# Equations

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$t=\frac{t}{\sqrt{1-\frac{V^2}{c^2}}}$

$m=\frac{m}{\sqrt{1-\frac{V^2}{c^2}}}$

$d=d{\sqrt{1-\frac{V^2}{c^2}}}$

and, of course, the famous one: $E=mc^2$

How did Einstein derive these equations?

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E=mc^2 is not einstiens own formulae

not everyone is aware of this and there are not many sites which say it plainly and simply, here are two though:

http://www.vttoth.com/emc2.htm

http://www.100megsfree4.com/farshores/rm04ein.htm

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Wow, I didn't know that. So, how did he derive the other three? Or should I say one, because they are based on the same derivation(is that even a word?)?

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E=mc^2 is not einstiens own formulae

not everyone is aware of this and there are not many sites which say it plainly and simply' date=' here are two though:

http://www.vttoth.com/emc2.htm

The first article complains about people calling it 'Eisntein's equation' (if it's called anything it's called the mass-energy equation) it does not say that Einstein w3as not the first to derive it. the second artilce is a load of crap E = mc^2 is a relativistic euation and yet the article tries to attribute it to Newton! As far as know Einstein was the first to derive this equation (actuially there was recently some controversy over whether an unknown itlain physicst may of just got their first).

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$t=\frac{t}{\sqrt{1-\frac{V^2}{c^2}}}$

$m=\frac{m}{\sqrt{1-\frac{V^2}{c^2}}}$

$d=d{\sqrt{1-\frac{V^2}{c^2}}}$

and' date=' of course, the famous one: [math']E=mc^2[/math]

How did Einstein derive these equations?

It should be:

$t = \gamma t_0$

etc.

The formulas for time dialtion and lenght contraction were not Einstein's. The formula for Length contraction (usually known as Lorentz-Fitzgerald contraction after the two phycists that discovered it independtly) precedes the theory of special relativty by 10 years, I believe time dialtion came only a yera before the STR.

All these equations can be derived from the Lorentz transformations (indeed the formulas for Lorentz-Fitzgerlad conbtarction and time dialtion really are just incomplete versions of the Lorentz transformations), the first and third ones are very easy to derive.

The second equation, these days wold be considered to be wrong as mass m is taken as the rest mass and thus invariant. E = mc^2 is not particualrly easy to derive, but can be derived by considering the absrption of a photon.

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E=mc^2 is not einstiens own formulae

not everyone is aware of this and there are not many sites which say it plainly and simply' date=' here are two though:

http://www.vttoth.com/emc2.htm

The first one did not state that Einstien did not come up with E=mc^2. It said that it was not "einstients forumula", and then went on to show how to derive it, which was work einstien contributed a great deal to.

The second link is just awful. A site that says Einstien is the "plagarist of the century" is pretty low on the credibility rating. Seems odd that so many people would defend him if he just made all that stuff up.

wikipedia seems to think the equation is Einstiens

http://en.wikipedia.org/wiki/E%3Dmc%5E2

same with britannica

http://www.britannica.com/ebc/article?tocId=9363491

Now, these may still be wrong, but if you are going to say its wrong, you will need some credible sources to back it up.

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whats more amazing is the three keplers laws. derived in the 15th century.

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umm, i'll look round for some sources. einstien did not 'make' the equations although he did put soo much work into prooving it, deriving at it and so on that it is regarded as his because without him it wouldnt have been much use in that it wouldnt have been proved etc, however it was not him who 'made' it.

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umm, i'll look round for some sources. einstien did not 'make' the equations although he did put soo much work into prooving it, deriving at it and so on that it is regarded as his because without him it wouldnt have been much use in that it wouldnt have been proved etc, however it was not him who 'made' it.

e = mc^2 is Einstein's, the Lornetz transformations and Lornetz-FitzGerald contraction and time dialtion aren't. What Einstein did was to to gather up all these sets of equations and but them into a single self-consistent theory in which they can derived from more basic axioms.

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ok, it is possible i am wrong, but from sites such as:

http://www.vttoth.com/emc2.htm

&

i thought that einstein had played a major role but was not the one to create the whole e=mc^2 formula.

i could be wrong, but those sites claim it is a common and justified thing to think it is einstiens, so i dont know...

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ok' date=' it is possible i am wrong, but from sites such as:

http://www.vttoth.com/emc2.htm

&

i thought that einstein had played a major role but was not the one to create the whole e=mc^2 formula.

[i']i could be wrong, but those sites claim it is a common and justified thing to think it is einstiens, so i dont know...[/i]

The first site is rather whiney, but all it says is that E = mc^2 should not be called Einstein's equation (instead it prefers to give the title to what I suppose would more commnly be called Einstein's fgield equation), it certainly does not say that E = mc^2 was not EInstein's.

The second site is rather conmtetious is trie sto completly obscur ethe fact that Einstein was the first to derive the genral case.

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