Funny story, I'm a retired Fire Captain, and we were doing a practice burn, this was an old house that the owner needed destroyed, so instead of hiring a demo crew, or some construction company, here in NC it's possible to have an inspection to make sure there is no asbesto, lol always thought that was an Italian sauce when I was a kid. Anyway after a pass it's given to the fire department so we can practice with a house on fire. Once we are finished with training, we set the house on fire and monitor it but we allow it to eat the entire house safely. So, now that you have an understanding, we were doing one of these and the location was by a freeway and there were a couple of homes thankfully far enough away from danger but still, the owners came out to watch. Well we had Bud water, it's a special can of Budweiser that is filled with their water and it's given out to Fire Departments and the like, it looks like a can of beer, blue and white has BUD on the side big and bold, even comes on a 6 pack plastic grouping, ha!so me and the crew we're all drinking away on our Beer Water as we called it...and it pulled out from the crowed watching us, our first Practice Burn Karen!!! Oh she was yelling and screaming about how we should all be ashamed drinking beer and putting out a fire, what sort of an example are we setting, she was Karen Level Queen and so annoying but we laughed and kept drinking, and so she comes through and gets in my face while I'm drinking a Bud Water and she asks for who was in charge I said me, I had a Chief there but I'm running guard here lol. I'm sipping away while she yells, Ahhhh, I gasp out harshly and tell her I can drink these all day like they were WATER! Hoping she would see as I also showed her. Well that did it, she was calling the police and sure enough out they came and of course it's a small town we know each other I explained and lol the Sheriff deputy looks around we are standing or sitting but all have a bud water in hand raising it up Cheers Brother! He laughs and says oh those! Karen meanwhile is going berserk! Especially when he takes a one we crack it open and slam our cans together and we throw back he tries to show her it's water, I do the same and then she slaps the can but her hand misses and hits me in the face! I said okay enough with her, I said remove her please. And with pleasure the Deputy tossed his can and quickly took hold of her, well she resisted and whipped her head back and head bunted the Deputy caused his nose to bleed, well accident, or not, he arrested her and off she went. We held our cans high as they left. So, when I say your comment it reminded me of our Beer Water and Karen. Hope you are well, have a great day and thanks for reading ❤
@brye687 I work in the beer industry. What you're looking for is called "Hop Water". A few brands like budweiser sells it, but its a new growing trend in the industry. It's a fad that'll die out, but by all means give it a try.
Audio Engineer here. I saw a video of the Swedish Air Force putting out a forest fire by detonating a bomb or missile in the airspace above. The concussive force of the explosion extinguished the fire.. it's a fascinating application of the physics of controlling the motion of air... now I gotta watch that video again. it's so badass!!
When I was a kid in the 80s, I remember my dad telling me about a dream he had. There was a forest fire, and a bunch of helicopters with huge speakers hanging off that were somehow extinguishing the fire. What a weird thing to dream. Later he decided that they must have been microwave dishes, and set out unsuccessfully to invent a way to extinguish fire with microwaves instead. ¯\_(ツ)_/¯
This actually seems kinda useful maybe for 0g firefighting in the future? Since putting water, CO2 or foam on stuff is way more difficult when you have to make it stick and can't just rely on gravity
That's a pretty interesting application. If you're in a 0g (or, more accurately, microgravity) environment, odds are good there's no air outside, so you could just vent the oxygen until the fire starves. But, sound waves would be a neat way to spend a vehicle's electrical power (via speakers) to fight a fire while conserving the oxygen needed to replenish the room.
@@Tacheonblack I thought more about the inside of a spacecraft or like larger space station if you don't just instantly wanna go to venting the entire atmosphere
Extinguishing fires via sound only works because the fuel is bound to the ground via gravity, with the heat and exhaust rising due to density. Flames in Zero G are weak as a result, but are still dangerous nonetheless. Agitating the fire in zero G would likely only work to make the flame stronger. The best way to extinguish fires in Zero G remains venting the oxygen from the burning room.
The thing is that there's no O2 in space (enough for a fire that is) except what we bring up there. It would probably be better to vent the oxygen temporarily to stop the fire. Zero G fires are extremely scary because gravity doesn't stop it from expanding in all directions very quickly. I think a large speaker device might be a bit impractical in Zero G as well.
Modern fire control systems for sensitive area's use a gas that's denser then air so you just fill the room and it suffocates the flame out. Sound would be tricky at best to knock a fire out in a data center but using non-flamable dense gas is super effective.
I work at an injection mold plant. A person working the press had a part come out on fire. The parts are made of nylon. He used a compressed air hose to try and put it out and the part was soft from the heat and he blew flaming nylon on the press and started a fire haha!
Can you put that speaker+vortex cannon combo into a smoke-filled chamber? It'll probably create some funky standing-esque waves, but I can't predict what they'd look like or how far they'd extend.
You wouldn't get standing waves without a reflecting surface and a freq high enough to become directional. Under around 120hz soundwaves become omnidirectional, it's why bass sounds like you are enveloped by it but you an tell the source of a symbol crash. Also, the tuning of a bass reflex enclosure means that above 120hz there is no sound being emitted from the port, it's acting as solid wall with this tuning. Most cabinets are tuned around 20-40 hz so it this freq the sound emitting from the port is 180deg out of phase with the driver, as the freq climbs the port becomes a restriction until essentially so soundwave can pass. So, yes, you can do what you envision with a reflecting surface, just not with a standard audio tuned bass reflex cabinet.
So happy I guessed the reason the speaker worked vs the fan. To be fair, I love car audio. I've messed with speakers all my adult life and know how they work physically. It still amazes me how electricity and magnetism interact. I will never get over how amazing that is.
nah, he did the fan dirty, he didnt even try to put a cone over the fan so the air would be directed to the fire JUST LIKE THE CONE OVER THE SPEAKER. Its just a bad comparison and bad science. I bet if the fan's air blowing was directed with a cone just like the speaker, it would just easily snuff out the fire
My nephew loves experimenting with fire and screaming. This is a perfect experiment for him! He needs to stop researching so much information about cadavers and true crime and focus more on the wonders of science. I just know that one day he will be a great firefighter, especially once he shifts his focus to loud fires and not missing pets. -Lenny
I would love to see how this concept would work when applied with a Rotary Subwoofer since they're capable of moving an even greater volume of air on a household scale.
I have this question too. I thought he would try different frequencies later but he kept using the same frequency. But then, I remember that sound ports are designed to work with a specific frequency so that's why he needs to use only one frequency.
I'm assuming the process of how this whole thing works is by moving air molecules in such a way that areas of rarefaction (low pressure) basically 'snuff out' the flame. I would say lower frequencies would work the best in this case as lower frequencies have longer wavelengths and thus larger areas of low pressure.
I can provide a little more detail on how the bass reflex port works. Speaker design is all about modifying the phase of the waves coming off the speaker cone, not providing airflow. The speaker cone emits positive waves off the front and negative waves off the back (180 degrees or pi radians out of phase), and if these waves meet they cancel out. If you run a speaker in open air it will have no bass response and the high-frequency response is determined purely by the dimensions of the speaker cone and your position relative to it. In a sealed speaker you contain the rear wave of the speaker and get a slowly-declining bass response, with the air inside the box acting as a spring which changes the resonance of the speaker and naturally protects the speaker from moving too far and breaking at low frequencies. In a bass reflex (ported) speaker the air inside the speaker box still acts as a spring at most frequencies, but now the plug of air contained in the port acts as a mass which forms a resonator that gets excited by the wave coming from the rear of the speaker cone. This is exactly the same thing that causes an empty bottle to whistle when you blow over the rim, a helmholtz resonator. The resonance of this system determines what frequency range will be boosted, which is accomplished by delaying the waves coming off the rear of the speaker so they're in-phase with the waves coming off the front of the speaker. This only works for a narrow frequency range, below which the speaker will put out less bass than a speaker with a sealed back because waves grow longer at low frequencies and the time delay from the helmholtz resonator is constant, thus the sound waves from the rear of the speaker cone will be out of phase with the front again at low frequencies (the useful range is where the waves are less than 90 degrees or pi/2 radians out of phase). The air inside the box no longer acts as a spring at very low frequencies, so ported speakers are more vulnerable to being damaged by driving them at bass frequencies below their tuning, and if the air in the port becomes turbulent the output level can suddenly hit a wall or even drop, along with a lot of distortion. The overall effect is a ported speaker can produce more bass in a certain range than a sealed speaker or use less power to do so, but you can't get as deep of bass safely out of a ported speaker as a sealed speaker without making the ported speaker very large and when it hits its limits it's very audible. For how this relates to the experiment in the video, the speaker will work better from the front at a different frequency than the rear. The velocity of the air coming out of the bass reflex port will be maximal at its resonant frequency, and the speaker cone will actually move almost zero distance at this frequency, so the velocity of the air at the front of the speaker will be minimal when it is maximal from the bass reflex port. If you want maximum velocity from the front of a reflex-loaded speaker, you need to use a frequency that's either below or above the resonance of the port, preferably above to operate it safely. If you can reach the front of the speaker cone, then you can find the port tuning by ear if you turn the speaker off and tap lightly on the speaker cone - it will ring at the port tuning frequency just like an empty bottle.
It would be interesting to experiment with this by blocking the port and trying to put out with speaker drivers on front in new video. A study on which frequency range works best for different fires would also be good in follow up.
@@johns6795 Yeah I think it's an open question right now whether the period of the wave matters or if you just want maximal velocity. It would be hard to test with a single speaker system unless there's an overwhelming effect from frequency because of how the physics works out for the speaker box. You'd want an overpowered system which can put the fire out across a wide frequency band to record the amplitude needed at each frequency, then compute the air velocity from the speaker parameters and recorded inputs/outputs.
After days of study for my semester exam in electroaccoustics I passed today, I wanted to relax and watch some RUclips. Looks like I just can't escape it :D Yet here you are putting an even greater explanation than our teacher and again broadening my understanding of the mechanisms in play. Great comment!
Cool video. If People are interested , what the speakers are generating through the tube is called a "synthetic jet". You can even generate propulsion with this principle.
@@neverstopz9045 Interesting question. Synthetic jets are produced in a medium such as the atmosphere or in water. It is not possible in the vacuum of space. If you look for "Acoustic and Thermoacoustic Jet Propulsion" there is a paper free for download where you can se the details and even Schiieren movies of the synthetic jet in the supplementary materials.
This is a method sometimes used for blowing out oil well fires. In that case, the "speaker" is an explosive, and in some cases (at least one in the ex USSR) a *nuclear* explosive. The shock wave blows out the flame in a way that not even a hurricane could.
I bet a "bass cannon" (For example the Bose Acoustic Wave Cannon) would work very well, even at a pretty good distance. I vote for a re-visit on this topic, but using a BAWC.
I had to idea ten years ago, try to make it on larger scale. It’s hard to find support. Btw you’ll need to adjust the frequency for that fire. You give the right resonating frequency. It’ll be out just like magic.
There is a Mythbusters episode where they make a giant subwoofer actuated by the drive shaft of a car. I'd love to see the extinguishing capability of something like that.
Thanks for the hint! Mythbuster where most effective with a low frequency (like here) dual wave by a human singer, but had not this vortex gun thingy..focusing the wave on a small area is important-but it seems the wavetype also is a factor. My picture of this effect ia now more complete.
Fun stuff!! Maximum air movement through a bass reflex port occurs at the port's tuning frequency, and is actually TWICE as much air movement as the front of the cone(s) because the Helmholtz resonance has a phase-inversion characteristic. At the port tuning frequency the cone movement virtually stops and the air in the port is what moves. Also, the rattly distortion you hear with the air cannon might be the woofers' suspensions going non-linear because the air cannon permits airflow out of the port more easily than airflow back into the port, in effect "sucking" the cones inward, and out of their linear excursion range.
This reminds me of something I saw years ago, but never saw again. I remember watching a video where they used a specific frequency to cause smoke and contaminants to congeal and fall out of the air. It was something they were thinking of using in industrial smokestacks and similar areas. Maybe you could check that out and try an experiment with that.
Revisit this with a rotory subwoofer that literally, turns fan blades and motor into a rotory subwoofer that hits frequencies so low (infrasound) and in high power that they can shake your house.
Sound affects more than fire... If you study a little you will realize that everything in this universe is frequency, sound. Matter oscillates in esoecific frequencies that form from tangible matter to the intangible. Frequencies can affect our biology and its functioning. This is the reason why many ancient cultures used sound as a method of treating illnesses or to better cope with an ongoing healing.
I bet sonic weapons could do exactly this. They're designed to be hyper-focused, kinda a laser of sound that makes your skin feel like it's burning. Also, look into recent research on the Acoustic Trap Display; which basically makes a hologram using sound to move tiny RGB beads super fast.
There's a beauty device called HIFU. It uses ultrasound energy to boost the collagen growth . So obviously """sound""" can kill ppl with the right frequency and energy.
This is why i sub to this channel. Little cool science facts I had ZERO knowledge of. Believe it or not you just helped me finish up my one shot campaign with this science experiment. It gave me an idea. Super random but you have a positive effect on people. Always remember that!
They can combine sound weapons and air cannon design so this would actually be able to fight large fires. This plus water and or suffocation chemicals depending on the fire would be very affected.
Going into why blowing can extinguish verses when it can make the fire hotter/bigger is great and answered one of my questions about fires in general. Praise God for access to videos that helps us potentially learn something everyday including science
@3:30 Could the effect of the vortex cannon be caused by curling the exhaust smoke towards the centre of the fire, that it reduces the oxygen inflow ? Could you make the same experiment with ventilated smoke layers to show the air-flow ? By the way, if you would create standing harmonic waves (at higher frequencies), would that cool the air ?
We used to sell those air vortex cannons where I work under the name "AirZooka" and let me tell you: They are a ton of fun. I can't tell you how many times I've blown peoples' minds by yanking a piece of paper out of their hands or smacking them in their rain ponchos. They'd be 25 feet away at the end of the room. My accuracy over the years was unrivaled... And what's fun is that the wind takes a few seconds to get there so that would throw them off too. This is definitely one of those products that you sell a lot more of if you are demonstrating them rather than just having them sitting on a shelf. You can find them online for about $20. Maybe less.
imagine hearing a dialogue that goes like: "FIREE!! FIREE!!" "get the speaker, QUICK!" lol. could mean different things based on the context and if it's actually a fire.
It is said that as we stand right now, firefighters are not well equipped for putting out fires on lithium batteries that are in electric vehicles and other products. I wonder if this would work on extinguishing lithium batteries on fire ? Maybe, that could be another future experience of yours! Thank you for sharing.!
The issue with battery pack fires is the battery pack itself becomes damaged and the massive amount of potential energy is shorted out. The fire is a symptom of the problem and putting it out without fixing or disabling the short will do nothing which is why currently the best they have is to down the whole battery pack in a big bath to just flat out prevent ignition. Some battery packs catch fire weeks or months after being damaged.
Probably not, fire is just a reaction that has reached a point of ignition which is a function of heat energy. Alcohol is probably an ideal example here because it will interrupt the evaporation and it will not continue to burn. Alcohol will just not remain hot enough to auto ignite(420 Celsius and alcohol evaporates at 78?C) as what does evaporate will burn immediately. Burning like this it is somewhat self regulating. Some house fires can reach, I *think* 1500 Celsius or more for some furniture foams and what not and what would happen is this fire would continuously re ignite - maybe for DAYS. There is nothing better than removing this heat than water so I would not count on it. Also - water can be hilariously bad for these kinds of liquid fires making this example an even more ideal counterpoint to drowning this situation with a fire truck.
What about starting fires with frequency’s from say a satellite shooting a beam hitting a specific material? Like what they did in Maui, might even have something to do with color as well, if anybody could figure it out I have faith in you
@@shinobuoshino5066 Okay. But there are converters (heterodyne), which make it possible to convert precisely the ultrasonic signal into an audible signal. Such as instrumentation for listening to the "noises" of bats, etc.
That is a venturi and we did it with light to split the muon from the electron neutrino....ours was highly tuned and completely separated the particles using laser on my channel.
My hypothesis halfway through was sort of right; I assumed the sound detached the fire from its fuel source and caused it to expend the fuel it could hold onto faster than it could resupply itself with.
The PORT that you are calling the 'Bass Reflex Port' is actually just the PORT... the Bass Reflex "port" is the rectangular ...umm... ... thing... above it... a Reflex Port is just a membrane that is able to move back and forth like a speaker and adds just a little bit extra 'ummpfh' to the bass... it's totally sealed and doesn't let air move between the outside and the inside of the speaker cabinet.... the Port you refer to is just an opening in the speaker cabinet that has a tube that just stick into the inside of the cabinet and ends with the smooth conical shape you see on the outside... this allows the speakers to move more freely as per their design and the tube acts as a wave guide which tunes the sound to be more like what the artist intended because the shape of the cabinet can change this in many ways..... Sound and sound reproduction absolutely fascinates me and the idea of extinguishing fire with sound alow is AMAZING!!! When I first saw that video you show of the two guy putting out a firte with a backpack linked to a tube that you aim at the fire, I ASTONISHED!!! Mainly because I understand how it's performing and it's not that the air is moving the way you show with the open port, it's putting out the fire with the vibrations.... It's kinda hard to explain the difference but I think you're gonna demonstrate this in the rest of the video (I paused it @ 2:30 just to explain all of this... lol) I think it's time to get back to the video :D lmao
The square thing above the port is the waterproof cover for the mic and usb inputs. The port he refers to is a reflex port and is sometimes called just a port. The "membrane" that you're talking about is called a passive radiator which this speaker doesn't have.
I really enjoy your videos man, you explain these scientific concepts in a way that everyone can understand. You're helping people become smarter and its a great thing you're doing. Keep up the good work Action Lab!
I was hoping you’d give a demonstration on how sound could put out active flames of a fire. The flame would go out, but you would still have the hot embers which could still catch fire. I guess the initial firefighting would be done by sound and second wave of Water or foam or whatever the cause would be. Thoughts? I absolutely loved your video!
On episodes like this I'd love to see you make a note about the safety measures you take. I know your setup is already plenty safe, but it's good to be teaching that even experienced people don't rely on confidence alone.
I love the idea of using multiple speakers and trying to pin point the sound waves on a given spot (the fire). You could use less force per speaker but maximise in a given spot, maybe even hit a given area like a printer focusing on a single point at a time untill the total flame is put out.
Sound is pressure waves, so in the high pressure areas the temperature will be higher. The answer to the second question depends on the music and your dance moves 😎
the specific frequency is at the right frequency to disrupt the airflow in a way that it disrupts the natural exhaust and intake of the fire enough that you dillute the air or choke the flame...
It is a bit of a wrong assumption. Fire happens because of three factors: Temperature, Fuel and Oxygen. What sound waves did is cooling down the air to room temperature by equalising heat across all of the air in sound waves reach. Consequently temperature is down and there is not enough energy to continue the chemical reaction that causes fire to appear.
Firefighters: *holding a giant megaphone* "Everyone, please, don't panic. This is not a drill. Leave the building via emergency doors immediately and organise in the yard. In case of inevitable exposure to smoke stay as close to the floor as possible, apply a wet rug for better respiration. I repeat: this os NO- oh, what? Th.. The fire is gone? But how, it was like consuming half the building?"
I’ve been asking firefighter RUclips creators about why this isn’t being implemented…one finally answered & he’d never heard of it. Our military has technology using sound frequency that can stop a large group of people in their tracks…& make em turn & run…bc they feel their insides heating up. ❤️☀️
I’m sure in the future with enough money and research poured into the technology it could be super effective. But as of right now it seems water is more efficient as putting out fires. Plus the sound may also be distracting to firefighters or people inside burning buildings and may obstruct communication in burning buildings.
3:11 "vortexes of air" . . . that's vortices . . . "vortices of air". I do have higher expectations for this channel with proper English than maybe some other channels. In a world where it seems more illiteracy is growing rampant, let's hold the line. :)
"Both "vortexes" and "vortices" are considered correct plural forms of the word "vortex." However, "vortices" is more commonly used in scientific contexts or formal writing, while "vortexes" is often used in everyday language." Chat GPT. Many sites for word "vortex" say that both are correct.
@@Su-27_433 Vortices is the only formally correct one, "vortexes" is a purely informal colloquialism. Same with vertex - it becomes vertices, not vertexes. Matrix becomes matrices, not matrixes.
Imagine firefighters throwing a rave party every time there's a fire
Funny story, I'm a retired Fire Captain, and we were doing a practice burn, this was an old house that the owner needed destroyed, so instead of hiring a demo crew, or some construction company, here in NC it's possible to have an inspection to make sure there is no asbesto, lol always thought that was an Italian sauce when I was a kid.
Anyway after a pass it's given to the fire department so we can practice with a house on fire. Once we are finished with training, we set the house on fire and monitor it but we allow it to eat the entire house safely.
So, now that you have an understanding, we were doing one of these and the location was by a freeway and there were a couple of homes thankfully far enough away from danger but still, the owners came out to watch.
Well we had Bud water, it's a special can of Budweiser that is filled with their water and it's given out to Fire Departments and the like, it looks like a can of beer, blue and white has BUD on the side big and bold, even comes on a 6 pack plastic grouping, ha!so me and the crew we're all drinking away on our Beer Water as we called it...and it pulled out from the crowed watching us, our first Practice Burn Karen!!!
Oh she was yelling and screaming about how we should all be ashamed drinking beer and putting out a fire, what sort of an example are we setting, she was Karen Level Queen and so annoying but we laughed and kept drinking, and so she comes through and gets in my face while I'm drinking a Bud Water and she asks for who was in charge I said me, I had a Chief there but I'm running guard here lol.
I'm sipping away while she yells, Ahhhh, I gasp out harshly and tell her I can drink these all day like they were WATER! Hoping she would see as I also showed her. Well that did it, she was calling the police and sure enough out they came and of course it's a small town we know each other I explained and lol the Sheriff deputy looks around we are standing or sitting but all have a bud water in hand raising it up Cheers Brother! He laughs and says oh those!
Karen meanwhile is going berserk!
Especially when he takes a one we crack it open and slam our cans together and we throw back he tries to show her it's water, I do the same and then she slaps the can but her hand misses and hits me in the face!
I said okay enough with her, I said remove her please. And with pleasure the Deputy tossed his can and quickly took hold of her, well she resisted and whipped her head back and head bunted the Deputy caused his nose to bleed, well accident, or not, he arrested her and off she went.
We held our cans high as they left.
So, when I say your comment it reminded me of our Beer Water and Karen.
Hope you are well, have a great day and thanks for reading ❤
Your story should end up in r/karens youtube videos lmfaooo @@dadtype2339
😂😂😂😂😂
Can civilians get Bud Water.
Would be great to drink when I'm the designated driver.
@brye687 I work in the beer industry. What you're looking for is called "Hop Water". A few brands like budweiser sells it, but its a new growing trend in the industry. It's a fad that'll die out, but by all means give it a try.
Imagine calling the fire department and instead of sirens you hear dubstep getting closer.
Rave Fighters
@@SealWithoutHat Rave Master
that is a cool idea for an anime
Doppler’s Effect😂
Why not used other frequencies? 😢
Maybe this is why fire force has such beefy sound effects
Underrated comment! 😂🔥
Ikr. I have headphone for that sole reason.
literally the most liked comment bruh@@dream.machine
i saw a youtube video, they used a "bruh" sound effect
Onml tho
Imagine a fire starts and someone just goes "DROP THE BASS!"
That be me !
Hi Niko
This s### fire fr
NIKO
Imagine a fire truck pulling up to a house fire strapped with a giant speaker and extinguishing the flames with sick dubstep beats
Great idea but everyone will go losing hearing ability
Audio Engineer here. I saw a video of the Swedish Air Force putting out a forest fire by detonating a bomb or missile in the airspace above.
The concussive force of the explosion extinguished the fire.. it's a fascinating application of the physics of controlling the motion of air...
now I gotta watch that video again. it's so badass!!
They've done it with oil well fires too.
do you have a link to that video? I want to check it out
They did this in Iraq to put out oil wells set on fire by Sadam
@@callmeandoru2627just look it up, I'll try to link it if I watch it later
Please 🔗
When I was a kid in the 80s, I remember my dad telling me about a dream he had. There was a forest fire, and a bunch of helicopters with huge speakers hanging off that were somehow extinguishing the fire. What a weird thing to dream. Later he decided that they must have been microwave dishes, and set out unsuccessfully to invent a way to extinguish fire with microwaves instead. ¯\_(ツ)_/¯
Now you can redeem the legacy :-D
Basscopter's
@@kingcosworth2643 bringing that hot fire! Wait...
That's.. yeah I can see that
no shot
This actually seems kinda useful maybe for 0g firefighting in the future? Since putting water, CO2 or foam on stuff is way more difficult when you have to make it stick and can't just rely on gravity
That's a pretty interesting application. If you're in a 0g (or, more accurately, microgravity) environment, odds are good there's no air outside, so you could just vent the oxygen until the fire starves. But, sound waves would be a neat way to spend a vehicle's electrical power (via speakers) to fight a fire while conserving the oxygen needed to replenish the room.
@@Tacheonblack I thought more about the inside of a spacecraft or like larger space station if you don't just instantly wanna go to venting the entire atmosphere
Extinguishing fires via sound only works because the fuel is bound to the ground via gravity, with the heat and exhaust rising due to density. Flames in Zero G are weak as a result, but are still dangerous nonetheless. Agitating the fire in zero G would likely only work to make the flame stronger. The best way to extinguish fires in Zero G remains venting the oxygen from the burning room.
The thing is that there's no O2 in space (enough for a fire that is) except what we bring up there. It would probably be better to vent the oxygen temporarily to stop the fire. Zero G fires are extremely scary because gravity doesn't stop it from expanding in all directions very quickly. I think a large speaker device might be a bit impractical in Zero G as well.
Modern fire control systems for sensitive area's use a gas that's denser then air so you just fill the room and it suffocates the flame out. Sound would be tricky at best to knock a fire out in a data center but using non-flamable dense gas is super effective.
I work at an injection mold plant. A person working the press had a part come out on fire. The parts are made of nylon. He used a compressed air hose to try and put it out and the part was soft from the heat and he blew flaming nylon on the press and started a fire haha!
I dont know what compelled you to think this was an indoor activity
he couldnt risk the wind affecting the result outdoors
Can you put that speaker+vortex cannon combo into a smoke-filled chamber? It'll probably create some funky standing-esque waves, but I can't predict what they'd look like or how far they'd extend.
You wouldn't get standing waves without a reflecting surface and a freq high enough to become directional. Under around 120hz soundwaves become omnidirectional, it's why bass sounds like you are enveloped by it but you an tell the source of a symbol crash. Also, the tuning of a bass reflex enclosure means that above 120hz there is no sound being emitted from the port, it's acting as solid wall with this tuning. Most cabinets are tuned around 20-40 hz so it this freq the sound emitting from the port is 180deg out of phase with the driver, as the freq climbs the port becomes a restriction until essentially so soundwave can pass. So, yes, you can do what you envision with a reflecting surface, just not with a standard audio tuned bass reflex cabinet.
@@kingcosworth2643took me a moment to realize you meant "cymbal" not "symbol" 😅
sounds like a cool project for you to do
It would be great if he could make artistic shapes. He could move on to 3D images.
This would be really cool to see!!!
“HONEY GET THE SPEAKER, THE KITCHEN IS ON FIRE!”
“T-THE WHAT?!”
"THE KITCHEN!"
🤣
"ITS A PLACE INSIDE A HOUSE WHERE PEOPLE PREPARE AND COOK THEIR FOOD, BUT THATS NOT IMPORTANT RIGHT NOW!"
"NO MOTHER, IT'S JUST THE NORTHERN LIGHTS"
SEYMOUR !!!!! @@assi4717
When the Bass slaps so hard that it's no longer Lit...
Underrated 😂
Underrated 😂😂
YOU NEED MORE LIKES!!!!!!!!
The track must've been fire
@@nefreston8503 rotff
So happy I guessed the reason the speaker worked vs the fan. To be fair, I love car audio. I've messed with speakers all my adult life and know how they work physically. It still amazes me how electricity and magnetism interact. I will never get over how amazing that is.
nah, he did the fan dirty, he didnt even try to put a cone over the fan so the air would be directed to the fire JUST LIKE THE CONE OVER THE SPEAKER. Its just a bad comparison and bad science. I bet if the fan's air blowing was directed with a cone just like the speaker, it would just easily snuff out the fire
@@randovid1you have no idea. You’re just guessing. I’ll trust those who show their process and do the experiments
My nephew loves experimenting with fire and screaming. This is a perfect experiment for him! He needs to stop researching so much information about cadavers and true crime and focus more on the wonders of science. I just know that one day he will be a great firefighter, especially once he shifts his focus to loud fires and not missing pets. -Lenny
We desperately need to get a giant subwoofers onto our firetrucks. 😂
Also, put a big one in every electric car! 😂
Reminds me of Mad Max, you've gotta get a guy on top that'll play guitar 24/7 too.
That'd be awesome. WE LIVE WE DIE WE LIVE AGAIN!!!
Some trucks actually do have them. They're called rumblers. They're special types of sirens but not able to put out fires unfortunately.
concert speakers playing def lefpard
Those subwoofers need to vibrate at 20 Hz.
Incredibly fascinating experiment. The whole idea about manipulating sound to diffuse fire is amazing. The potential of science never ceases to amaze.
Fr
I would love to see how this concept would work when applied with a Rotary Subwoofer since they're capable of moving an even greater volume of air on a household scale.
Can a rotary sub do 70 Hz
Grah
Air vortex with the capacity to expand filtering the air frequency to update the balance, volume and thres. Great formula
What I want to know is if this can put out a thermal runaway fire. Regular methods don’t work but maybe this will.
But what's the best frequency to put out the fire? Or does the best frequency change based on the flame's size and other factors?
I have this question too. I thought he would try different frequencies later but he kept using the same frequency. But then, I remember that sound ports are designed to work with a specific frequency so that's why he needs to use only one frequency.
it sounds like a frequency made within a range of typical backyard generators, lets say somewhere between 800hz and 2500 hz
I'm assuming the process of how this whole thing works is by moving air molecules in such a way that areas of rarefaction (low pressure) basically 'snuff out' the flame. I would say lower frequencies would work the best in this case as lower frequencies have longer wavelengths and thus larger areas of low pressure.
@@ImadZeryouhme when im schizo and spread random misinformation
Bass frequencies move more air, so there does not need to be a specific frequency, but probably the lower hertz the better
I can provide a little more detail on how the bass reflex port works. Speaker design is all about modifying the phase of the waves coming off the speaker cone, not providing airflow. The speaker cone emits positive waves off the front and negative waves off the back (180 degrees or pi radians out of phase), and if these waves meet they cancel out. If you run a speaker in open air it will have no bass response and the high-frequency response is determined purely by the dimensions of the speaker cone and your position relative to it. In a sealed speaker you contain the rear wave of the speaker and get a slowly-declining bass response, with the air inside the box acting as a spring which changes the resonance of the speaker and naturally protects the speaker from moving too far and breaking at low frequencies.
In a bass reflex (ported) speaker the air inside the speaker box still acts as a spring at most frequencies, but now the plug of air contained in the port acts as a mass which forms a resonator that gets excited by the wave coming from the rear of the speaker cone. This is exactly the same thing that causes an empty bottle to whistle when you blow over the rim, a helmholtz resonator. The resonance of this system determines what frequency range will be boosted, which is accomplished by delaying the waves coming off the rear of the speaker so they're in-phase with the waves coming off the front of the speaker. This only works for a narrow frequency range, below which the speaker will put out less bass than a speaker with a sealed back because waves grow longer at low frequencies and the time delay from the helmholtz resonator is constant, thus the sound waves from the rear of the speaker cone will be out of phase with the front again at low frequencies (the useful range is where the waves are less than 90 degrees or pi/2 radians out of phase). The air inside the box no longer acts as a spring at very low frequencies, so ported speakers are more vulnerable to being damaged by driving them at bass frequencies below their tuning, and if the air in the port becomes turbulent the output level can suddenly hit a wall or even drop, along with a lot of distortion. The overall effect is a ported speaker can produce more bass in a certain range than a sealed speaker or use less power to do so, but you can't get as deep of bass safely out of a ported speaker as a sealed speaker without making the ported speaker very large and when it hits its limits it's very audible.
For how this relates to the experiment in the video, the speaker will work better from the front at a different frequency than the rear. The velocity of the air coming out of the bass reflex port will be maximal at its resonant frequency, and the speaker cone will actually move almost zero distance at this frequency, so the velocity of the air at the front of the speaker will be minimal when it is maximal from the bass reflex port. If you want maximum velocity from the front of a reflex-loaded speaker, you need to use a frequency that's either below or above the resonance of the port, preferably above to operate it safely. If you can reach the front of the speaker cone, then you can find the port tuning by ear if you turn the speaker off and tap lightly on the speaker cone - it will ring at the port tuning frequency just like an empty bottle.
amazing.. thx for explaining this very tehnical
It would be interesting to experiment with this by blocking the port and trying to put out with speaker drivers on front in new video. A study on which frequency range works best for different fires would also be good in follow up.
@@johns6795 Yeah I think it's an open question right now whether the period of the wave matters or if you just want maximal velocity. It would be hard to test with a single speaker system unless there's an overwhelming effect from frequency because of how the physics works out for the speaker box. You'd want an overpowered system which can put the fire out across a wide frequency band to record the amplitude needed at each frequency, then compute the air velocity from the speaker parameters and recorded inputs/outputs.
After days of study for my semester exam in electroaccoustics I passed today, I wanted to relax and watch some RUclips. Looks like I just can't escape it :D Yet here you are putting an even greater explanation than our teacher and again broadening my understanding of the mechanisms in play. Great comment!
Благодарю за пояснение
Cool video. If People are interested , what the speakers are generating through the tube is called a "synthetic jet". You can even generate propulsion with this principle.
I wonder if that could be used in space travel?
@@neverstopz9045 Interesting question. Synthetic jets are produced in a medium such as the atmosphere or in water. It is not possible in the vacuum of space. If you look for "Acoustic and Thermoacoustic Jet Propulsion" there is a paper free for download where you can se the details and even Schiieren movies of the synthetic jet in the supplementary materials.
@@neverstopz9045 I doubt it. Even sound cannot travel through space, space is a vacuum, hence no medium for the movement of particles.
This is a method sometimes used for blowing out oil well fires. In that case, the "speaker" is an explosive, and in some cases (at least one in the ex USSR) a *nuclear* explosive. The shock wave blows out the flame in a way that not even a hurricane could.
Dubstep firefighters sounds like a show I'd watch.
"wiggling the flame to death"
This is my new favorite line
mine too ma, mine too
- Excuse me can you keep it low a bit. we're trying to sleep over here.
- Oh sorry I was trying to blow a fire out.
I bet a "bass cannon" (For example the Bose Acoustic Wave Cannon) would work very well, even at a pretty good distance. I vote for a re-visit on this topic, but using a BAWC.
Forget that. Use a rotary subwoofer, much more power.
**Di-di-di-Disco Panzer**
Wouldn't it be a cool little extinguisher for small home fires? Rechargeable and non-toxic.
I had to idea ten years ago, try to make it on larger scale. It’s hard to find support. Btw you’ll need to adjust the frequency for that fire. You give the right resonating frequency. It’ll be out just like magic.
I love how straightforward your videos are! Direct, to the point, all relevant information and graphics to help, assist, and teach. Thank you!
There is a Mythbusters episode where they make a giant subwoofer actuated by the drive shaft of a car. I'd love to see the extinguishing capability of something like that.
There was also Mythbusters episode when they tried to extinguish flames with sound waves.
Voice Flame Extinguisher | MythBusters | Season 5 Episode 8
Thanks for the hint!
Mythbuster where most effective with a low frequency (like here) dual wave by a human singer, but had not this vortex gun thingy..focusing the wave on a small area is important-but it seems the wavetype also is a factor.
My picture of this effect ia now more complete.
They also tested the "brown note" theory with massive speakers. Adam was wearing a nappy (diaper).. 😂
Fun stuff!! Maximum air movement through a bass reflex port occurs at the port's tuning frequency, and is actually TWICE as much air movement as the front of the cone(s) because the Helmholtz resonance has a phase-inversion characteristic. At the port tuning frequency the cone movement virtually stops and the air in the port is what moves. Also, the rattly distortion you hear with the air cannon might be the woofers' suspensions going non-linear because the air cannon permits airflow out of the port more easily than airflow back into the port, in effect "sucking" the cones inward, and out of their linear excursion range.
I don't know what you just said, but I completely agree.
I concur
I was hoping you would explore different frequencies to see if there's a range that is especially effective at extinguishing fire
This reminds me of something I saw years ago, but never saw again. I remember watching a video where they used a specific frequency to cause smoke and contaminants to congeal and fall out of the air. It was something they were thinking of using in industrial smokestacks and similar areas. Maybe you could check that out and try an experiment with that.
Interesting... making particulates of substances precipitate out of exhaust fumes or in industrial process chambers, "SOUNDS" fascinating.
That's fascinating!
Oh hey! I remember seeing that too! I think it was, um maybe, on "Beyond 2000" or "Tomorrow's World".
I hope I serve long enough to see technology like this be used in firefighting
i remember seeing a video somewhere where some dudes tried to build a flying saucer that hovers using sound... no idea if it was real or not.
"OH NO A FIRE!"
"Quick DJ, DROP THAT BEAT!"
Revisit this with a rotory subwoofer that literally, turns fan blades and motor into a rotory subwoofer that hits frequencies so low (infrasound) and in high power that they can shake your house.
Smart
My thought too
Came here for this exact comment
Sound affects more than fire... If you study a little you will realize that everything in this universe is frequency, sound. Matter oscillates in esoecific frequencies that form from tangible matter to the intangible. Frequencies can affect our biology and its functioning. This is the reason why many ancient cultures used sound as a method of treating illnesses or to better cope with an ongoing healing.
Every day I learn wild new stuff on RUclips.I’ve never seen anything like this 😮.
I bet sonic weapons could do exactly this. They're designed to be hyper-focused, kinda a laser of sound that makes your skin feel like it's burning. Also, look into recent research on the Acoustic Trap Display; which basically makes a hologram using sound to move tiny RGB beads super fast.
Sperm whale clicks can potentially vibrate a person to death.
There's a beauty device called HIFU. It uses ultrasound energy to boost the collagen growth . So obviously """sound""" can kill ppl with the right frequency and energy.
Your too slow 🥶
The image of firefighters pulling out a large speaker and playing a sick beat at the house fire gave me a good chuckle
This is why i sub to this channel. Little cool science facts I had ZERO knowledge of. Believe it or not you just helped me finish up my one shot campaign with this science experiment. It gave me an idea. Super random but you have a positive effect on people. Always remember that!
They can combine sound weapons and air cannon design so this would actually be able to fight large fires. This plus water and or suffocation chemicals depending on the fire would be very affected.
based on the proven effectiveness shown in this video, i recommend all people replace their fire extinguishers with party speakers
Going into why blowing can extinguish verses when it can make the fire hotter/bigger is great and answered one of my questions about fires in general. Praise God for access to videos that helps us potentially learn something everyday including science
I went to engineering school with those guys. Theirs was capstone project that won that year. Smart dudes.
1:58 "That's pretty disappointing. Now I actually DO have a kitchen fire."
lol
Well the frequency is finally used to cure cancer in US (approved by FDA) and it can do so much more, like 432Hz.
2:47 don't make sparks near alcohol, kids
@3:30 Could the effect of the vortex cannon be caused by curling the exhaust smoke towards the centre of the fire, that it reduces the oxygen inflow ? Could you make the same experiment with ventilated smoke layers to show the air-flow ? By the way, if you would create standing harmonic waves (at higher frequencies), would that cool the air ?
AMAZING.....you created electronic "Whistler Waves" they are extremely low freq.
We used to sell those air vortex cannons where I work under the name "AirZooka" and let me tell you: They are a ton of fun. I can't tell you how many times I've blown peoples' minds by yanking a piece of paper out of their hands or smacking them in their rain ponchos. They'd be 25 feet away at the end of the room. My accuracy over the years was unrivaled... And what's fun is that the wind takes a few seconds to get there so that would throw them off too. This is definitely one of those products that you sell a lot more of if you are demonstrating them rather than just having them sitting on a shelf. You can find them online for about $20. Maybe less.
imagine hearing a dialogue that goes like:
"FIREE!! FIREE!!"
"get the speaker, QUICK!"
lol. could mean different things based on the context and if it's actually a fire.
It is said that as we stand right now, firefighters are not well equipped for putting out fires on lithium batteries that are in electric vehicles and other products.
I wonder if this would work on extinguishing lithium batteries on fire ? Maybe, that could be another future experience of yours! Thank you for sharing.!
The issue with battery pack fires is the battery pack itself becomes damaged and the massive amount of potential energy is shorted out. The fire is a symptom of the problem and putting it out without fixing or disabling the short will do nothing which is why currently the best they have is to down the whole battery pack in a big bath to just flat out prevent ignition. Some battery packs catch fire weeks or months after being damaged.
Got to love the testing "I gonna have a Flaming Frying Pan and a giant speaker!" In my house this would end up with a 911 call.
At least he only burned alcohol instead of frying oil 😂
The future of firefighter tech
Not if the World Economic Forum and Fox News has anything to say about it!
Yeah, like put out an electrical fire If it effective enough to worth the price.
Probably not, fire is just a reaction that has reached a point of ignition which is a function of heat energy. Alcohol is probably an ideal example here because it will interrupt the evaporation and it will not continue to burn. Alcohol will just not remain hot enough to auto ignite(420 Celsius and alcohol evaporates at 78?C) as what does evaporate will burn immediately. Burning like this it is somewhat self regulating. Some house fires can reach, I *think* 1500 Celsius or more for some furniture foams and what not and what would happen is this fire would continuously re ignite - maybe for DAYS. There is nothing better than removing this heat than water so I would not count on it. Also - water can be hilariously bad for these kinds of liquid fires making this example an even more ideal counterpoint to drowning this situation with a fire truck.
Hmm wonder if we can make a firefighter suit to emit this frequency to keep the fire off them. Like a shield
Once again, you've answered a question I never asked but found incredibly interesting. Keep answering those questions. Happy New Year. 😎
i am amazed as well, it really works!
What about starting fires with frequency’s from say a satellite shooting a beam hitting a specific material? Like what they did in Maui, might even have something to do with color as well, if anybody could figure it out I have faith in you
But what app do you use? Strange that a smartphone can generate ultrasound to put out a match (as seen in your video) or do anything else.
If it was ultrasound you couldn't hear it.
@@shinobuoshino5066 Okay. But there are converters (heterodyne), which make it possible to convert precisely the ultrasonic signal into an audible signal. Such as instrumentation for listening to the "noises" of bats, etc.
putting off fire with a fire music is actually fire 🔥
"Wiggling the flame to death" now that's something new that I've learnt
It is a beautiful demonstration! I guess vibrating air slow down lamirar flow of fresh and hot air streams, so that how it probably works, isn't it?
6:14 Refrigerator at grandma's house at 3:05 am
"it's not putting it out"
"Clearly it's not putting it out"
...
Continues to play with the blower♥️😂
You, sir, are the biggest dork.
And with that being said, I freaking love you, man. Keep up the excellent work, and I watch all your videos!
This looks like the most reckless and out of control video yet
That is a venturi and we did it with light to split the muon from the electron neutrino....ours was highly tuned and completely separated the particles using laser on my channel.
Neutrinos are Italian Neutrons..
😂
Interesting seeing you here.
wut
mmm yes, i love cooking up my fresh alcohol on a monday morning 1:41
me too
really good if u cant find some beer just cook some alchohol and drink it up yum yum yum
This technology needs to be studied and hopefully used to fight forest fires.
What would happen if you also introduced water vapor into the vortex, would it put out the fire faster?
My hypothesis halfway through was sort of right; I assumed the sound detached the fire from its fuel source and caused it to expend the fuel it could hold onto faster than it could resupply itself with.
Sound and frequencies are under rated.
Your production quality is skyrocketing. Loved the firefighting speaker 😂
Fire: burns fiercely
Action lab: Im gonna wiggle you to death
Thanks!
It would be really cool to implement this into firefighter gear
4:15 i think that the fan it just provides more oxygen to the fire.
The PORT that you are calling the 'Bass Reflex Port' is actually just the PORT... the Bass Reflex "port" is the rectangular ...umm... ... thing... above it... a Reflex Port is just a membrane that is able to move back and forth like a speaker and adds just a little bit extra 'ummpfh' to the bass... it's totally sealed and doesn't let air move between the outside and the inside of the speaker cabinet.... the Port you refer to is just an opening in the speaker cabinet that has a tube that just stick into the inside of the cabinet and ends with the smooth conical shape you see on the outside... this allows the speakers to move more freely as per their design and the tube acts as a wave guide which tunes the sound to be more like what the artist intended because the shape of the cabinet can change this in many ways.....
Sound and sound reproduction absolutely fascinates me and the idea of extinguishing fire with sound alow is AMAZING!!! When I first saw that video you show of the two guy putting out a firte with a backpack linked to a tube that you aim at the fire, I ASTONISHED!!! Mainly because I understand how it's performing and it's not that the air is moving the way you show with the open port, it's putting out the fire with the vibrations.... It's kinda hard to explain the difference but I think you're gonna demonstrate this in the rest of the video (I paused it @ 2:30 just to explain all of this... lol) I think it's time to get back to the video :D lmao
The square thing above the port is the waterproof cover for the mic and usb inputs. The port he refers to is a reflex port and is sometimes called just a port. The "membrane" that you're talking about is called a passive radiator which this speaker doesn't have.
I liked this so more people can see it :)
I really enjoy your videos man, you explain these scientific concepts in a way that everyone can understand. You're helping people become smarter and its a great thing you're doing. Keep up the good work Action Lab!
jbl flip 6 be vibing
I was hoping you’d give a demonstration on how sound could put out active flames of a fire. The flame would go out, but you would still have the hot embers which could still catch fire. I guess the initial firefighting would be done by sound and second wave of Water or foam or whatever the cause would be. Thoughts? I absolutely loved your video!
On episodes like this I'd love to see you make a note about the safety measures you take. I know your setup is already plenty safe, but it's good to be teaching that even experienced people don't rely on confidence alone.
I would guess most people don't want a decent portion of the video to be about safety precautions and setup.
@@libtrs838 Correct? "My daughter has the fire extinguisher, just in case" is barely 2 seconds?
0:58 best part 😂
I love the idea of using multiple speakers and trying to pin point the sound waves on a given spot (the fire). You could use less force per speaker but maximise in a given spot, maybe even hit a given area like a printer focusing on a single point at a time untill the total flame is put out.
"Ahhh a fire!" "Call the fire department!"
**Rave music**
"We're saved, dance!"
Question:
Would sound waves increase the temperature in the room? or make you feel hotter?
Sound is pressure waves, so in the high pressure areas the temperature will be higher. The answer to the second question depends on the music and your dance moves 😎
Ah, so that's what my neighbors are doing, they're just constantly trying to put out fires all the time.
Yes
Simply Science! Amazing 😲🔥
Love your videos man!
the specific frequency is at the right frequency to disrupt the airflow in a way that it disrupts the natural exhaust and intake of the fire enough that you dillute the air or choke the flame...
It is a bit of a wrong assumption. Fire happens because of three factors: Temperature, Fuel and Oxygen. What sound waves did is cooling down the air to room temperature by equalising heat across all of the air in sound waves reach. Consequently temperature is down and there is not enough energy to continue the chemical reaction that causes fire to appear.
1:00 Someone needs to create a gif from this
They should. I don’t know how though :(
I'll do it.
Firefighters: *holding a giant megaphone* "Everyone, please, don't panic. This is not a drill. Leave the building via emergency doors immediately and organise in the yard. In case of inevitable exposure to smoke stay as close to the floor as possible, apply a wet rug for better respiration. I repeat: this os NO- oh, what? Th.. The fire is gone? But how, it was like consuming half the building?"
7:33 "or maybe not" 😂 CLASSIC Action Lab. Love it. 😂
I’ve been asking firefighter RUclips creators about why this isn’t being implemented…one finally answered & he’d never heard of it. Our military has technology using sound frequency that can stop a large group of people in their tracks…& make em turn & run…bc they feel their insides heating up. ❤️☀️
I’m sure in the future with enough money and research poured into the technology it could be super effective. But as of right now it seems water is more efficient as putting out fires. Plus the sound may also be distracting to firefighters or people inside burning buildings and may obstruct communication in burning buildings.
Next time neighbour house on fire,the other neighbour around started a disco.
Sick! I actually wondered if soun had any effect on air. Now I know. Thanks dude. 😁
6:50 The way he says it is hilarious
3:11 "vortexes of air" . . . that's vortices . . . "vortices of air". I do have higher expectations for this channel with proper English than maybe some other channels. In a world where it seems more illiteracy is growing rampant, let's hold the line. :)
No one cares
@@ratanasorn8080well said
@@ratanasorn8080I care
"Both "vortexes" and "vortices" are considered correct plural forms of the word "vortex." However, "vortices" is more commonly used in scientific contexts or formal writing, while "vortexes" is often used in everyday language." Chat GPT. Many sites for word "vortex" say that both are correct.
@@Su-27_433 Vortices is the only formally correct one, "vortexes" is a purely informal colloquialism. Same with vertex - it becomes vertices, not vertexes. Matrix becomes matrices, not matrixes.
Imagine a firefighter come to the scene with spongebob's jellyfish jam on maximum volume.
Where can i see his video about the air vortex cannon at 3:15?
@5:11 I didn't know we blow oxygen. I thought we blow CO2
We breathe out quite a bit of oxygen as well as co2