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Cosmology
If you want to understand what the Universe is, how it began, evolved, and will eventually end, astrophysics is the only way to go.
We frequently say it's 2.725 K: from the light left over all the way from the Big Bang. But that's not all that's in the Universe.
There are two fundamentally different ways of measuring the Universe's expansion. They disagree. "Early dark energy" might save us.
In movies and TV shows, aliens look like pointy-eared humans. Is this realistic? If evolution is predictable, then it very well might be.
From before the Big Bang to the present day, the Universe goes through many eras. Dark energy heralds the final one.
Known as primordial black holes, they could thoroughly change our Universe's history. But the evidence is strongly against them.
A wild, compelling idea without a direct, practical test, the Multiverse is highly controversial. But its supporting pillars sure are stable.
With launch, deployment, calibration, and science operations about to commence, here are 10 facts that are absolutely true.
The boiling new world, which zips around its star at ultraclose range, is among the lightest exoplanets found to date.
Astrophysicists once believed in a static Universe, containing only the Milky Way galaxy. Science definitively proved otherwise.
After more than two decades of precision measurements, we've now reached the "gold standard" for how the pieces don't fit.
A few years ago, the first dark matter-free galaxies were announced, and then immediately disputed. Now, there are too many to ignore.
Our Solar System's outer reaches, and what's in them, was predicted long before the first Oort Cloud object was ever discovered.
No matter how hard we try, we will never reach a final theory that unifies scientific knowledge. The very nature of science doesn't allow it.
Previously, only the brightest and most active galaxies could pierce the obscuring wall of cosmic dust. At last, normal galaxies break through.
From hellishly hot planets to water worlds, some distant planets are like nothing in our Solar System.
The majority of the matter in our Universe isn't made of any of the particles in the Standard Model. Could the axion save the day?
There's a big difference between the notions of 'false vacuum' and 'true vacuum' states. Here's why we don't want to live in the former.
But the upcoming James Webb Space Telescope compels us to add, “so far.” Beginning with its 1990 launch, NASA’s Hubble Space Telescope revolutionized our conception of the Universe. This photo of […]
The highest-energy particles of all come from space, not human-made colliders. When it comes to the most energetic particle collisions of all, you might think that the Large Hadron Collider […]
Why are the rest masses of fundamental particles related like this? When it comes to the nature of matter in the Universe, the Standard Model describes the known elementary particles perfectly […]
More energy means more potential for discovery, but we’re topped out. If your goal is to discover something completely novel, you have to look in a way that no one else […]
Whatever’s lurking out there, it isn’t all, or even mostly, normal matter. When it comes to the Universe, it’s only natural to wonder what, exactly, it is that makes everything up. […]
“Hubble’s Law” is only an approximation, and breaks down when we need it most. From anywhere in the Universe, you can choose to look out at any other galaxy that’s present. […]
It happened more than once, and needed to. Here’s why. If there’s one thing you can be certain about when it comes to outer space, it’s that it’s transparent, not opaque, […]
If it wasn’t a singularity, how small could it have been? Today, when you look out in any direction as far as the laws of physics allow us to see, the […]
Both made monumental contributions that were far ahead of their time. It’s hard to believe, but the idea that the Universe was dominated not by normal matter but rather by dark […]
When you mix science with speculation, you get speculation. But the underlying science is still real. Whenever you hear the phrase, “it’s just a theory,” it should trigger alarm bells in […]
It could evolve, strengthen, decay, or not be alone. Our known Universe contains matter, radiation, and dark energy. While matter (both normal and dark) and radiation become less dense as […]
Going to smaller and smaller distance scales reveals more fundamental views of nature, which means if we can understand and describe the smallest scales, we can build our way to […]