The Universe is expanding, and individual, bound structures are all receding away from one another. How, then, are galaxies still colliding?

Since the dawn of history, humans have pondered our ultimate cosmic origins. Now in the 21st century, science has gone beyond the Big Bang.

"Asking the question of, where did the entire universe come from, is no longer a question for poets and theologians and philosophers. This is a question for scientists, and we have some amazing scientific answers to this question that have defied even the wildest of our expectations."

There are some 26 fundamental constants in nature, and their values enable our Universe to exist as it does. But where do they come from?

One of the most promising dark matter candidates is light particles, like axions. With JWST, we can rule out many of those options already.

Astronomers see spiral and elliptical nebulae nearly everywhere, except by the Milky Way's plane. We didn't know why until the 20th century.

Perhaps the most well-known equation in all of physics is Einstein's E = mc². Does mass or energy increase, then, near the speed of light?

From the tiniest subatomic scales to the grandest cosmic structures of all, everything that exists depends on two things: charge and mass.

The CMB gives us critical information about our cosmic past. But it doesn't give us everything, and galaxy mapping can fill in a key gap.

Dark matter doesn't absorb or emit light, but it gravitates. Instead of something exotic and novel, could it just be dark, normal matter?

When we divide matter into its fundamental, indivisible components, are those particles truly point-like, or is there a finite minimum size?

The ultimate multi-messenger astronomy event would have gravitational waves, particles, and light arriving all at once. Did that just occur?

A young, nearby, massive star, whose protoplanetary disk appears perfectly edge-on, was just viewed by JWST, with staggering implications.

If humanity lives in an otherwise barren Universe, we'll have to forge philosophy that fills the void.

Here in our Universe, both normal and dark matter can be measured astrophysically. But only normal matter can collapse. Why is that?

First discovered in the mid-1960s, no cosmic signal has taught us more about the Universe, or spurred more controversy, than the CMB.

It's the ultimate game of cosmic "cover up," as the dimming occurs when a circumbinary disk from a nearby star passes in front of T Tauri North.

Matter is made up largely of atoms, where atomic nuclei can contain up to 100 protons or more. But how were the heaviest elements made?

Cosmic inflation, proposed back in 1980, is a theory that precedes and sets up the hot Big Bang. After thorough testing, is it still valid?

Physicist Don Lincoln explains why mathematics is a powerful tool for scientific modeling, but is not a science itself.

The discovery of ultra-bright, ultra-distant galaxies was JWST's first big surprise. They didn't "break the Universe," and now we know why.

Our Universe isn't just expanding, the expansion is accelerating. Instead of dark energy, could a "lumpy" Universe be at fault?

A recent measurement has simultaneously settled an ongoing scientific debate while puzzling scientists.

On larger and larger scales, many of the same structures we see at small ones repeat themselves. Do we live in a fractal Universe?

It's not only the gravity from galaxies in a cluster that reveals dark matter, but the ejected, intracluster stars actually trace it out.

Did the Milky Way form by slowly accreting matter or by devouring its neighboring galaxies? At last, we're uncovering our own history.

Our galactic home in the cosmos — the Milky Way — is only one of trillions of galaxies within our Universe. Is one of them truly our "twin?"

When three wise men gifted baby Jesus with gold, frankincense, and myrrh, they had no idea one was made from colliding neutron stars.

Carl Sagan was far from the first to declare we are the children of ancient stars.

Matt Strassler's journey into fundamental physics culminates in a brilliant explanation of the Higgs field. Enjoy this exclusive interview.