Contemporaneous anecdotes from visitors to his lab reported a beautiful pure red spot of light, redder than any possible in nature, coming from a machine. Since it happened in the past, does that make it alleged? I don't think apocryphal works - its not an urban legend, its from documented letters etc.
UC Santa Cruz does Tesla coil demos with a person dressed in a Faraday cage, and IIRC they said that (like someone else commented) the skin effect due to the high frequency means you probably won't die from it going through your heart, but the fact that the current is limited to a very small depth into your skin means the current density actually is quite high and will likely cause damage.
Hard to say. Maybe not much, due to the environment and the skin affect- high frequency electricity tends to flow near the surface of a material. This isn't a van der graff generator though, it can still produce a significant current, and is potentially (probably) lethal. It probably won't hurt, again due to the high frequency. The aftereffects would definitely hurt though.
I've built a Tesla coil (inspiring me to major in electrical engineering later on) and have been shocked by them on a couple occasions. Sadly, the skin affect doesn't apply to human skin -- it only applies to materials which are conductors at high frequencies. Due to the water content + the resistance inherent in the material, human flesh doesn't exhibit skin effect properties.
If this hits your skin, you probably won't feel it due to the high frequencies involved, similarly to how you won't hear sounds over ~20khz. Your body wont' be able to process it neurologically. You will, however, get a really nasty burn from it, which can get bad if you don't sense the initial shock. If it hits your torso, you could potentially experience heart rhythm issues, but unlikely.
Voltage and frequency dangers are funny things. The most dangerous voltages are from about 50V to 1000V because it interferes with your nervous system -- lower and the current is too low to affect you, and higher causes you to reflexively release. The most dangerous frequencies are ~1Hz to ~10kHz. They're most likely to mess with your cardio rhythms in a bad way. Funny thing about this is that the most dangerous voltages and currents are found in household voltages -- 120V@60Hz (220V@50Hz in Europe).
Neato, sophomore ECE here (been taking more CS so far). I've also built a tesla coil, however due to massive paranoia from 12V spot welds during FIRST robotics I have avoided getting shocked. I always had the skin effect quoted at me so I parroted it back, but the permeability of water is extremely low, so thats pretty dumb. Just goes to show you should question everything
In reference to your description of the danger of different voltages and frequencies...is it still dangerous (potentially life-threatening) to get shocked outside of these ranges, or do things work out well in the vast majority of the cases? This is new to me, I got a bit curious.
It's not really a question of safe vs unsafe so much as increased danger in that range. Stand in the wrong place at a GW power-plant and you might just end up as a ionized cloud in short order. But, even without massive tissue damage things can still be incredibly dangerous.
I got to hold it last weekend! Surprisingly light - felt around 5 kg. Sadly it doesn't have a trigger in the slot you'd expect it to have one, just a (safely covered) switch.
Pretty cool to actually see it after months of noticing parts Rob left on tables at the local hackerspace...
I read a biography of him a while ago, but I can't recall which one, and it seemed too pulp-ey (which in a way was appropriate since so much of what he did seemed to spring from the pages of pulp sci-fi).
I don't understand. Do you propose to use the Earth as a big field magnet and generate electricity by letting it move through a big conductive coil? So as the Earth orbits about the Sun, you could slow it down while enjoying free electricity... right?
Yep, I was listening to this yesterday and it got me thinking.
www.thewonders.com/multimedia/Ask_The_Wonders_May_19_2010.mov (2:16)
Q: "Can 0-point field energy be harnessed?"
A: "Have you ever heard of the Tesla coil? Use that more often, that's all it takes. Magnetic energy tapped into the planet's electromagnetic field produces more than sufficient energy to power the planet with approximately 258 trillion inhabitants on it. ..there is movements towards the technology but it is not yet truly being supported by governments. ..the financial, the technological aspects of it is alluding some of your scientists. ..we would suggest to them to simplify their mathematical equations rather than complexify them as they're trying to do."
