In certain physics textbooks, one starts with the assumption (in a one linear and one time dimension) that(adsbygoogle = window.adsbygoogle || []).push({});

1) x^{2}- c^{2}t^{2}= x'^{2}- c^{2}t'^{2}

I don't want to go into that. Let us start from there.

Now, if you assume that

2) x = vt, then

3) x' = 0 always because the origin is moving at v along the x-axis so that x' is always zero.

Using those three bits of information one can derive the Lorentz equations:

x' = [tex]\gamma[/tex](x - vt)

t' = [tex]\gamma[/tex](t - xv/c^{2})

where [tex]\gamma[/tex] = SQRT[1 - v^{2}/c^{2}] (I can't get the square root to come out in LATEX)

I have tried, tried, tried to do that but I cannot.

Anyone can help?

If I substitute the Lorentz equations back into the above three bits of information, it will work out but that's backwards. I want to do it forwards.

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# Derivation of an old-time formula

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