Re: how the laser happened

On Tue, 25 Jun 2024 09:55:00 +0200, Jeroen Belleman
<jeroen@nospam.please> wrote:

On 6/25/24 00:02, john larkin wrote:

On Mon, 24 Jun 2024 16:22:31 -0400, Joe Gwinn <joegwinn@comcast.net>
wrote:
 

On Mon, 24 Jun 2024 00:22:06 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
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john larkin <jl@650pot.com> wrote:

On Sun, 23 Jun 2024 22:09:42 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>

john larkin <jl@650pot.com> wrote:

On Sun, 23 Jun 2024 18:08:52 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>

john larkin <jl@650pot.com> wrote:

On Sun, 23 Jun 2024 16:39:56 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
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On Sun, 23 Jun 2024 05:03:34 GMT, Jan Panteltje wrote:
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On a sunny day (Sat, 22 Jun 2024 17:23:40 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v571as$3rs0j$2@dont-email.me>:
>

On Sat, 22 Jun 2024 06:19:49 GMT, Jan Panteltje wrote:
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On a sunny day (Fri, 21 Jun 2024 11:32:56 -0700) it happened john
larkin <jl@650pot.com> wrote in
<1ghb7jt3882078r19n6jjgtirv25q27805@4ax.com>:
>

On Fri, 21 Jun 2024 17:56:36 +0100, Cursitor Doom <cd@notformail.com>
wrote:
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On Fri, 21 Jun 2024 06:05:21 -0700, john larkin <jl@650pot.com>
wrote:
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There was a thread somewhere above about photon wave/particle
duality.
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This is worth reading:
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https://www.amazon.com/How-Laser-Happened-Adventures-Scientist/dp/

0195153766

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Einstein, in one of his fits of genius, predicted in around 1916
that under the right conditions, a photon could pass by an excited
atom and the atom would kick in another photon, or add to the wave
amplitude, depending on how you feel about these things. He called
it stimulated emission. He also declared that the laws of
thermodynamics made this effect impossible to use in practical
situations.
>
In 1951, Charles Townes invented a work-around trick and built the
maser, a gaseous microwave oscillator. His superiors thought he was
crazy to dispute Einstein and almost threw him out of grad school,
but it worked.
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In 1960, Theodore Maiman at HRL made the first ruby laser, and Bell
Labs soonafter made a HeNe.
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What's interesting is that any decent neon sign shop could have
built a HeNe laser in 1920.
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HRL sounds like a very cool place, up in the hills above Malibu.

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Wasn't that where Jane Mansfield used to go out bathing?
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>

Keep your mind on electronics, young man.
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The Getty Museum is in Malibu. Go there if you can. Hearst Castle,
too,
up the road a bit.

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I've been to Malibu, even did some work there...
Did not go to any museum, but did go to the beach.

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Did you see Jane? What about lobsters? Any lobsters around?

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Na, but some other beatiful women I met.
Last time we went looking for edible seaweed ...

>
Argh! Never mind. I believe Jane had terrible problems with lobsters when
she went out bathing in Malibu. But you don't know anything about that,
clearly. It obviously wasn't publicised in Holland.

>
This thread is about lasers, not lobsters.
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>

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Well, Schawlow famously said, ?Anything will lase, if you hit it hard
enough.?
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I expect that includes lobsters.
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Cheers
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Phil Hobbs

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But no, seriously, there must be some laser action, or at least some
sort of stimulated emission, some sort of super-fluorescence, in
nature somewhere.

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Sure. Cosmic masers occur in interstellar giant molecular clouds, for
instance.
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The lifetime of suitable upper states drops steeply with increasing energy,
which means that visible laser action requires much stronger pumping.
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While that can in principle happen naturally, it would be in places with a
lot of other stuff going on, so it would be less noticeable.
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You don?t have resonators in interstellar space, so it wouldn?t be highly
directional.
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Cheers
>
Phil Hobbs

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I was thinking about a biological laser too.
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I could imagine an eyeball with some sort of stimulated emission
effect, in the vitreus humor or in the retina, to improve night
vision, basically a photon amplifier.

>
Difficult. For a start, you need a pump source of high intensity and
narrowish bandwidth, and there are no biological examples that I know of.

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Biology does make meta surfaces of various kinds, usually to make
reflectors impossible to make any other way, from beetles that look
iridescent to bird feathers.
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>

Nature seems to use any effect that's not flat impossible, whether
biologists approve or not.

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True, if there is a need.  Laser eyes seem like it would attract the
wrong kind of attention.
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Joe Gwinn

 
I was thinking of amplification to improve night vision.
 

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Nature chose the cheaper way: A cascade of amplifiying chemical
reactions.
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Jeroen Belleman

A photon might be absorbed and lost without invoking a chemical
response in the retina, and be wasted. A lossless preamplifier would
help.

There would be bandwidth issues, but nature is inventive.

The idea could be experimentally tested, fairly easily.