Radio waves vs light waves

So why can't we use high-intensity lights powered by a nuclear reactor
as a source of space propulsion?


They can. But the F is small, so you need a lot of t to reach much of a v, as
long as you are far enough from a g.

Such systems have only been developed in science fiction however because we are
not yet doing enough interstellar travel, and people are uncomfortable with
nuclear reactors in space.

Jose

--
(for Email, make the obvious changes in my address)

radar technicians have accidently had eye damage from looking into a working
antenna...


or even looking away from... as proximity is the only important factor, not
orientation.

Jose


--
(for Email, make the obvious changes in my address)

John,

....Compare with Bosons, which like to be in the same state.

Not true. There used to be great herds of bosons, and they would roam
across several states in the great plains. They're gone now.


But now, the Bozos roam there.

--
Thomas Borchert (EDDH)

"Peter Duniho" wrote in message ...
"Ross Oliver" wrote in message
...

Everyone else has focused (!) on wavelength, but no one has mentioned
radiated power.

That's because the question was "does my lens focus the radio waves", not
"is my retina being cooked".

There have been cases of people getting their eyeballs and other body
parts "cooked" by exposure to strong RF, particularly microwaves, due
to the same principle by which your (duh) microwave oven works. Tissue
damage occurs because of simple heating of molecules of matter from
the sheer raw power of the RF, not due to any "focusing" of
wavelengths.

The eyes, due to the high water content, are especially susceptible to
such damage.

"Dennis O'Connor" wrote in message
...
Larger is better, however... Look at the dish at Arecibo for example..
http://www.rainforestsafari.com/observe.html

Radio antennae such as that one use reflection, not refraction, to focus
radio waves. In fact, I'm not aware of a single refractor radio antenna.

Similarily, a camera lens that works efficiently at lower light levels
will
be larger in diameter for a given focal length than one that doesn't work
as
efficiently... i.e., an f:2.8 lens versus an f:1.4 lens..

Larger optical lenses are "faster" (i.e. lower f- number) because they
gather more light. It has nothing to do with wavelengths.

Pete

"One's Too Many" wrote in message
om...
There have been cases of people getting their eyeballs and other body
parts "cooked" by exposure to strong RF

So?

"Teacherjh" wrote in message
...


Ok, so just what IS a photon?

A photon is a contrivance that has turned out to be unnecessary. (see "In
search of Schrodinger's Kittens")

"Tim Witt" wrote in message
om...
Jim Weir wrote in message
. ..
You kept it out of technobabble, but you kept it far from the truth.

So how about explaining what was untruthful, rather than offering a
drive-by shooting critique. I read these posts to get smarter not as
a forum for putdowns.

Mr. Weir gets offended when people post over his head. It is only his way
of expressing his displeasure.

Weir is a big asset to small GA, so he can pretty much express his
displeasure as he pleases.

"Peter Duniho" wrote in message
...
"Ross Oliver" wrote in message
...

Everyone else has focused (!) on wavelength, but no one has mentioned
radiated power.

That's because the question was "does my lens focus the radio waves", not
"is my retina being cooked".

A front silvered mirror will.

"Teacherjh" wrote in message
...

So why can't we use high-intensity lights powered by a nuclear reactor
as a source of space propulsion?


They can. But the F is small, so you need a lot of t to reach much of a
v, as
long as you are far enough from a g.

Such systems have only been developed in science fiction however because
we are
not yet doing enough interstellar travel, and people are uncomfortable
with
nuclear reactors in space.

Here is something interesting Jose.

Although light is not conducted like RF, light behaves very much like RF in
a wave guide.