# Length Contraction Debunked

Discussion in 'Physics & Math' started by MacM, Jan 27, 2006.

1. ### DaleSpamTANSTAAFLRegistered Senior Member

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Do you really want to develop a theory that can only explain one scenario?

The idea should be to develop principles, not scenarios. Once you have a good set of principles you should be able to apply them to every scenario. If you cannot apply them to every scenario then you should be able to explicitly list the assumptions which, if violated, make the theory inapplicable.

-Dale

3. ### PersolI am the great and mighty Zo.Registered Senior Member

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Yeah, so your going to try to debunk length contraction by first assuming that length contraction is wrong.
Bravo.

5. ### MacMRegistered Senior Member

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That is not what this is about. It is about the fact that the existing thoery is flawed.

7. ### MacMRegistered Senior Member

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Since that assumption was not made your post is worthless as usual.

8. ### funkstarratsknufValued Senior Member

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This is wrong.

In the frame of the "moving" observer, the line can have arbitrary length d' and velocity v', such that d'/v'=t'=57.74 seconds (which is all that you stipulated). For instance, if d'=1000cm and v'=17.32c then t'=57.74s. Or if d'=10cm and v'=0.1732c then t'=57.74s. So both length contraction and length dilation is consistent with the line passing the observer in 57.74s on his clock. Hence d'=100cm does not follow from t'=57.74s.

This, of course, is really fucking obvious, because we have 1 linear equation (d'=v' * 57.74s) with 2 unknowns d' and v', which has infinitely many solutions. Or to use an analogy, if someone tells you that I can do a lap on a racetrack in 57.74s, that in itself does not (and cannot) tell you how long each lap is.

There isn't a unique solution to d'=v't' unless you know values for two of the variables. That's just the way it is. You cannot, not even in principle, prove length invariant from time dilation alone. It's impossible.

But you're welcome to try some other way, of course.

9. ### MacMRegistered Senior Member

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What a crock. It should be obvious to most that this situation has the in crowd cornered. Now they want to claim that the moving frame can be totally independant with velocity, distance and time. HeHeHe.

NO. There is one solution. distance remains fixed, accumulated time is 1/2 in the moving fame and veloicty is frame dependant.

10. ### superluminalI am MalcomRValued Senior Member

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Mac,

Are you arguing that an equation of N variables can be solved (i.e. evaluated to a unique solution) with < N variables in hand??? Or < N simultaneous equations???

Just curious.

11. ### PeteIt's not rocket surgeryRegistered Senior Member

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I call it physics, you call it horseshit. Interesting.

That would be Dale's scenario

It looks easy enough to me. The markers are moving at about 7/8 the speed of light, so in 8m/c the markers have moved 7m and the photon has moved 8m to reach the next marker.
According to your model, The moving-frame clocks tick fewer times than the rest frame clocks between any two given events. So if the rest frame clock ticked 8 times during the photon's journey between markers, then the moving frame clock ticks 4 times during the same journey.
Remember, this is based completely on *your* model, Mac.

Last edited: Jan 30, 2006
12. ### PeteIt's not rocket surgeryRegistered Senior Member

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So you claim that not only is there no basis to think that length contraction could happen, but that your argument solidly proves that it can't happen?

Consider this suggestion again:
If d in the moving frame were 1000 cm, then the clock would still accumulate 57 seconds if the velocity of the line were 17.32c.

Note that we're changing nothing in the rest frame, in wihch d=100cm, t=115s, and v=0.866c

Your rebuttal before was that you didn't see any reason for length to change in the moving frame. But so what? You claim to have proof that length can't change... so where is it?

Last edited: Jan 30, 2006
13. ### Billy TUse Sugar Cane Alcohol car FuelValued Senior Member

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I agree and I am still waiting for you to do so in the thread "Is time universal ... "

When you cease ducking and weaving or ignoring it, I will then read your new one. Tell why you think both the explosions on the train and in the ground frame are both simultaneous, if that is your view.

Please stop starting new threads to avoid the old one. That thought experiment is almopst a year old and you have yet to "address the one presented or admit you can't" as you put it.

14. ### DaleSpamTANSTAAFLRegistered Senior Member

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MacM, your transform has a variant c. Nobody (or at least not I) will claim that any of the relativistic results are necessary if c is variant. Your example here has nothing to do with finding inconsistencies in SR. At best all this could show is that for time to dilate and distance to not contract c must vary in a specific way.

-Dale

15. ### MacMRegistered Senior Member

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Be curious. My arguement was made clear.

16. ### PeteIt's not rocket surgeryRegistered Senior Member

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Clearly he is.

17. ### superluminalI am MalcomRValued Senior Member

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Ok then. As always, enjoying the MacM show!

18. ### MacMRegistered Senior Member

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You do seem to become foolish when cornered. You think you have proven anything by increasing the rest frame from 0.866c to 8.66c so that you can claim the moving frame is independant of the rest frame?

What a joke.

19. ### MacMRegistered Senior Member

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I gave yo a reply. Can you dispute it? I thought not. Based on a more logic solution the explosions are simultaneousl in all frames and what is not the same is the observation of when light arrived at the detectors. The reason I gave was that you are looking at different photon in different frames.

Now you can accept that or reject it . I really care less.

20. ### MacMRegistered Senior Member

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Like I said before. My view is based on solid physics. If that upsets your apple cart invariance so be it. You still cannot claim length contraction without ignoring the dilated tick rate of the moving clock used to measure distance via d = vt.

Taking the tick rate into consideration (the only rational and physics reality thing to do) then distance becomes invariant and it is computed velocity that varies with frame. PERIOD.

21. ### PeteIt's not rocket surgeryRegistered Senior Member

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Obvious typo. Now corrected.

In the rest frame:

d = 100cm
t = 115s
v = 0.866c

In the moving frame:
d=1000cm
t=57s
v=17.32c

Prove this is impossible.

22. ### DaleSpamTANSTAAFLRegistered Senior Member

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Sure I can. I have already derived it twice on this forum in the last week or two.

-Dale

23. ### MacMRegistered Senior Member

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Before Apollo they used to ask prove the moon isn't made of green cheese. You were more correct with 8.66c in the rest frame. At least you had kept the link and conversions right. Now you simply wnat to ask it be proven that there is any link between frames.
I suggest emperical data already does that.