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.

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).

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!!

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."

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.

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.

0:55 It's as if the chicken starts laughing at Cody's suggestion of "safety first".

Hey Cody, what kind of laser is that?

you should try in an other atmosphere without oxygen

I'm quite surprised. I would have expected all the self-oxidizing compounds to burn.

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.

1 min 35 seconds in; That's a really interesting way of making paper art

+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.

Why is there still gravity in a vacuum? Wouldn't the gravity particles just get sucked out along with the air? :P

Fascinating results! This has changed my preconceptions about vacuum physiochemestry!

Just want to say Cody I love seeing all the content you are putting out there. Awesome work man really good to watch

Sweet! This is something I kinda requested back when you did the explosions in the chamber.

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

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.

It's so awesome to see your channel grow so fast!! Good job Cody :)

I learn so much more from these videos than from school

Can you drink liquified ice?

I enjoy the extra clips at the end of the videos. Keep up the good work, Cody!

Great video as always!!! The importance pressure for the chain reaction was new to me.

Ah.... the gimp was acting up towards the end of your demonstration

How come there's a comment posted 9 hours ago? This was uploaded 30s ago!?! KZfaq pls...

An awesome video Cody! Very informative and amazing production :applaud

cool vid Cody. I did not expect that! it's so cool to watch your experiments and explanations. thanks dude

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.

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?

another killer cody's lab experiment! thanks for sharing Cody!

Congratulations Cody, that must be a first for something. Your diligence paid off.

Would Logan's exploding paste work in a vacuum? Love the Chronos footage, thanks for the video.

I like how the birds interrupted you at the end of the video. "Hey! Enough of that!" :D

That slow motion burn in the end was GOLD.

Almost 1 Million subscribers buddy ! Well deserved, great videos !

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

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'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.

The most interesting experiment I have seen from you Cody, I especially like what you said about the fire square.

Bold prediction: the sun is not burning gas (But don't ask me for what it really is...I have no idea.)

I was surprised thermite could ignite so easily with the laser - just how powerful is that thing?! oO

This was really amazing and a very good demonstration, complete and scientifically sound. Thank you!

Nice find Cody ....... Great. That means everything which is confined and dense burns faster.

On this episode of "Does it Vacuum?" Explosives.

Hah! Didn't expect that to happen! I'm referring to him knowing Scott Manley.

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!!

best video ever! TY Cody!!

8:43 "In the vacuum, there's nothing there" : that's quite true :p

You should make a Tripod for your Laser, so it doesn't wiggle around

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.

One of the best videos!

How powerful is your laser Cody pls replay

What's a link to buy that laser you use to start the fires?

Cool video man! I enjoy this channel so much :]

I appreciate your videos, Thank you!

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.

2:19 Can't have too much disturbsion!

That black powder part is fascinating. Great video all around.

Very interesting stuff. As always.

Try a tiny bit of flash powder and see if it will ignite as a whole in a vacuum

You should write a paper on the Fire Square.

Subscribing exactly because of what top comment said, and obviously because the content is great. Keep it up, man.

Love it! answered lots of questions.

I wonder how they would react in an inert atmosphere like Argon, or in CO2.

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.

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.

Hey Cody awesome channel. Have you ever thought about doing a series of experiments where you go more in depth with the explanations of whats going on step by step? I am a chemistry student, but just starting out, and these experiments sometimes seem like they have so much going on at one time and watching the experiments are of course super cool but a more in depth explanation would be lovely so I could learn myself and maybe attain a working knowledge of the world around me. Again awesome channel keep it up!

What animal was causing all that ruckus?

what's the power of your laser? Really interesting video btw

Wow, great experiment. Got my brain ticking. Subscribed :)

Awesome video! I did not know this was this difficult.

Does a tree falling in a vacuum not make a sound when not observed?

Yes if the oxidizer is in the fuel.

Great experiment

nice experiment, your videos are great!

Hey Cody, an idea for another vacuum chamber experiment is to put a Newtons Cradle in it.

Since you seem to enjoy eating insane stuff (in safe doses obviously), could you maybe try to confirm the apparent sweet taste of lead acetate lead sugar? Also, compare it to normal table sugar.

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!

Seamless cuts. Pretty nice.

Test a model rocket in the vacuum chamber, pleeease!

*would take NASA $2,000,000 to conduct the same experiment*

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.

Cody: great stuff as usual! Have you considered using a mild centrifugal effect to see if you could replace atmospheric pressure with that to retain particulate proximity? Perhaps with a remote trigger glow bulb to attempt ignition within the chamber.

Conclusion: use thermite in vacuum SRB:s.

Try mercury fulminate or cesium in water

I think that it's not directly pressure that counts but to having a medium that transfers the heat.

Hey Cody amazing videos and by far my favorite channel!! was wondering if you could so some of these experiments safely in a compression chamber instead. For example seeing what paper and thermite would do at double atmosphere or something. Thank you and keep up the great work! :-)

100 views 30 seconds ago

So if there's no combustion in a vacuum how did they get back from the moon?

This video is great science right here!

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.

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.

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

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.

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. :)

dude Flat earthers are using this video now. man they piss me off with taking shit out of context.

I wonder, if we ever went to Mars, would guns work there since gun powder doesn't ignite?

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 :)

awsome video man! 2 thumbs up for you forsure! Did you do this all on your own buck?