/sci/ - Science & Math

>>11650833

OK, rewind a bit further to 10^-42 seconds of age. And pack all of the galaxies in the entire observable universe into a space 10^-20 of the width of a proton. That's the Planck length. And here, physics kind of goes out the window. See, at this point, general relativity comes into serious conflict with quantum mechanics. And we need a theory of quantum gravity, a so-called theory of everything, to go further. These theories don't play nice together. We leave it alone because we don't actually know whether the universe was really ever this small. Remember, we've been rewinding the universe using basic general relativity. Is that valid? Well, we don't yet have direct evidence from those very early stages. But there are some clues still visible at later times. And those clues tell us we've missed something huge.