----- Original Message ----- From: "Christopher Strevens" <Christopher.Strevens@xxxxxxxxxxxxx> To: "karl shah-jenner" <shahjen@xxxxxxxxxxxx>; "PhotoForum educational network" <photoforum@xxxxxxxxxxxxx>
Sent: Sunday, February 21, 2016 3:30 PM Subject: RE: Re: 10 years The transfusor contains one, it is another effect he found. Sent from my Windows Phone ________________________________ From: karl shah-jenner<mailto:shahjen@xxxxxxxxxxxx> Sent: 21/02/2016 07:15 To: PhotoForum educational network<mailto:photoforum@xxxxxxxxxxxxx> Subject: Re: 10 years an intersting phtographic element to this: " Tesla brought back from Colorado was pretty photographs, including the famous one that shows him calmly sitting in a chair reading while many megavolts of lightning flashes above his head. In distributing the photograph, Tesla was forthright about the fact that it was a double exposure: first the sparks were photographed with no one nearby, and then the machine was turned off while Tesla seated himself near it and the photographer set off a flash charge. " the image from the 1890's is so famous now, yet few realize it was photographic 'trickery' that brought it to exist. anyhoo, the point - Years back I read in an electronics magazine of a boy in the 20's or 30's in the US with a keen interest in physics but a particularly bad grasp of maths who built a large tesla coil - which when fired up managed to blow the coils in cars for quite some distance around. a mischievous person could potentially harm digital data at a distance without needing to gain access. note too that it doesn't need to be the classic 'tesla coil' design to harm, neon transformers too when pulsed could zap stuff If anyone feels the desire to pratt about with a tesla coil I'd advise them not to.. but if you, firstly learn the maths to ensure the frequencies generated are permitted and safe and secondly, here's a page about how to deal with a relatively small one safely. I draw your attention to "The most dangerous components in the Tesla Coil are all part of the relatively low voltage (10,000-volt) circuitry" http://scipp.ucsc.edu/edu/tesla/teslacoil/safety.html
