Up Next
Back to Show
PBS Space Time
Why is the Earth Round and the Milky Way Flat?
Season 2
Episode 20
Our universe is not a very diverse place when it comes to shapes. Large celestial bodies become spheres, galaxies become discs, and there is little room for variation. Why is this? Well it turns out physics has some pretty strict rules when it comes to creating new planetary bodies.
Support Provided By
16:28
Could sending a quantum twin across the galaxy make you both old and young at the same time?
17:39
It's possible that an event horizon is forming right behind and you won't know until its too late.
20:48
Are there no alien signals to find... or do we need to update how we search for them?
14:27
Physicists hope Planck stars can save us from black hole singularities and paradoxes.
17:41
Galaxies older than the universe? Webb's findings keep defying our best explanations.
16:16
Earth's core: solid or liquid? Yes — we know more about distant galaxies than our own interior.
14:42
Gödel found a time-travel solution in General Relativity, revealing spacetime can loop on itself.
18:46
Tardigrades can survive almost anything—even most of Mars. But one Martian chemical stops even them.
18:18
The Higgs boson may open a portal to hidden particles that could explain dark matter.
19:02
The universe expands faster. “Dark energy” may not be constant after all.
16:26
There’s a new generation of experiments that may unlock the gravity particle.
18:33
The universe thrums with quantum fields, except something may be missing: the sterile neutrino.