Why is there a speed of light? Why is there a speed of sound? These have never made sense to me. From what I can find (and remember from Physics class), light travels at 186,000 miles per second and sound at 761.2 miles per hour. The speed of sound is more variable than the speed of light. 761.2 mph is when the air is 59 degrees. Presumably it gets a bit faster or slower as the air temperature changes, but that doesn’t change my fundamental question. Why do they have a specific speed?
Speed is the rate at which something’s position changes. With normal things, like a baseball, the speed depends on a number of things. If I throw the ball at 98 mph (because I can totally throw a 98-mph heater), the ball’s speed is 98. But if I stand on a train moving at 100-mph and then throw my 98-mph fastball, the ball will be traveling at 198-mph. It’s additive. Except it’s not for light and sound.
If I stand on that 100-mph train and turn on a flashlight, the light still travels at 186,000 miles per second. Doesn’t it seem like it should travel at 186,000 mile per second plus 100-mph? It does to me. Why not add the speeds together? With sound, if I stand on the 100-mph train and shout, the shout doesn’t travel at 861.2-mph. It’s stuck at 761.2 (assuming it’s 59 degrees out). It’s weird.
Plus, shouldn’t the initial speed change depending on how much force is put into it? Why does a shout travel at the same speed as a whisper? Why do those blinding construction lights move the light at the same speed as a Christmas light? I wish I could understand it.
