experiments point to the possibility that light speed is constant and relative. two beams travelling at the speed of light (c) toward each other still hit each other at c, rather than "2 * c". also ive been reading that photons do not experience time lapse or distance, their path is 0 distance 0 time lapse, it appears differently to us. read this amazing website, it really helped me understand some these hard to understand phenomena.

http://quantumweird.wordpress.com/quantum-weirdness-a-matter-of-relativity-part-5/

you might read them parts 1-5 in order, but part 5 blew my mind -i had very little background when i read this, have read 3-4 books about it, no college classes or anything.

This post was edited by juliusjuice on Dec 29 2008 10:13pm

Imagine that since light must bend around objects of great mass, it is stretched when we perceive it. Here is a visual illustration I made to help you see it better:




Edit: Yes I know I forget the "L" in "light years" in the picture, but it's too late now.
Edit: JuliusJuice, photons do not travel at a constant rate. The 'speed of light' refers to photons travelling theoretically unimpeded.

This post was edited by bex9 on Dec 30 2008 09:59am

Eternal tachyonic dark anti-matter is like googol^centillion light centuries away.

link or it didn't happen

@bex, it still means light has been travelling for 78.8 billion years. just because its been stretched, doesn't mean it has travelled for a less amount of time.
distance = rate* time
78 billion light years still has to equal c * 78 billion years
the only way around this, is if c is NOT constant but instead MUCH faster

Here's the best illustration:



red line=path of light
orange line=distance between two objects now

you need to explain this in greater detail because i still do not see how this bypasses the distance formula

Well you need to account for space expansion. The light should have traveled d=Vt only if you assume that it has started traveling now. However, if you assume the light started traveling say 10 bil years ago, the universe was smaller(assuming it is expanding now) and the distance between two objects was smaller, therefore light had smaller distance to travel than the current distance between those objects.
Say if the universe was not expanding, the initial distance between a star and Earth(for example) would be 1 bil lightyears, so light would have only 1bil lightyears to travel whether now or 10bil years ago. However, since space is expanding, even light emitted 10 bil years ago(when the distance was 1bil lightyears) would have to travel further to account for space expansion(like the object is being pulled away).

so basically inflation. space is expanding and thus objects (or light in this case) move with velocities that do not match their speeds. ie, their speed is not necessarily their velocity
but unless space was expanding at a rate very close to light speed, it would have gotten to us at a MUCH sooner time. not only that but phycists say inflation occured only moments after the big bang, and does not continue to do so today (or when the universe was millions of years old for that matter) and lastly i dont see what this has to do with gravitational bending

This post was edited by Kamikizzle on Jan 1 2009 07:26pm

That was probably my fault, when i started this thread i was thinking to myself how light could travel further than its speed allowed it to in a certain time period and then someone said it followed a curved path -- and then only way i knew space was bent was by big gravitational fields...so then i started thinking, but how could space be naturally bent if there was no mass in it (obviously when huge masses came into existance they were far behind light i assume, so therefore space 'had to be flat')...that was my assumption anyways, but now I see how it works...well i don't really, but its a more viable solution than 'space is bent by itself'

Yes, agree.