I know it sounds odd but if a car at night with it's lights on is passing me by @ 25 mph isn't the light from the headlights traveling @ light-speed plus 25 mph?
That's a great question. it's those types of questions which lead Einstein to realize the general theory of relativity. You see no matter from what perspective the speed of light is measured, now focus on this, it is always measured as the same. Remember that speed is a measure of the distance traveled in a certain amount of time, or Distance/Time. So one person in a stationary car will measure the speed of light to be 299,792,458, but someone in a car moving at a rate of 100 meters/sec would measure the speed of light as the SAME. HOW IS THIS? This was completly bafeling to scientists, they didnt know how to explain this. Well since we would normally expect the person in the moving car to register the speed of light as either +100 m/s or -100 m/s depending on which way the car is going, either towards the light or away. But since we measure the speed of light as the same or basically that the viewers disagree on how far the light has traveled. Since they disagree on how far the light has traveled or distance, then the only way to balance the equation is that they disagree on the time that it took. So its like this time 1.........................TIME 2 --------- ...........=.......------------- distance 1................DISTANCE 2 (notice I put the first in all lowercase to give the idea that both are smaller, and the second in all caps because both are bigger the time and the distance) or like this 2/2 = 23/23 So that's basically how Einstein came up with the general theory of relativity and causes what we know as time dilation I hope that kinda helps you visualize
You've got a lot to learn about relativity.
