On Wed, 30 Sep 2015 14:50:08 -0700 (PDT), wrote:

On Monday, September 28, 2015 at 7:28:37 PM UTC-4, Ed Huntress wrote:
On Mon, 28 Sep 2015 18:54:39 -0400, "Jim Wilkins"
wrote:

"Ed Huntress" wrote in message
.. .
On Mon, 28 Sep 2015 14:37:47 -0700 (PDT), wrote:

On Sunday, September 27, 2015 at 3:37:38 PM UTC-4, Ed Huntress
wrote:
On Sun, 27 Sep 2015 15:15:06 -0400, Joe Gwinn

wrote:

In article , Ed
Huntress
wrote:

On Sun, 27 Sep 2015 11:06:54 -0400, Joe Gwinn

wrote:

In article , Martin Eastburn
wrote:

Well you are looking at baby lasers.

In the 70's - late - I saw a 8 'barrel' cut 1/2" steel plate
like butter.

Lasers are for Engineering and Research are different than
the
table top lasers used to study lenses.

All it has to do on an ICBM or MIRV is to create a bump or
snag.
A high energy pulsed machine gun type would cause massive
friction
burns that melt down by friction any ICBM or MRV.

This isn't new technology. The magic in this stuff is shoot
an ICBM with a shotgun and it kills itself.

Unless one is well-placed over enemy territory, the launch
rocket is
out of reach. At the target end, it's raining reentry
vehicles, each
of which is equipped with a very good ablation shield to
survive
reentry. It takes a very large laser to drill that shield.

Joe Gwinn

The lasers Martin is talking about were the chemical lasers
that were
pumped with a chemical reaction, and that could put out a
continuous 1
MW beam. They've been abandoned as weapons for several reasons.
They
just aren't practical.

The laser types being developed now are solid-state, mostly
diode-pumped fiber lasers developed from industrial cutting and
welding lasers.

There are other types of lasers under development that hold
promise
for weapons. Right now, in industry, we're all waiting for
high-power
direct-diode lasers. There are some prototypes working now.
They could
make extremely compact weapons.

Yes, but megawatts are really not enough - everything is too
critical
to carry off under battlefield conditions. Needs to be tens of
megawatts, and a hundred would make this a duck shoot against all
but
reentry vehicles (which will spin and have mirror finishes by
then).

These issues and stories come up in Aviation Week from time to
time.

Joe Gwinn

Well, how much you need is a matter of what you're trying to do.
Right
now, fiber laser bundles putting out on the order of 30 kW are
able to
shoot down drones and disable speedboats. They apparently can
shoot
down small rockets, like the ones Hamas and Hezbollah shoot at
Israel.
The Israelis want a bunch of them, fast.

At 100 kW, you have a pretty useful battlefield weapon. They'll
have
that soon. At 1 MW, you're able to burn through some armor.

For the shorter ranges they're working with now, it's more a
matter of
focus (BPP, if you're into lasers) and tracking. The beam(s) is
focused with lenses; it doesn't depend on the parallel beams
themselves. The tracking must be absolutely amazing to place a
steady
laser spot on a flying drone for a few seconds and shoot it down,
but
that's what the shipboard systems can already do.

Star Wars is still a ways off.

Again, that's because since the Spanish American war and the time of
Nicola Tesla the US military has financially focused in on metal and
chemical fashioning side of the military (that benefitted fossil
fuel concerns) and relatively nothing went toward military
electrophysics or electromagnetic research and production.

You seem to have a belief that the military could create magic if
they
just knew what technologies would be available 50 years in advance.

As for long-range Star Wars lasers to knock out ICBMs, what do you
do
if it rains?

--
Ed Huntress

When I was closely involved with that stuff, before the push toward
COTS, military electronics were about 20 years ahead of civilian use.
https://en.wikipedia.org/wiki/Commercial_off-the-shelf

Remember the comment that the missing Malaysian airliner could have
been tracked if it carried the right technology? I built prototypes of
it in ~1995.

-jsw

DARPA has pushed laser technology for decades.

That's beside the point. The military has always devoted the lion's share of resources to other areas. Fighters, bombers, infantry, self-propelled armor, etc. Weaponized electrophysics got hardly any comparable financing.

I don't think you're right about that. The government has funded a lot
of laser research. During Star Wars, it was a huge amount.

The understanding of laser physics took some time. If you look at the
earlier books on lasers versus what it known today, it's startling.
I'm having a heck of a time keeping up just with the industrial
developments.

Research sometimes takes time and coming up with ideas more than just
money.

--
Ed Huntress