Cosmology

Cosmology

black hole
Quantum entanglement links information between particles across space and time. So what happens when one of them falls into a black hole?
A radio telescope observes a distant galaxy; insets show a magnified view of the galaxy—home to the most distant laser—and a spectral graph. Illustration attributed to IDIA.
Forget about the terawatt lasers we're making on Earth. The Universe makes natural ones thousands of times more powerful than the Sun.
The fundamental building blocks of reality are indivisible: quanta that cannot be split or divided. Our understanding remains incomplete.
White lines intersect around a central, glowing sphere on a black background, creating a complex geometric and abstract pattern that suggests how nothing can persist when the universe dies.
Long after the last star burns out, the Universe will experience its end state: a heat death. Will everything prior then be meaningless?
quark gluon plasma primordial soup
Before we formed stars, atoms, elements, or even got rid of our antimatter, the Big Bang made neutrinos. And we finally found them.
Visualization of the timeline of the universe, from the beginning big bang to the present.
The Universe is expanding, the expansion is accelerating, and some galaxies even recede faster-than-light. Can we see a change in real time?
A luminous dying sun with jets and swirling clouds appears at the center of a dark background, encircled by concentric patterns—an image reminiscent of Hubble’s stunning cosmic view.
Before Sun-like stars die, they transition from AGB red giants into preplanetary nebulae. Here's how Hubble sees the famous Egg Nebula.
An older person sits on a chair against a white backdrop, with a colorful outer space scene digitally added around the background.
1hr 3mins
Astronomer Jill Tarter explains why SETI is really about technology, patience, and learning how to tell alien signals from our own.
A dense field of distant galaxies and bright stars against a black background, as captured in a JWST early galaxies deep space telescope image.
Many collaborations have used JWST to take deep-field images: some wider and some deeper than others. Here's how it can surpass them all.
Image of a star field with numerous galaxies; several objects are circled in white, and one object is marked with an “X” near the center.
The Universe formed stars, galaxies, and even galaxy clusters extremely early on in our cosmos. This new marvel is one more JWST surprise.
cosmic rays
At the upper limits of what's energetically possible, cosmic rays still persist. What happens if a human gets hit by the most energetic one?
Our great hope is that today's indirect, astrophysical evidence will someday lead to successful direct detection. What if that's impossible?
A deep space image showing a field of distant galaxies with several regions zoomed in to highlight faint, small JWST objects.
Just like animals, galaxies often have bizarre, unusual, or even unique properties. But finding many, all at once, really does raise alarms.
Raisin bread expanding Universe
Even in an expanding Universe, we expect both redshifted and blueshifted galaxies. But nearly every one we see is redshifted. Here's why.
Many view the development of fringe, alternative theories as a useless waste of time. But when they can be tested, it shows what reality is.
A deep space image shows numerous distant galaxies and stars against a dark background, including several bright spots shaped by a gravitational lens cross, with diffuse light sources scattered throughout.
Gravitational lenses arise when foreground masses and background light sources properly align. Einstein rings are rare, but crosses abound.
black hole
It's not about particle-antiparticle pairs falling into or escaping from a black hole. A deeper explanation alters our view of reality.
Diagram showing light from a distant galaxy bending around a red-hued massive object, reaching telescopes on Earth via different paths and at different times.
The VENUS survey isn't about planets at all, but about finding multiply-lensed supernovae. The ambition? To save the expanding Universe.
Five panels show NASA Chandra images of Kepler's supernova remnant as it expands over 25 years, with increasingly diffuse blue filaments against a starry background; a composite is shown in the last panel.
Back in 1604, Johannes Kepler discovered the Milky Way's last naked-eye supernova. Here's how NASA's Chandra sees it over the 21st century.
A colorful map shows the distribution of nearby galaxies, with distances and redshift factors labeled, created by DESI; NSF, NOIRLab, and Kitt Peak logos are visible.
The seeds of cosmic structure that were planted back during the Big Bang grew into the cosmic web we see today. What is it telling us?
laniakea
When objects are gravitationally bound, they cannot escape from one another's influence. How does that work within the expanding Universe?
zeno's paradox
Travel half the distance to your destination, and there's always another half to go. So how do you eventually arrive? That's Zeno's Paradox.
Even the youngest galaxies are often dust-rich, even with very low levels of heavy elements. Nearby dwarf galaxy Sextans A explains why.
A galaxy cluster with a faint purple glow, showing a dotted yellow circle in the center, surrounded by distant stars and galaxies.
Astronomers have found starless gas clouds before, but Cloud 9 might be the most pristine one of all, with big lessons for cosmic history.
cosmic rays
Particles are everywhere, including particles from space that stream through the human body. Here's how they prove Einstein's relativity.
quantum communications
Perhaps the most remarkable fact about the Universe is simply that it, and everything in it, exists. But what's the reason why?
An artist's impression of an ultra high energy cosmic ray.
The highest-energy particles could be a sign of new, unexpected physics. But the simplest, most mundane explanation is particularly iron-ic.
JADES galaxies
While humanity has been skywatching since ancient times, much of our cosmic understanding has come about only recently. Very recently.
A nebula in space glows with bright purple, pink, and blue hues, surrounded by stars and cosmic dust where new stars form in our expanding universe.
Our Universe doesn't just expand and cool, but the expansion itself is accelerating. Can stars form under such structure-erasing conditions?
Diagram illustrating Earth's orbit around the Sun, showing the tilt of Earth's axis, the seasons, equinoxes, solstices, and directions to celestial poles.
Earth orbits the Sun while spinning on its tilted axis, with two annual occasions marking that maximal tilt. That's where solstices arise.