Field of knowledge
Physics
The fundamental forces governing reality
Videos
Level 1
Foundation
Coming soon
Level 2
Basics
Coming soon
Level 3
Advanced
Coming soon
Level 4
Masters
Coming soon
Empty Space Might Not Be Empty, Or Smooth
Two of physics' most trusted theories — the one that explains gravity and the one that explains atoms — flatly contradict each other once you zoom in far enough, leaving no real answer for what's happening inside a black hole. One proposed fix says space itself isn't smooth at all. It's made of tiny woven threads, with a smallest possible size that nothing can go below.
There Is No Such Thing as "Right Now"
Every GPS satellite in orbit carries a clock that engineers deliberately mistune before launch — because left alone, it would drift from Earth time by 38 microseconds a day. Behind that fix is one of the strangest proven facts in physics: there's no single "now" shared by everyone in the universe, only clocks running at different speeds depending on how fast you're moving and how close you are to a strong gravity source.