- #1
polystethylene
- 17
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Hello all, new to the forum, so I hope this question isn't out of place or I'm contravening some rules, apologies if i am.
Anyway, I got linked to this...
http://www.webspawner.com/users/relativity/
Now, I had a SR course in the 1st year of uni, and I'm revising for a cosmology exam this year, (my third), so I'm comfortable with SR and its workings.
Problem is, I can't find the reasoning to debunk this rubbish, I know the solution is probably simple =/ The best I can think of is this:
In 1-D: one observer traveling at 0.6c towards a beam of light, observed from our 'rest' frame. Gallilean relativity says in the frame of the observer @ 0.6c, the light beam should be observed to be 1.6c, but is actually c as we all know. Therefore, the apparent length contraction and time dilation as seen by us at rest act to 'reduce' this to c. This is what is described in the link above. I suspect it could be this reasoning that causes the issue?
Anyway, if the observer @ 0.6c is moving away from the beam, galillean rel. says observed speed by moving guy is (1-0.6)c = 0.4c. The argument in the link says 'how can time dilation and length contraction act to increase this to c?
Well I'm thinking, taken from the rest frame of the observer @ 0.6c, we appear to move at 0.6c towards the light beam, i.e. the situation that allows length contraction and time dilation to correct for c.
I feel like in engaging in thinking about this (and it's seriously been bugging me), I've overlooked something fundamental that makes even the very proposal of this problem ridiculous. I just can't spot it.
Sorry that was a long and rambling first post, but I'd love to put my mind to rest on this one.
Thanks
Anyway, I got linked to this...
http://www.webspawner.com/users/relativity/
Now, I had a SR course in the 1st year of uni, and I'm revising for a cosmology exam this year, (my third), so I'm comfortable with SR and its workings.
Problem is, I can't find the reasoning to debunk this rubbish, I know the solution is probably simple =/ The best I can think of is this:
In 1-D: one observer traveling at 0.6c towards a beam of light, observed from our 'rest' frame. Gallilean relativity says in the frame of the observer @ 0.6c, the light beam should be observed to be 1.6c, but is actually c as we all know. Therefore, the apparent length contraction and time dilation as seen by us at rest act to 'reduce' this to c. This is what is described in the link above. I suspect it could be this reasoning that causes the issue?
Anyway, if the observer @ 0.6c is moving away from the beam, galillean rel. says observed speed by moving guy is (1-0.6)c = 0.4c. The argument in the link says 'how can time dilation and length contraction act to increase this to c?
Well I'm thinking, taken from the rest frame of the observer @ 0.6c, we appear to move at 0.6c towards the light beam, i.e. the situation that allows length contraction and time dilation to correct for c.
I feel like in engaging in thinking about this (and it's seriously been bugging me), I've overlooked something fundamental that makes even the very proposal of this problem ridiculous. I just can't spot it.
Sorry that was a long and rambling first post, but I'd love to put my mind to rest on this one.
Thanks
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