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General Relativity
To Fred Hoyle, the Big Bang was nothing more than a creationist myth. 75 years later, it's cemented as the beginning of our Universe.
When cosmic inflation came to an end, the hot Big Bang ensued as a result. If our cosmic vacuum state decays, could it all happen again?
So far, gravitational waves have revealed stellar mass black holes and neutron stars, plus a cosmic background. So much more is coming.
Although many of Einstein's papers revolutionized physics, there's one Einsteinian advance, generally, that towers over all the rest.
Without wormholes, warp drive, or some type of new matter, energy, or physics, everyone is limited by the speed of light. Or are they?
Want to avoid getting "spaghettified" by a black hole? Steer clear of the smaller ones.
Here's why the answer may forever elude scientists.
Physicists have yet to pinpoint the hypothetical matter that keeps galaxies from flying apart. Now they have a new focus.
Thanks to observations of gravitational waves, scientists were able to settle a longstanding debate over the speed of gravity.
For generations, physicists have been searching for a quantum theory of gravity. But what if gravity isn't actually quantum at all?
The brilliant mind who discovered the spacetime solution for rotating black holes claims singularities don't physically exist. Is he right?
Our intuitive understanding of time is very different from a physicist's understanding of time. How do we reconcile these views?
Roger Babson wanted a “partial insulator, reflector, or absorber of gravity” — something, anything, that would stop or dampen it.
All matter particles can act as waves, and massless light waves show particle-like behavior. Can gravitational waves also be particle-like?
If the Universe is expanding, and the expansion is accelerating, what does that tell us about the cause of the expanding Universe?
Everything we observe beyond our Local Group is speeding away from us, omnidirectionally. If the Universe is expanding, where is the center?
If you said "with the Big Bang," congratulations: that was our best answer as of ~1979. Here's what we've learned in all the time since.
Einstein's theory of general relativity introduced the concept of space having a shape. So, what is the shape of space?
There's a quantum limit to how precisely anything can be measured. By squeezing light, LIGO has now surpassed all previous limitations.
From the Big Bang to black holes, singularities are hard to avoid. The math definitely predicts them, but are they truly, physically real?
In the quest to measure how antimatter falls, the possibility that it fell "up" provided hope for warp drive. Here's how it all fell apart.
Sci-fi enthusiasts have long hoped that a substance called antimatter might experience gravity opposite that of ordinary matter. It doesn't.
A more distant galaxy liked the lens so much that it went and put a ring on it. Here's the science behind this remarkable cosmic object.
This measurement is crucial to confirm that one of the assumptions of Einstein’s theory of gravity is valid.
Dark matter hasn't been directly detected, but some form of invisible matter is clearly gravitating. Could the graviton hold the answer?
The matter that creates black holes won't be what comes out when they evaporate. Will the black hole information paradox ever be solved?
When it comes to predicting the energy of empty space, the two leading theories disagree by a factor of 100 googol quintillion.
Newton thought that gravitation would happen instantly, propagating at infinite speeds. Einstein showed otherwise; gravity isn't instant.
When the average person has a "theory," they're just guessing. But for a scientist, a theory is the pinnacle of what we can achieve.
The Universe isn't just expanding, the expansion is also accelerating. If that's true, how will the Milky Way and Andromeda eventually merge?