The Big Theoretical Physics Problem At The Center Of The ‘Muon g-2’ Puzzle In early April, 2021, the experimental physics community announced an enormous victory: they had measured the muon’s magnetic […]

And could Earth-based life provide the seeds for biology elsewhere? Today, on Earth, there’s an enormous variety and diversity of life on our planet. Every single surviving lifeform appears, in […]

Even 13.8 billion years after the Big Bang, we can reconstruct the first 3 minutes. About 100 years ago, we began to truly understand the nature of the Universe for the […]

Enough mass in one location will always create a black hole. But not all masses are possible. If you take enough mass and compress it into a small enough volume […]

When you measure not just light, but light’s polarization, you learn so much more. It’s been over 100 years since the first solution for a black hole was discovered in General […]

Something isn’t adding up, but it isn’t a calibration error. It’s been nearly 100 years since we discovered that the Universe was expanding. Ever since, the scientists who study the […]

Both views are equally spectacular, but unequally informative. Every so often, a creative amateur project highlights our professional achievements. This mosaic shows the region between the constellations of Cygnus and […]

Is a proton fundamentally more ‘quarky’ or ‘gluey’ in nature? One question that every curious child winds up asking at some point or other is, “what are things made of?” Every […]

One image can give over 100 times the data we now get from Hubble. NASA’s Hubble Space Telescope, launched in 1990, revealed the previously unseen Universe. The most distant galaxy ever […]

It’s how successful our current theories are. Some 500 years ago, there was one scientific phenomenon that was, without controversy, extremely well-understood: the motion of the celestial objects in the sky. […]

Even before the Big Bang, energetic radiation was always present. When it comes to the physical Universe, the notion of “nothing” may truly be possible only in theory, not in […]

It could have had any curvature at all. So why is it flat? What is the shape of the Universe? If you had come along before the 1800s, it likely never […]

And what might we learn as we collect new, never-before-seen data? If you took one of history’s top scientists from 100 years ago and dropped them into today’s world, what […]

The Universe’s idea of a ‘typical star’ has changed dramatically over time. When you look out at the Universe today, you’re not seeing it exactly as it is at one particular […]

Dark matter was thought to be cold and collisionless. But maybe that’s not the full story. If you look out at the Universe and measure all the matter out there, including […]

If you want to get the Universe we see, a multiverse comes along for the ride. When we look out at the Universe today, it simultaneously tells us two stories about […]

‘Reductio ad absurdum’ won’t help you in an absurd Universe. Throughout history, there have been two main ways humanity has attempted to gain knowledge about the world: top-down, where we […]

By the end of the decade, we may discover one million black holes. A large enough mass in a compact volume inevitably forms a black hole. Both inside and outside the […]

The definitive answer requires better, unbiased data. Despite all the advances that have occurred in human history, one extraordinary puzzle still remains right in our own backyard: we aren’t sure how […]

Are space and time real like atoms are, or is spacetime just a calculational tool? When most of us think about the Universe, we think about the material objects that […]

Debris from Pluto-sized collisions, not aliens, are streaming through the galaxy. In 2017, scientists discovered an object passing through our Solar System that was unlike anything else we had ever seen. […]

NASA’s SOFIA mission is upgraded and back in action, and the Cigar Galaxy makes a perfect target. In theory, cold, neutral gas is the key to stars and galaxies. A visualization […]

The inevitable long, slow decline is accelerating, and there’s nothing we can do. The Universe, as it is today, is less active, is forming fewer stars, and is creating fewer chances […]

Science was never the same after meeting ‘the particle who lived.’ Back in the early 1930s, there were only a few known fundamental particles that made up the Universe. If you […]

Just say no to artist’s illustrations. This is what the Universe actually looks like. The Universe we observe often surpasses our greatest imaginings. This 20-year time-lapse of stars near the center […]

Think there are habitable super-Earths out there? Think again. Here in our Solar System, we have two very distinct types of planets: small, terrestrial, rocky worlds, with thin (or no) atmospheres […]

Time always moves in the same direction, but what if the Universe were contracting? As we step forward in time, a number of things always seem to happen together. Objects […]

We have two ways of measuring the expansion rate. Here’s the harder one. If you want to understand where our Universe came from and where it’s going, you need to measure […]

Binary pulsars are doing what no other measurement has done: measure our galactic acceleration directly. Even though the majority of the matter that makes up our Universe may be completely […]

If you thought it was just one rich region in space, look deeper and wider. Shining brilliantly in January’s skies is the Great Orion Nebula. By 10 PM every night in […]