116 comments

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very cool! Can we get a link to a not terrible website with real information?
> Performing security verification

> Verify you are human

Does anyone else command + w on first sight of a cloudflare screen?

I'll tolerate that but that new QR recaptcha that wants a selfie is 'hell fucking no' from me 100% of the time.
I sure hope humans are in the loop at those companies, reviewing pics that aren't recognized as faces. If I ever see one of those captchas, they'll get to see some things that no human has ever, or should ever, see.
There are captchas that demand selfies now? I have never heard of that before and it sounds completely crazy.
Nah, I just have my clanker deal with it. It's better at those stupid puzzles than I am.
Cloudflare doesn't do puzzles. It either says you're a bot or you're not a bot.
Love when something decides I'm a bot and the decision is final. (Looking at you, CPU-World -- it even lets me know my IP address has been banned for "abuse", too.)
Right. Because IP addresses uniquely identify people. /eyeroll
Even if I were behind CGNAT (which I'm not), you don't see that message if you're already blocked. They won't even serve you the signup page then.
Patchright is a patched playwright that clears turnstile and other similar automation hostilities
> Ángela Karime Venegas Hernández is 16 years old and has an idea no one else had.

...meanwhile, some folks were doing this at George Mason University were doing this back in 2015[1]:

> The fire extinguisher uses low-frequency sound waves to douse a blaze. Engineering seniors Viet Tran and Seth Robertson now hold a preliminary patent application for their potentially revolutionizing device.

[]: https://patents.google.com/patent/US10569115B2/en

[1]: https://www.youtube.com/watch?v=uPVQMZ4ikvM

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This exists and we still put out fire with spraying water?

Why do we live in stone age and work on slop machines instead?

Pangram reports 100% AI; it may be an artifact of translation, but...
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Wtf is wrong with you? This time it was invented by a non-White non-male which is much more impressive.

Cool extinguisher, Angela. Want to bring it to the White House?

I'll bet that high school girl's science was better than what's in that youtube (it wouldn't be hard)
that comparison says more about you than about how high school girls science is
This channel (The Action Lab) is great, it sets an amazingly high standard for clarity of explanation, and for practical combination of experiments and theory, all while being appealing to a broad audience. Most educators would be extremely proud to produce work that's accurate to the standards of a university professor, while remaining appealing to middle-schoolers. I can't imagine what more you want from the content.
he called oxygen the fuel for the fire
tl;dr -- aside from the point about fuel, you mostly don't disagree with him. You have different definitions for the same terms he uses, and you draw your system in a different place than he draws his. Both of you make reasonable choices. A youtube video is not an academic paper, and cannot start by rigorously defining the system under discussion.

> he called oxygen the fuel for the fire... it's not the fuel for the fire

I think you're correct here, from chemistry definitions oxygen is not fuel, because breaking its bond consumes energy rather than releasing it. However, I don't think the host is trying to give perfectly precise chemistry definitions here, he's trying to explain how fire burns, and calling oxygen 'fuel' makes it clear to his audience that oxygen is required for combustion. I think your objection here is similar to objecting that voters in the US elect electors rather than candidates -- it's correct, but not necessary if you're explaining the concept of democracy.

> the port actually decreases the efficiency of the speaker by letting the negative bass note sine waves cancel out the positive sine waves from the front of the speaker, but this is done to tone down the "boominess" of the speaker at its resonant frequency, thus making the speaker more "neutral" sounding

I don't know much about bass reflex speakers, but I read the wikipedia page in decent depth, and it appears to me that you are wrong, or perhaps using a different definition than the field itself uses. From the wiki page: "This port enables the sound from the rear side of the diaphragm to increase the efficiency of the system at low frequencies as compared to a typical sealed- or closed-box loudspeaker or an infinite baffle mounting... Depending on the exact relationship between driver parameters, the enclosure volume (and filling if any), and the tube cross-section and length, the efficiency can be substantially improved over the performance of a similarly sized sealed-box enclosure." [0]. I bet I can see where your disagreement comes from though -- I think you're arguing that adding the reflex speaker cancels some of the power going through the main speaker, and therefore must result in decreased total_power_out/total_power_in (forgive me if I misunderstand). This is a sensible way to define efficiency, and I think you're correct that total_power_out is strictly decreased. However, there are also other sensible ways to define efficiency, eg, instead of total_power_out you might care about the perceptually-weakest frequency the speaker generates, to ensure the sound is "balanced" to a human ear. You might then define efficiency as num_spectral_bins*min_weighted_spectral_power_out/total_power_in. I have some experience optimizing perceived smoothness, and we used a metric very similar to this. Without fully knowing what you mean or what he means, I think you're disagreeing over terms, not correctness.

> but in any case, what he says about the "bulk" movement of air (he should probably call it net, i mean all air is bulk by nature) there is no way that the speaker pumping air in and out of the cavity could turn into net movement in one direction... the air coming out was directionally focused from the cone? and sucking back in was amorphous and somehow not detected by his device?

I think you're agreeing with him here, his explanation matches yours. We can break a full period of oscillation into two sections: a high pressure section (the air molecules being pushed away from the speaker), and a low pressure section (air being pulled back). The high pressure section travels _coherently_ through the air cannon, mostly moving air molecules in a single direction (as you say, it is "directionally focused from the cone"). The low pressure segment pulls air back into the air cannon, but it is _not_ coherent (as you say, it is "amorphous"). During the low section, molecules can flow t...

what you are calling agreement between me and him I don't see at all. I'm not going to watch that video again. I could watch another one and tell you what's wrong with that one, that would be more interesting.

I know the field of loudspeakers/acoustics very well, what I've said so far and will say now is all off the top of my head, and it's unlikely that it's in his head at all. We're not going to research a number like 5% more efficient because that's a complete waste of time, let me explain. "We" measure loudness of sound on a decibel scale, that is tenths of a Bel, and the Bel scale is a logarithmic scale, more or less because that's how human hearing perception works, I guess because that's how sounds occur in nature (evolution). But what that all translates to is, to be perceived as "twice as loud" requires a 10 decibel increase; that corresponds to an increase of 10 times the power. On a smaller scale, a 3 dB increase requires doubling power. 3dB is perceptible, but minimally so. So for a tiny 3db increase in loudness requiring 2x the power, is anybody interested in an 5% inefficiency increase taking us to needing 2.1? no, nobody is interested in that, they don't make power amplifiers with ".05 times more power!"

now, as to the comparison of tuned ported/bass reflex compared to acoustic suspension (which is what sealed box refers to): acoustic suspension is NOTORIOUSLY ineffient; it is also notoriously good sounding, and in a compact amount of space like an apartment living room the inefficient power is not important to achieving high sound volumes to create a symphony listening experience.

But that is not true of infinite baffles (consider a speaker mounted in a wall), so to lump together infinite baffle with acoustic suspension and call something else 5% more efficient is just plain wrong, but who cares because 5% is nothing on a logarithmic scale.

(space efficiency btw is very important in most people's living spaces, and that's where acoustic suspension really wins)

the goal is not efficiency, it's good sound. bass reflex improves its sound by cancelling the resonant frequency which would be overly loud otherwise. acoustic suspension also tames the resonance, but with an entirely different method, the speaker box is small enough that the compression of the air acts as a spring, where the entire surface of the (paper) cone is supported by the sealed air cushion; the acoustic supsension loudspeaker driver itself does not need a spring in that setup, but it is required for other applications of loudspeakers.

he didn't ask himself any questions about the difference between the air cannon and his bass reflex port plus air cannon setup. The frequency of of audio, even very low bass notes would be minimum 20 Hz (that is unrealistically low for most sound systems), and the normal air cannon "balloon snap" is not really comparable. A test he could do would be to keep the speaker cavity filled with smoke and see if a 20 Hz signal blows 20 smoke rings a second: guarantee, it does not, but it might do something interesting. the relatively slow swirl of the smoke ring is a turbulence after effect phenomenon

but lets go back to why I wrote my original comment. incels here were making fun of a mexican high school girl and using that video to point out she had accomplished nothing. so to give her the same credit every high school student deserves for their science fair project, I thought I'd point out that this youtube genius could also be made fun of.

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Watching that dude is like watching a child doing science and then using AI to explain the result. If he makes someone curious enough to do experiments on their own it's still a win though.
Prior to “using AI to make videos” he did a phd in chemical engineering. I actually think his explanations and experiments are always very well thought through and presented in a entertaining way
I watch all his videos and they are so easy to understand when to lots of other popular science experiment channels. No high fi stuff, a guy doing experiments with simpler tools available and it's mostly the way he explains things.
It is easy to come away with that idea if you just watch one of his videos. He is very good at clear explanations that get to the essence of an idea and makes it seem simple. Sure, it's at an educational level of detail, but it is accurate on that level.

But if you watch a number of his videos it becomes clear that this is clarity that comes from deep knowledge and sophistication. His channel is also in my opinion notable for having a huge variety of demonstrations, rather than the standard set that is done by a lot of people. There are many things that I've seen only him do, out of my set of science and engineering channels. Which is not to say I know for sure that he is for sure the only one who does them, but it's definitely a more-diverse-than-average set of demonstrations done over the years.

It also, on a more brute level, simply predates AI by a number of years and therefore can't be just an AI script, nor do I see any reason to believe he has switched to using AI to write the scripts.

There is a saying that ideas are cheap. Only delivery matters.
Wasn't it Edison that said that!
Probably stole it from Tesla... :)
It's kinda a throw-away remark in the middle, but I thought it was really cool to realize that speakers produce an on-axis net-blow and an off-axis net-suck.
Was looking for a video on this specific work, but only found this [1] where the English translation seems AI-generated. It reminded me of thermoacoustic refrigeration which I found cool (heh) when I had encountered it many years ago - where the compression and rarefaction of sound waves is used to pull out heat. The fire extinguisher seems to operate on a different principle though - it needs to generate a specific kind of turbulence to push out oxygen from the fire site.

[1] https://www.youtube.com/watch?v=TGO7Jdfll7c

[2] https://en.wikipedia.org/wiki/Thermoacoustic_heat_engine

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I wonder if one could use a thermal camera (or some other, high speed sensor) and some kind of feedback loop to squelch it and keep it disrupted until it cools. Or conversely, manipulate the flame for more complete combustion (in industrial processes).

But granted, I have trouble seeing this work on a large scale without much more sophisticated sonic wave tech.

Yes, I kind of discovered that in a dream, in which I extinguished a fire by teleporting away oxygen. It worked, until I stopped teleporting. The oxygen came back and the fire started again. When I eventually woke up I thought about it and I told to myself that I should have chilled the place, not that it matters in real life. I was also proud of my subconscious' understanding of physics.
Same application spectrum as CO2 fire extinguishers I'd imagine (which we use for expensive lab hardware that we don't want to get damaged by water, foam, ..., but which are utterly useless for anything more substantial).
out of curiosity, would something like this hurt a human? I assume the sound waves must be pretty powerful to put out a fire.
Seems like a standing wave thing to halt airflow rather than "overpower with Bill & Ted's Awesomeness!".

Depending on what they have going, it might be loud, might not.

There's plenty of links in Dublin comments for other instances of the tech being developed at least partially, and at least one for in-home fire suppression. Given that last one, I'm thinking it operates on the basis of resonance rather than amplitude to disrupt combustion.
It's a standard subwoofer speaker put on a can with a hole in it (literally a ported speaker, with the same goals of a ported speaker). Subwoofers can definitely harm human ears, but definitely not human flesh. Just don't put your ear up to it.
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Not exactly acoustic but reminds me of a high school science project we had one year, something along the lines of put out a candle with a contraption. My partner and I rigged up a balloon to be popped by the candle, and the balloon pop blows out the candle. Probably not an original idea, but I don't think any other group in the class tried a similar approach. Worked like a charm.
This seems to be a known technology but hasn't made it as a product.[1] It might have potential for very specific types of extinguishing, such as grills and grain silos, where the distance from extinguisher to trouble spot is fixed.

[1] https://www.mdpi.com/2571-6255/8/4/129

The real barrier is that Big Extinguisher’s whole revenue model is based on bottle expiration dates.
Oooh.. from the title I thought this was about an extinguisher for when your guitar catches fire. Makes more sense now
At other frequencies, sound can actually intensify flames, depending on the surrounding environment. Standing waves and the frequency of the sound (FM) are likely factors in this phenomenon. However, it’s not advisable to use sound as a method for extinguishing fires.
Why does it matter that she's Mexican?
because of people like you who cannot read an innocuous detail without turning hysterical. if it doesnt matter why did you open your mouth?
Because it's a Chilean blog about feel good stories in Latin America, just like it says on the tin.
Because they’re known to have lower IQ making this ingenuity more remarkable.
Found the Argentinian.
Could you please stop posting unsubstantive comments and flamebait? You've unfortunately been doing it repeatedly. It's not what this site is for, and destroys what it is for.

If you wouldn't mind reviewing https://news.ycombinator.com/newsguidelines.html and taking the intended spirit of the site more to heart, we'd be grateful.

Is everything that offends you considered unsubstantive?
Do you intend to observe the guidelines or not?
Do you like pineapple on your pizza?
Seems to matter to you
No, it doesn't. You're just making a baseless assumption. There's nothing wrong with asking a neutral question.

I wasn't implying anything, just wondering why it needs to be in the title.

Haha I loved this: in a thread where everybody is talking about the technology, the merits of the kid "discovering" it and all that, invariably there's the guy who enters the room and shouts "why does people care that she is Mexican!!"

Like... nobody cared, until the guy mentions it. And then he replies back "no I don't care she's Mexican, why do you bring their origin!!!"

FWIW I saw these news in my local news Spanish language sources (yep, Im Mexican too) a couple of days ago. And found the majority of the reporting at that time was exactly a "cool science project" thing.

When I saw it here on HN I was surprised. I even thought like "wow, maybe I didn't put a lot of attention, and it's something bigger". But apparently it's just sloppy reporting, in a telephone-game kind of thing: Some Chilean news saw the headline, and decided to report it as "Mexican 16yo invents X", which draws clicks. Then English based news took it and further deformed the actual facts.

Hopefully this kid gets invited to some podcasts or whatnot and gets something from this. Also hopefully it helps other kids get more interested in sciency projects.

When an oil well goes off, high explosives can be used to extinguish it. Maybe this is the same principle.
More modern techniques are less violent. I understand one heavily used in Kuwait was to place a ~10 meter hollow pipe above the blown out well so the flame could be displaced from the well head, then injecting water or nitrogen at the base of the pipe to put out the fire.
Buoooo, boooring; I wanna see explosions
To clarify, Red Adair and company did take part in the remediation effort in post Gulf War Kuwait:

  Many consider his crowning achievement to be his central role in containing the Kuwaiti oil field fires of 1991 that threatened planetary environmental consequences as well as incalculable lost revenues for oil producers. Following a scorched earth retreat policy, Saddam Hussein's defeated army set ablaze more than 700 of Kuwait's 1,000 oil wells. Adair was among the first responders, and his team squelched fires at 117 of the nation's most productive wells. 
https://www.asme.org/topics-resources/content/red-adair-to-t...
..has been around for a long time.

DARPA worked on it 10+ years ago.

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I struggle to understand why this article is interesting or upvoted.
when i was in the 5th grade (give or take a couple years), there was an innovation project where we were to bring in and present to the class an invention.

i remember a girl inventing what i now know to be a "flexible weighted dip tube" – think of it as a shampoo bottle that you can pump upside down – and was amazed.

like this submission, the flexible straw wasn't really invented by the student. at best it was independently discovered, but this patent was from at least twenty five years before: https://patents.google.com/patent/US3547296A/en

to that end, i wonder what the point of presenting these inventions as your own are – especially in the time of the internet when prior art is so easily discovered. or, did i miss the point?

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I suspect she was pushed along by adults, with particular motives, more than anything.

Regardless, nobody involved is honest, and I suspect the honest ones were told the be quiet.

They're either dishonest, or they're too stupid to know how to use the internet. You pick. Seriously, what's the alternative here? The only exception would be an honest person too afraid to speak up, to correct the dishonest/incompetent people, and I could agree with that. I don't blame the kid though.
> i wonder what the point of presenting these inventions as your own are

Because if you independently invented it then it is your own.

The value to the student is not necessarily that the idea is novel to everyone else but that is novel to her. And of course the process of invention and development is something that many people never experience, and is valuable in itself.

I invented a steam engine when I was in 5th grade. It wasn't completely novel nor efficient, but I invented it independently, and my science teacher showed enough interest to spur a 50-year warm memory.

Praising kids for achievements is a net positive. They use it to focus their energy into future growth and development.

The article is science-reporting trash, of course, but praising the kid is a good thing.

This is something from science fiction or a comic book. Super cool!
Wow, must be the same school that keeps pumping out students who invent water powered cars and machines that turn plastic into gasoline
Are you not loving the diversity goy?
Signed up to simp for Enoch Powell? I’ll grant you that’s original.
My favorites are:

"Power a light with a lifted rock": Actually does work and you can buy this product, but it's a dimmer light for less time than the inevitable marketing diagrams indicate. Not useless but the fawning news stories over the science fair prodigy always makes this sound like an unbelievably brilliant solution rather than a rather niche hack even in the poor rural parts of the world. In the 2020s a standard solar panel, battery, and LED light are much better in every way and far more flexible.

"Provide power for a poor rural village from a kicked soccer ball": An absurdly tiny amount of power, at the cost of creating a soccer ball that is soft and doesn't move when you kick it very much, precisely because it's extracting energy from the kick and that energy isn't available to be kinetic energy. No child would ever play with this ball. Have still seen this idea at least three times now despite the fact that if the reporter spent 15 seconds with the actual ball they'd realize it's a complete non-starter.

"Science project demonstrates new way to kill $PATHOGEN": It turns out killing things in a petri dish is really easy. It means nothing about human health outcomes in a body. In fact pretty much anything about a pathogen in a petri dish - improving resistance to something, destroying resistance to something... it's really easy to do lots of things in a petri dish.

"Water from the air": Doesn't work in practice because the place this needs to be deployed to is precisely the place that doesn't have water in the air. It does work in places that have water in the air but those places also don't need super expensive condensed water when they have water already. I personally live in a place where humidity is basically 90-100% every day in spring, summer, and fall. We don't carefully capture our dehumidifier's water.

These are all things I've seen multiple times each.

"No child would ever play with this ball. Have still seen this idea at least three times now despite the fact that if the reporter spent 15 seconds with the actual ball they'd realize it's a complete non-starter."

No child would use it, but those would be really awesome in my Muay-Thai classes.

""Water from the air": Doesn't work in practice because the place this needs to be deployed to is precisely the place that doesn't have water in the air."

There is literally no place on earth where the relative humidity is that low outside the Antarctic dry valleys. Even in the Mojave Desert here, I have a water from air condenser out atop a miner's hotel blasted into rock. I even posted the GPS coordinates to it here on HN. It works great, and produces enough clean water daily for several people. It does need a recharge on the carbonate rock and charcoal, though.

My favorite was the student who demonstrated small, leaf-like solar panels on a tower, and claimed that somehow they were more efficient than a single panel.

No. Not possible. Not even going to do the math. Dumb. Somewhat more wind-resistant... unless you add up the support structure weight AND the loss of efficiency when the "leaves" are wind-deflected.

But "Green!", so it got attention.

My favorite was the kid who invented the cool clock.
I will not ask if she patented it, or if others had the idea before, or if it is ready to be productized.

Just simply: it is great that young people, driven by personal curiosity, go and explore their ideas, find solutions to long-standing challenges.

Billiant, keep inventing!

The real advancement, not brute forcing mathematical equations like some company does and claims revolutionary breakthrough. How many ideas like this has come from AI companies' models?
Prove you are a human to continue.

No, I dont think I will. closes website

Cloudflare at the forefront of gatekeeping everything on the website

The whole Internet will turn into that unfortunately, it's because of AI agents abusing/overwhelming online resources.
The article starts with a lie: Ángela Karime Venegas Hernández is 16 years old and has an idea no one else had.

As others have mentioned it's not the first time.

So, is the reporter willfully lying, or is so incompetent that couldn't even do a simple Google search? I don't know which is worse.

It's shitty reporting. The girl "discovered" the effect by herself, devised a way to use it as a project, and shitty newscasters blew it out of proportion [pun intended]