1905 was a wild year for physics, Einstein’s “Golden Year”, the year he published his Nobel Prize winning paper on the Photoelectric Effect, and ofc, on his Theory of Special Relativity.
What’s it about though? Really, it comes from the idea of Inertial Frames of Reference and the core principle behind all of physics: the idea that physics is supposed to work the same absolutely everywhere.
It’d be weird if one corner of the room was, for some reason, hotter than the Sun, wouldn’t it? Or if I threw a baseball, it’d be kind of fucked if it started accelerating exponentially upwards into space, dontcha think? I think so, hopefully you don’t think it’s weird that physicists make this assumption (considering you probably do the same yo).
So, back in whenever-the-hell year it was, Maxwell churned out a mathematical representation of Electric and Magnetic Fields with his theory of Electromagnetism, famously combining the two concepts cleverly into one word (and one field, called the Electromagnetic Field). I guess Einstein must’ve admired him or whatever (not saying he din’t know how to pick his idols), because he really wanted to do the same thing with space and time, creating the concept of Space-Time! (wooaah wtf is that, idk!).
This unification of Maxwell’s was pretty revolutionary, but it had a strange conclusion: the speed of light is always constant. Or rather, it’s just always the same speed.
Now by intuition, most people would agree that velocities are additive – as in, “‘I’m walking 5 mph forward on a 50 mph train, how fast am I going?’, ‘Idk kek, 55?;)'” – I’d hope you got that at least.
But if you were to shine light in front of the train, wouldn’t it be going slower relative to you? Like, shouldn’t you be able to go fast enough that it looks like it’s barely getting ahead of you? Einstein supposedly did LSD a lot as a kid or something, and thought about riding a light beam, so when he got to University he went looking for an answer. And what’d he find?
According to Maxwell, “Naw dawg. It’d travel at c for you, c for him, c for her, c for EVERYBODY!”
People thought this was fucky, and rightfully so. But Maxwell literally said IDGAF and Einstein went along with it, put pen to paper, and reached his final conclusions and explanations of how the Universe is actually just real fucky.
The main results:
- Spontaneity is relative (‘You scream, I scream, we all scream, or we would but we’re still waiting on Bobby.’ – “I was on time tho!”)
- Time is relative (just remember the plot of Interstellar, that’s how I do it)
- Lengths contract in the direction of motion
- Matter has an intrinsic energy associated (what is it? E=mc…squared?)
- Newton wasn’t totally right, but still, give the guy credit. He invented Calculus.
All of the discussion and derivation of the various ideas behind Special Relativity are surprisingly easy, I find. Seriously, go watch Interstellar if you’re still confused, and come back with an appreciation of Mathew McConaunnhy (htf do you spell it? McConaughey. Google, thank you! I bet even he gets it wrong sometimes…) and his impenetrable acting ability (it’s like he’s only ever played one role: “Mathew McConaughey is Mathew McConaughey playing ___________” you fill in the blank from IMDB)