimes intuitive, large-scale phenomena can give us incredible insights into the extremely unintuitive world of quantum mechanics.

We were recently visited by a traveler from outside our solar system. This is the first time we’ve ever seen an object that came to us from interstellar space. It's name is 'Oumuamua.

Find out about the last time and the next time the Earth will be hit by a Gamma-ray Burst.

We can now map the interiors of stars by “listening” to their harmonies as they vibrate with seismic waves.