Re: A new tool for in-building work

[Robert "J." Hansen <rjhansen@xxxxxxxx>]

> Maybe so, but it'll never see through walls - it's Laser technology,
> not Radar technology!

The really cool thing about free-electron lasers is that you can tune
them to emit just about any wavelength you like--including radio waves.
So yes, it is possible to make a laser that sees through walls.  :)
Although I really, really doubt this device is a free-electron laser...

> I'm dubious about this 'radar flashlight', though; remembering hos Tom
> Clancey was hooked on a peice of sci-fi tech that would never have
> worked in the first place, and with no offence to the other Roger, not
> withstanding hand held battle field radar systems, are we sure this
> hand-held flashlight radar tech actually (a) exists, and (b) works as
> advertised?

I share in the skepticism, but Georgia Tech is generally regarded as one
of the US's finest engineering schools.  If such a device *did* exist,
I'd expect it to have come out of Georgia Tech or someplace similar.

The prior device--the Electro Kinetodynamics Somethingorother--was
flawed because they claimed that it listened to the characteristic radio
signal of the human heart.  The problem is that to pick up a radio
signal that's emanating at between 1 and 2 Hz, you'd need a huge
antenna.  At 1 Hz, your wavelength is 300 million meters.  I'd love to
see a half-wavelength or quarter-wavelength antenna made to pick up that
signal...