Atomic nuclei form in minutes. Atoms form in hundreds of thousands of years. But the “dark ages” rule thereafter, until stars finally form.

With any occupation comes a risk of health and safety hazards. When it comes to being Santa Claus, the challenges are unique.

While ice itself is slick, slippery, and difficult to navigate across under most circumstances, skaters easily glide across the ice.

The first elements in the Universe formed just minutes after the Big Bang, but it took hundreds of thousands of years before atoms formed.

The brilliant mind who discovered the spacetime solution for rotating black holes claims singularities don’t physically exist. Is he right?

In the early stages of the hot Big Bang, there were only free protons and neutrons: no atomic nuclei. How did the first elements form from them?

In the early stages of the hot Big Bang, matter and antimatter were (almost) balanced. After a brief while, matter won out. Here’s how.

For a substantial fraction of a second after the Big Bang, there was only a quark-gluon plasma. Here’s how protons and neutrons arose.

In the very early Universe, practically all particles were massless. Then the Higgs symmetry broke, and suddenly everything was different.

In the earliest stages of the hot Big Bang, equal amounts of matter and antimatter should have existed. Why aren’t they equal today?

When the hot Big Bang first occurred, the Universe reached a maximum temperature never recreated since. What was it like back then?

Some 13.8 billion years ago, the Universe became hot, dense, and filled with high-energy quanta all at once. Here’s what it was like.

Cosmic inflation is the state that preceded and set up the hot Big Bang. Here’s what the Universe was like during that time period.

With such a vast Universe and raw ingredients that seem to be everywhere, could it really be possible that humanity is truly alone?

Space weather poses a tremendous threat to all satellites, knocking all computer systems offline. Is that a recipe for Kessler syndrome?

Dark energy is one of the biggest mysteries in all the Universe. Is there some way to avoid “having to live with it?”

From the earliest stages of the hot Big Bang (and even before) to our dark energy-dominated present, how and when did the Universe grow up?

In general relativity, white holes are just as mathematically plausible as black holes. Black holes are real; what about white holes?

The most common element in the Universe, vital for forming new stars, is hydrogen. But there’s a finite amount of it; what if we run out?

The Universe is 13.8 billion years old, going back to the hot Big Bang. But was that truly the beginning, and is that truly its age?

Practically all of the matter we see and interact with is made of atoms, which are mostly empty space. Then why is reality so… solid?

Holograms preserve all of an object’s 3D information, but on a 2D surface. Could the holographic Universe idea lead us to higher dimensions?

In the 20th century, many options abounded as to our cosmic origins. Today, only the Big Bang survives, thanks to this critical evidence.

No matter how good our measurement devices get, certain quantum properties always possess an inherent uncertainty. Can we figure out why?

At a fundamental level, only a few particles and forces govern all of reality. How do their combinations create human consciousness?

In all the Universe, only a few particles are eternally stable. The photon, the quantum of light, has an infinite lifetime. Or does it?

Our Universe requires dark matter in order to make sense of things, astrophysically. Could massive photons do the trick?

For some reason, when we talk about the age of stars, galaxies, and the Universe, we use “years” to measure time. Can we do better?

If you think of the Big Bang as an explosion, we can trace it back to a single point-of-origin. But what if it happened everywhere at once?

Is the Universe finite or infinite? Does it go on forever or loop back on itself? Here’s what would happen if you traveled forever.