If everything was hot, dense, and super close-together at the Big Bang, what kept us from collapsing into a singularity? The Big Bang is one of the most counterintuitive ideas […]

Ever hear of Hawking radiation? Or the black hole information paradox? Time to get your fix! In memory of Stephen Hawking’s life, I’ve decided to share the physics behind his greatest […]

Even our scientific heroes can’t be right about everything. Let’s learn the lessons that they never did. In the 1960s, a young theoretical physicist named Stephen Hawking rose to prominence as […]

LISA, the Laser Interferometer Space Antenna, will not only be the space-based successor to LIGO, but will predict black hole mergers up to years in advance. Across the Universe, innumerable masses […]

It isn’t just for merging neutron stars, anymore. Over the past three years, there’s arguably been no greater scientific discovery than the direct detection of gravitational waves. The two LIGO […]

If nothing can escape from beneath the event horizon, where do these phenomena come from? The most important feature of a black hole is that it has an event horizon: a […]

Would there be only blackness past the event horizon? Or something more? Black holes are some of the most perplexing objects in the entire Universe. Objects so dense, where gravitation […]

The Event Horizon Telescope has come online and taken its data. Now, we wait for the results. Black holes are some of the most incredible objects in the Universe. There are […]

How did black holes get so supermassive so fast? Astrophysics may be about to find out, thanks to three big 2017 discoveries. There’s a big problem when we look at […]

We’ve come so far since 2015; what do we know about dark matter now that we didn’t know then? Back in 2015, the dark matter situation was pretty straightforward: the large-scale […]

A new look at the intertwined lives of two of the 20th century’s greatest minds. In the years prior to World War II, physics was in an odd, post-revolutionary state. Quantum […]

Do we need quantum gravity? We sure do… and here’s how we’re trying to get there! Our current best theories describing the Universe, general relativity for gravity, quantum field theory for […]

For the first time, we’ve seen neutron stars merge. At last, the gravitational and electromagnetic sky are one. “It’s becoming clear that in a sense the cosmos provides the only laboratory […]

It’s a fascinating idea, but how does it fare as a scientific theory? “Something is happening here and this is going to have an impact.” –Robert Dijkgraaf, on Verlinde’s work The […]

Three eyes are so much better than two. Here’s why. “Einstein’s gravitational theory, which is said to be the greatest single achievement of theoretical physics, resulted in beautiful relations connecting gravitational […]

For the first time, the gravitational wave sky and the astronomical sky might be coming together. It’s a new era, at long last. “Presently thought to be the most powerful explosions […]

When matter falls in, black holes grow. But Hawking radiation says that black holes decay. Who wins? “Maybe that is our mistake: maybe there are no particle positions and velocities, but […]

Black holes shouldn’t be this big, much less this big so many billions of years ago. Yet here we are. “Ultramassive black holes — that is, black holes with masses exceeding 10 billion […]

Falling into a black hole is forever… but could a tether to the outside pull you back out? “Nobody ever did, or ever will, escape the consequences of his choices.” –Alfred A. […]

Did they perform their analysis sub-optimally? Maybe. But gravitational waves were seen no matter what. “We hope that interested people will repeat our calculations and will make up their own minds […]

Now we know, on every scale. “There is no such thing as perpetual tranquillity of mind while we live here; because life itself is but motion, and can never be without […]

Never heard of SKA, the square kilometer array? Once it starts taking data, you’ll never forget it. “Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for […]

Gravitational waves and electromagnetic ones don’t need to go together. But physics says it’s possible; what do the observations say? “The black holes collide in complete darkness. None of the […]

Every star must eventually run out of fuel and die… but did you know the galaxy itself will come to an end someday? “Unless one says goodbye to what one loves, […]

A live-blog event happened a week ago, but you can catch the entire thing anew here, right now! “We have never observed infinity in nature. Whenever you have infinities in […]

You might think that it should be all black, but then how would we see it? “It is conceptually interesting, if not astrophysically very important, to calculate the precise apparent shape […]

Was it really a low-entropy state? And what does that mean for the second law of thermodynamics? “Entropy shakes its angry fist at you for being clever enough to organize […]

We’ve never seen an event horizon, nor directly imaged a black hole. Thanks to a worldwide effort, victory may at last be in sight. “Never look down to test the ground […]

How to turn a galaxy on, once and for all. “Speculating and predicting what lies beyond the boundary is fascinating. Finding out is even more fascinating.” –Wallace H. Tucker When two […]

Merging black holes are some of the most extreme events in the Universe. Could a modified event horizon reveal quantum gravity? “The bedrock nature of space and time and the unification […]