23 Jun
2022
23 Jun
'22
12:47 a.m.
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?
---
David W. Jones
gnome(a)hawaii.rr.com
exploring the landscape of god
http://dancingtreefrog.com
Sent from my Android device with F/LOSS K-9 Mail.
23 Jun
23 Jun
12:57 a.m.
"David W. Jones" <gnome(a)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.
--
David Kastrup
1:29 a.m.
On Wed, Jun 22, 2022 at 10:57:10PM +0200, David Kastrup wrote:
I was of the opinion that laser-based interferometry
microphoning off
window panes had already been standard fare of secret services for
decades.
Indeed this not new, and there are many variations of such methods.
Some don't even use a laser, just a high speed camera.
To be precise, none of them actually pick up sound. They capture
vibrations which are either caused by sound (as for eavesdropping),
or which cause sound (when recording an instrument such as a guitar).
Even the method used in this case to measure the interference is not
really new, it has been used mutatis mutandis in other applications.
--
FA
9:45 a.m.
On 6/22/22 10:57, David Kastrup wrote:
"David W. Jones"<gnome(a)hawaii.rr.com>
writes:
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 think my favorite sound-producer is still a pipe organ in a cathedral. :)
--
David W. Jones
gnome(a)hawaii.rr.com
authenticity, honesty, community
http://dancingtreefrog.com
"My password is the last 8 digits of π."
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.
2:53 p.m.
david <gnome(a)hawaii.rr.com> writes:
On 6/22/22 10:57, David Kastrup wrote:
I have no idea whatsoever. It doesn't sound too healthy to be breathing
around those things.
"David W.
Jones"<gnome(a)hawaii.rr.com> writes:
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?
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.
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
29 Jun
29 Jun
10:37 p.m.
New subject: organ bellows duty (Re: Optical microphone sees sound like never before)
David Kastrup:
...
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.
...
There are still pipe organs that you can manully power.
We have one here in Börstil, and yes I have tried it in 2008.
Here are some random pictures from that day:
http://aspodata.se/tmp/organ/
Regards,
/Karl Hammar
912
days inactive
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days old
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karl＠aspodata.se