Astrophysics

Astrophysics

Parker Solar Probe
It would get rid of our hazardous, radioactive, and pollutive waste for good, but physics tells us it's a losing strategy for elimination.
A dense cluster of young stars and bright blue-white spots set against a dark reddish-brown background, with scattered sparkles of light from numerous stars in the outer Milky Way, captured stunningly by JWST.
Almost all of the stars, planets, and interesting physics happens in the inner portions of galaxies. Is that conventional wisdom all wrong?
View of Earth from a spacecraft window with "T-MINUS" displayed in bold text overlaying the image.
These startups, space agencies, and aerospace giants are building humanity's next off-world homes.
Rows of identical Earth-like planets stretch out into the vast copy multiverse, with a dark starry background visible between them.
Within our observable Universe, there's only one Earth and one "you." But in a vast multiverse, so much more becomes possible.
atom illustration
Most fundamental constants could be a little larger or smaller, and our Universe would still be similar. But not the mass of the electron.
Image of Mimas, one of Saturn's moons, partially illuminated. The large Herschel crater is prominently visible on the right side of the moon's surface.
The existence of another watery world in the outer solar system may offer clues to how such seas form — and hope for another spot to search for life.
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.
In the expanding Universe, different ways of measuring its rate give incompatible answers. Nobel Laureate Adam Riess explains what it means.
The image shows a bright spot labeled "JADES-GS-z13-1-LA," seemingly an impossible light captured by the JWST, surrounded by measurement markers, including a scale bar for 1 kpc and 0.28 arcsec. Filters and colors are listed at the bottom.
The Lyman-α emission line has never been seen earlier than 550 million years after the Big Bang. So why does JADES-GS-z13-1-LA have one?
A detailed image of two galaxies in space, one with spiral arms on the left and the other, more elliptical, on the right, surrounded by distant stars.
Galactic activity doesn't just arrive when supermassive black holes feast on matter. Before, during, and after all create fascinating signs.
uap ufo UAPs UFOs
Although a great many unidentified sights have been seen in the skies, none have conclusively demonstrated the presence of aliens. So far.
A detailed image of the moon with visible craters and surface textures, set against a dark sky filled with numerous stars.
Finding life beyond our Solar System requires understanding its host planet.
A graph depicting projectile motion with displacement on the vertical axis and time on the horizontal axis. The projectile's trajectory forms a perfect parabola, with initial velocity u and angle θ clearly indicated.
Taught in every introductory physics class for centuries, the parabola is only an imperfect approximation for the true path of a projectile.
A person is giving a presentation at a podium with a large abstract, colorful light pattern displayed on a screen behind them.
Inflation, dark matter, and string theory are all proposed extensions to the prior consensus picture. But what does the evidence say?
A satellite orbits Earth against a backdrop of space. Below, the Earth's curvature and cloud formations are visible, making our planet seem even bigger.
The observation that everything we know is made out of matter and not antimatter is one of nature's greatest puzzles. Will we ever solve it?
zero gravity flight stephen hawking
The mass that gravitates and the mass that resists motion are, somehow, the same mass. But even Einstein didn't know why this is so.
JWST deep field vs hubble
The "little red dots" were touted as being too massive, too early, for cosmology to explain. With new knowledge, everything adds up.
Comparison of weight on Earth and Mars for a 1 kg mass. On Earth: gravity = 9.81 m/s², weight = 9.81 N. On Mars: gravity = 3.72 m/s², weight = 3.72 N; demonstrating that weight and mass are not the same across different planets due to varying gravitational forces.
Here on Earth, we commonly use terms like weight (in pounds) and mass (in kilograms) as though they're interchangeable. They're not.
A black and white image of a curled fern leaf is centered on a black background with faint, star-like specks, capturing an ethereal beauty reminiscent of Sara Walker's scientific explorations.
In "Life As No One Knows It," Sara Imari Walker explains why the key distinction between life and other kinds of "things" is how life uses information.
So far, Earth is the only planet that we're certain possesses active life processes. Here's what we shouldn't assume about life elsewhere.
cosmic inflation
The Universe isn't just expansion, but the expansion itself is accelerating. So why can't we feel it in any measurable way?
A colorful, abstract scientific illustration with a central glowing sphere, circular patterns, and various lines and circles suggesting quantum connections or uncertainty data points, on a dark background with blue accents.
No matter how good our measurement devices get, certain quantum properties always possess an inherent uncertainty. Can we figure out why?
A circular illustration depicting the observable universe with various galaxies, stars, and cosmic structures emanating from a central point, symbolizing the solar system and hinting at how far away the Big Bang occurred.
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?
every square degree
The Universe is 13.8 billion years old, going back to the hot Big Bang. But was that truly the beginning, and is that truly its age?
cosmic inflation
Many contrarians dispute that cosmic inflation occurred. The evidence says otherwise.
pulse light quantum tunnel barrier
In all the Universe, only a few particles are eternally stable. The photon, the quantum of light, has an infinite lifetime. Or does it?
Raisin bread expanding Universe
The big question isn't whether the Universe is expanding at 67 or 73 km/s/Mpc. It's why different methods yield such different answers.
A painting of a group of people standing in front of a church.
The original principle of relativity, proposed by Galileo way back in the early 1600s, remains true in its unchanged form even today.
A vast expanse of outer space densely populated with numerous stars, including the typical star, and celestial objects of varying brightness against a dark background.
Most stars in the Universe are located in big, massive, Milky Way-like galaxies. But most galaxies aren't like ours at all.
Two astronauts in orange spacesuits and helmets prepare for a mission. A digital countdown displays "T-MINUS," with an Artemis mission patch visible on one spacesuit.
These missions will put us one step closer to the ultimate goal: crewed trips to Mars.