The quest for a quantum theory of gravity is the holy grail of physics. Here’s why it’s murkier than anyone expected. If you want to fully describe how the Universe […]

If you think nothing can move faster than light, check out this clever way to defeat that limit. Nothing can move faster than the speed of light. When Einstein set forth […]

The Planck length is a lot smaller than anything we’ve ever accessed. But is it a true limit? If you wanted to understand how our Universe operates, you’d have to examine […]

The summer solstice is the longest day of the year, but doesn’t have the earliest sunrise or the latest sunset. Here’s why. The length of a day on planet Earth might […]

It’s where Earth’s axial tilt with respect to the Sun is most extreme. Here are the consequences. Today is June 21st, 2019: the day of the solstice. Although there are […]

Has the mystery really been solved? Doubtful. The real science goes much deeper. For perhaps the last year or so, a small galaxy located not too far away has captivated the […]

13.8 billion years isn’t close to enough time, but if we wait long enough, even our Sun will become one. The Big Bang happened approximately 13.8 billion years ago, and it […]

Everything on Earth is made of atoms and their building blocks. Without this one rule, they’d never make anything interesting. Take a look around you at everything on Earth. If […]

Neither one reflects the other; they’re both blue for entirely different reasons. If you’ve ever been curious about the world you live in, you’ve probably wondered why the sky is […]

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

Both effects could be responsible for a redshift. But only one makes sense for our Universe. In physics, like in life, there are often multiple solutions to a problem that […]

While the web of dark matter (purple) might seem to determine cosmic structure formation on its own, the feedback from normal matter (red) can severely impact galactic scales. Both dark […]

A new study claims that dark energy is changing with time. Here’s what it would mean, if true. For the past generation, we’ve recognized that our Universe is a particularly dark […]

Sometimes, chemistry can be more important for color than even physics. All across the world, volcanic eruptions remind us of the destructive power residing beneath Earth’s surface. You might be used […]

If you photograph the Sun at the same time every day, you get a bizarre figure-8 shape: an analemma. Here’s why. At any time of day, you could theoretically set up […]

When two black holes merge together, about 5% of their mass gets lost. Where does that information go? Do merging black holes lose information? They absolutely must, according to General […]

With 1.6 billion households in the world, how does Santa do it? With a little Christmas magic… and a lot of science! How does Santa Claus do it? In one long […]

If you think you have problems today, be glad you’re not moving at the speed of light. Special relativity, even though it’s over 100 years old, is still one of the […]

When you emit gravitational waves, they have to pass through the Universe. But do they gravitate, too? When you travel through the Universe, it isn’t just a free ride through […]

The best books, calendar, accessories and more are all just one click away. Every year, there are no shortage of wonderful, exciting, informative gifts you could get for those who matter […]

A special isotope of plutonium is necessary for missions to Mars and beyond. But we don’t have enough, and aren’t making more fast enough. As 2018 comes to a close, NASA […]

With the right material at the right temperature and a magnetic track, physics allows you to never lose energy. The idea of levitating off the ground has been a staple of […]

The expanding Universe really is accelerating, and no dusty scenario can explain it. 20 years ago, our understanding of the Universe underwent a revolution. For generations, we had known the Universe […]

Einstein’s explanation is the only one that works. When Newton first proposed the law of universal gravitation, it marked the very first time that we realized the same rule governing how […]

We can go to deeper and deeper levels, finding more fundamental quantities as we do. But is there a truly fundamental quantity? What is the Universe, at a fundamental level, […]