How did Einstein come up with the idea that space itself wiggles like a wave?
Added 2025-04-30 11:55:05 +0000 UTCPhysicists don’t just pull this kind of stuff out of their ass. There’s basically a standard procedure: when you derive some complicated equations, you start analyzing them in simple limiting cases to figure out what they might predict.
Like when you're cooking and think:
“What if I swap the meat for fish, mayo for ketchup, and so on.”
So. On November 25th, 1915, at the Königlich Preußische Akademie der Wissenschaften, Einstein dropped his big one: the Einstein Field Equation (yep, that’s the real name, not that baby formula E = mc², which, by the way, is incomplete: you need momentum in there too). God, I was so fucking done trying to find the original paper, you’d cry if you knew the pain. And yeah, in modern notation, the equation looks a bit different.
The second pic explains it way better:
G_μν - Einstein tensor (describes spacetime curvature)
T_μν - stress-energy tensor (describes distribution of matter and energy)
G - gravitational constant
c - the speed of light
Now, Einstein already knew from electrodynamics (hi, Maxwell) that oscillating fields give you light. So he thought: why the hell wouldn’t gravity have waves too?
So yeah, it was actually a logical next step: check if those equations have wave-like solutions. And turns out- they do.
If you want, I can totally write out the derivation....
but fair warning: it’s gonna hurt.
I also attached the link with article I took the equation:
https://einsteinpapers.press.princeton.edu/vol6-trans/
Doc 25,
Page 118
And yes:
Turns out I lied…
The post was technically the day AFTER TOMORROW,
but i have the excuse: time flows differently between us...
