🚀 go-pugleaf

In article <391@nikhefh.UUCP>, jona@nikhefh.UUCP (Jona Oberski) writes:
> Question: Which things - common instruments, consumergoods, etc. - would not
> exist if we would not have Einstein's Theory of Relativity: "ETR"?

It's hard to separate any development that came after relativity from
the influence of relativity.  Quantum mechanics, for example, is not
directly dependent on relativity, but I believe the prime developers
were greatly influenced by Einstein's approach.  However, I'll assume
that your question means what if the Schroedinger equation were known
but not the Dirac equation.  (If the Schroedinger equation goes away,
so do transistors and integrated circuits, among other things.)

Without the Dirac equation, I don't believe we would understand
nuclear magnetic resonance (NMR) or be able to use the phenomenon in
analysis.  (I'm not very knowledgeable in this field, so experts
please correct these comments.)

NMR has been used for many years in organic chemistry and more
recently in biochemistry to determine molecular structures.  While we
would certainly have some sorts of plastics without NMR, I doubt we
would have anything like the vast number and variety tailored for
specific properties that we have today.  Nor would we have most of
the synthetic fibers or products like Teflon, Tyvek, and lots of
others.  I'm not sure about application to pharmaceuticals, but I
suspect that many drugs would not exist and the biochemical actions
of others would not be understood.

NMR has also been used for a few years now for medical imaging.
(It's referred to as "magnetic resonance imaging" or "MRI" to avoid
negative public reaction to the word "nuclear").  It probably saved
my brother's life a couple of years ago, when doctors were able to
use MRI to find soft tissue problems that didn't show up on X-rays or
CAT scans.

Another application that comes to mind is X-ray diffraction analysis,
which is widely used for studying crystals of all kinds.  Studies of
semiconductors and viruses probably have had the greatest practical
effects, but I'm not really sure how important the relativistic
corrections are.

Finally, if you are willing to accept intangibles, how about the
reassurance that the Sun will not become a nova or supernova?
Relativity is crucial in understanding the processes that actually
cause novae and supernovae, and we now know that these processes are
not important in the Sun.

>  By the way, do you like the idea:
> "The only commonly-known physicist's theory is without practical value".

No.
-- 
Steve Willner            Phone 617-495-7123          Bitnet: willner@cfa2
60 Garden St.            FTS:      830-7123           UUCP:   willner@cfa
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