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General Relativity
We've now detected hundreds of gravitational waves with LIGO, Virgo, and KAGRA. What if we tried Weber's original method in the modern day?
16mins
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“The messy reality of it is that all of these very smart people, including Isaac Newton, were talking to other people.”
Nearly 100 years after being theorized, the strange behavior of the neutrino still mystifies us. They could be even stranger than we know.
We've long known we can't go back to infinite temperatures and densities. But the hottest part of the hot Big Bang remains a cosmic mystery.
Observations with the Hubble space telescope helped cement dark energy and reveal the Hubble tension. How are these two things so different?
Inflation's two main criticisms, that it can predict anything and that the "measure problem" remains unsolved, can't erase its successes.
23mins
"Could black holes be the key to a quantum theory of gravity, a deeper theory of how reality, of how space and time works? Well, I think so."
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?
The hot Big Bang is often touted as the beginning of the Universe. But there's one piece of evidence we can't ignore that shows otherwise.
As we gain new knowledge, our scientific picture of how the Universe works must evolve. This is a feature of the Big Bang, not a bug.
Since even before Einstein, physicists have sought a theory of everything to explain the Universe. Can positive geometry lead us there?
Just 13.8 billion years after the hot Big Bang, we can see 46.1 billion light-years away in all directions. Doesn't that violate...something?
Two supermassive black holes on an inevitable death spiral push the limits of Einstein's relativity. New observations reveal even more.
The Big Bang was hot, dense, uniform, and filled with matter and energy. Before that? There was nothing. Here's how that's possible.
Realizing that matter and energy are quantized is important, but quantum particles aren't the full story; quantum fields are needed, too.
Once you cross a black hole's event horizon, there's no going back. But inside, could creating a singularity give birth to a new Universe?
From high school through the professional ranks, physicists still take incredible lessons away from Newton's second law.
A few physical quantities, in all laboratory experiments, are always conserved: including energy. But for the entire Universe? Not so much.
If you want to understand the Universe, cosmologically, you just can't do it without the Friedmann equation. With it, the cosmos is yours.