Ask HN: Is there microscope equivalent for sounds? | Hacker News Reader

Ask HN: Is there microscope equivalent for sounds?

39 pointstarikozket25 comments

For instance, are we able to hear DNA's sound yet? Is it possible?

The previously posted comment that includes the statement, "But, I think at small scales sound is closer to buffeting (like how water is the consistency of gelatin for microscopic organisms, waves can't propagate)" at least gets to the idea of fundamental physical constraints. Brownian motion[1] shows that movement of molecules (which is what sound is) happens through mechanisms that don't scale down as well as propagation of light. You can magnify light down to images of much smaller objects than you can listen to sounds from small objects because small objects don't make specific sounds, but rather are buffeted around themselves by essentially random motion of the fluids that surround them.

[1] https://en.wikipedia.org/wiki/Brownian_motion

Sound can be recovered partially from visual observations of any vibrations (to some degree, this is your how CD works). So technically, you can 'listen' to bacteria with a compound phase contrast microscopes, which are used to observe living organisms.

With DNA its trickier. First of all, it's too small to be seen using compound (optic) microscopes. While an electron microscope scans a specimen, so either you have to do its with a frequency way higher than any vibrations, or 'focus' on a single place to 'listen' to it (pico stethoscope). There are few further complications, such as you may burn a hole though the specimen, not forgetting that it also requires special treatment to be observed in an electron microscope.

This was interesting story from 2014 http://newsoffice.mit.edu/2014/algorithm-recovers-speech-fro...

At a party I met an artist at residence at MIT who claimed to have a Eukaryote sized hook stepping force up to a man sized fly fishing rod.

But, I think at small scales sound is closer to buffeting (like how water is the consistency of gelatin for microscopic organisms, waves can't propagate)

Joe Davis. http://www.viewingspace.com/genetics_culture/pages_genetics_...

We can amplify very quiet sounds. But I'm not sure why you want to "hear DNA's sound" and considering that biological processes occurring at the organ level will be much louder, it would be difficult.

DNA's resonant frequency is in the gigahertz range, so you won't be able to hear it anyway.

Sound is a bulk movement in some medium. So there isn't a useful concept of sound when you're dealing with atomic or molecular phenomena.

If individual atoms move at all they do it at very high frequencies. So there's no bulk audible movement to amplify.

The equivalent of increasing visible angular resolution would be increasing the sample rate and slowing the replay rate. You can do this easily for audio sample rates, and with a lot of extra equipment and a bit of hand waving you can convert optical or RF sampling to audio. But it still doesn't quite map to hearing in the way that microscopy maps to sight.

Any changing value that is not a perfect progression can be converted into sound.

If you can measure it and it's changing rates, you can transform it into the human audible range.

Edit: It would likely be more interesting to listen to the DNA sequence itself. That is possible, though so far I'm just seeing an interpretation of the dna letters into musical notes: http://www.tokenrock.com/dna_music/dna_into_music.php instead of something like raw data to pcm... Not a clean transformation.

Related to this topic, there are some ways of visualizing sound. Some options are:

* Spectrograms: https://en.wikipedia.org/wiki/Spectrogram

* Vectorscopes: https://en.wikipedia.org/wiki/Vectorscope

Digital audio workstations [DAWs] (used often by producers of electronic music) have lots of tools for visualizing audio in this way.

Here's an example of how some of the above work in FL Studio, a popular DAW: https://www.youtube.com/watch?v=jfnWlLS6Bqg

Something like a highly focused, microwave frequency carrier, laser doppler vibrometer? ;-)

You can listen to collisions at the LHC!

http://lhcsound.hep.ucl.ac.uk/page_sounds_higgs/Higgs.html

Of course these collisions don't actually make sound, these are "sonifications" of data recorded by the ATLAS detector, for some interesting events.

http://lhcsound.hep.ucl.ac.uk/page_sonification/Sonification...

There was a great talk on Ted by Michael Rubinstein, with cameras they are able to extract audio from objects (visually) and they are able to detect the tiniest motions on magnify them, definitely worth watching:

https://www.ted.com/talks/michael_rubinstein_see_invisible_m...

It's a bit like asking whether there is a microscope for color. Color is how we perceive certain wavelengths of light. Sound is how we perceive certain frequencies of waves propagating through air. There are ways to look closely at light, and ways to closely observe vibrations in a medium, but color and sound are in our minds.

Light and sound are physical phenomena that can be measured, reproduced, and ultimately amplified. The microscope is an example of very direct amplification, which has no parallel for amplifying microscopic sounds that I am aware of.

Well if the microscope is an amplifier of light then of course the amplitude of sound can also be increased, and sounds that were too faint to be audible may become audible. There's your parallel. I can't say whether the analogy is actually well-founded, because I don't know whether it makes sense to speak of magnification as amplification. It strikes me as off, though. A large mirror can amplify light by collecting more of it, without magnifying the resulting image, can't it?

I think one of the issues with the microscope analogy is that microscopes provide their own light source and the object obstructs the light to produce a signal. The objects themselves don't emit light, where as the DNA is assumed to already be emitting sound (vibration) that needs to be amplified.

If I had to picture a "light amplifier" I would think of a laser or something like a photomultiplier/image intensifier tube, not so much a microscope.

Not sure what a "sound magnifier" might actually be. There exist apparatuses called "acoustic lenses" but I don't believe they are used for applications that might be considered analogous to a microscope. Perhaps something like a stethoscope, or just a horn (think of the horn on early gramophones) might be considered as allowing humans to hear sounds that would otherwise be too faint to hear.

A microscope reflects light off an object to measure its optical properties, and bends the light with a lens to magnify its size.

The audio equivalent would be more of a sonogram than the amplifier I think you are looking for.

While off the topic, I always thought a stethoscope was like a crude microscope for sound :)

a laser interferometer can be used as a "sound microscope" by projecting the fringes and converting them to sound with a photodiode.

Yes, it's called a stethoscope.

oh my mistake it has been done http://viewingspace.com/genetics_culture/pages_genetics_cult...

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