Yea, I know that the wavelength of the x-rays has to be longer than the spaces in the conducting wrap. Thought it was...mea culpa. With regard to jet engines...they're not entirely enclosed, are they? I've tried a couple of hair-brained experiments at home here...cell phone in a covered pot, call it and it doesn't ring. But, what I was really interested in was microwave ovens. The cell phone does ring inside a microwave. However, I thought that might be due to the power line acting as an antenna. Cell phone radiation must be of a longer wavelength than microwaves so, it has to be stopped by the faraday cage that surrounds the U-wave oven. Anyway, I'll check the wavelengths...if everything's on the level, the X-rays would have to be longer than the spaces between the crystals that make up aluminum foil if the foil will stop it, right? back to the books. Dave ________________________________ From: Charlie Falke <chfalke@xxxxxxx> To: leicareflex@xxxxxxxxxxxxx Sent: Mon, December 20, 2010 1:48:09 PM Subject: [LRflex] Re: Kodachrome On 20-Dec-10 4:10 PM, David Simms wrote: > It is possible to nullify the effect of x_rays by wrapping the film in metallic > foil. Since X-rays are part of the electromagnetic spectrum, they will not > penetrate a conducting envelope. Naturally, they sell lead envelopes for this > purpose to help air travelers preserve film. But, there's no reason why it has > to be made of lead, aluminum foil will do just as well. > Try Googling "Faraday cage". > > Dave > Clearwater, BC > Dave, The lead bag reduces the x-ray exposure, but the operator will just crank up the gain until he can see through it. Aluminum will have very little effect. A Faraday cage works on EMF of much longer wavelength than X-rays, (large with respect to the Faraday cage) or on electrostatic fields. We've X-rayed jet engines while they were running. -- Charlie Falke _____ /\ | __/\__/------/__) |(____\/_________/ "One test result is worth | |/ `o one thousand expert opinions" - Wernher Von Braun 0 N4003M "Imagination is more important than knowledge" - Albert Einstein ------ Unsubscribe or change to/from Digest Mode at: http://www.lrflex.furnfeather.net/ Archives are at: //www.freelists.org/archives/leicareflex/ ------ Unsubscribe or change to/from Digest Mode at: http://www.lrflex.furnfeather.net/ Archives are at: //www.freelists.org/archives/leicareflex/