The old model of the universe came from Euclid and Newton: a 3D grid with time moving forward at an unflinchingly steady speed. As simple as a stack of graph paper under your alarm clock. This old model worked well for a very long time. Even when Fizeau discovered the uniformity of the speed of light, no one noticed a thing- until Einstein.
Einstein did some thought experiments that showed how Fizeau’s discovery was impossible within the old model of the universe. When moving near the speed of light, the stack of graph paper starts to bend, and the alarm clock changes speeds.
Imagine i am driving at near the speed of light past the earth. At the exact moment i pass you on earth, we both turn on giant flashlights pointed in the direction i am driving. What would you see? Well, remember light moves the same speed in all reference frames, so you would see the two beams of light moving away from us both equally. But what happens once i’ve moved forward a distance? You still see two beams extending out equally, but somehow my beam would seem shorter than yours since the starting point of my beam moves forward as i move forward. The same end points but your start point precedes mine. got it?
Remember the simple equation: distance= time X speed. Speed of light is fixed, and the time of the experiment is whatever we make it to be, so thats fixed as well. Somethings got to give, the only variable remaining is distance. You and i have both turned our beams on for the same amount of time, and our beams are traveling at the same speed; distance itselt must be able to fluctuate.
Hey, distance is space. You measure 9 feet with a tape measure, you’re measuring 9 feet of space right? What Einstein showed was how those measurements were wrong according to anyone moving in relation to yourself. Space itself can be scrunched up or stretched out.
Its a theory of course, but there needs to be a theory. The problem of light exists whether you like it or not. Somethings got to give, since space seems to be the only thing left in the equation, space must be the variable thats got some give. or so the theory goes. . .
Ok, uh, i thought i could do ‘time’ in this one as well but my head hurts. next one i guess.