In response to the recent claim in New Scientist that conical cavities
full of microwaves will accelerate in the direction of their wide end,
I've computed the actual distribution of force on the walls of a
"truncated spherical cone" for its resonant modes.
http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html
I realise this is overkill as a refutation of a claim that violates
conservation of momentum, but it was fun to work out the details. I found
one thing that took me by surprise: parts of the cavity wall will
experience a net *tension* in certain modes!
--
Greg Egan
Email address (remove name of animal and add standard punctuation):
gregegan netspace zebra net au
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