"william mook" wrote in message
om...
The ultimate in solar collectors must be the deposition of solar
collectors onto the solar surface. The sun puts out 3.86x10^26 watts
of power. Distributed over a sphere whose radius is equal to the
radius of Earth's orbit this falls to a little less than 1,400 watts
per square meter. But on the solar surface this energy density
exceeds 60 megawatts per square meter! Clearly, if we could figure
out how to build useful devices that operate under the extreme
conditions of the solar surface, we could collect solar energy 40,000x
more efficiently than we can on Earth!

Any ideas?

The business model would be as follows;

(1) build a factory that makes the equipment that operates on the
solar surface.

(2) Launch the equipment in a rocket to Jupiter.

(3) Execute a gravity assist from Jupiter to cancel all orbital
motion, allowing the equipment to fall toward the sun.

(4) Somehow slow the equipment to survive its 'landing' on the solar
surface - perhaps using solar sails.

(5) Unfold the equipment on the solar surface, and beam 60 megawatts
per square meter to anyplace in the solar system (or beyond) you need
it.


Interesting things to keep in mind;

About the sun;
http://blueox.uoregon.edu/~jimbrau/a...r16.html#facts

About optics;
http://www.licha.de/AstroWeb/article...php3?iHowTo=16

http://www.astro.ufl.edu/~oliver/ast...copeoptics.htm

About astrodynamics;
http://www.go.ednet.ns.ca/~larry/orb.../gravasst.html

(you can cancel orbital speed as well as add to it!)

A thin film system capable of operating on the solar surface could
process quite a bit of power. A square kilometer for instance has a
million square meters and could process over 60 trillion watts of
power. At a few grams per meter a 'sheet' this size could weigh only
a few tons. Something people could build today.

Using conjugate optics
http://www.futureworld.dk/tech/ether...n/phasecon.htm

It is possible to energize a thin film laser medium and then
interrogate that system with another laser, extracting a large portion
of the energy contained in that medium and delivering it to where its
required.

The accuracy which things can be delivered large distances are limited
by Rayleigh's limit;

Theta = 1.22 Lambda / Diameter

GREEN LANTERN OPTICS:

So, if lambda is 500 nm and diameter is 1 km then theta is;

Theta = 1.22 * 500e-9 / 1e3 = 5e-10 radians

Multiply this angle by 150 million km (1.5e9 m) and we can see that a
1 km diameter optically active film producing laser beams efficiently
on the surface of the sun could create a spot that's 0.75 meters
across on the surface of the Earth (capable of putting over 60
trillion watts into that space too - depending on laser and optical
efficiencies! But even an overall efficiency of 1% yeilds 600 billion
watts per square kilometer)

This is more energy than humanity currently uses. With the ability to
produce multiple beams we can deliver this energy to billions of users
simultaneously and power any manner of industrial or transportation
processes. Including space transportation systems.

A quadrillion watts - 1e15 watts - enough to power a starship
-requires 16 square kilometers. A circle 4.5 kilometers across on the
solar surface processes this much power.


Stretching our beam out to 1,000 AU from 1 AU, and noting the increase
in diameter, we can see that we can deliver this beam to a 'spot' 250
meters across 1000 AU from the sun. At this point, we can reflect the
beam around the sun and use the sun's own gravity to focus it reliably
any distance we like from the sun, to be used by owners of laser light
sails anywhere in the galaxy.

But of course, we need to figure out how to make something work
reliably on the solar surface. Which I haven't done.

Again, any suggestions?

Keep taking the pills.