Help understanding relativity?

Inside the spaceship time seems to pass normally. You don’t observe any slowing and you age normally. It’s only observers in other frames of reference who see the time dilation (slowing).

When you turn on a light, those photons still travel at speed c as usual & that’s what you measure with your ship-bound equipment. All observers everywhere agree that light travels at exactly c – which is the basis for all the other weird effects.

There’s a “Straight Dope” column devoted to this topic: If you turn on your headlights while driving at the speed of light, what happens?

I know nothing about relativity, but I remember the quote: “Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. THAT’S relativity.” I know it’s not much help but I just couldn’t resist throwing it in there. ;)

@gasman
So to you it would feel like going faster than the speed of light? I know they would think time is normal but they would feel like they’ve gone faster than light

Let me answer your last question. Light does not travel in anything the way that sound travels in air. Its speed is totally unrelated to the speed that you are traveling. There had been a conjecture that space is filled with ether, though which light travels, but the Michelson-Morley experiment proved that was not the case. About half way down the page, there is a pointer to an animation that does a good job of giving the idea behind the way the experiment was set up.

You’re traveling at 99% light speed relative to your home planet. Everybody is equipped with powerful telescopes. The folks at home see your time passing very slowly while theirs seems normal as usual. Meanwhile, your time and distances measurements seem normal inside your spaceship but you observe that time back home is passing very slowly and distances (along the direction of travel) are compressed. Nobody sees anyone’s time seeming to go faster than normal.

In other words, with observers moving relative to one another, each sees the other’s time slowed down and distances compressed. Nobody ever feels that time or distances are distorted within their own frame of reference. Weird but true.