🚀 go-pugleaf

In article <391@nikhefh.UUCP>, jona@nikhefh.UUCP (Jona Oberski) writes:
> 
> What would YOU answer to the following:
> 
> Question: Which things - common instruments, consumergoods, etc. - would not
> exist if we would not have Einstein's Theory of Relativity: "ETR"?
> 
> Some answers (and some comments): 
> A1. No nuclear energy, nor bombs. (????).
> A2. No lasers. (??; hardly common experience).
> ...
> By the way, do you like the idea:
> "The only commonly-known physicist's theory is without practical value".

A1)  Despite Eistein's aversion for the oversimplified expression "E = mc^2",
two young physicists at the time were stimulated by this expression to consider
the release of energy by the transmutation of matter through fission (I wish I
could recall their names).  They were told that it wasn't feasible by Einstein,
but the same concept must have occurred to others.  The possibility of
the release of atomic energy through fission was openly discussed in the
technical literature before WWII, with the war putting a damper on any
further discussion.  The famous energy and mass expression is one consequence
of ETR.  It is likely that the release of atomic energy (bombs, reactors)
would still have been realized, even if E=mc^2 wasn't around for conceptual
guidance, through the work of Rutherford et al.

A2)  Einstein did contribute to an understanding of the laser, but not through
special relativity.  Einstein developed a simple model for electronic
transitions in atoms (for those specialists, recall the Einstein A and B
coefficients) which provides a good description of the lasing process.

  Again, my memory fails, but there is a good book available by a
philosopher/sociologist of science which argues that special relativity is
not a theory of physical interactions but rather a theory of measurement.
Newton's physics assumed and left unstated the procedures by which measurements
on physical systems are made (recall the absolute reference frame which is
implied by Newton).  Einstein merely clarified the procedures by which
measurements on physical systems are conducted, and their limitations.
From this understanding of how measurements are made, all sorts of consequences
for how physical theories must be constructed and the effects can be
demonstrated (e.g., speed of light limits, time dilation, etc.).
In carefully specifying the limitations of measurements for classical physical
systems, special relativity has had a profound effect on practicing physicists
since the 1920's.  All particle accelerators have been designed assuming
that special relativity is rigorously correct.

                                        Patrick Wyant
                                        Engineering Physics Lab
                                        E.I. du Pont de Nemours
                                        Wilmington, DE
                                        *!uunet!eplrx7!wyant