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Pushing 800W of Wireless Power at 5 Meters
Joe Decker writes "The Nevada Lightning Laboratory has experimented with Nicola Tesla's methods of wireless power transmission to push 800 Watts over 5 meters, besting MITs mark of 60W over 2 meters last year. (May I dream of wireless laptop power? I hate power cords.)"
800 Watts over 5 meters, ...
(May I dream of wireless laptop power? I hate power cords.)
I think I'll pass on that. Don't really want that sort of power aimed directly at the boys.
I've seen more watts over more distance all my life.
http://www.nssl.noaa.gov/primer/lightning/ltg_damage.html
You just don't want to stand between the source and the destination...
May I dream of wireless laptop power? I hate power cords
Depends - do you want kids in future?
Yes, you can. But I have it already. It's called a battery.
You could probably run a car on the stray emissions of a city. But running one car per city is mostly useless. There would be fights over who'd get to sit up front.
You clearly do not know anything about Cyrillic. The 'H' you refer to is actually an 'n' and the backwards 'N' is actually a 'i' type sound. The 'C' is an 's'.
Another problem that any physics professor will tell you (after pointing out that "the boys" are not going to be in any more danger from that than they are from your cell phone, since neither would be likely to operate at a frequency at which the human body is resonant) is that any bit of metal can act as an antenna. All it takes is to have one piece of wire inside your laptop that happens to be the right resonant frequency for the power that is being transmitted and ZAP! I for one would not want my sensitive electronics that can be fried by static electricity in the wrong place to be anywhere near something like that.
People who live near (under) high-voltage cross-country power lines can tell you about harvesting electric fields. People have been known to run wires through their attics, parallel to adjacent high-voltage lines, and run lights off them. It's considered power theft, which I think is a shame, because it helps make the rest of the house a little more liveable, with fewer shocks from touching light switches or heating vents.
In Moab, Utah, there's a popular bike trail with the parking area right under a major power line. There are audible snapping and popping sounds coming from bikes on car-top racks. I keep meaning to wire up a capacitor bank and see how far it charges up while I'm out on a ride, but I haven't had time yet to build that.
Nostalgia's not what it used to be.
We finally have a method of male contraception that doesn't involve surgery, abstinence, or a woman's permission! I'll take that laptop, son. I'm too old for more kids!
We already had one, it's called slashdot.
The MIT group is not proposing to use omnidirectional (or directional) radiative energy transfer, which indeed would radiate most of the energy into the environment, and only a small fraction into the receiver, and even that could be eliminated if something (e.g. a person) walks between the source and receiver.
They are proposing non-radiative resonant energy transfer, in which both the source and receiver are resonant oscillators at a particular frequency coupled via the near field (non radiatively), and hence preferentially transfer energy compared to anything else that is not resonant (with a long lifetime) at the same frequency. Furthermore, they are using resonators that only couple through their magnetic fields (the electric fields are largely within capacitors inside the device), which further reduces absorption of energy by the environment (because most materials are non-magnetic, energy dissipation is largely via ohmic heating, i.e. by the electric fields). Because of this, almost all of the losses take the form of resistive heating in the devices themselves; only a miniscule fraction is dissipated in the surrounding environment (e.g. a person).
Of course, this being Slashdot, it's not surprising that most posters never RTFAed and post nonsense "it's just like an inductive transformer" (nope, those don't use resonance) or "it's just like an antenna" (nope, that is radiative transfer) or "Tesla looked at this a century ago" (nope, people like Tesla were concerned with power transfer over long distances, which necessitates radiative mechanisms and hence low efficiency).
If a thing is not diminished by being shared, it is not rightly owned if it is only owned & not shared. S. Augustine