Shaking Buildings Over a Mile Away!

hi I really think you're gonna like this video today [Music] if you're familiar with the channel you know that we do some pretty high-energy videos and I don't just mean me the huge drone the jet engines the megawatt lasers were pretty familiar with high energy experiments but today we're going to ramp things up a couple of notches and so I want to reiterate the written warning disclaimer that we gave at the beginning of this video even though what I'm gonna show you here is very easy to do it is dangerous and so I'm gonna repeat the warning don't try this yourself if you're just interested in the explosions you can skip ahead but what I would like to start out with is what's going on here and why this is important we got into the idea of looking at hydrogen burning because I built a pulse detonation engine and based on research papers it looks like a hydrogen oxygen fuel will be the optimal combination for a pulse detonation engine in addition we're building a high-altitude balloon experiment and we thought about the idea of using hydrogen as a low-cost alternative to helium as the lifting gas after doing this research it's pretty clear to me that the detonation engine is going to benefit from the use of hydrogen and oxygen but the use of flammable hydrogen in a large lifting bag or a large weather balloon and not so sure that is a good idea but you can make up your own mind after you see the video what basically is going on when we are making explosives that we're talking about explosives is we're looking at two primary categories one is the decomposition type of explosives examples of that would be say TNT trinitrotoluene RDX one of my favorites which is glycol tri nitrate and uranium-235 this type of reaction occurs when a particle or a molecule that's relatively stable will when triggered will decompose or reconfigure two reaction products that are even more stable and in the process gives up a lot of heat the other category of explosive is a burning type combustion type of explosive and that is say gasoline in your engine or say dust and a grain silo dust air burning hydrogen and oxygen burning and deuterium and tritium in a fusion reactor now sticking with just the chemical reactions for today the process of the decomposition is an intramolecular process it tends to be very fast and typically you have reaction speeds that are in the range of about six to eight kilometers per second the burning type of reaction is sort of two stage you have to get these moderately stable precursors together then they have to react to form a more stable reaction product and so it tends to be slower typical burn velocities in in that category are in the two to two-and-a-half kilometer per second range with the one exception of hydrogen and oxygen properly mixed or in an optimal mixture you can achieve speeds as much as four kilometers per second is the fastest burning type of reaction you can get other than hydrogen and fluorine and you don't want to work with fluorine now basically what happens when we are burning hydrogen and oxygen is that hydrogen and oxygen don't exist in the atmosphere as single atoms hydrogen exists as a diatomic molecule H bonded to H on similarly is a diatomic molecule oxygen and oxygen and at room temperature even though these molecules can be in the same volume same container they don't burn because this bond here is called a covalent bond it means that essentially the electrons are being shared by the two partners and it's reasonably stable the same thing holds for the oxygen and so even if they approach each other inside of a volume of gas essentially these bonds are stable enough that the two partners are not able to exchange partners in order to form the reaction product which is as I'm sure you know h2o which can be drawn like this now this bond however is temperature dependent essentially what's happening happening at anything above absolute zero is this bond is vibrating there's an intra molecular vibration of thermal vibration the hotter you get the gas the more vigorous this vibrates and effectively if you got this hot enough the particles would actually disassociate so the bond weakens as the temperature rises in addition as these particles are bouncing into each other the hotter you get the mixture the more vigorously they're bouncing into each other and the more they distort their electron clouds and so you can draw this in sort of a modification of what's called an energy diagram and effectively what this is representing is that unless you can get these bonds to convert unless you can add enough energy so that these bonds begin to stretch and become weak enough and unless you can cream them into each other hard enough they won't react you have to get over this energy barrier but if you reach the ignition temperature which is sufficiently weakening the bonds and increasing the kinetic energy of the interactions you can then cause these to form more stable bonds and in the process give up a lot of energy it takes a lot of energy to disassociate water into hydrogen and oxygen and you get a lot of energy when you form the water so it's easy to make hard to break now the heat that's given off by this process is expressed in both thermal radiation actually photons are being emitted by this radiation heat but most of it is actually retained in the water molecule as extremely vigorous vibrations of the H o bond it's actually so hot that some of these will actually dissociate but the point is this is vibrating very very vigorously and so what happens is if you get say a little lowly oxygen molecule here that's sort of meandering around and eventually gets to this point here it can pick up some of that vibrational energy heat the oxygen molecule and also send it careening out at a very very high velocity where it may just run into another potential partner and begin this reaction all over again this process will progress from the ignition point outward in what's called a flame front now if you have a terrible mixture say you've got tons of extra hydrogen or tons of extra oxygen or you have a parasitic buffer gas like atmospheric nitrogen it will interfere with this transfer of this energy that's being absorbed by the oxygen and it will cause some of that energy to be lost to the parasitic gases to be radiated out into the unreacted material outside of the flame front now this is hopefully what happens in your car engine because this heat that's distributed from the reaction zone will spread out isotropically that means evenly in all directions and as the burn progresses the temperature inside the volume will slowly increase eventually when it's all burnt you'll reach an equilibrium temperature and then everything will begin to cool down however if you have an optimal mixture of these two components and no parasitic gases there's nothing to interfere with this transfer of energy this movement of the energy to new potential reaction products and this reaction occurs or this transfer of energy occurs supersonically just like light is the speed limit in space time at which information or effect can be transmitted from one point to another the analogy in matter is the speed of sound it is the limit at which elastic collisions can transmit energy or an effect throughout the medium and when the reaction is occurring at above the speed of sound effectively all of the reaction products around the flame front outside not yet involved are not affected by that none of the heat is distributed to it so none of the other gases warm the pressure doesn't go up the volume doesn't expand and none of the energy is being distributed to the rest of these gases as a result they're just sitting fat and happy unaware of the devastation that's headed toward them as the consequence all of the energy is concentrated in this very thin flame front that's moving out supersonically away from the reaction zone and when I say thin I mean thin like microns thick and because that concentrated energy is in that thin sheet of expanding gases the pressures and the temperatures are in order of magnitude meaning a factor of 10 higher than they will eventually reach when all of this gas is burned and you reach equilibrium maximum temperature in addition unlike the isotropic expansion and heating in a gas volume shockwaves tend to be directional and so they not only will move away from the initiation point in a favoured direction but they can actually reflect off of the inside of a container they can even reflect off of pressure variations within the gas so you not only get a concentration of the energy in time because it's so thin but you can get a concentration in location because the the shockwaves can focus so you can reach orders of magnitude hundreds of times the peak pressure that you would equilibrium reach and when the full learning occurs at the point of contact with a shock wave and that's how it can cut through steel and that's how it can shatter concrete now if you're gonna try to burn this as efficiently as possible use up all of the potential energy what you want is what's called a stoichiometric mix and that's a chemistry term for sort of the perfect blend of hydrogen and oxygen so that when the reaction is complete you've used up all the oxygen you don't have any hydrogen left over everything has been consumed and the way you determine what that that golden ratio is is you balance the equation now in chemistry balancing an equation can be a real headache if you've got a very complex reaction but in this case it's actually a very simple thing to do it's kind of interesting to see how this works now the typical way of writing this is we have a diatomic molecule so we have h2 and similarly we have a diatomic molecule we have Oh - in order to balance this we can see that we have to use at least two oxygens so therefore we need to make at least two waters but in that case we then have two times two hydrogen's or four hydrogen's required on this side so therefore we do this and voila we've balanced the equation and what this means is we need two hydrogen molecules for every oxygen molecule or at standard temperature and pressure room temperature and atmospheric pressure that means we need twice the volume of hydrogen as oxygen so a cubic meter of this would require two cubic meters of this now if you want to dig a little deeper down the rabbit hole there's another principle called cross section or reaction dynamics and it turns out that because these particles are vastly different in their mass the oxygen is 16 times heavier than the hydrogen and tends to be a large molecule moving at about 300 meters per second at room temperature the hydrogen is a very small molecule that's why it leaks out of balloons and it's traveling at about 1,200 meters per second so if what we do is we use a combination that's actually a little rich we're gonna waste a little hydrogen and we use three parts of hydrogen to one part of oxygen we will get an increase in the detonation velocity and it's probably because the hydrogen is carrying away the energy more quickly because it's so light but we can reach 4000 meters per second with an optimal mixture and that's what we're going to be using for our experiments now another kind of nice thing about working with hydrogen and oxygen as an explosive is it's non-toxic the hydrogen and the oxygen are toxic the water certainly isn't toxic most decomposition type of explosives are very toxic they're poisonous for example nitroglycerin is a powerful drug less than a milligram absorbed into your system is a potent vasodilator it actually relaxes the smooth muscles inside blood vessels and that's why people who get angina chest pain related to a relative low flow of blood in the heart can relieve that by taking less than a milligram of that material that drug and ingesting it it will dilate some of the secondary blood vessels in the heart improve blood flow and the cramp goes away what's significant though is if you try to fabricate or you try to synthesize nitroglycerin you will get a cracking headache because it does the same thing to the small blood vessels in your brain increasing inter-cranial pressure finally oxygen and hydrogen is a rather diffuse low-density gas mixture and so you can work with it a little bit more safely than you can with any high explosive because even a very small quantity of that will blow a hole in your bench and send shrapnel every place so with that in mind let's go ahead and mess around with it okay so what we have here is a plastic container with some bubble juice in it this is a slight modification of the formula that nighthawk and light gave on his channel describing the enormous bubbles that he makes in the formula that he uses we'll go through the modification when we do the video on the big bubble machine that's gonna be coming up in the near future but in any case what we're gonna do is we're gonna use this bubble juice to make some bubbles using different gas mixtures and then we're going to ignite them now the first mixture I'm going to show you is just pure hydrogen in the red balloon for the H Balmer line for you astronomers and spectroscopy and got a little valve I'm going to open the valve and we're going to form some bubbles in here because my cameraman did not volunteer for this I'm gonna do this know moisten up my hands a little bit and I'm gonna grab a lump of bubbles and we're gonna ignite this cool huh let me see if I got a little bit more I could do it again here okay kind of neat now what we're going to do is we're going to use the oxygen and the hydrogen mixture and this is a different animal so we're going to use some safety equipment in this case and one thing you'll notice is that I'm not going to use my gloves even though I'm wearing the hearing protection and the eye protection I don't need that alright and for you headphone wearers this is a warning this is going to be loud so you might want to turn things down alright here we go whoa different animal right now there isn't there is an unexpected side effect from doing this and that is you can't do this without smiling yes it's hilarious and what was funny is about ten days ago I was messing around out here blowing up bubbles and jumping around and having a ball and so I wanted to show my family so I invited my wife out here and my kids and they were looking at this and we were blowing up bubbles and smiling and laughing and having a ball and then I hear a knock on the door back there and so I thought oh the neighbors so opened up the door and it's a delivery guy I think it was from FedEx or UPS he was a new guy I didn't recognize him and he went ahead and he looked at me and he said aren't you that guy on YouTube and I'm like well yeah and it's not implausible as channels gotten big enough that I have been recognized by a few few strangers but he said I really liked that video that you did on chocolate a couple of months ago and I said oh yeah I really because you know I still got the chocolate up there you know we've got some leftover and he said yeah I really like that video is really good and I said would you like to see an explosion and he's like and I said nah it'll be alright so I go ahead and I give him a pair of headphones put it on and I did the explosion in front of him and he jumps back and he's like smiling likes it like this and I said would you like me to do it again and I went ahead and he's like yeah so I did it again and he's grinning like a little kid and I think the reason you have to laugh when you do this is because it's kind of a goofy combination of goofy bubbles and the devastating power of the explosion you just don't expect it seriously though the reason this is important is because pulse detonation engines are at the forefront of research in both jet engines and rocket engines because the fact is the shockwave is such an efficient way of converting the chemical energy into directional kinetic energy that even the highest performance military jet engine on afterburner might approach exhaust velocities on the order of mm almost Mach 3 but when i detonate these ittle piddy bubbles the shockwave and the gas is rocketing away from my hand at over Mach 9 and that's why I wanted to bring up the point about the gloves is that when I did this second reaction it hurts a little bit but it's like getting slapped with a ruler it's not warm in the first case I needed the gloves because it's kind of hot but because all of the energy is being carried away by the shockwave there's very little heat left over and that's what makes this such an efficient thrust source because you're not exhausting an incandescent gas it's more like a laser it's almost coherent it's a directional kinetic energy that occurs when the reaction happens and the only real problem with building these pulse detonation engines beside it achieve injustice is because it is so powerful that effectively it tears the equipment apart so if we're going to get into bigger explosions we're gonna need to go outside okay so this is the test stand that we built in order to blow up some balloons and I commandeered one of my son's antenna tripods as a support and I fabricated this apparatus to detonate the balloons if you look you'll see that there's a red hydrogen line going in this side an oxygen line coming in here and that both of them go into this t piece which runs through two check valves one for each line that prevents retrograde filling of one gas into the other line so that we don't contaminate the supply lines typical industrial check valves won't op at the low pressures that the balloon will create and so we're actually using aquarium check valves which work very well to prevent retrograde flow the tea piece is then attached to a your lock fitting that has a six millimeter or quarter inch diameter stainless steel tube that goes from this point here about a yard or a meter up here and exits at the end right up here then surrounding that is a larger diameter nylon in electrical insulating tube that goes from here all the way up and not quite to that same point and then finally there's an aluminum fitting here that has a larger diameter aluminum tube that goes around the nylon tube and again gets nearly to the top there's a small piece of silicone tubing that acts as a seal gasket so the only way for gas to get in and out is through the port up here and then finally there's a piece of aluminized tape that's attached over the gasket so that we end up with a discharge spark that's going to occur between the tape and this inner tube you can see that we have a high voltage line hooked up here and a grounding line that's hooked up here so that we can create the spark up here these very long wires then proceed to go about 30 feet away so that I can get far away from this and at that point I have a high-voltage power supply that produces about a 40,000 volt one kilohertz frequency microsecond pulse train that produces a very hot spark to initiate the explosion up here you'll also notice that there is a set a third fill tube here that fills a gap between the outside of the nylon insulator tube and the inside of this larger diameter nylon grounding - and there is a small port located here that allows gas to flow here between here and this point and we'll get to that a little bit later now you'll see the sign below there is a bit of an inside joke and if you're interested you can look it up but if you want to hint look at Princeton University and if you want another hint look up IV mic and when you get the answer you'll know what tight we had considered using as an alternative to the one that we ended up with in any case what I'm gonna do is I'm gonna attach an a balloon up here with pure hydrogen and we're gonna use that as a baseline okay so I've just filled this with pure hydrogen and I'm gonna show you that when I use the spark this doesn't work the reason is is there's no oxygen in there so I have to detonate this or explode this with an external flame just like the bubbles inside ready three two one pretty cool huh now what we're gonna do is gonna do the same thing but an oxygen hydrogen mixture okay so what we're gonna do is I'm gonna use these rings as ways of measuring the volume so I can get the three to one ratio one ring is about 50% larger than the other and using the equation 4/3 PI R cubed for the volume of a sphere if we use the smaller ring and we fill with oxygen we'll know when we have one part of oxygen so my cameraman's gonna turn on the oxygen and begin filling the balloon with just pure oxygen to start almost good and then he's gonna fill it with hydrogen good okay now in this case it's going to be a lot louder so I'm going to put on the headphones and again for you headphone users we're going to go ahead and give you a warning here [Music] [Music] pretty cool huh from just this tiny little balloon now you'll see some videos on YouTube where some chemistry professors will fill up a balloon with some oxygen and some hydrogen tie it to a string and ignite it with a candle at the front of a chemistry class trying to get the semester chemistry students interested in chemistry through explosions difference here is that because we're using an optimal mixture not the typical stoichiometric mixture this is a much more brilliant or rapid explosion furthermore because we are igniting this from the center of the balloon with an extremely hot spark instead of this the explosion having to travel across the whole distance of the balloon with an external flame we're detonating and producing an exploding shell that is moving outward from the center so essentially the balloon is blowing up about three times faster than it would typically do in one of these other demonstrations so that's what makes this a much more powerful demonstration because of the fact that we're optimizing the way the explosion occurs in this and the direction that the shock wave is traveling but from this tiny little balloon we've got a pretty impressive result nevertheless I bet I know what you're thinking am i right let's try it how can you not smile [Laughter] okay we just managed to blow all the snow off of our roof and it's a pretty good reverb now as you might guess we're not going to go any bigger than this we're not going to fill a weather balloon with this it's just too much in addition for safety once we filled this balloon up what we did is we confirmed the size and then we disconnected the lines to the supply tanks just in case the check valves weren't working we didn't want any chance that we would retrograde send a detonation back up the line but an interesting application of this is that about 6070 years ago during World War two in that era they didn't have very sophisticated electronics very lightweight electronics capacitors and flash lamps and so for reconnaissance purposes they needed a very powerful and compact lightweight light source and so what they developed was called an argon bee OMB you tube or argon candle or argon flash and basically what happened is they took a very powerful small high explosive and placed it inside of a larger cylinder in which they injected some argon gas so that what would happen is that the detonation wave as it progressed through the gas would compress it heat it and it would glow it would glow it a tremendously bright level of light because the argon unlike nitrogen oxygen hydrogen is a noble gas and does not have intramolecular vibrations to eat up some of the energy so it has a very low specific heat so in the shockwave heated it it reached very high temperatures and would produce light all the way from the deep UV into the visible by exploding this thing below low flying airplanes you could actually illuminate large fields for doing photography back at the time when electronics would have been pretty inconvenient to carry onboard a lightweight aircraft so what we're gonna do is we're gonna wait a little bit of time until it gets darker out and then we're going to fill again one of these balloons but in addition to placing the hydrogen and oxygen in there we're going to place a second balloon on top of there and it's going to stretch over that side port that I was talking about and we're gonna fill it with a thin layer an additional layer around the inner balloon of pure argon and so when the shock wave exits the inner balloon it will compress that argon and produce a very bright light so we're gonna wait till it gets dark we're gonna fill up the double balloons and we're gonna repeat this experiment one more time and we'll see how bright a light we can make 5 4 3 2 1 let's bring everything in close soon but so if the cops come there's nothing here let's just like throw it in quick so aside from messing around and once again annoying our neighbors there are some interesting applications where a hydrogen oxygen explosive could be useful and one of them is the ability to disarm an explosive mixture you know when you light a firecracker fourth-of-july you're gonna set off a firecracker and it goes off you light the fuse you run away from it no big deal but when it fails to go off you know you wait a little while then you go over there and you kick it and maybe pour a little water on it but what do you do if you've got a really large explosive at what point would you ever feel safe to approach it again well one of the interesting things that we're building is a shaped charge using a metal liner that is placed in the end of a pressure vessel that we can fill up to 20 atmospheres with a hydrogen oxygen mixture we're going to hopefully produce a concentrated jet of supersonic material that can potentially grill through large distances drill drill large distances through armor plate or steel or concrete but importantly although we're using the same check valve technology that we use to fill the balloons we are also going to add a solenoid that will allow us to dump the gas mixture if for whatever reason it doesn't go off or we decide that we want to disarm it one of the nice things about an explosive like an hydrogen and oxygen explosive is that you can disarm it now these huge containers will have several hundred thousand foot-pounds of energy available and unlike say a balloon which is just throwing supersonic balloon fragments around this is far more dangerous and so if we're going to be detonating something like this what we're gonna do is we're gonna dig a trench we're gonna produce a build a bunker so that anything that explodes is gonna be kept underground and safe and we really can't do this in this kind of weather so we're gonna have to wait a little bit of time before we get to that video but hopefully what we've shown you already is pretty interesting and kind of exciting and a lot of fun and makes a lot of people smile if you'd like what we're doing please subscribe to the channel hit the bell give us a comment I read them all and if you have questions I try to answer as many as I can and that interaction really helps to build the channel because what's happened over the last few years since about 2016 is YouTube has redirected people away from their original content creators they're trying to become a Netflix or an Apple TV and so that what made YouTube YouTube was original content by youtubers and after about 2016 if you hadn't grown your channel large it's almost impossible to do so now if you're dependent only on YouTube's promotion so the biggest thing that you could do for us is to share the videos where whatever you do to sort of direct people toward the channel will help us to grow and the bigger we get the more we can afford to do because as you can guess what we do here although it's a lot of fun it costs a lot of money and it takes a lot of time and by promoting this and helping us to grow we can do even more and we can produce more videos more frequently in any case I want to thank you very much for watching I wish you a very good evening stay safe and take care [Music]

Channel: Tech Ingredients

Views: 602,403

Rating: 4.9438143 out of 5

Keywords: Hydrogen, Oxygen, Shockwave, Detonation, Pulse Engine, Explosions

Id: l9CI6KSV560

Length: 35min 51sec (2151 seconds)

Published: Fri Jan 17 2020

Reddit Comments

[u/ralph8877]

Explosion:

https://youtu.be/l9CI6KSV560?t=1877

[u/firmakind]

Pretty interesting actually, lots of knowledge. Now I want to see the slow mo guys team up with him to do that argon balloon again.