Cosmology

Cosmology

A surreal painting ponders is time travel possible, with melting clocks draped over a tree, ledge, and abstract form in a barren landscape against distant cliffs.
Theoretical physicist Brian Greene explores the potential particles of time and why we could, in theory, travel forward in time but not back.
John Templeton Foundation
finite or infinite
As far as we can tell, there's no limit to how far it goes on; only a limit to how far we can see. Could the Universe truly be infinite?
farthest galaxy
We've fooled ourselves before with galaxies that look just like this one. The evidence we have simply isn't strong enough.
In the latest edition of the Starts With A Bang podcast, we talk with soon-to-be Dr. Arianna Long about galaxies, from birth to today.
cosmic rays
Our Universe requires dark matter in order to make sense of things, astrophysically. Could massive photons do the trick?
Illustration of two hands touching or aligning a series of parallel lines and chevron patterns, all overlaid with a blue filter, evoking the precision and symmetry often found in mathematics.
5mins
Michio Kaku believes math is the mind of God.
John Templeton Foundation
The story of how Jupiter, Saturn, Uranus and Neptune were made isn't a universal one. Some gas giants were built different.
gravitational waves
To study the origin of the Universe, we could build a constellation of six expensive spacecraft — or we could just use the Moon.
how many planets
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?
Galactic archaeology has uncovered a spectacular find: the Milky Way already existed more than 13 billion years ago.
cosmic dark ages
The James Webb Space Telescope could help scientists learn about the cosmic dark ages and how they ended.
coldest place in the universe
Empty, intergalactic space is just 2.725 K: not even three degrees above absolute zero. But the Boomerang Nebula is even colder.
The far infrared reveals both the coldest and hottest gas in the Universe, and can teach us what no other wavelength range can.
Is there any good reason for assigning North and South the way we do, or could we have just as easily done the reverse?
el gordo colliding galaxy cluster
The laws of physics state that you can't create or destroy matter without also creating or destroying an equal amount of antimatter. So how are we here?
existence of God
Despite all that we've learned about the Universe, there remain unanswered, and possibly unanswerable, questions. Could "God" be the answer?
how many planets
Shortly after planet Earth formed, life took a permanent hold on our surface. But just how common is such an outcome?
how much dark matter
If dark matter exists in a large halo in our galaxy, made up of particles, then it's passing through us constantly. But how much?
is the multiverse real
Is the multiverse real? It's one of the hottest questions in all of theoretical physics. We invited two astrophysicists to join the debate.
galaxies without dark matter
Out of all the galaxies we know, only a few little ones are missing dark matter. At last, we finally understand why.
symmetric
If the electromagnetic and weak forces unify to make the electroweak force, maybe, at even higher energies, something even greater happens?
With 1550 distinct type Ia supernovae measured across ~10 billion years of cosmic time, the Pantheon+ data set reveals our Universe.
space expanding
Yes, the Universe is expanding, but you might wonder, "How fast is it expanding?"
asymmetry
The Universe has asymmetries, but that's a good thing. Imperfections are essential for the existence of stars and even life itself.
parallel universe
In scientific theories, the Multiverse appears as a bug rather than as a feature. We should squash it.
how many stars
There are ~400 billion stars in the Milky Way, and ~2 trillion galaxies in the visible Universe. But what if we aren't typical?
m81 group
Just 12 million light-years away, the galaxies Messier 81 and 82 offer a nearby preview of the Milky Way-Andromeda merger.
travel straight line
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.
James Webb Hubble
Hubble's deepest views of space revealed fewer than 10% of the Universe's galaxies. James Webb will change that forever.