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New Technology Uses Lasers to Transmit Audible Messages to Specific People

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Re: New Technology Uses Lasers to Transmit Audible Messages to Specific People

#61

Post by ricardobeat »

koonsolo wrote: post #47
rkagerer wrote: post #35

Earlier quoted context omitted.

Those depressing sentiments reflect an unfortunate reality of our time. The world wasn't always bloated with spammy advertising, and I'm hopeful that fad will eventually give way to more human-friendly business models. Yes, any new technology comes with potential for abuse. But I'm still excited that maybe one day this tech could be miniaturized enough (or deployed responsibly) to give me wireless virtual earbuds wit…

A consumer always pays, whether by paying or looking at advertisements. But the modern world offers nice alternatives now. I can watch movies and episodes without ads (thanks to Netflix), and can listen to all the songs in the world without ads (thanks to Spotify). Because I pay instead of watching ads. A lot of platforms and products offer the choice between looking at ads or letting you pay. But of course, everyone…

That’s a very bright view that doesn’t fully account for reality: Netflix has a tiny sliver of humanity’s film archive available, and while Spotify fares much better it still excludes a lot of content. In general you cannot pay to see the missing pieces in either, they are simply not available anywhere.

Re: New Technology Uses Lasers to Transmit Audible Messages to Specific People

#62

Post by ricardobeat »

gmueckl wrote: post #55

Two big caveats with this tech (from the paper): - it's really silent. They claim that the signal is audible, but under pretty much ideal conditions. - creating arbitrary sound with this approach is hard. Each laser sweep generates a sharp wavefront that is audible, but that only eorks ehen the sweep is at the speed of sound. This limits the frequency at which you can emit those pulses and their shape is fixed, too.…

It states 60db - that’s normal conversation volume. Does the paper say otherwise?

Re: New Technology Uses Lasers to Transmit Audible Messages to Specific People

#63

Post by ddorian43 »

bryanrasmussen wrote: post #53
webdwarf wrote: post #38

Imagine the scary future of retargeting. - Doctor, I hear voices in my head - Don't worry, it's just ads

I wonder if you could, with the right combination of technologies, induce schizophrenia in a subject. Of course since I am in Europe my wondering will not be turned into a DARPA grant.

Schizophrenia has multiple symptoms. Currently there's only "hearing voices".

Re: New Technology Uses Lasers to Transmit Audible Messages to Specific People

#65

Post by gmueckl »

ricardobeat wrote: post #62
gmueckl wrote: post #55

Two big caveats with this tech (from the paper): - it's really silent. They claim that the signal is audible, but under pretty much ideal conditions. - creating arbitrary sound with this approach is hard. Each laser sweep generates a sharp wavefront that is audible, but that only eorks ehen the sweep is at the speed of sound. This limits the frequency at which you can emit those pulses and their shape is fixed, too.…

It states 60db - that’s normal conversation volume. Does the paper say otherwise?

I could not find a reference to 60dB in the paper. It states 30dB SPL in the relevant plot, which is very quiet.

Re: New Technology Uses Lasers to Transmit Audible Messages to Specific People

#66

Post by gmueckl »

diegoperini wrote: post #39
amenghra wrote: post #26

There are stories of people having their orthodontic braces act as a radio antenna. Only the person with the braces would hear something. This writeup is short: https://www.recordonline.com/article/20091118/Health/9111803... . There's also a (busted) Mythbusters around picking up radio signals thru fillings.

It would be so cool if that's the way how radio technology was discovered.

No, that was absolutely not what happened. The discovery of radio waves happened in two parts: first, Maxwell completed the fundamental equations for electrodynamics by postulating that a temporally changing electrical field must be creating a magnetic field around it. Otherwise the behaviour of plate capacitors would be inconsistent. This brought the equations into a form that rather obviously allowed the derivation of a wave equation. Then it took about 20 years IIRC until Hertz managed to prove in his lab that these waves exist and can be both created and detected.

Re: New Technology Uses Lasers to Transmit Audible Messages to Specific People

#67

Post by bryanrasmussen »

ddorian43 wrote: post #63
bryanrasmussen wrote: post #53

Earlier quoted context omitted.

I wonder if you could, with the right combination of technologies, induce schizophrenia in a subject. Of course since I am in Europe my wondering will not be turned into a DARPA grant.

Schizophrenia has multiple symptoms. Currently there's only "hearing voices".

hence the phrase: right combination of technologies.

Re: New Technology Uses Lasers to Transmit Audible Messages to Specific People

#68

Post by gmueckl »

danielecook wrote: post #17

I don’t understand it entirely. What do they mean when they say they are sweeping the laser at the speed of sound?

This is unintuitive: the laser makes air heat up and expand. This is how the acoustic waves are created. But this alome is not enough for audible sound. Higher amplitude is required. They get it by "piling up" a wavefront (in colloquial terms) by moving the laser exactly as fast as the wave is moving away. This heats up more air and the additional expansion adds to the already traveling wavefront.

Re: New Technology Uses Lasers to Transmit Audible Messages to Specific People

#69

Post by ddorian43 »

bryanrasmussen wrote: post #67
ddorian43 wrote: post #63

Earlier quoted context omitted.

Schizophrenia has multiple symptoms. Currently there's only "hearing voices".

hence the phrase: right combination of technologies.

Missed that, sorry. Maybe with a psychotic pill (like there's atypical antipsychotics)
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