[LAU] Optical microphone sees sound like never before

[David Kastrup]

david <gnome at hawaii.rr.com> writes:

> On 6/22/22 10:57, David Kastrup wrote:
>> "David W. Jones"<gnome at hawaii.rr.com>  writes:
>>
>>> https://www.sciencedaily.com/releases/2022/06/220622101415.htm
>>>
>>> If sound can be seen optically, can it be generated optically? Say, to
>>> go with a hologram?
>> I was of the opinion that laser-based interferometry microphoning off
>> window panes had already been standard fare of secret services for
>> decades.  I don't think you really want to use the kind of lasers that
>> successfully push surfaces around.
>>
>> Plasma speakers<https://en.wikipedia.org/wiki/Plasma_speaker>  are
>> enough of a high-energy ickiness.
>>
> Yah, I thought that a laser able to generate sound would be a bit too
> strong to use around people.
>
> Plasma speakers. Fascinating. Is there a connection between the volume
> of the plasma and the frequency range it can produce? Such as, needing
> a bigger box of plasma to produce bass frequencies?

I have no idea whatsoever.  It doesn't sound too healthy to be breathing
around those things.

> I think my favorite sound-producer is still a pipe organ in a
> cathedral. :)

There is a reason you'll find no pipe organ these days that will work
when electricity fails.  In times before electrification, bellows duty
was hard work.

Reed organs or their little nieces accordions are a lot more economical
with air.  And lots of instruments are more economical with energy than
most loudspeakers.  That isn't all surprising, given that they work with
dedicated oscillators while loudspeakers cannot afford resonances.

-- 
David Kastrup