
Mysterious Gamma-ray Flashes in Earth's Atmosphere - J3L2404
http://science.nasa.gov/headlines/y2010/29jan_firefly.htm
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electromagnetic
Question: Would this effect be harnessable for interstellar communication
through a modified AM/FM usage? Should SETI be looking for this?

Gamma rays are one of the universes longest travelling emissions that remain
unobstructed by background dust, so I wonder if it would ever be harnessable
to provide interstellar communication to our nearest neighbors. In theory,
you'd only have to establish receivers. Also would it be scalable to use on a
gas giant (as to our current knowledge, they're presently more plentiful than
rocky planets, and may be necessary to the evolution of habitable planets) to
send an amplified message?

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wglb
Well, I have wondered for a long time about lightning itself and how we could
harness the energy from that. There doesn't seem to be much work going on with
that.

I imagine that you could do both, but it is not clear yet how to do either one
of them.

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electromagnetic
Like all good ideas regarding electricity, Tesla already had it.

Tesla coils operate in reverse to turn high-voltage into high-current. This
was the base of Tesla's idea for wireless electricity. One Tesla coil can
deliver power through the air to another coil, however it typically only has a
fraction of the power of the input. However Tesla coils are capable of
receiving atmospheric electricity (lightning) and outputting current, however
only Tesla appeared interested in this.

A large enough Tesla coil could survive a lightning strike and produce huge
amounts of high voltage direct current, which is incidentally exactly what's
required for producing hydrogen.

It would be nice to see a company build a large tesla coil capable of
surviving lightning strikes to produce hydrogen for fuel cell vehicles.

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wglb
Any thoughts on why it hasn't been done as yet?

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electromagnetic
My guess would simply be because the applications are limited in the West.
Europe would have no demand for the technology as yearly lightning strikes can
be less than .1/KM^2, while parts of the US can easily get to >50/KM^2. Lots
of Africa, and many parts of the southern hemisphere, can receive lightning
strikes of >200/KM^2 yearly.

Aside from the US and Australia, quite literally no technologically advanced
country gets lightning on the scale needed for this to have the great
potential it has. Even though much of Asia has high lightning strikes, China
and Japan have virtually none. Leaving just India who would have the means to
research something like this.

Honestly I believe the major problem is the current produced. A positive
lightning strike can hit at 300kA, and electrical discharged requires a
voltage of 3 million volts/meter traveled (IIRC a lightning bolt averages 100
million volts). This means to get it down to 110V, you're likely dealing with
~300 gigaAmperes. >60 Amps will allow you to weld 16 gauge steel wire. So you
would have to have enough conductive material to handle the flash-heating
produced by a surge of 300gA. This flash heating may, however, be productive
if use was intended for a power plant as it would provide massive amounts of
flash-boiling.

Another problem, however, is that the receiver has to be high enough that no
alternative route is provided to the lightning, or nothing will be received.
However, creating an ionized path above the receiver (or multiple paths at 45
degrees away from the receiver) would enable it to 'catch' a lot of strikes,
increasing strike rates.

I'd say it's certainly possible with present off the shelf technology, however
I doubt its very practical and at worst, you could vaporize a lot of valuable
copper.

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dbz
What would be really cool:

1) We find out these flashes are all over the place 2) We put a ton of
batteries in space powered by these flashes and send them to earth 3) Number
two is cost efficient

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ryanisinallofus
The causins are here!

