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Cosmology
When it comes to our Universe's origins, scientists discuss the Big Bang, cosmic inflation, and other theories. Why doesn't "God" come up?
On the largest scales, galaxies don't simply clump together, but form superclusters. Too bad they don't remain bound together.
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.
When the Hubble Space Telescope first launched in 1990, there was so much we didn't know. Here's how far we've come.
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?
With over 300 high-significance gravitational wave detections, we now have a huge unsolved puzzle. Will we invest in finding the solution?
1hr 18mins
“Could black holes be the key to a quantum theory of gravity, a deeper theory of how reality, of how space and time works?”
The measured value of the cosmological constant is 120 orders of magnitude smaller than what's predicted. How can this paradox be resolved?
13mins
"We've sent out one or two little messages, but we certainly aren't investing billions of dollars shouting out into the cosmos saying, "Hey, we are here. Come say hi.""
The relic signal that first proved the Big Bang has been known and analyzed for 60 years. Join us at the frontiers of modern cosmology!
The CMB has long been considered the Big Bang's "smoking gun" evidence. But after what JWST saw, might it come from early galaxies instead?
19mins
"It's a very, very beautiful calculation, but it's the best example I know of the relationship between these rather abstract quantities perhaps and something that you can look at in a telescope."
Originally, the abundance of bright, early galaxies shocked astronomers. After 3 years of JWST, we now know what's really going on.
For over 50 years, it’s been the scientifically accepted theory describing the origin of the Universe. It’s time we all learned its truths.
Is the Universe's expansion rate 67 km/s/Mpc, 73 km/s/Mpc, or somewhere in between? The Hubble tension is real and not so easy to resolve.
The ANITA experiment found cosmic rays shooting out of Antarctica. One interpretation claims "parallel Universes," but is that right?
Different methods of measuring the Universe's expansion rate yield high-precision, incompatible answers. But is the problem robustly real?
The tiniest galaxies of all are the most severely dominated by dark matter. Could black holes be the cause of the extra gravity instead?
If you want to understand the Universe, cosmologically, you just can't do it without the Friedmann equation. With it, the cosmos is yours.
Viewing Uranus's largest moons with Hubble, astronomers hoped to find darkening on the trailing side. They found the exact opposite instead.
The first galaxies were irregular blobs of gas and stars. But modern features, like spiral arms and bars, appeared earlier than expected.
If the Universe is 13.8 billion years old today, but different ages the farther we look back, what does it mean for a star to be the first?
The COSMOS-Web has just finalized their release of their full field: larger and deeper than any other JWST program. Here's what's inside.
For decades, astronomers have claimed the Milky Way will merge with Andromeda in ~4 billion years. Here's why, in 2025, that seems unlikely.
"The stars made our minds, and now our minds look back."
In our Universe, dark matter outmasses normal matter by a 5-to-1 ratio, shaping the Universe as we know it. What if it simply weren't there?
It rotates on its axis, revolves around the Sun, moves throughout the Milky Way, and gets carried by our galaxy all throughout space.
The long-elusive neutrino was shown to have a bizarre property no one expected: mass. New, tightest-ever limits have profound implications.
Many were hoping that JWST would find the first stars of all. Despite many hopeful claims, it hasn't, and probably can't. Here's how we can.
Here in our Universe, time passes at a fixed rate for all observers: one second-per-second. Before the Big Bang, things were very different.