# Is a length contraction just a visual thing?

Discussion in 'Pseudoscience' started by absolute-space, Feb 22, 2016.

1. ### absolute-spaceRegistered Member

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May I suggest you learn to read and stop making accusation that are not even there to begin with. What exactly do you think I am incorrect about? I have not inferred anything is incorrect. As for evidence, you have provided no physical evidence but only words which mean very little in respect of physical evidence.

3. ### absolute-spaceRegistered Member

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Likewise, why not just answer the question and provide any experimental evidence you have of an object contracting in physical length?

Provide the evidence and your justification of the physical contraction and then I will believe in a physical length contraction as well of the visual contraction.

I have suggested an experiment using sensors that would without doubt show any change in length relative to the stationary observer.

My belief of the ''fact'' is withheld until an experiment like the suggested is performed.

5. ### originHeading towards oblivionValued Senior Member

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But you did make an incorrect statement.
I included your quote stating that you think length contraction is just a visual thing. I stated that you are incorrect - was that not clear enough?
Of course you have.
Oh come on, there is no evidence that you will accept, your mind is made up. You don't like what relativity has shown us about reality so you have decided to ignore it and live in a fantasy world. That is your choice, but don't expect us to abandon reason and join in your fantasy.

Just another example showing that arguing with a crank is a waste of time.

7. ### absolute-spaceRegistered Member

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You reply with more accusation, the only relevance to the thread is the above sentence. Yes I said I think that length contraction is a visual thing, not an illusion , a visual thing to be clear. You posted early in the thread, do not forget the ruler contracts to, insinuating the actual physical condition of the object changed in length. My opinion is it does not, your opinion is it does, the burden of proof is on you to show it does , it is not for me to convince you it doesn't .

If I had posted something of such, ''photons do not exist'', you would ask me to provide proof and evidence, so I am asking for your proof.

8. ### exchemistValued Senior Member

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But he has replied to that, saying the same as what I said, has he not?

9. ### absolute-spaceRegistered Member

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280

I have spent the time and gone back, I think I may of read it wrongly , my apologies .

10. ### absolute-spaceRegistered Member

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There is no problem with the train travelling a constant speed, but obviously it has to accelerate first to get to a speed.

11. ### exchemistValued Senior Member

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Fine so how about focusing on your second scenario, which can as you say be treated as a constant velocity scenario? This is what I have tried to do and what Q-reeus has tried also to do.

As I say, has he not answered this, in a way that is consistent with what I said about it? Are you OK with those answers or, if not, what further difficulties do you see?

12. ### krash661[MK6] transitioning scifi to realityValued Senior Member

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comical more pathetic nonsense-- how typical.
also--since when have you ever typed " carry on" except when you seen me type it too you.

13. ### originHeading towards oblivionValued Senior Member

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Which is wrong.
I didn't insinuate anything. I clearly stated that there is a change in length.
Which, to be blunt, is the worthless opinion of layman who does not have the education to have a worthwhile opinion.
The proof is Special Relativity and the experiments that all support SR. By the way, since you are taking the counter position the burden of proof is on you.
You have been given ample proof which you ignore because of you don't like the implications of SR.

You're like all the other cranks that come here trying to disprove relativity with your arm waving misconceptions. We have seen it all before, you might as well be proclaiming the world is flat...

14. ### krash661[MK6] transitioning scifi to realityValued Senior Member

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on a graduate level and also most of the time on a undergraduate level-- you are required not too use wiki.

15. ### absolute-spaceRegistered Member

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Your version is correct and Q-reeus version is correct, but neither correct unless we conduct the actual experiment.

The experiment is simple , two aligned lengths, 4 aligned sensors, observers, add motion, result

16. ### absolute-spaceRegistered Member

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If you are insisting the physical length changes then prove it with an experiment?

Prove the pirate ship ride at a fair, swinging left and right contracts in physical length?

17. ### exchemistValued Senior Member

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Not sure why you insist on an experiment. The theory of relativity is one of the most over-determined theories in physics. Every time a measurement has been made, of whatever sort, it has been found to predict the outcome correctly. Personally I think doing yet another experiment of this sort would be a sheer waste of time.

18. ### absolute-spaceRegistered Member

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Can I ask as an experiment ever been done of this sort experiment that shows without doubt one way or another if the actual physical length contract?

19. ### Confused2Registered Senior Member

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The times would either be recorded at the point of measurement by synchronised clocks ( https://en.wikipedia.org/wiki/Einstein_synchronisation ) or any signal transmission delays allowed for so that the 'earlier' and 'later' are independant of the position of 'the observer'.

20. ### originHeading towards oblivionValued Senior Member

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SOURCE
Heavy ions that are spherical when at rest should assume the form of "pancakes" or flat disks when traveling nearly at the speed of light. And in fact, the results obtained from particle collisions can only be explained when the increased nucleon density due to length contraction is considered.

What is that you say? You won't accept that evidence. Imagine my surprise!!

$L=L_o \sqrt{1-\frac{v^2}{c^2}}$

What is that you say? You won't accept that because it is only math. Imagine my surprise!!

You cranks are so boring and science is so interesting...

21. ### exchemistValued Senior Member

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See Origin's reply. It is hard to do except with subatomic particles, as the speeds involved have to be so high that the energy, time and length required to accelerate them limits the size of the test objects that can be considered in practice, but that's life ( and that of course is why these effects were not predicted until the early c.20th, when the speed of light could be measured accurately for this first time in history.)

22. ### rpennerFully WiredValued Senior Member

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In science, a theory is a framework for predicting the behavior of a wide class of phenomena within a certain domain. So the physical theory of special relativity is supported by a great number of empirical observations. The reality of length contraction is a necessary consequence of those empirical observations as it is an elementary consequence of treating two coordinate systems as equally applicable (Principle of Relativity) and endorsing Newton's principle of Inertial and the observation that all observers see the speed of a particular beam of light in vacuum as traveling at the same speed, c.

That's not an illusion. The object is shorter when length and its non-zero motion are not perpendicular. The choice of which coordinates to use is a choice, but that choice has consequences if you want to talk about things like length. It turns out that length is not fundamental in special relativity, because it is a geometry which preserves the space-time interval $c^2 (\Delta t)^2 - ( \Delta \vec{x})^2$ and not length $| \Delta \vec{x} |$.

origin likes this.
23. ### Russ_WattersNot a Trump supporter...Valued Senior Member

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Because it appears your purpose here is to troll and waste peoples' time. That annoys people.
I just did. You won't even say if you were aware of it, so for now I see no reason to explain further!
The one with the train on the first page? It doesn't address length contraction for what it is.