Every physical theory has constants in it. The gravitational constant is remarkably uncertain. When we first began formulating physical laws, we did so empirically: through experiments. Drop a ball off […]

Some wildfires will always be unavoidable. But nature, thankfully, recovers relatively quickly. The past few years have brought some devastating wildfires to large parts of the American west. A wildfire […]

It took hundreds of thousands of years to make atoms for the first time. If things were just a little different, it could have taken an eternity. When it comes […]

Our Universe may not be all there is, was, or ever will be, after all. There’s been a lot of speculative ideas put forth about the Multiverse, and I dare say […]

With every second that goes by, tens of thousands of star disappear from our reach. And it’s getting worse. It’s been nearly a century since scientists first theorized that the Universe […]

Never draw a conclusion, no matter how ‘obvious,’ without doing the experiment first. We all love our most cherished ideas about how the world and the Universe works. Our conception […]

The Universe is an enormous place, but we can’t see all the way back to the beginning. Here’s the latest record-breaker. No matter how far back we look in the […]

The ices and rock aren’t green, and neither are the tails. So where does a comet’s green color come from? Every so often, with extreme regularity, comets will plunge from beyond […]

The story of John Couch Adams, “the man who failed to discover Neptune,” and his cosmic redemption. Perhaps its human nature to want to only think positive thoughts about our […]

Three great things all align this August, making the Perseids a can’t-miss show. Here’s how to take advantage. When it comes to meteor showers, we have these dazzling pictures in […]

Mars will never look as big as the full Moon. But it isn’t even the biggest planet. From humanity’s perspective, the Sun and Moon always dominate Earth’s skies. The Moon and […]

It wasn’t just the Milky Way and Andromeda two billion years ago. Here in the Local Group, our two largest galaxies dominate: Andromeda and the Milky Way. Our Local Group of […]

Our best physical theories predict that a multiverse exists. But if we can’t test it, is it really scientific? The Universe is all there ever was, all there is, and […]

A new set of images from NASA’s Chandra X-ray observatory shows us what we’ve never seen before. The Pillars of Creation, 7,000 light years away in the Eagle Nebula, represents one […]

If we know how big the observable Universe is, why can’t we figure out how big the unobservable part is? 13.8 billion years ago, the Big Bang occurred. The Universe was […]

There’s a halo of dark matter permeating every galaxy, and that means its particles pass through us, too. The Universe, despite all the planets, stars, gas, dust, galaxies, and more we […]

Forget the spectacular explosions we create here on Earth. The Universe outdoes us in every way imaginable. Forget mere chemical reactions; in space, matter-energy conversion creates unprecedentedly powerful explosive events. […]

There are only two perfect numbers that fit on the calendar: 6 and 28, making June 28th Perfect Number Day. Find out what makes a number perfect, and why they matter. […]

Intelligent aliens, if they exist in the galaxy or the Universe, might be detectable from a variety of signals: electromagnetic, from planet modification, or because they’re spacefaring. But we haven’t […]

The Universe is expanding, but different techniques can’t agree on how fast. No matter what, something major has got to give. Look out at a distant galaxy, and you’ll see it […]