Life arose on Earth very early on. After a few billion years, here we are: intelligent and technologically advanced. Where’s everyone else?

Many contrarians dispute that cosmic inflation occurred. The evidence says otherwise.

And either way, is energy or information conserved? When two things in the Universe that “always” occur meet one another, how do you know which one will win? Gravitational waves, […]

Scalars, vectors, and tensors come up all the time in science. But what are they? One of the major goals of science is to describe our reality as accurately as possible. […]

Are dark matter and dark energy both two sides of the same coin? When it comes to the Universe, what you can easily see isn’t always reflective of all there is. […]

The Big Bang is our accepted origin of the Universe. But is there another possibility? Since the mid-1960s and the discovery of the Cosmic Microwave Background, the Big Bang has […]

Forget the speed of light or the electron’s charge. This is the physical constant that really matters. Why is our Universe the way it is, and not some other way? There […]

The history of life on Earth took many meandering turns before it gave rise to us. When Earth first formed, all the raw ingredients for life — atoms, molecules, a potentially habitable planet […]

We’re a long way from the beginnings of life on Earth. Here’s the key to how we got there. The Universe was already two-thirds of its present age by the time […]

A climate catastrophe 2 billion years ago almost ended life on Earth. Here’s the biggest lesson of all. Although it was more than 4½ billion years ago that planet Earth formed, […]

One moment, every particle in the Universe was massless. Then, they weren’t anymore. Here’s how it happened. In the earliest stages of the hot Big Bang, the Universe was filled […]

Saw “Solar System Questions” by xkcd? Here’s what science thinks it knows. “Put two ships in the open sea, without wind or tide, and, at last, they will come together. […]