Cosmology

Cosmology

A split image shows a star field on the left and a COSMOS-Web survey area diagram on the right, with labeled NIRCam and MIRI footprints alongside the moon for scale, highlighting galaxies explored by JWST science.
By deeply imaging a large volume of space, COSMOS-Web provides JWST's widest cosmic views. Its gravitational lenses reveal a big surprise.
As the Universe ages, it continues to gravitate, form stars, and expand. And yet, all this will someday end. Do we finally understand how?
From here on Earth, looking farther away in space means looking farther back in time. So what are distant Earth-watchers seeing right now?
a black background with circles and a star in the center.
Proposed over 2000 years ago by Democritus, the word atom literally means uncuttable. Revived in 1803, today's "atoms" can indeed be split.
A diagram illustrating one of the biggest mysteries: the origin of the universe, from the Big Bang and inflation to today, showing the formation of atoms, stars, galaxies, and the ongoing expansion of space.
From the Big Bang to a prior period of cosmic inflation, our cosmic origins are clearer than ever. Yet these 5 big mysteries still remain.
A circular diagram illustrating the observable universe, showing planets, stars, galaxies, and cosmic background radiation layers—revealing where Big Bang echoes still linger.
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?
black hole
All of the matter that we measure today originated in the hot Big Bang. But even before that, and far into the future, it'll never be empty.
planck temperature polarization
The hot Big Bang is often touted as the beginning of the Universe. But there's one piece of evidence we can't ignore that shows otherwise.
LIGO Livingston
10 years ago, LIGO first began directly detecting gravitational waves. Now better than ever, it's revealing previously unreachable features.
ESO milky way
Questions about our origins, biologically, chemically, and cosmically, are the most profound ones we can ask. Here are today's best answers.
A dense star field with dark, irregular dust clouds—where cosmic dust come from—obscures parts of the glowing stars in the Milky Way.
Dust is ubiquitous in the modern Universe, appearing in nearly all galaxies. But our cosmos was born dust-free. So where does it originate?
A drawing of a group of people soaring in a plane, embodying cosmism.
In revolutionary Russia, a group of forward-thinking philosophers offered an alternative to both futurism and communism.
It's the origin of our entire observable Universe, but it's still not the very beginning of everything.
Book cover for "Facing Infinity: Black Holes and Our Place on Earth" by Jonas Enander, featuring a starry night sky, a swirling black hole graphic, and a faint silhouette of a priest gazing into the cosmic abyss.
In this excerpt from "Facing Infinity," Jonas Enander examines how John Michell conceived of "dark stars," or massive bodies with enough gravity to trap light, all the way back in 1783.
Two identical, intricate, circular geometric patterns with symmetrical, multicolored lines and shapes are displayed side by side on a white background—each subtly reflecting the argument against theory of everything’s promise of perfect symmetry.
The Holy Grail of physics is a Theory of Everything: where a single equation describes the whole Universe. But maybe there simply isn't one?
Abstract 3D geometric surface with intersecting translucent orange and brown planes, inspired by the amplituhedron theory of everything, set against a blurred orange background with white network lines.
Since even before Einstein, physicists have sought a theory of everything to explain the Universe. Can positive geometry lead us there?
An artist's impression of a cluster of stars.
With several seemingly incompatible observations, cosmology faces many puzzles. Could early, supermassive stars be the unified solution?
As we look to larger cosmic scales, we get a broader view of the expansive cosmic forest, eventually revealing the grandest views of all.
a red and orange abstract background with lines.
Explanations for the cosmic speed limit often conflate mass with inertia.
An abstract animation of white, textured patterns symmetrically forming on a blue and black background evokes the mysterious dance of dark energy, subtly hinting at its weakening presence as if guided by the precision of DESI.
The Universe isn't just expanding; the expansion is accelerating. If different methods yield incompatible results, is dark energy evolving?
The Universe was born incredibly hot, and has expanded and cooled ever since. Could life have begun back when space was "room temperature?"
space expanding
Just 13.8 billion years after the hot Big Bang, we can see 46.1 billion light-years away in all directions. Doesn't that violate...something?
An image of an ancient black hole
At the center of Hubble's famous "cosmic horseshoe," a very heavy supermassive black hole has been robustly measured. How is it possible?
Amplifying the energy within a laser, over and over, won't get you an infinite amount of energy. There's a fundamental limit due to physics.
creation of adam sistine
When it comes to our Universe's origins, scientists discuss the Big Bang, cosmic inflation, and other theories. Why doesn't "God" come up?
laniakea
On the largest scales, galaxies don't simply clump together, but form superclusters. Too bad they don't remain bound together.
bounce ball
Whether you run the clock forward or backward, most of us expect the laws of physics to be the same. A 2012 experiment showed otherwise.
every square degree
When the Hubble Space Telescope first launched in 1990, there was so much we didn't know. Here's how far we've come.
Green abstract image with floating, glowing funnel-shaped objects and spherical wireframe shapes evokes a black hole universe, all set against a misty green background with ethereal light streaks.
Once you cross a black hole's event horizon, there's no going back. But inside, could creating a singularity give birth to a new Universe?
gravitational wave effects on spacetime
With over 300 high-significance gravitational wave detections, we now have a huge unsolved puzzle. Will we invest in finding the solution?