Cosmology

Cosmology

A bright star shining in a dark sky filled with numerous smaller stars. The larger star appears at the center with a noticeable twinkle effect.
The standard picture of our Universe is that it's dominated by dark matter and dark energy. But this alternative is also worth considering.
A black and white particle track image on the left and a colorful representation of a neutrino.
The properties of a ghostly particle called a neutrino are coming into focus.
A graphical representation illustrating the concept of the big bang and the subsequent expansion of the universe, depicted by a transition from a singular point of energy to a wide, grid-like spread of galaxies and celestial elements
On the largest of cosmic scales, the Universe is expanding. But it isn't all-or-nothing everywhere, as "collapse" is also part of the story.
Einstein with his class of students in 1896
There are many things that separate science from ideology, politics, philosophy, or religion. Follow these 10 commandments to get it right.
A series of sun positions during sunset over a landscape, with trees in the foreground and mountains in the background, creating a pattern of glowing points in the sky.
Sure, there's less daylight during winter than summer, as your hemisphere is tilted away from the Sun. But darkness goes deeper than that.
bounce ball
Our thermodynamic arrow of time explains why the entropy of any isolated system always increases. But it can't explain what we perceive.
moon two faces
The near and far sides of the Moon are so different from each other, and no one is sure why. New lunar samples could confirm a wild theory.
All telescopes are fundamentally limited in what they can see. JWST reveals more distant galaxies than Hubble, but still can't see them all.
A melting clock drapes over a bare tree branch in a surreal, barren landscape with simple geometric shapes and muted colors.
7mins
“We could be wrong. But if we are right, it’s profoundly important.” Leading mineralogist Dr. Robert Hazen on the missing law of nature that could explain why life emerges.
John Templeton Foundation
An artist's impression of a cluster of stars.
There was a time where no starlight was visible throughout the entire cosmos. That time was short-lived: shorter than astronomers imagined.
The sharpest optical images, for now, come from the Hubble Space Telescope. A ground-based technique can make images over 100 times sharper.
Comparison chart showing the Standard Model particles on the left and the hypothetical SUSY particles on the right. The red arrow highlights the SUSY gluon (g-tilde). Before we give up supersymmetry, consider how these theoretical particles could revolutionize our understanding of physics.
Almost 100 years ago, an asymmetric pathology led Dirac to postulate the positron. A similar pathology could lead us to supersymmetry.
parallel universe
The Universe's history, from cosmic inflation to the Big Bang to the present, is known. But whether it's infinite or not is still a mystery.
universe temperature
Although the Big Bang occurred at an instant in time long ago, we still see the light from it. Will the evidence ever disappear completely?
Known as hypervelocity stars, we originally thought just one would be ejected every 100,000 years. The real number is much greater.
A computer-generated image of a bright celestial object with an accretion disk, possibly representing what the sun looked like when it was born.
Newborn stars are surrounded only by a featureless disk. Debris disks persist for hundreds of millions of years. So when do planets form?
A composite image shows the sun's path in the sky at different times of the year over a grassy landscape, with three arches of sun positions represented by dots, illustrating the earliest solstice.
On June 20, 2024, the summer solstice occurs at its earliest moment since 1796: when George Washington was President of the USA. Here's why.
Two breathtaking pictures of a galaxy and a star taken by the Hubble telescope, highlighting the beauty and cosmic magnitude that fuels the Hubble tension.
There are two different ways to measure the expansion rate of the Universe, and they don't agree. And no, new measurements don't help.
Two people are tandem skydiving, falling through the air above a landscape of fields, mountains, and coastline under a clear sky.
Is gravity weaker over distances of billions of light-years?
A new all-time record! JWST's discovery of JADES-GS-z14-0 pushes the earliest galaxy ever seen to just 290 million years after the Big Bang.
Abstract representation of a cosmic event with a burst of particles emanating from a central point, blending astrophysical imagery with geometric designs.
If you bring too much mass or energy together in one location, you'll inevitably create a black hole. So why didn't the Big Bang become one?
A deep space image showing numerous galaxies of different shapes and sizes scattered across a dark background, with many stars and cosmic objects, including the ancient Methuselah star, also visible throughout.
The Universe is precisely dated at 13.8 billion years old, but astronomers claim the Methuselah star is 14.5 billion years old. What gives?
proton internal structure
It's 2024, and we still only know of the fundamental particles of the Standard Model: nothing more. But these 8 unanswered questions remain.
Stellar explosion
The expanding Universe, in many ways, is the ultimate out-of-equilibrium system. After enough time passes, will we eventually get there?
A diagram of the solar system illustrates the heliosphere, detailing the termination shock, heliopause, and bow shock, along with the paths of Pioneer 10, Pioneer 11, Voyager 1, and Voyager 2. This visual representation underscores key aspects of fundamental science in our cosmic neighborhood.
Some think the reason fundamental scientific revolutions are so rare is because of groupthink. It's not; it's hard to mess with success.
big crunch
For nearly 25 years, we thought we knew how the Universe would end. Now, new measurements point to a profoundly different conclusion.
A close-up of a metallic conical structure, set against a dark wireframe background. The structure has reflective surfaces and appears to be part of a scientific or industrial apparatus.
Scientists are searching for dark matter particles that are trillions or even quadrillion times lighter than the more traditional searches. 
planetary nebulae infrared spitzer
In ~7 billion years, our Sun will run out of fuel and die. So will every star, eventually. Here are the different fates they'll encounter.
hubble tension
The mutual distance between well-separated galaxies increases with time as the Universe expands. What else expands, and what doesn't?
CERN_ATLAS_Detector The standard model in physics
With new W-boson, top quark, and Higgs boson measurements, the LHC contradicts earlier Fermilab results. The Standard Model still holds.