Re: The fallacy of affirming the consequent

[Mark Sylvester <msylvest@XNET.IT>]

At 17:45 09/04/03 +0200, Pentcho Valev wrote:

> Look at Einstein's "Relativity: the special and general theory". Let us
> assume that A is the postulate of the constancy of the speed of light:
>
> A:  x = ct  <->  x' = ct'

The second postulate.



> which is a biconditional and can be read: if and only if x=ct then
> x'=ct'. Then Einstein introduces a relation of which A is obviously a
> corollary (Einstein
> explicitly recognizes this):
>
> B:  (x' - ct') = L(x - ct)

As far as I recall, I have to write another line to proceed: (x - ct) =
L(x' - ct')

...and isn't this symmetry between the two reference frames justified by
the first postulate, not deduced from A?

The linearity of the transformation is a further issue, but not the main
point, I'd have thought.

Mark



Mark Sylvester
UWCAd
Duino Trieste Italy