Warfare at the Speed of Light

unassimilatible writes "From the They Said It Couldn't Be Done Dept., the Oakland Tribune reports that the Lawrence Livermore Labratory is ensuring that the Pentagon, inside of a decade, could be armed with a beam weapon that is near-instantaneous, gravity-free and truly surgical, focusing to such hair-splitting accuracy that it could avoid civilians while predetonating munitions miles away - perhaps someday even being mounted on Humvees."

Predicting the future

[Kufat]

It's pretty funny that in the 50's, SF writers thought we'd have weapons like this and things such as moon bases by about 1980, but they also that there would be superpowerful computers...with vacuum tubes.

Re:The ultimate defense

[jjohnson]

Not really. That's like saying you can simply swat bullets away. There's too much energy in lasers for common mirrors to reflect--they simply melt. As I understand it, modern mirrors for targetting lasers are wicked things like nitrogen-cooled mercury, controlled by pizoelectrics.

Re:Weapon?

[skintigh2]

I'm sure there must be a civil use for such a laser, but I can't think of one.

Using a laser as a rock drill is probably the least efficient method of drilling possible, it would make poisonous fumes, and those fumes would block the laser beam.

As for missiles, if the missle is shiney the laser will be reflected. I think.

The moon idea might work... maybe the fumes would disperse faster in zero atmosphere, and it might be cheaper than sending equipment.

I would guess a high power laser would vaporize a kernal before it could pop, but I would love to see a test!

"Laser"
"Laaaaaaaser"
Sorry, I had to get that out of my system.

Medical research vs Military research

[hotwheel]

When will we stop spending R&D money on weapons and start spending on disease control, and quality of LIFE programs? I know of a half million people with spinal cord injuries who would gladly forgo laser-based weaponry so they might forgo the use of a wheelchair. Does anyone have budgetary numbers reflecting the spending variances between medical and military R&D in the public sector / private sector?

Re:They've done it already!

[nihilogos]

The main problem is that any reflecting surface can act as a mirror, meaning that you are constantly at risk of the laser beam bouncing back and obliterating you.

I am guessing that "lasers of mass destruction" would operate in the ultraviolet. There aren't many materials that will reflect ultraviolet light back at you. At best it might glance off a mirror if it hits at a shallow enough angle.

range evaluation of Laser Weapons

[jonniesmokes]

From my internet research of high energy lasers, it appears that the longest range that a laser will have in the forseable future is 6 miles through the atmosphere. In space a laser can go forever, but in the air thermal blooming, atmostpheric turbulence and normal attenuation make it impossible to blast things farther.

Thermal blooming is a big problem. A laser heats up the atmosphere around it which causes the index of refraction of the air to change which changes the direction and focus of the beam. And this is a non-linear chaotic system. You can't aim a beam a long way through the atmosphere. So that mean you can't use laser beams to shoot down incoming missiles unless you station the laser really close to the targets. And even if you do that, you can only start shooting when the missile is within 6 miles or so of the target. And even then if its bad weather - no go.

Laser weapons have some fundamental physics problems to overcome. It would be good if the US goverment told the tax payers about this before spending tons of money on them.