-------- Original Message --------
From: jim bell
Within the last couple of months, I think somebody was arrested for planning some sort of "X-ray death ray". http://nypost.com/2015/08/18/kkk-member-built-death-ray-machine-to-kill-musl... But only a dweeb doesn't know that X-rays cannot be focussed. (With one very obscure exception not applicable here. Find it and get an "attaboy!". )
Its called Grazing Incidence
https://en.wikipedia.org/wiki/X-ray_optics
Microwaves, OTOH, can be focussed rather easily. The frequency is 2.45 Ghz, at about 1 Kilowatt. (wavelength about 12 centimeters.) I'd have to consult a Radio Amateur's handbook, but a modern dish (intended or Directv or Dish network) could probably get 15-20 db of gain, compared with isotropic. An old-style 8-foot dish probably would do 30 db gain. That would be 100 kilowatts ERP.
Such an unshielded (open) device would probably impair WiFi at 2.5 Ghz severely, if you're close to it, say a few hundred feet away. Fortunately, I think microwave ovens have better than 60 db of shielding. A few 10s of feet, away, hardware damage might occur if that full 1 kw were allowed to leak out. Jim Bell
wirelesswarrior@safe-mail.net
Its called Grazing Incidence
Ten out of ten for knowing what it was, but minus several million for using Wikipedia as the reference. Peter.
Attaboy!!!
From: "wirelesswarrior@Safe-mail.net"
Within the last couple of months, I think somebody was arrested for planning some sort of "X-ray death ray". http://nypost.com/2015/08/18/kkk-member-built-death-ray-machine-to-kill-musl... But only a dweeb doesn't know that X-rays cannot be focussed. (With one very obscure exception not applicable here. Find it and get an "attaboy!". )
Its called Grazing Incidence https://en.wikipedia.org/wiki/X-ray_optics >Microwaves, OTOH, can be focussed rather easily. The frequency is 2.45 Ghz, at about 1 Kilowatt. (wavelength about 12 centimeters.) I'd have to consult a Radio Amateur's handbook, but a modern dish (intended or Directv or Dish network) could probably get 15-20 db of gain, compared with isotropic. An old-style 8-foot dish probably would do 30 db gain. That would be 100 kilowatts ERP. >Such an unshielded (open) device would probably impair WiFi at 2.5 Ghz severely, if you're close to it, say a few hundred feet away. Fortunately, I think microwave ovens have better than 60 db of shielding. A few 10s of feet, away, hardware damage might occur if that full 1 kw were allowed to leak out. Jim Bell
On Wed, 23 Sep 2015 02:59:18 +0000 (UTC)
jim bell
But only a dweeb doesn't know that X-rays cannot be focussed. (With one very obscure exception not applicable here. Find it and get an "attaboy!". )
Isn't it possible to focus any sort(frequency) of EM wave, at least in theory?
Its called Grazing Incidence
On 9/22/15, Juan
... Isn't it possible to focus any sort(frequency) of EM wave, at least in theory?
in theory, with "metamaterials", yes. in practice this is akin to the perfect invisibility cloak problem, full of devilish details... a full spectrum Superlens for any EM freq would be quite handy indeed :) best regards,
participants (5)
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coderman -
jim bell -
Juan -
Peter Gutmann -
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