Surprisingly, not for a paper, just some general....curiousity.
I've been reading a lot on physics lately. Brian Greene's two books, some stuff by Michio Kaku, Richard Feynman and the latest by Bodanis (I think that's who wrote it..) about E=mc^2, not to mention dozens of sites on the internet, including this one, mind you.
I understand bits and pieces, but I still have a few questions and I thought the gurus here might have the answers.
Okay...first. I understand that c is squared, what I don't understand is why. Bodanis remarks that s'Gravesande found that when he dropped his metal spheres into soft clay he noticed that if he propelled the second ball twice as fast it fell into the clay four times as far, three times as fast, it fell nine times as far into the clay. Kaku termed it "force multiplier" and further explained that in similar instances it worked the same. He wrote that a car increasing speed from 20 mph to 80 mph had increased in speed some four times and logically, the car moving at 80 mph should have four times as much 'energy' as the car moving at 20 mph, but in reality, the car moving at 80 mph has sixteen times as much 'energy' as the car moving at 20 mph.
Every book, I've read (unless I managed to miss it somewhere or misunderstand
) fails to explain "why." They just say it is or that's the nature of energy. So...why? Is just taken for granted that the force multiplier effect is there or is there a reason why?
One more...
Kaku and Greene explain that if I could watch a car travelling at about the speed of light (since you can't really travel at the speed of light, which, again, I sort of understand
) the car would look compressed toward the direction of motion. That the height of the car (or whatever) would stay the same, but lengthwise it would compress like an accordion. As I understand it, inside the car everything would be 'normal,' it's only from the outside looking in that it gets crunched. As the car slowed down and eventually stopped, everything would be back to 'normal' from everyone's point of view. Kaku asks who was really compressed, you? or the car? He further states that "According to relativity, you cannot tell, since the concept of length has no absolute meaning."
So, the question is...why compressed? I get that nobody really knows why it happens, but do they know why 'compressed?' I mean, if length has no absolute meaning, why can't the car look elongated? Why doesn't it stretch?
That's all for now, but I've got some questions on general relativity as well if anyone's interested.