Harry Tuttle Wrote:
-------------------------------------------------------
> I've never understood the whole "time would slow
> down if you travel faster than the speed of light"
> thing...
>
> How did they come up with that? It doesn't really
> make sense to me... Does it have something to do
> with time being relative?
>
> Anyone have enough of a grasp on that concept to
> explain it?
What are the implications for the nature of reality if the speed of light is constant?
This question was the starting point for Einstein's theory.
And if you think about it, the implications are pretty weird. In short, because the speed of light is constant, we must change the way we understand the meaning of time.
For example, if you fire a bullet a bullet that goes 100 mph from a car going 50 mph, the speed of the bullet will be 100 + 50, or 150 mph. (That's Newtonian physics.)
But if you shine a flashlight while standing still, OR from a car traveling at 50 mph, the light will travel at the exact same speed. (Something Newtonian physics does not account for.)
(For purposes of clarity, both the bullet and light hypotheticals assume movement through a vacuum, i.e., no cross-winds to affect the bullet's speed, and no
change in medium that might affect the light speed).)
In a sense, the theory of relativity (which might more aptly be named the
theory of invariance) is reverse-engineered from this starting point, i.e., the constancy of the speed of light.
To get a handle on the idea of time slowing down, I would suggest:
Watch this video:
http://www.youtube.com/watch?v=tpbGuuGosAY&NR=1 [The narrator says that Einstein solved the mystery of "what gravity is." I don't think that's quite accurate; we know how gravity behaves, but not
what it is as such.]
Read Chapter 12 in this book (an "idiot's guide" book, but well-written; to grasp Einstein's discovery, it's very helpful to understand the existing science that he built upon):
http://books.google.com/books?id=875TTxildJ0C&pg=PA159&lpg=PA159&dq=%22If+the+speed+of+light+is+constant,+*%22&source=bl&ots=W9wxOs0Vje&sig=S2cDhif1o-w3qoq2rjkExM8m_sk&hl=en&ei=DppgTJTtI8GC8gb224m2DQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBEQ6AEwADgU#v=onepage&q=%22If%20the%20speed%20of%20light%20is%20constant%2C%20*%22&f=false
Watch this video (somewhat rambling, first 6 minutes are bs, and he gets to the point around the 16-minute mark):
http://www.youtube.com/watch?v=7Kdq_1bcAYs&feature=related (Note in particular the discussion of the "twin effect" at about 25:00 as to the question of whether time dilation is actual or not.)
With these principles in hand, you can use Google to fill in the blanks in your understanding.
And thus the ignorance of the ignorant will perish, and the intelligence of the intelligent will multiply.