Re: Solar powered lasers in space

In article <1189603948.133528.201480@xxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Willie.Mookie@xxxxxxxxx wrote:

4-wave mixing systems that use active holographic techniques to
control a powerful laser have allowed lasers to penetrate sputtering
vapor and maintain focus on a target by avoiding the sputtered
particles. The same techniques have been used to track targets.

At a distance of a few meters, the technique can deal with things in a
matter of microseconds.

These systems are easily adapted to controlling beams from space and
having the beams avoid unwanted targets while at the same time
illuminating desireable targets.

From LEO, the time delay is significant.

How high are the space-based beam emitters? Let's call it 300 km, so
the round-trip light travel time is a nice round 2 milliseconds. How
fast would you need to move your hand through the beam in order to
outpace its ability to avoid illuminating your thumb? Let's call the
width of your thumb a nice round 2 centimeters.

Two centimeters in two milliseconds. That's a nice round ten meters per
second. And it's an easily achievable speed. Wave your hand quickly
through the beam and the system won't be able to avoid your thumb. A
bird flying into the beam at a sedate ten miles per hour would have the
leading half inch of its head and wings exposed to the full strength of
the beam. A small aircraft flying at 200 knots would travel more than
20 cm in the time it takes for the active holographic technique to
respond.

And that's the last I'm going to say about it.



The length and style of the rest of your post have successfully
convinced me that you are indeed the William Mook you claim to be.
Congratulations.
.

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