Is Fire Possible in a Vacuum?
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- เผยแพร่เมื่อ 20 ก.ย. 2024
- I attempt to set fire to various substances in a near vacuum environment.
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This is great, now we can cite this video whenever movies and games show us burning wreckage on the surface of Mars.
Now, if you fancy playing with electricity - you should try running a Jacobs ladder and reducing pressure. My prediction is the sparks rise because of convection, but as the atmosphere pressure drops the sparking will convect more slowly and eventually you'll just end up with glowing electrodes.
For bonus points, replace the air with a noble gas and show the colours.
Scott Manley get this up so Cody sees it
Are you going to promote Cody's Lab on your channel?
Scott Manley the sparks travel through a conductive channel of ions in the air. I doubt one would form in a vacuum and the Jacobs ladder would just stop working.
Scott Manley wouldn't the conductive metal case of the vacuum chamber interfere with the experiment?
xeomorpher so you're saying electric arcs are impossible in space? couldn't electrons just jump the void if there was a high enough voltage differential?
20 seconds in and he's already doing something. Thank you for not being one of those channels that like to talk for 5 minutes before they do anything (not just science related, literally anything).
If Cody just talked for 30 minutes id still watch
This guy knows what's up.
Proof we never went to space. Did your head just explode at my comment? Waiting for the NASA fan boys to come it’s rescue.
There was a physics guy from Holland years ago, who offered a reward to anyone to prove rockets can traverse space in a vacuum.
For real.
As a Fireman we never refer to the "fire triangle" like taught in grade school. We refer to it as the "fire tetrahedron" because of the chemical reaction that is needed between the other three parts. We even have extinguishing agents like the old Halons and purple K that their main idea is to break the reaction not just separating one of the main parts. Awesome videos!!
FFEMTRICH halon and purple k separate one of the three parts breaking the chemical reaction...oxygen. halon displaces it, ppk forms a powdery layer preventing oxygen from penetrating. Both are designed and used to separate 1 of the 3 parts of a fire triangle...oxygen.
4:21
One of those clumps of gunpowder on the left side just said "screw the system, I'm running away and becoming a helicopter."
It was a rocket without the rocket
Cody, my PhD was thermites and metal combustion reactions, so I have an amusing snippet.
If you want to see a metal burn in vacuum, you should pick something like porous silicon + NaClO4. The reason thermites do not burn is because the reaction proceeds by metal oxide decomposition - oxygen - which then burns. The oxygen expands very soon, and fails to sustain combustion. That's why the lump thermite burnt - it could trap oxygen due to its density.
Rocket candy burns in the gas phase, so it is difficult for it to burn at low pressures - the gases diffuse away very fast.
Message me to discuss more combustion.
The second ball of thermite was only different in that it had no moisture or trapped gasses in it that could expand. I do not believe it was "lump thermite" any more than the first pile. The first pile didn't burn because trapped water vapor had more room to expand, stealing energy from the reaction. Thermite needs an enormously high temperature to stay ignited, and the cooling caused by the energy being lost to expansion is what halted the reaction.
Thanks for the confirmation. It will be nice to see your suggestion in action.
I did not know this. Thanks for the info!
so heating more candy in close proximity should eventually ignite it in a vacuum?
It's interesting if paper soaked say, potassium chlorate, would burn. Or some energetic polymer like GAP or simply celluloid.
I'm curious if items in a pure oxygen atmosphere at 21% of atmospheric pressure will burn as well as they will in normal air and pressure.
why 21% specifically?
its the percentage of oxygen in the atmosphere
zach burke thats the percentage of oxygen in the atmosphere
Because air comprises of 21% oxygen, 78% Nitrogen and ~1% other trace gases. I presumed that having a pure oxygen at 21% of atmospheric pressure would give roughly the same amount of oxygen to burning items as it does in normal air at normal pressure. It's probably different, though, since nitrogen has a different density than oxygen.
Learn something new every day! Thanks guys!
you should try in an other atmosphere without oxygen
Rodolphe Giammatteo j'y ai pensé à cette idée, je pense que cela fonctionnerait pour les combustions ou le comburant est déjà présent dans le combustible
This. How about 100% nitrogen at atmospheric pressure.
ruski blyat
Rodolphe Giammatteo ahem* a vacuum already has so little oxygen to do anything with
Oops. I should have checked the other replies before posting above. This one is essentially the same as mine. Sorry!
Fascinating results! This has changed my preconceptions about vacuum physiochemestry!
Holy crap Cody! You are getting REAL close to 1Mil Subs dude!! Grats dude, you do such a good job making entertaining and educational content I share with my kids regularly.
Hey Cody, what kind of laser is that?
Keystone Science A blue one.
A big one. I'd guess about 1-2 watts. They sell them comercially. Pretty expensive, though.
3-5 Watts.
I'm curious of the wavelength
@@userequaltoNull 8 watts he said somwhere
0:55 It's as if the chicken starts laughing at Cody's suggestion of "safety first".
I'm quite surprised. I would have expected all the self-oxidizing compounds to burn.
They would if the chamber was smaller and the gasses could fill the chamber enough to provide their own pressure, pretty sure.
Gun Sense (drmaudio) Basic science, there must be pressure.
So if he packed that rocket candy fuel in a small pipe or a straw, it would have ignited?
Yes R-candy in a pipe would still burn and make thrust. As proven by NASA using SRBs in space semi commonly.
That is why he suggests the fire triangle into a square including pressure, which seems to be a key part of combustion. Very interesting and quite astounding.
+Cody'sLab
I read a short story by Robert A. Heinlein called "Misfit". Its about crew of men going to an asteroid to set up a small base on its surface. While on the spaceship, on the way to their destination, a portion of the crew experience some space sickness and end up losing their lunch. The way they decide to clean their uniforms is by hanging them inside the airlock and expose them to space for a couple of minutes. This removes all of the water from the vomit, so when they bring the uniforms inside, all they need to do is beat the dust that remains out of the cloth.
As soon as I read this I wondered if this would actually work. So... anyway, just an idea... put'n it out there...
I don't know if you would want to use actual barf in any experiment, perhaps you could use mud instead. Of Course I don't know if stomach acid would behave any differently or not.
Maybe babyfood could be used in place of barf?
It depends on the duration and whether it's exposed to sunlight (and how far away is the Sun) or not. Exposed to sunlight in Earth's orbit, frozen (because it would partially freeze) water in barf would take some short time to sublimate away. In shadow and insulated from contact with materials heated by the Sun, it would remain frozen indefinitively
Worth a try...
It would work - in fact that vacuum chamber he's using is a freeze dryer. It specifically uses the vacuum to dry food products.
thats basically how liofilisation works (astronauts ice cream) jist that water is frozen there
1 min 35 seconds in; That's a really interesting way of making paper art
1:35
That slow motion burn in the end was GOLD.
Sweet! This is something I kinda requested back when you did the explosions in the chamber.
Patreon. We get to watch the videos before everyone else in a lot of cases.
x9x9x9x9x9 how?
not bad content btw, you should start uploading again
Dr. Grenade Patreon is basically a monthly fee to get priority to videos and a few other benefits. Also I am a little confused. who should start uploading again?
Why is there still gravity in a vacuum? Wouldn't the gravity particles just get sucked out along with the air? :P
Well see gravity particles are rather sticky and very difficult to remove; fortunately they have a fear of heights and will let go during a fall.
Gravitons and graviolies aren't affected by vacuum
MrArcticShadow Because gravity is a lie and the earth is flat.
Can gravity particles stick to teflon? I think so because otherwise our pans would be flying around...
Israel Raizer Cruvinel Well graviolies (similar to raviolies) stick quite well, but the gravitons slip right off. And as everyone knows, one without the other is pointless.
Bold prediction: the sun is not burning gas
(But don't ask me for what it really is...I have no idea.)
I've often heard discussion of the "fire Tetrahedron", with the fourth point being the chain reaction itself. This is taught in shipboard firefighting as one method of extinguishing fires: certain extinguishing agents disrupt the combustion reaction, giving crewmen time to cool down/break up/suffocate/etc. a fire that is otherwise unapproachable due to heat or hazards. As you've seen, a vacuum interrupts that continuous chain reaction. While individual pieces may burn, it isn't enough to spread to other pieces of the fuel.
Nice find Cody ....... Great. That means everything which is confined and dense burns faster.
I reckon the gunpowder would have burned better as a very fine powder, so that the gasses are not let out from between the spaces of the grains
Interesting hypothesis and I may test it sometime (particularly with the thermite), I'm sure most anything to increase burn rate would help but multiplying just about any number by another that is really close to zero still results in close to zero right?
Try pumping in different levels of oxygen and see what difference this would make.
Gotta update that profile pic
hey7328 the gasses would only expand faster
hey7328 good idea
Would Logan's exploding paste work in a vacuum?
Love the Chronos footage, thanks for the video.
Interesting idea! my guess is no, but this is defiantly going on the list of things to test.
Cody'sLab You should try to ignite somthing (like a candle) under atmospheric pressure, while its burning you start to pressurize it. Might be intresting to watch.
Green Silver I'm pretty sure it wouldn't it doesn't have its own oxidizer but sincet has iodine that might become elemental again
It will go on the list, no matter how reluctant. Cody will make it happen.
(not making fun of you for mispelling, just thought the mispell made for an amusing sentence)
"defiantly going on the list" lol.
Ah.... the gimp was acting up towards the end of your demonstration
In the case of thermite, I wouldn't call it pressure. It's confinement. It's actually heat being retained by the atmosphere, but in vacuum it's being removed by rapid convection - hot products are being expelled away. In atmospheric pressure, gases don't spread out fast enough and a lot less heat is lost.
Gas producing exothermic reactions are smothered with the loss of atmosphere or don't appear if vacuum already exists. Those that don't produce gas can be just insulated and confined. No binder needed even in weightlessness. A quantity of thermite in a thick, cored asbestos brick with an asbestos plug, would sustain the heat and there would be enough activation energy for a chain reaction to occur.
So it's a bit complicated set of factors that need to be examined for each reaction specifically. It's good you made this video.
I think that it's not directly pressure that counts but to having a medium that transfers the heat.
I like how the birds interrupted you at the end of the video. "Hey! Enough of that!" :D
Hey Cody,
Great video. is it possible for you to back fill your vacuum chamber? it might be interesting to try these again in different atmospheres like nitrogen, CO2 or methane! It could help you decide whether it's pressure or oxygen that's the predominant factor in halting combustion.
That's a good idea on how to test his proposal of changing fire triangle to square.
I'd suggest something like Argon. Easy and cheap to get.
And unlike Nitrogen or CO2 won't be part of the reaction.
(Many of these high energy combustion reactions strip the O2 from CO2 or create Nitrogen oxide products because they are burnt in air)
Yeah using an inert gas would be great, I think Helium would be a better choice though since its easier to acquire and cheaper.
Filling the thing with something glammable like methane and then trying to light stuff on fire inside doesn't seem very safe...
Maybe back-fill with methane and inject a tiny stream of oxygen to make an inside-out fire!
Can you drink liquified ice?
depends on the ice
Cody'sLab ice XVI?
I choose sodium hypochlorite ice.
LMFAOOOO
leddit armie?
Congratulations Cody, that must be a first for something. Your diligence paid off.
I enjoy the extra clips at the end of the videos. Keep up the good work, Cody!
i wonder if the gunpowder would burn under pressure but in an oxygen-free gas like nitrogen. if the nitrate present in the gunpowder itself does indeed break down into oxygen to feed the combustion and your theory about the gasses expanding too fast in vacuum is accurate, then it should ignite under the pressure of any gas, correct?
I doubt that
There’s a concept called partial pressure where you only take into account the pressure a certain gas contributes to the atmospheric pressure
In this case the partial pressure will be pretty much negligible just like in vacuum
Either way the oxygen will have been dispersed into the whole chamber so quickly that they couldn’t sustain any combustion
@@slippinchillin that seems like sound logic, perhaps you're right. it's very possible it would dilute amongst the other gasses too quickly to work.
@@slippinchillin I don't agree with that. Partial pressure would apply to a combustion reaction that requires oxygen in the air to burn. However, I'm pretty sure the OP is referring to the reactions that have their own oxidizer. If outside pressure is what's needed to confined the oxygen gas produced, then any inert gas should suffice. It won't expand rapidly because there is pressure this time.
I was surprised thermite could ignite so easily with the laser - just how powerful is that thing?! oO
Jason Doe He used magnesium powder instead of aluminium powder. Magnesium thermite is quite easy to ignite. I even managed it to ignite with visco fuse.
Experimente 99 interesting, thanks.
On this episode of "Does it Vacuum?" Explosives.
In fire science, we actually already have been referring to the fire triangle as the "fire tetrahedron" for some time, the fourth point being chemical reaction, for the precise reason that you demonstrated with the baked thermite. Since it contained its own oxidizer and didn't depend on offgassing to sustain the reaction, the chemical reaction was still able to proceed even in the absence of atmospheric pressure and oxygen.
Also, this is why you have two hoses on a car fire. Magnesium fires can be extremely hard to extinguish at normal atmospheric pressures.
That the black powder didn't burn makes sense, but I'm quite surprised that the rocket candy didn't stay lit. Fascinating. I'm also surprised that there were enough volatiles in the Fe2O3 to keep it from burning before you cooked them out. And I'm very impressed that you were able to get the thermite reaction to be self-sustaining. Nice work.
Could it be the rocket candy doesn't burn because due to the vacuum the energy it usually uses to sustain the combustion is spent on the expansion of the gases to fill the near-vacuumed chamber? So it's not any problem with combustion just where the energy goes rather?
I think that is exactly it.
Cody'sLab Hi Cody,
can you make a simple solid rocket motor our of rocket candy and test that in a vacuum?
because these burn on the inside it is possible to maintain some pressure in the motor while the outside is still a vacuum.
best regards,
Robert
Cody'sLab, could you do an different mixture of Rocket candy, adjust the mixture to be ideal for low pressures
more oxidizer? (up the ratio)
contain it in a tube, like a rocket fuselage?
Ah yes, I just made a post very similar to this one! My thoughts exactly.
@ Jace Walton - the presence of oxygen is not the problem, but rather the fact that things cool as they expand. With less pressure, and therefore more room to expand, the reaction is cooled too quickly to maintain ignition. While the laser is on the substrate, it does oxidize and burn, but the reaction doesn't propagate because there's not enough heat remaining to allow the oxygen to do any further oxidizing.
Very interesting take on it. Got me thinking. I would like him to try to burn the rocket candy remains post vacuum test
I have an idea @Cody'sLab could you get a bottle of gold plating solution (it's sold on amazon) and extract the gold out of it I'm curious how much is actually in it I know it would be very little
Hah! Didn't expect that to happen!
I'm referring to him knowing Scott Manley.
@Papa Legba Then that would make you a paranoid denier of science and conclusions based on observations and reason.
@Papa Legba Holy shit this is too rich.
But please, explain to me why you think that Scott doesn't think that those laws apply in space? He talks about nothing but just that. Burning fuel turns the energy stored in the propellent's chemical bonds into heat and motion. If you don't buy it then I don't know what kind of answer you're looking for, since that guy spends an obscene amount of time talking about these things, in great detail. Whoever told you that obviously didn't take the time to use their brain.
You can do two more experiments:
1- vacuum oven: heat-up the material as a whole, not a small area with a pin-point laser. It's likely the material will all ignite as it heats-up, not in a chain reaction.
2- inert atmosphere: fill the chamber with inert gas at atmospheric pressure: nitrogen, helium or argon.
This video came out great Cody, as was enjoyable to view. I know I made a negative comment on a video you used this laser in the past. The science you did was great in that video, but the light from the laser made a massive glare on the glass. I could not see what you were doing at that time. I was super disappointed when that happened. In this video it is clear as day, perfect job. Great work, as always!!
What's a link to buy that laser you use to start the fires?
Rody Davis probably from wickedlasers[dot]com. they don't deliver to the us anymore.
Based on the shape of the dot I'm guessing self built. You can make half watt violet lasers out of some Blu Ray drives if you know what you're doing. If you don't, I would strongly recommend not doing it.
I have a broken ps3 maybe I'll give it a try. Thanks guys
If you need people commenting here to "get you a link to buy a fire starting laser", then you should not operate any laser at all cause you'll be a danger to yourself and others.
Such lasers are so powerful that even diffused reflection on a wall WILL injure your eye, and the smallest mistake made will destroy part of your retina. This is not a case of "it might". IT WILL.
Do not buy those things before being thoroughly educated on optics and electromagnetism. Buy a 5 mW laser pointer instead.
Relax dude, just dont point it in your eye youll be fine.
I wonder how they would react in an inert atmosphere like Argon, or in CO2.
Try a tiny bit of flash powder and see if it will ignite as a whole in a vacuum
Almost 1 Million subscribers buddy ! Well deserved, great videos !
another killer cody's lab experiment! thanks for sharing Cody!
How come there's a comment posted 9 hours ago? This was uploaded 30s ago!?! TH-cam pls...
Hannes Dendoncker Patrons from patrion get it first. forgive my spelling lol 😂
The people who support Cody on Patreon get priority. Sometimes thats 2 days sometimes thats just a few hours. But heres the good news no one from patreon ever leaves the stupid "first" comment.
yeah this one was out last night on patreon
Alright, thanks guys :D
Wouldn't it be a fire triangular-based-pyramid instead of a fire square? With two data points, you have a line between them, right? One dimension. With three date points, you have a triangle, right? Two dimensions. If you add in another data point, you get a triangular-based-pyramid, right? Three dimensions. Maybe I'm going about this wrong.
A tetrahedron? Yeah, I can see the appeal of that.
Fire tetrahedrons are a thing. The fourth thing is chain reaction, for which a confinement must exist, something Cody sees as pressure, but it's not pressure.
8:43 "In the vacuum, there's nothing there" : that's quite true :p
"Maybe we should modify the Fire Triangle into a square."
You should try publishing this as an official theory. As humanity explores space more, this small change could make a huge difference in how people think about flammability in spacecraft and during colonization of other planets!
I'd be interested to see what happens in an inert gas, rather than a vacuum. A lot of the problems seemed to be that the chain reactions were halted by either the fuel, oxidising component or heat leaving the system with no resistance.
Would gaseous ignition work if you had a small enough space so the gasses could fill the area and build pressure? After all, it's said that guns work in space, after all.
yes, in fact I've done it many times in other videos.
could you try this low preassure test on some other primary explosives (Ag2C2, PbN6 for example) or molecules with high oxygen content like nitroglycerine or guncotton
*****
That's what I figured and assumed, but thank you for confirming!
*would take NASA $2,000,000 to conduct the same experiment*
And 5 years, 3 environmental studies, 6 employee lawsuits, and 2 Congressional reviews.
this was their first and final experiment, the moment they knew it was impossible
Well nasa would use actual rocket engines and fuel
they are taking 32 billions a year from tax money and laughing in our faces, spending the money in whores and booze.
Probably because they would test it in 0g as well, which requires launching things to space if you want more than 90 seconds.
How powerful is your laser Cody pls replay
Ethan Wild u can replay yourself
Toh Yong Sheng reply？
Just want to say Cody I love seeing all the content you are putting out there. Awesome work man really good to watch
Wanted to suggest using hypergolic fuels to test if they work in a vacuum. A hypergolic fuel is basically two liquids combined to create a fiery reaction - an oxidizer and a fuel, without having to use a ’source of ignition'. The ignition is created simply by combining the two liquids. The temperature must be cold in order to turn the specific gas (oxidizer) into a liquid to create a reaction with the liquid fuel.
You can use dinitrogen tetroxide, commonly referred to as nitrogen tetroxide as the oxydizer, and use analine as the liquid fuel.
You should write a paper on the Fire Square.
What for? Science is blowing stuff up AND recording your findings. In ancient times people recorded it with pen and paper, but there is nothing special about it being in writing. This video is a recording of the experiment and it is also published... So its kind of a "paper" if you think about it. (just, the reviewers here are sub par usually ;)
kistuszek _What for?_
Because getting a paper published would be a feather in his academic cap, and nice padding for is CV.
It's also good experience.
RonJohn63 why? I’d never even heard of “fire triangle” until this video. Apparently it’s used to teach kids, who would waste time writing a paper trying to correct it
2:19 Can't have too much disturbsion!
Hey Cody, an idea for another vacuum chamber experiment is to put a Newtons Cradle in it.
I assume it will still work because of newtons third law of motion, and because rockets do work in space and it is almost a perfect vacuum.
But is might go for longer as there is no air to transmit sound to.
The acetone clearly combusted, but didn't spread from grain to grain - you can see individual grains being propelled by the combustion after the laser had ignited them. My hypothesis is that in normal atmosphere, the surrounding gas limits this movement and also spreads the heat to the other particles, causing them all to ignite.
I would also further hypothesize that if you were to have a large crystal of acetone peroxide instead of small grains, it would probably all burn in the chamber after ignited... or it might explode, considering it is a primary high explosive and I wouldn't really want to try to crystallize that stuff.
at 11:42 i totally agree witrh cody - pressure is a necessary factor for flame to occur! This means one cannot produce flame/fire in a vacuum, which means rocket thrust generators that burn liquid hydrogen/oxygen mix cannot work in a vacuum!!
@Mudkip909 now all we need is an actual demo to see if you are right!! got one?
@Mudkip909 one also has to bear in mind the fuels/oxidiser exiting the nozzle are entering the vacuum of space so there would be no pressure acting on those fuels/oxidiser just like in cody's demo!!
no pressure no flame!!
if you thjink i'm wrong let's see that demo i mentioned earlier!
What animal was causing all that ruckus?
probably one of his birds
A living experiment. I mean a "pet". Okay both.
Does a tree falling in a vacuum not make a sound when not observed?
It does make for a decade's worth of conferences in philosophy, where the answer will inevitably be "it doesn't matter, nothing matters anyway, we're all figments of our own imagination".
@tetrabromobisphenol lulz.
Conclusion: use thermite in vacuum SRB:s.
What a great collection of surprising results!
Cody, you are a quintessential scientist, and I am humbled to know I don't match up.
I probably made more false predictions watching this video than any other. :)
This is why I love physics. There are still surprises around every corner.
Very cool, Cody! This explains why model rocket enthusiasts need to use balloons for confinement if they choose to use BP propellants for their parachute ejection charges, and why most folks have switched to piercing CO2 powerlets to get the necessary gas. :)
Best scientific debunking video : burning needs 4 not 3 conditions. Every science college teachers should be tied up and forced to watch this video, Then, untied if they confess teaching lies.
Or maybe they just know wrong.
@Christian Gingras a little ridiculous to say they were "teaching lies", it's more the fact that "an atmosphere" is pretty much guaranteed here on earth, so it's going to be a given in any normal circumstance unless you're literally teaching astronauts, at which point I'm sure it comes into the discussion.
Well since there is no pressure the oxidizer would spread really quickly making the amount near the fuel insufficient for combustion. I bet if there was a lot more oxidizer per fuel it would burn. Or if it was mix much better
So if there's no combustion in a vacuum how did they get back from the moon?
Chris young I assume the nozzle of the rocket increases the pressure allowing combustion to continue. If Cody had packed the thermite, gunpowder or candy into a confined space it might have done better.
Chris young oxidisers and enough pressure.
Pre-pressurized fuel ingredients that contain a large volume of oxygen or other oxidant in a large combustion chamber that then vents through a nozzle to provide directed high velocity propulsion. The pre-pressurized component isn't needed to be pressurized for the combustion to take effect- it's just done that way for maximum storage capacity to minimum space consumed.
what do you mean?
I probably should have just googled a silly question like that
Just figured I'd let you know that some of this content was used in one of those "we didn't go to the moon" type videos. I thought it was funny. It was his only point for "thrust can't work in a vacuum", and so he used the gunpowder thing. XD
Pure Cody. A simple experiment, some would say with a predictible outcome, until he tries a baked thermite. My mind was blown a bit (pun intended). And all of this is well commented and explained. Love it, Cody, keep at it!
Great Video Cody, and congrats on your soon to be 1 million subscribers. Awesome channel, keep it up. Your format shows everyone how science cab be applied practically at home and you don't have to be in some fancy lab.
dude Flat earthers are using this video now. man they piss me off with taking shit out of context.
lmao how dare they use this video about combustion in a vacuum to debunk rockets in space which use combustion in a vacuum. Using rocket fuel and simulating conditions in outer space and specifically mars and other planets. Totally out of context man shit!
yes it is out of context when they leave out the last thing cody says lol 12:37 "what you really need is a case around it to catch those sparks and build pressure if your using it as a rocket lol what is it you think they do in space? internal combustion and throw the exhaust out the back. to every action there is an opposite reaction. picture it like throwing a ball in space the ball would go one way you would go the other.
@Critical Minded for someone using the name you're using you sure don't seem to be thinking critically. I don't need to rewrite everything @loded25 has already said, but it should be little more than common sense. Rockets aren't just burning tiny bits of fuel out in the vacuum of space, surely you don't think that's how rockets work do you??
Test a model rocket in the vacuum chamber, pleeease!
Try mercury fulminate or cesium in water
Subscribing exactly because of what top comment said, and obviously because the content is great.
Keep it up, man.
It seems like even the smallest amount of gas expands so much and so fast that it blows everything apart before it has any chance to ignite. Reminds me of the experiment in wich you can see the airflow created around high voltage electrodes with flower.
Realy expected the rocket candy to burn, that's a frikin solid lump of verry well mixed fuel with an oxidant. Perhaps the nitrate decomposes and the oxygen gets sucked out by the vacuum from the molten mass? Also in vacuum things evaporate (or sublimate) at lower temperatures, potentialy lowering the maximum temperature the suggar mix can reach just enough to prevent full ignition. Maybe in the thermite, part of the iron formed molten iron evaporates, making enough gas to blow things apart, slowing the reaction down.
This is so surprising, did not expect the vacuum to have such a huge impact. Fascinating :)
100 views
30 seconds ago
Patrons had it for a while.
Hussam Askar 242,107
Cody, how about looking at drying wet objects like wet paper or wet sugar cube by dropping the atmospheric pressure?
The water may boil for a little bit then freeze and just start
sublimating. The sublimation usually soaks up enough energy that it
will often maintain the solid state without some sort of external
heating. This is dependent upon the vacuum obtainable though.
Subliming, or melting and vaporizing take the exact same amount of
energy, so it's just a matter of rates.
As the surrounding pressure decreases, the partial pressure of
the water increases. This increases evaporation rate. If you have a
pump capable of evacuating 1 cubic foot of air per minute, if that same
cubic foot contains 30% more water, it will evaporate faster.
When we were testing in an anerobic chamber we had to clean all surfaces with alcohol (sometimes twice!) in order to get to our spec limit of 10^-6 Torr. When you were "burning" did you notice significant changes in pressure in the chamber? Any gases released would then potentially get captured and removed by the vacuum pumps. Our chamber required a super cooled plate to capture free molecules but as it continued to capture, its efficiency was reduced, and often requiring several cycles to go below 10^-5.
Oh. Really cool stuff! Thanks!
'This is used in amateur rockets because they are readily available.'
Thanks for reminding me how strict my parents are.
Really interesting video.
One question came up to my mind, sorry for my ignorance, but how does the laser dont burn through the vacuum chamber´s door?
It's so awesome to see your channel grow so fast!! Good job Cody :)
Cody: you should retry those materials in solid form, rather than powder form. (Gun powder can be caked with alcohol. Make a paste, let the alcohol evaporate. Your thermite was almost the same.) Note that the rocket candy, your point of aim was very different for the vacuum - center rather than end.
That's incredible - I thought for sure that as long as an oxidizer was present, it would burn. My theory is slightly different but related to yours as to why it won't burn - when things expand, they cool. Just like an aerosol can that gets cold as the gas is allowed to expand. I think at least part of the reason they won't burn is because the negative pressure allows for more expansion, and therefore reduces the energy (re: temperature) to continue the ignition.
As soon as I can find a cheap steel pot or pressure cooker, I'm making a vacuum chamber. I've been wanting to do these kind of experiments for years, and you've inspired me to actually go through with it.
Get a paint pot.
To differentiate between the role of pressure and the role of oxygen, you need to repeat the experiment with an inert atmosphere (possibly nitrogen, but Helium might be easy as well).
Maybe its not just a combustion triangle, but also has 'pressure' in the catalyst category. It seems that solids even with an oxidizer and ample ignition will still not readily combust at low pressure. We may be able to stop fires with a partial nonlethal vacuum that can kill a fire without robbing everyone caught in the middle completely of oxygenated atmosphere.
Your comment at the end made me wonder: How well would a thermite mixture work as rocket fuel? You should try it!
This is great, and makes the science behind the tuning of internal combustion engines make much more sense. The fire square needs to be a thing.
wow i didnt know that pressure was a factor in combustion. I knew about the fire triangle but it's actually a square just like in your tumbnail XD Thx Cody
Great video as always!!!
The importance pressure for the chain reaction was new to me.
cool vid Cody. I did not expect that! it's so cool to watch your experiments and explanations. thanks dude
he just went through the whole scientific process in one video. that's awesome
That one piece of gunpowder at 4:23 that propels itself into a spiral.
great video cody, but the fire triangle already had a fourth requirement added which is "a continuous chemical reaction" so I guess pressure would make it a pentagon :)
If you want to experiment with pressure and burning things with it's own oxidiser, a tube would be required to contain it in one instance so it's own pressure is the one at work in the vacuum, then on the other hand you could try oxygen free atmospheres as well.
I don't really think we need to add pressure to the fire triangle. The problem here was that one of the components of the fire triangle was escaping because the reaction was being done in a vacuum. Confining the reaction or putting it under pressure doesn't add something that was missing.
Anyway, the more interesting part of this video was what happened to the smoke. It was noted that it fell when in a vacuum but it's interesting to consider why. There was no upward plume, I think, because the plume is caused by the smoke being dragged up by air warmed by the reaction. In a vacuum there's no warm air so the smoke goes out in all directions as we saw. The smoke then fell down which we also don't see at atmospheric pressure. I suspect this is because, under vacuum, there's no Brownian motion to keep the smoke particles aloft. There's a-whole-nother video right there...
ya pressure makes sense- individual particles have to be close enough together to transfer energy to the next particle- and when you have a reaction going it creates pressure which would tend to push particles apart.
set a small pane of glass on top of the thermite pile to provide the pressure and contain the sparks yet let the laser through.
In fire science, they teach the fire tetrahedron, which includes the chain reaction of the burning process.
The most interesting experiment I have seen from you Cody, I especially like what you said about the fire square.