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Lorentz contraction

by matheinste
Tags: contraction, lorentz
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cfrogue
#379
Dec2-09, 07:55 PM
P: 687
Quote Quote by JesseM View Post
What the hell are you blabbering about cfrogue? I didn't say you couldn't prove anything false. I said you couldn't prove the length contraction equation false using a scenario in which you violate one of the conditions that are required in order for the the length contraction equation to apply. If you want mathematical analogies, here's one--

Define the "Law of real inverses" to say: for any nonzero real number R, the number has an real inverse 1/R such that R times its inverse 1/R equals 1.

cfrogue-style argument: but look, zero doesn't have a real inverse! Therefore the "Law of real inverses" is false!

Can you see why this argument would be pretty stupid?
You are getting frustrated.

You are applying universal generalizations you know do not apply.
cfrogue
#380
Dec2-09, 07:57 PM
P: 687
Quote Quote by matheinste View Post
This is not a valid mathematical argument. You are trying to prove that the statement "there exists a greatest integer" is false by demonstrating that, given any integer, you can produce one that is greater by adding 1 to it. However if there were a greatest integer you would be unable to add 1 to it to make a greater one. You are assuming result before you have proved it.

Matheinste.
I suggest you look at the original Archimedes proof.

It is clear to me you do not know how to argue by Reductio ad absurdum.

I do this all the time.
cfrogue
#381
Dec2-09, 07:59 PM
P: 687
Quote Quote by matheinste View Post
This is not a valid mathematical argument. You are trying to prove that the statement "there exists a greatest integer" is false by demonstrating that, given any integer, you can produce one that is greater by adding 1 to it. However if there were a greatest integer you would be unable to add 1 to it to make a greater one. You are assuming result before you have proved it.

Matheinste.
I suggest you look at the original Archimedes proof.

It is clear to me you do not know how to argue by Reductio ad absurdum.

I do this all the time.

The properties of the Integers is that if n belongs to the integers then n + 1 belongs to the integers.

This is Peano arithmetic.
matheinste
#382
Dec2-09, 08:05 PM
P: 1,060
Quote Quote by cfrogue View Post
I suggest you look at the original Archimedes proof.

It is clear to me you do not know how to argue by Reductio ad absurdum.

I do this all the time.
I have.

That there is no greatest integer is true. It is called the Archimedean property of numbers.

It does not use this "proof".

You are absolutely categorically wrong in your proof. It is a common mistake that many people make and is completely compatible with many of your arguments.

You may get away with wordplay and ambiguityy with verbal atguments in relativity but you cannot get away with it in mathematics.

Matheinste.
JesseM
#383
Dec2-09, 08:13 PM
Sci Advisor
P: 8,470
Quote Quote by cfrogue View Post
You are getting frustrated.
Yes, frustrated by the stupidity of your arguments.
Quote Quote by cfrogue
You are applying universal generalizations you know do not apply.
No idea what you mean by "universal generalizations". Here was my analogy again:

Define the "Law of real inverses" to say: for any nonzero real number R, the number has an real inverse 1/R such that R times its inverse 1/R equals 1.

cfrogue-style argument: but look, zero doesn't have a real inverse! Therefore the "Law of real inverses" is false!
Tell me whether you agree or disagree that this is a stupid argument. Now, here's why it's analogous to the length contraction example:

Define the "law of length contraction" to say: if an object's length is measured in two different inertial frames, and the object is rigid and moving inertially throughout the period that both measurements are made, and if one of the frames sees the object to be at rest while the other frame sees it to be moving at speed v, then Lmoving = Lrest * sqrt(1 - v^2/c^2).

cfrogue: but look, if the two measurements are made in a period of time where the object isn't rigid and isn't moving inertially throughout, then it's not true that Lmoving = Lrest * sqrt(1 - v^2/c^2)! Therefore the "law of length contraction" is false!
So if the first argument is stupid, this second argument must be equally stupid, for exactly the same reason.
cfrogue
#384
Dec2-09, 08:20 PM
P: 687
Quote Quote by matheinste View Post
I have.

That there is no greatest integer is true. It is called the Archimedean property of numbers.

It does not use this "proof".

You are absolutely categorically wrong in your proof. It is a common mistake that many people make and is completely compatible with many of your arguments.

You may get away with wordplay and ambiguityy with verbal atguments in relativity but you cannot get away with it in mathematics.

Matheinste.
Silly.

Prove it is wrong.
matheinste
#385
Dec2-09, 08:28 PM
P: 1,060
Quote Quote by cfrogue View Post
Silly.

Prove it is wrong.
I cannot be bothered.

I have learnt from experience that if you have decided you are correct, no amount of logical argument will convince you otherwise. However in this case there is no doubt, your proff is invalid.

Matheinste
cfrogue
#386
Dec2-09, 08:39 PM
P: 687
Quote Quote by matheinste View Post
I cannot be bothered.

I have learnt from experience that if you have decided you are correct, no amount of logical argument will convince you otherwise. However in this case there is no doubt, your proff is invalid.

Matheinste
No problem.

I cannot show you Reductio ad absurdum.
matheinste
#387
Dec2-09, 08:43 PM
P: 1,060
Quote Quote by cfrogue View Post
No problem.

I cannot show you Reductio ad absurdum.
That's quite obvious as you do not understand correctly it yourself.

Matheinste.
cfrogue
#388
Dec2-09, 09:07 PM
P: 687
Quote Quote by matheinste View Post
That's quite obvious as you do not understand correctly it yourself.

Matheinste.
If you want, I can show you some math arguments of mine if you could follow them.


Yea I know, you understand everything.
matheinste
#389
Dec3-09, 12:18 AM
P: 1,060
Quote Quote by cfrogue View Post
If you want, I can show you some math arguments of mine if you could follow them.

That's very kind of you but I have plenty of textbooks and the mathematicians on the math forum are very helpful, and rigorous. Perhaps you should let them look at your above proof and comment on it.

Matheinste.
jtbell
#390
Dec3-09, 05:52 AM
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P: 11,632
It appears unlikely that this thread will make any substantive progress, so it is now closed.


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