It might be the biggest conundrum facing cosmology today. But perhaps it’s not a controversy; it might be a clue. https://soundcloud.com/ethan-siegel-172073460/starts-with-a-bang-44-the-expanding-universe/ One of the biggest conundrums in the Universe surrounds the […]

And why Einstein’s quest for unification was doomed from the start. If you wanted to answer the question of what’s truly fundamental in this Universe, you’d need to investigate matter and […]

Xenon-124 isn’t stable, and the direct detection of its decay could lead us to an even greater prize. Our Universe is old: 13.8 billion years old, to be precise. Many of […]

Our outer Solar System, from Jupiter to Neptune, isn’t unique after all. In the early 1990s, scientists began detecting the first planets orbiting stars other than the Sun: exoplanets. The easiest […]

If a star spins and then collapses, what happens to its angular momentum? The most common way to form a black hole in the Universe is to have a massive […]

A single thought experiment reveals a paradox. Could quantum gravity be the solution? Sometimes, if you want to understand how nature truly works, you need to break things down to […]

Now that we’ve seen our first one, we want more, and we want them better. Here’s how to get there. To resolve any astronomical object, you must achieve resolutions superior to […]

It’s the technique, from the Event Horizon Telescope, that brought us a black hole’s image. Here’s how it works. The Event Horizon Telescope has accomplished what no other telescope or telescope […]

And what do we still have left to learn? The original idea of a black hole goes all the way back to 1783, when Cambridge scientist John Michell recognized that a […]

When the Universe gives us clues, we ignore them at our own peril. When you approach the world scientifically, you seek to gain knowledge about how it works by asking it […]

If parallel Universes or the multiverse are real, we might someday encounter a visitor who hails from another one. Here’s what to do. There are a lot of things that are […]

We assume that life is ubiquitous in the Universe. But what if it’s just us? When it comes to the question of extraterrestrial life, humans optimistically assume the Universe is prolific. […]

What should a black hole look like? Our theoretical predictions are about to meet our first observations. In science, there’s no moment more exciting than when you get to confront […]

In all the Universe, there’s only one Earth. But can we find the other worlds that are like ours? Even though the ingredients for life have been confirmed to be practically […]

There is a fundamental difference between matter and antimatter. But not enough of one to explain our Universe. Our Universe is a vast and enormous place, and if there’s one […]

It’s rare but spectacular when the Moon passes in front of another planet. Here’s how to see it. From our perspective on Earth, the night sky appears virtually unchanged with the […]

Earth wasn’t the only potentially habitable planet in the early Solar System. What happened to Mars? If you could travel back in time to the early stages of the Solar System, […]

The visible light portion of the spectrum is tiny compared to the whole thing. Here’s what we’re missing. When you look at the Milky Way in visible light, you might see […]

The transition across a quantum barrier is known as quantum tunneling, and the amount of time it takes for such a transition to occur had never been measured before. For […]

Even if we don’t destroy ourselves, we always have the Universe to contend with. Wiping out all life on Earth is hard, but causing mass extinctions is easy. The 1991 eruption […]