The great double nickle speed limit in the sky, the speed of light. Sure, I can buy the concept that using a ground fixed accelerator and magnetic fields, that it takes up more energy to accelerate particles as they approach light speed. But I can't buy it that this has any bearing on the speed limit of my starship Enterprise (fuel capacity might limit speed, but nothing to do with light).
For one thing, if there is some speed limit in the sky, then define for me some place that is not moving that can then be used to define when you hit the speed limit. The surface of the earth is moving. The planet is moving. Everything is moving. So there is no definable state of non-movement. Therefore, no definable speed limit.
Another problem. If nothing can travel faster than light. What about the case of an observer who observes a vehicle traveling toward his left ear at say .9 light speed. And a second vehicle traveling toward his right ear at .9 light. Then aren't the two vehicles traveling at something greater than light speed relative to each other? Einstien groopies say that there is some wierd math that proves that I might observe this condition, but that the two vehicles would observe each other traveling at less than light.
Ok.
And I've got a bridge to sell you.
I think I can explain it to you in a way you will not only understand, but accept. Give me a little time.
What you are not appreciating is that the speed of light is a limitation on relative velocity. There is no such thing as absolute velocity. The speed of light is not some magical brick wall that you smack up against as you go faster and faster.
Relative to yourself, you are always going at a velocity of zero. When we Earthlings say that you are travelling close to the speed of light, we mean that you are travelling close to the speed of light relative to us. If you don't look out the window of your spaceship, you will have no way of knowing how fast you are going. Or rather, you know exactly how fast you are going: you are standing still, and it is the Earth that is moving.
So what does happen, then? You have to understand that time is a dimension. The key feature of the dimensions of space is that there is a transformation--rotation--that transforms one axis of the coordinate system into another. Let's say I have a ruler lying along the x-axis. It has a certain size in the x direction, say 1 meter, and very small size in the y-direction. If I pick a different point of view, by rotating my coordinate system slightly, the x length becomes shorter by a factor equal to the cosine of the angle of rotation, and the y length becomes longer by 1 meter times the sine of the angle. In other words, some of the x size has transformed into y size. Simple.
In the case of time, there is a different transformation that does this: the Lorentz transformation. Instead of turning by a certain angle, different points of view are generated by changing relative velocity. The greater the relative velocity, the shorter the moving object appears, just as our rotated ruler became shorter in the x-direction (this is called Lorentz contraction). At the same time, the time between events--such as the ticks of a clock--becomes longer, just as our ruler became longer in the y-direction (this is called time dilation).
So how does this affect the addition of velocities? Let's suppose you really get cooking in your ship, so that you're only 10 meters per second shy of the speed of light, as viewed from Earth. On board you have a high-powered rifle, which you will fire in your direction of travel. What do you see, and what do we see from Earth?
You see the bullet fly forward at 1000 meters per second, as if your ship were standing still. As far as you're concerned, your ship is standing still. We see something different. Time is moving more slowly on your ship...by a factor of more than 22 million! If we wait long enough, we might see the bullet creep forward by a tiny fraction of an inch with respect to your ship. It may be going ever so slightly faster than your ship, but it certainly isn't going faster than light with respect to us.
Another problem. If nothing can travel faster than light. What about the case of an observer who observes a vehicle traveling toward his left ear at say .9 light speed. And a second vehicle traveling toward his right ear at .9 light. Then aren't the two vehicles traveling at something greater than light speed relative to each other? Einstien groopies say that there is some wierd math that proves that I might observe this condition, but that the two vehicles would observe each other traveling at less than light.
That's exactly right, except that the math isn't weird. In fact, it's accessible to anyone who's had middle school algebra. Each vehicle sees the other closing at a velocity of v1+v2/(1+v1v2/c²)=0.9945 c.
Ok. And I've got a bridge to sell you.
You're hardly in a position to reject it out of hand when you've refused to look into the math (which really is simple). But that's beside the point: all of these claims are experimentally testable. And believe me, they have been tested more thoroughly than you would ever imagine. Nobody has taken Einstein's word for it: clocks really do slow down and lengths really do shrink, to exactly the extent predicted by Einstein.
Look up the Michelson-Morley experiment.... Basically Michelson, a Russian immigrant, Annapolis graduate and naval officer was recognized as the best experimental optical physicist in the world at the time. He invented the Michelson interferometer to measure any change in the speed of light from the Sun in the morning when the Earth's rotation was towards the Sun and in the evening, when the Earth was rotating away from the Sun. Given the sensitivity of his apparatus this should have been a piece of cake. (The experiment is not unprecedented, Bradley in 1727 had observed that the apparent position of a star varies with the direction of the Earth around the Sun, much as the apparent direction of rain is changed when we drive through the rain in a car.)
He was surprised to discover that there was absolutely no difference. No theory could adequately account for this result until Einstein's theory of relativity. Einstein held that the speed of light - derived from Maxwell's Equations and predictable from measurements of the magnetic and electical properties of space that apparently had nothing to do with the speed of light - were fundamental physical quantities and the same in any non-accelerated reference frame.
One prediction of the theory of relativity is that if you were stationary with respect to another observer and he and you each established a laboratory and measured the speed of light you would agree. If he and his laboratory was later moving at, say, half the speed of light with respect to you and you shone a laser beam in his direction, both of you would measure the same speed for the mutally observed laser light as you did before, even though you both would agree that each of you was moving with respect to the other.
I know it sounds counter-intuitive, but it turns out that's the still the best explanation of things that are observed every day. You either have to take it on faith or learn more physics.