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 […]

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 […]

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 […]

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, […]

It’s not simply Hubble’s Law anymore, but the real history is far more complex than the stories you’ve heard. One of the most mind-blowing facts in our existence is that space […]

The answer has nothing at all to do with the Higgs boson. In this Universe, there are very few fundamental properties that cannot be derived from something simpler. The rules governing […]

The Large Hadron Collider allowed us to complete the Standard Model. Even so, what we have is incomplete. Here’s what could come next. The Large Hadron Collider is the most powerful […]

Your fate is only rarely determined at birth. Ultimately, every star has a chance to get there. Three times in the past 1,000 years, a portion of humanity has looked up […]

Representation matters. Meet five stellar women in physics who were unjustly denied their place in history. Nobel season is now over, with another year in the books of celebrating the scientists […]

Planets can ‘discover’ nuclear power on their own, naturally, without any intelligence. Earth did it 1.7 billion years before humans. If you were hunting for alien intelligence, looking for a surefire […]

If the Sun is 93 million miles away, why does sunlight filtering through the clouds or the trees spread out? Rays of sunshine are one of those natural sights that leave […]

The world’s greatest clockmaker sent a clock to the new world, and everything went haywire. The reason why will shock you. For millennia, humanity’s one-and-only reliable way to keep time was […]

LIGO’s enormous arms contract and expand as gravitational waves pass through them. But, puzzlingly, so does the light within them. For the past three years, humanity has known a new kind […]

Of all the experiments performed and measurements made involving fundamental particles, none has ever violated the Standard Model. Until now. If there’s one thing you can count on physicists for, it’s […]

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 […]

Dark matter is our leading theory for a reason. New, detailed studies of the smallest galaxies could kill off the most studied alternative. When you look out at the Universe, […]