Why does collapsing a bubble with a sound wave produce light?

https://akshatjiwannotes.blogspot.com/2025/10/why-does-collapsing-bubble-with-sound.html

by akshatjiwan • 9 months ago

21 27 9 months ago

akshatjiwannotes.blogspot.com

HPsquared2• 9 months ago

I suppose it would also produce nitrogen oxides.

akshatjiwan6• 9 months ago

Very likely. The hot plasma generated would form oxides when it's cooled. I read a few papers a while back focussed around generating ammonia and other nitrogenous compounds. I can't find the link to the one I read but apparently other researchers are doing something simillar

https://arxiv.org/html/2505.23850v1

In air bubbles NOx would be likely but it would probably lead to nitric acid production after reacting with water. Here's a paper by NASA that pretty much confirms your intuition

https://ntrs.nasa.gov/api/citations/20050215681/downloads/20...

HPsquared2• 9 months ago

Interesting. Nitric acid could be a chemical signature that could be measured, then. Maybe ozone also? I'm thinking equipment monitoring for cavitation.

tobr• 9 months ago

Holy hypertext, this is a hard-to-read post.

dfedbeef• 9 months ago

Internet 5.0, every word is a link. Scrolling is done with your brain, clicking is done with by flexing your nostrils

unshavedyak• 9 months ago

Sneezes are security risks. Sounds neat

lloydatkinson• 9 months ago

I sometimes wonder what people are thinking (or apparently not thinking) when they link to their personal sites and blogs and it's totally unreadable. I think they are so used to it they don't see any problems with it.

defanor• 9 months ago

It looks a bit messy to me, neglecting usage of hyperlinks, but at the same time highly legible (does not mess with fonts, colors, or the layout too much), lightweight, works without JS, does not geo-block me or require to solve captchas, not paywalled, not blocked here, is straight to the point. So perhaps still more easily readable than most of the other submissions found on the HN front page.

akshatjiwan6• 9 months ago

Apologies. I write everything in plain text on my mobile and just copy paste it to blogger/fb. Most platforms automatically create clickable links (hn also does that) but apparently blogger does not do it.

I like full links on the post because it makes it easier to backup. If I embed them in anchor tags they'd have to be parsed from the formatted web page or I'd have to store data as an html file. I don't want to do that.

md is a good alternative and slowly I'm migrating my files to GitHub.

smusamashah• 9 months ago

Is there a better link?

uvaursi• 9 months ago

Are Reddit posts allowed to be submitted to HN?

_tk_• 9 months ago

What?

sophrosyne42• 9 months ago

1. How do you extract energy out of it? It's surrounded in a water bath that would evaporate leading to cessation of bubble formation.

Sounds like a perfect use-case for the tried and true steam turbine. You can never beat a steam turbine.

sandworm101• 9 months ago

Steam is the medium, not a fuel. Low-temp steam just above the boiling point doesnt carry much energy. It would also be very wet, which plays havoc with mechanical systems. I dont see how this tech could ever produce the hot/dry steam needed for turbines.

sodaclean4• 9 months ago

Sonoluminescence is not power positive. Fusion would be trivial to prove with a neutron detector- so saying "theres debate" is arguably dishonest.

Sonoluminescence is weird and awesome enough as is: cavitation that produces light.

akshatjiwan6• 9 months ago

Researchers have reported neutron detection but these results have not been reproduced and some scientists have attributed this detection to 'noise'. Bubbles are tiny they have very small amount of gas in them so detecting that is not exactly straightforward... I think

for example a in a 1um radius bubble the total mass of gas would be ~ 10^-18kg.

Personally I doubt fusion occurs inside bubbles. Even if we take the highest reported temp 30000K that's way below what's required for fusion.

Also bubble literature is full of fantastic claims—one that comes to mind is assertion that pressures of around 10Gpa can be generated which seems highly improbable because that's likely to induce phase change in the fluid.

However it's quite possible that I'm wrong. Because bubble science keeps on throwing new surprises.

Ekaros• 9 months ago

Wouldn't fusion also mean net energy generation? Or at least much higher than inputs... So there should be lot more energy in system than expected.

close04• 9 months ago

Collect it directly at the audio jack and skip the water-bubble-light chain entirely. You won’t get out more than the energy of the sound wave you put in, you’ll get quite a bit less actually.

docfort• 9 months ago

This was a passion of mine decades ago, but Putterman's lab jump-started interest after the cold fusion debacles. Some fun videos and pictures on the lab website. https://acoustics-research.physics.ucla.edu/sonoluminescence...

ortusdux• 9 months ago

A lot of work goes into minimizing cavitation in marine systems as it tends to waste energy and cause damage to propellers. That being said, there has been a lot of research lately into using sustained cavitation to purify and distil water. The energy released can be enough to boil water, kill pathogens, and generate free radicals to further sterilize the water.

https://iwaponline.com/wst/article/86/2/302/89569/Hydrodynam...

NoSalt• 9 months ago

I may not be a working professional in the field of physics - I only had a couple of classes in college - but I absolutely love physics! It seems like magic, and when you learn how it works, you feel like a magician. It's awesome!

akshatjiwan6• 9 months ago

It certainly is a great hobby. I'm not a physicist either but I keep reading papers and taking courses on YT about areas I'm interested in — Materials science,plasma, Electrostatics,fluids,thermodynamics etc.

Good thing is science doesn't change like tech. Once you learn something it's for life. No need to keep learning new frameworks/tools every year. It's stable and yet immensely flexible.

With AI research and studying has become a lot easier. Give it a try if you're interested.Now is a great time to start.

Why does collapsing a bubble with a sound wave produce light?

Related Stories