In article , Iain Churches
wrote:

"Jim Lesurf" wrote in message
...
In article , Iain Churches
wrote:

"Jim Lesurf" wrote in message


Ahem:-) It's a long cone actually, Jim,

Well, to a physicst, a 'cone' is just a tune whose cross-section
varies along the length. :-)

I read the above as "'just a tube whose cross-section varies along the
length" Hope that was correct.

Yes. Typo.

It seems that, to a musical instrument designer. the difference between
a cone and a tube is of great importance. As the design is based on
physics, one would have thought that the difference would be important
to a physicist too:-)

That may show that you're not a physicist. :-)

The point here is that from the *physics* point of view a 'tube' and a
'cone' can be analysed using the same type of approach, and the phusics of
their behaviours are related. This means you don't have to dream up
entirely 'new' ways to analyse, design, etc every time you encounter a
slightly different object. One of the aims of physics is to have a minimal
set of equations/models/hypotheses/axioms/properties/symmetries that then
cover *everything*.

That doesn't mean that the different details of behaviour aren't exploited.
So although a waveguide and a feedhorn (antenna) are used for different but
related purposes the underlaying physics of them is the same. You just
change the details to suit.

So the differences appear in the applications, not in the physics.

Slainte,

Jim

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