On 03/29/2010 01:59 PM, Bill Nettles wrote in part:
If you know the source, use the correct name.
1) I am all in favor of using the "correct name".
2) But what is the correct name?
There is a divergence of opinion as to the correct name.
When I say "there is a divergence of opinion" the quoted
clause is *not* an opinion; there is overwhelming
objective evidence of the divergence.
People who prefer one name should not be too quick to
correct people who prefer another name, especially when
both names are in widespread, longstanding, and current
use by thoughtful experts who work in the field.
Defining gamma rays so that the only allowable source
is the nucleus is not the only definition. It is not
true that all references say the same thing. It is
not true that all journal editors will insist on this
one source-based definition. There is overwhelming
objective evidence of what I am saying.
You shouldn't think that annihilation radiation is a
special case because it is "almost" a nuclear process.
The term "gamma ray" is commonly applied to synchrotron
radiation, which does not involve anything resembling
a nuclear process: http://www.google.com/search?q=wiggler+%22gamma+rays%22
As another example, the term "gamma ray" is commonly
applied to high-energy bremsstrahlung http://www.google.com/search?q=bremsstrahlung+%22gamma+rays%22
even though the same physical process at lower energy
would produce what we usually call X-rays. This is an
instructive example because it shows the overlap between
the two terms.
3) Ideas are primary. Terminology is at best secondary.
Terminology is important only insofar is it helps us
formulate and communicate the ideas.
Loosely-defined terminology is sometimes a source of
confusion, but sometimes not. Sometimes the meaning
is obvious in context. For example, when somebody is
talking about "511 keV gamma rays" there is AFAICT no
possible confusion.
Arguing about terminology is usually a waste of time.
I recommend tolerance. You can use whatever terminology
you like. It's your choice. However, keep in mind that
other people may choose differently.