Missile Defense

"...Nobody who has ever shot a gun at a target, and experienced how hard the bullseye is to hit, compared to the outer circle, can possible believe that..."

That's a baseless assumption about what folks can believe, Robert. Ever shoot a gun that has no recoil and whose masless bullet travels at 300,000km/Sec? Of course not...

What does Napolean's first artillery course have to do with laser aiming, Robert?..

Few things would seem to be impossible , smartalix but spinning an ICBM that needs to be guided to a very specific trajectory to release its MIRV bus would seem impractical. Remember that the inertial navigaion system for an ICBM controls a vectored thrust rocket...

To melt a piece of ice, you have to heat it to its melting temperature, and then add the heat of fusion -- everybody knows that...

What we were talking about, Robert was locating and tracking the target. According to dirac, a lower power wider beam laser would be used to illuminate the actual rocket body so that the high power narrow beam laser can hit it...

That is that, for controls, you need optical quality (small spreading angles) maybe 10-20 times more precise than Space Telescope has.

Even if your information input for targeting was perfect (and it isn't).

Things expand when heated, and do it unevenly, and things distort.

And for Space Telescope levels of presision (not good enough for a death ray) just a little distortion messes up the optics beyond all hope and caring.

Excellent response. I underestimated you.

Regarding a rotating missile during launch, why would it be impossible?..

Didn't see this post before, smartalix or I would have answered right away...

Yes, the inverse square law does apply but you need to consider that it applies within the solid radial volume of the beam. For example a point source like a distant star radiates all its energy into a spherical volume, 2pi radians on each axis...

Miracles found by people who can barely be trusted to check simple trigonometry and optics -- and do simple energy balances.

Gisterme, I think the example you chose, to support your position, actually argues strongly against it.

Naa. That was 1969 technology...

sets out some technical arguments clearly, but it seems to me, when I check, and you can check too, that it makes the implicit assumption that, for a lasar weapon system, "what you can see you can hit."

MD6410 http://forums.nytimes.com/webin/WebX?14@63.Wfkma5HHEaS^3801225@.f0ce57b/6897.... MD6411 rshowalter 7/2/01 4:42pm
MD6413 rshowalter 7/2/01 4:53pm .... MD6414 rshowalter 7/2/01 4:56pm
MD6415 rshowalter 7/2/01 5:05pm ....

" What are the characteristics of the thing you're shooting -- how do properties of the bullet (or lasar beam) change with distance?

Lasar light is better than ordinary light because it is in phase -- and phase interactions don't cause it to spread as it travels -- so lasar beams can be very intense, and they can be as tight as the optics that generated them.

That optics generates a spreading angle -- and the spreading angle will be greater (for a real military lasar - which is a chemical lasar -- much greater) than the angular resolution of Space Telescope...