Talk-Polywell.org

While the idea is feasible per se (even if placing a 50-70GW laser with annexed power is something I would call more than just "complex" as the author does), I am not a big fan of such a technology.
Not being able to stop and actually "explore" the targeted star system makes the whole project of a limited value.

I like it.

High resolution video of our closest neighbours is a lot more valuable in my mind than a multi-billion dollar space based gravity wave detector.

I wonder if you could launch small payloads with a combination of ground and space based laser arrays.

Fibre lasers are pretty amazing things. They are only getting cheaper.

Not being able to stop and actually "explore" the targeted star system makes the whole project of a limited value.

While I agree in concept, there is value to getting a flyby probe to collect and transmit data back. That said, it would certainly be a long research project.

For slowing down there are electromagnetic drag sails of various configurations.

Crawdaddy wrote:I like it.

High resolution video of our closest neighbours is a lot more valuable in my mind than a multi-billion dollar space based gravity wave detector.

I wonder if you could launch small payloads with a combination of ground and space based laser arrays.

Fibre lasers are pretty amazing things. They are only getting cheaper.

According to WUWT, they could pay for it by reallocating the NASA climate budget.

One use of this technology they didn't mention would be to stand off the system a good distance in space, and point your wafer craft at a target on earth. A small hardened bullet size payload of a few grams accelerated to relativistic speed. Too small and fast to be detected by radar, no time to react.

You might not know what the target was, but the laser driver would not be overlooked.

hanelyp wrote:You might not know what the target was, but the laser driver would not be overlooked.

The Mote in God's Eye

KitemanSA wrote:

hanelyp wrote:You might not know what the target was, but the laser driver would not be overlooked.

The Mote in God's Eye

Incidently, a title of a great Niven book! Although I don't think you meant the book, just using the meaning.
For relativistic weapons, I was reminded of a much less known book called The Killing Star, by Charles R. Pellegrino and George Zebrowski. Very depressing book, but worth reading IMO.

JoeP wrote:

KitemanSA wrote:

hanelyp wrote:You might not know what the target was, but the laser driver would not be overlooked.

The Mote in God's Eye

Incidently, a title of a great Niven book! Although I don't think you meant the book, just using the meaning.
For relativistic weapons, I was reminded of a much less known book called The Killing Star, by Charles R. Pellegrino and George Zebrowski. Very depressing book, but worth reading IMO.

Actually, I did mean the Niven/Pournelle book. Best of the series, though the Gripping Hand was not too bad.

Went over a bit on relativistic weapons on another forum recently.

How long does it take to get up to speed? How far out does that put you, and how much warning? Light will always travel faster, so the launcher/accelerator lasers will always be visible before the projectile hits, it's just a matter of how much warning you have.

If the material to build exists on the far side of the moon, and the Nazi leaders and scientists escaped there at the end of the war, they could build thousands of laser drivers, park them in orbit way off behind the moon. Then when the moments right, they launch. The light source would remain concealed since they aim for where the targets will be later at quarter light speed.

Relevant:
http://arstechnica.com/science/2016/04/ ... -centauri/

http://www.nytimes.com/2016/04/13/scien ... wking.html

"Within two minutes, the probes would be more than 600,000 miles from home — as far as the lasers can maintain a tight beam — and moving at a fifth of the speed of light."

If the target was the Pentagon, or Kremlin, Statue of Liberty, etc., there wouldn't be much time to detect the Laser Driver, especially if the laser sail obscures it. After that, your trying to detect a bullet attacking you at quarter light speed.

Good luck with that.