Elon musks- Flying Car.. BUSTED!!

Elon Musk has this amazing amazing new idea to enhance his Tesla cars by adding SpaceX rocket technology to them I personally really think this is actually going to be happening and he tends to not joke around with too much stuff like this he really loves making the ludicrous happen I mean just think about that for a second how awesome it would be to have the most modern SpaceX technology on a Tesla not saying the next-gen Roadster special upgrade package will definitely enable it to fly short hops but maybe certainly possible just a question of safety rocket tech applied to a car opens up revolutionary possibility clear that the rocket car finally flew oh actually no it's a really really stupid idea and distri why I'll be calling on a guy who Elan musk fans probably think as somewhat of an authority on the subject one is on musk now one my last video where I was just showing some of the practical difficulties of dealing with compressed gas there were lots of comments that said Elon Musk was just joking here he wasn't serious it's kind of difficult to sustain that when you see some of his other tweets David Jenkins right I reckon it's an adapted cold gas thrusters used in their upper stage rocket guidance using plain old compressed air to which Elon Musk replies using the configuration you described plus an electric pump to replenish air when car power draw drops below max power alper make sense but we're going to go a lot further yeah he's talking about how he's gonna implement this doesn't sound like he's joking to me rocket thrusters for real yes what are they gonna burn nothing hi Ultra high pressure compressed air well just a phone call gas thrusters so why is this such a stupid idea well let's start with the most obvious question of all so what are cold gas thrusters well it's pretty much what it says on the bottle thebe compared gasps bottle so that's all you do is you get a cylinder of compressed gasp air say for instance and then you use to open it up the gas comes out and you get some thrust because of that the downside is of course they don't provide much thrust in fact there are some of the least efficient thrusters that you can get now compressed gas as an energy storage system is quite modern Spacek technology this is one of the oldest ideas out there I mean really old the first torpedoes ran on you guessed it compressed air all right there was no cold gas thrusters they fell it through a little internal combustion engine type thing that ran the propeller but there's a big problem with using compressed gas like this is energy storage and that's su vent it quickly it gets cold really golde really quite quickly it's a thermodynamic property you cannot get around it and that means that you get a lot of thrust at the beginning and then its ability to provide thrust gets progressively less as the gas gets colder now this has been known about for over a century so the very first torpedo design this tried things to get around this first of all you put some big radiator fins just so try and get some heat into that cooling gas which of course increases the energy that you get out of that compressed gas or even better you know just inject the fuel straight into the compressed gas in this little engine thing and hey presto you've more or less got an internal combustion engine apart from you doesn't have to compress the gas from the atmosphere because it's coming directly from a compressed gas bottle in fact you know if you look at it like that this is basically what cold gas thrusters basically are with our regular rocket engine you inject fuel and an oxidant into a combustion chamber it burns there is a big expansion of gas and that's what provides your thrust however you can pretty much do the same thing but you just don't add fuel the downside is of course is it's a cold gas thrusters it doesn't provide much thrust in fact they are there almost bottom-of-the-barrel in terms of how much thrust you get per kilo of propellant now you may notice you know just looking around that you don't see many cold gas thrusters around on cars while internal combustion engines fairly common and there are two very very good reasons for this and what to the point there are very very good reasons what Elon Musk's idea of putting coal gas thrusters both to hold the car maneuver and maybe make it fly is a really stupid idea and this is the moment that you've waited for what we call on the guy who Elan musk fans probably think of as the greatest authority on this sort of thing billionaire and the inventor of the wheel sorry the hyper disc Elon Musk there are some drawbacks to flying cars they they are essentially it's a helicopter with wheels and they they make a lot of noise there's a lot of wind force and the probability of suddenly falling on your head if if they're a bunch of flying cars around is much higher than if they're or not so you got it that's why flying cars are completely impractical they make too much noise and they create too much air Plast the fact that cold gas thrusters are bloody noisy but it's about 100 psi and it doesn't really make any difference whether you get the thrust from a cold gas thrusters or from a propeller in both cases you're accelerating gas to provide lift or thrust the able arts gonna be almost exactly the same in both cases I mean look let's just get on the same page check this is a 50 liter cylinder here I have a 50 liter gas bottle and he's about 50 kilos which is pretty heavy to the point where so they're pretty heavy things now this one's actually argon but we're gonna say assume for the sake of argument it's compressed air as it would be with Elon Musk's cold gas thrusters so let's assume this is an air cylinder for the moment so if I take the top off this cylinder and it's at one atmosphere pressure then the volume of the cylinder is 50 liters the density of air is about one gram per liter so there would be about 50 grams in this cylinder now if I put twice as much gas in the cylinder the pressure goes up to two atmospheres 2 bar and the amount of gas in the cylinder goes from 50 grams to a hundred grams and now if I go from 2 bar to 20 bar another order of magnitude 20 atmospheres then it goes from 100 grams in this cylinder to 1 kilo and if I go from 20 bar up to 200 by 200 atmospheres then there's gonna be about 10 kilos of gas in this cylinder and it turns out so at the moment the Sun there is closed this is the primary regulator which tells me how much pressure there is in this cylinder and it's just sort of 200 atmospheres and then I've got a secondary regulator here who's going to tell me what the pressure is so I'm just gonna put on a white now a couple of bar and we're gonna open it so that's just a couple of bar a couple of our I can hold with my finger not that big of a deal if I Jack this up - oh I know 6 bar yeah it gets harder the hole with my finger all right and if we jack it up to about 10 bar and now it gets really difficult hole with my finger I can't do it my ass 10 bar if I take this off and open the cylinder that's 200 bar which as you can tell it's gonna be loud so let me get a wrench and I'll do that so this is not going to be 200 bar okay make sure you actually braced into the wall loud enough Oh blast comes off that there anyway so that's what 200 bar looks like and that's basically what Elon Musk would be proposing to use to accelerate and decelerate his cars a which is an absolute farce on so many levels now this surgeon there is quite a lot of destructive energy packed into these high pressure gas bottles he'll you know what originally taught this well it's gonna take the sound a little time to get here but the first thing you're gonna hear is the sound of a high pressure helium gas bottle failing then the sound of the explosion arrives yep it was a high pressure helium bottle Freeling and rupturing the propellant tanks this is why the cheapest and safest way to handle high pressure gases is in big steel cylinders like this and even though it was the cheapest are about a hundred bucks per shot now sure you can about half the weight of these cylinders if ya if you don't mind about the cost and make them out of composite materials like Elon Musk wants to do with his car but this will greatly increase the price maybe not something you want to be doing if you're laying off people to try and get the prices of your cars down but all these cylinders take in the region of 200 power because that's when it really gets quite difficult to contain all of this energy I mean just to give you a feel on these things for the safety limits these big steel cylinders are only allowed to be pressurized to one half of their failure limit because you don't want to go near the failure limit and with the composite cylinders it's one fifth of the failure limit why well 200 or debar is a lot of pressure and you have - respect your high-pressure gases 14 pounds per square inch 14 psi is about one bar but whatever let's not worry too much about the little numbers let's just say about 10 psi is 1 bar blast injuries to expose personnel represented by this dummy is usually severe over 3 psi here it was 6 psi so this is about a 1/2 bar overpressure and it throws a guy round like this a 200 bar over pressure of a rupturing cylinder is terrifying it's something you don't want to be anywhere near let alone being on the inside of a car with one of those cylinders one of these cylinders rupturing in your car means all but certain death but if you want an idea of the thrust that you can get out of a cylinder like this the bow has sheered clean off and that's a very good sign it looks like the cylinder flew straight and true at 40 miles per hour the air tank turned the cinder block to the cinders you know this was an optimum situation for this tank what this tank did is as good is it yes well okay I'm going to assume the mythbuster cylinder is about a 200 per cylinder like mine that weighs about 50 kilos those numbers are probably in the right ballpark and when they open up this cylinder it accelerated to 40 miles per hour at 40 miles per hour which is about 18 meters per second and so the energy is just 1/2 MV squared which is about 8,000 joules 8 kilojoules enough energy to shoot this bottle some 50 feet 15 odd meters into the sky so if we would put that 8 kilojoules of energy into our Tesla how fast would it be going well the Tesla weighs about 2 tons so half of the mass is about one time 1000 kilos so V squared is going to be about 8 so V is going to be about 3 meters per second nope that was 7 miles per hour that sort of thing not looking so good here this one may be the slowest ever but hey these are just some bull park numbers from cylinders losing vowels you know this was an optimum situation for this tank what this tank did is as good as it yes how would the rocketry people approach this so hold on this is all actually kind of coming together there is some serious possibility here I can't believe it but wait I should totally believe in I mean after all I have played around with fire extinguisher powered hovercraft now roll tree folk have a way of working out how much bang for the buck you can get out of your propellant and whilst it's correct it's not necessarily the most obvious you see here on earth we typically equate weight to mass because they're essentially the same thing seeing this gravity is essentially a constant here on earth yeah this makes them pretty interchangeable numbers however technically they're not mass is mass while weight is like thrust is a force it's a mass times by an acceleration the acceleration that you experience due to gravity so say my mass is 100 kilos that means my weight is 1,000 Newtons now specific impulse is how much impulse how much thrust you get in one second per ball one kilo of fuel but they expressed that one kilo as a force as a weight and somewhat confusingly if you actually go through all the numbers here you find that this metric actually his units of seconds but it's basically how much bang for the buck do you get out of one kilo of fuel so a simple example the Saturn 5 had a take-off mass of about 3,000 tons three million kilograms all its weight was 30 million Newtons so if you want to take this thing off the thrust that the rocket is providing must be equal to its weight you need to provide 30 million Newton's of thrust well the specific impulse of the Saturn 5 engines was about 260 seconds so the kilograms of fuel you need to burn per second is about 30 million divided by 2,600 which means you consume about 11 tons of propellant per second voyage is about right yes another opportunity to talk about both Tesla's and rocket science I couldn't be more excited let's get started so cool a Tesla mass is about two tons 2,000 kilograms or 20,000 Newton's the specific impulse of a cold-cast thruster is about 70 seconds 20,000 divided by 700 is about 30 kilograms per second and say he's ready to get about 10 kilos in one of these cylinders you wouldn't need three of these cylinders just to get your Tesla off the ground for one second but hey this is the best case scenario that you get near the optimum 70 or so seconds of specific impulse from your cold cast thruster in reality you're gonna get nowhere near that because the amount of useful thrust that you get out of a cylinder drops as the pressure drops so if you have say 50 or so liter cylinder with two hundred atmospheres at 200 bar on it each bar that you put into that cylinder extra has about the same mass they all weigh about 50 grams so if you're venting the cylinder you get a lot more thrust out of the first 50 or so grams that comes out of the cylinder venting it from 200 bar down to 199 bar then you're gonna get out of it when you vent the 50 grams going from 2 bar down to 1 bar I mean he's a nice simple example using my low pressure compressor which only goes up to just under 10 bar impressive start right here I've got a compressor and that taught you the pressure in the compressor so at the moment it's empty and it's sat on top of a balance with the exhaust from the compressor pointing upwards so this will essentially measure our thrust and it'll weigh it within 10 or so grams and just to give you a feel of the SIL thrust that we're gonna get off this thing that's a chocolate bar and mounds in America bounty in England and they wear down all 60 grams so I should joke in 60 grams okay so let's see let's fill up the compressor first and see how much thrust we can get off about I think this thing goes up to 8 bar [Music] good so now we have about $8 in the compressor tank so I'm gonna sear this then I'm just gonna hold the exhaust open yeah and [Music] that's that so you can instantly see the problem that you only get the good thrust of a cold gas thrusters at high pressure so this up here is going to be a specific impulse of let's say 70 seconds and then of course zero is zero which means on average if you're just gonna empty a cylinder you're only gonna get a specific impulse of about half the maximum value my sim practice means it's not three cylinders like this that you have to empty in one second to lift your Tesla off the ground you have to empty about six cylinders like this just to lift your Tesla off the ground for one second and at which point we can probably step back and address all the Elon Musk fans who have been complaining like crazy saying yes but you assumed he's car we need two tons when he actually read something like 1.7 well yes if you now include the weight of six of these cylinders which is about 300 kilos his car weighs about two tons but that's nothing we wasn't even started yet because that was me being generous you see eelain's talking about using in the electric pump I think a compressor is the technical term to replenish the air when the car power drop drops below max pack power output make sense but we're gonna go a lot further I'm not too sure about that Elon I mean it's a great idea using compressors onboard the car to give you unlimited instant thrust just at the push of a button it's that simple and wonder how long it'll take to fill those cylinders now obviously you're gonna need a high-pressure air compressor something will go up to about 200 bar bear in mind this is just an electric tin bar gas compressor with a tiny reservoir [Music] so you're gonna need something like this which weighs about 50 kilograms the compressor alone weighs about as much as one of these big gas bottles and it pumps about a hundred liters of air per minute now you'll recall that a 100 liters of air weighs about a hundred grams 0.1 of a kilo per minute and to fill a cylinder like this with 10 kilograms of gas that means you would have to have this thing running for about a 100 minutes about two hours just to fill one cylinder so the air pump could draw power from the power pack whenever there's spare power to be had which is apparently most of the time a bear in mind you gotta fill six cylinders like this just to get your car off the ground for one second so with just 150 kilogram compressor it would take about 12 hours to fill all six cylinders or if you went for ten also compressors half a ton of compressors in your car you could probably get that answer one hour sure the weight of your car would be almost entirely compressors and cylinders and [Music] you hope to get it to fly for one second now at the moment you may have noticed that I've kept everything down to basically a 50 liter 200 bar cylinders a useful used benchmark because that's when the safety limits for these things typically run out however apparently you shall or must wants to go up to the best part of a thousand bar do you have to have air tanks or they suck in the air okay yeah it's a electric pump well pump it up for like 10,000 psi and how fast are we talking 0-60 how fast you want to go in a giant gas cylinder on the backseat of his car coincide with Ilan's replied on me on Twitter asking how big the co Peavey's would need to be in order to have a substantial impact on performance his response would be that they replace the back seats of the Roadster with the co PV tanks I mean let's just ignore that by the time you get up to that sort of pressure you need five stage compressors he's gonna put it well let me just put 10,000 psi which is what Elon Musk is proposing in the perspective the chamber pressure of a howitzer when it's firing maxes out at about five times the pressure of the cylinder the Elon Musk wants to put in on the back seat of his car yeah the back seat of his car is now literally a bomb but what if rather than trying to get the car off the ground you use that to augment acceleration or for emergency braking well six cylinders or so we'll get you an acceleration of ten meters per second squared for about one second so it gives you a velocity of about 10 meters per second that's not bad that's like 20 miles per hour but but on the downside you can only do it for one second every 12 or so hours and all it took with adding another half also ton of weight to the car and turn your car into a compressed air deathtrap not that any of this remotely matters anyway because Elon Musk himself pointed out the problem with using air to accelerate the cars there are some drawbacks to flying cars they are essentially it's a helicopter with wheels and they they make a lot of noise there's a lot of wind force and the probability of suddenly falling on your head if if they're a bunch of flying cars around is much higher than if they're or not doesn't matter whether you're giving that air thrust from cold gas thrusters or propellers it just creates way too much noise and way too much air blast having 200 bar gas jets on the back of your car it's just a recipe for inadvertently killing anyone who happens to be standing behind your car at the touch of a button but what really catch me is just how devoted the cult of Musk is to such crazy ideas I mean you only have to look at the videos that I've done on the most demonstrably stupid ideas of Elon Musk and it seems to be a fairly simple correlation the more stupid the idea is and them easy it is to debunk the more the cult of Musk turn up to downvote it I mean remember we're don't we use giant meaty fossil fuel powered rockets to replace airplanes I mean that definitely goes against Tesla's green initiatives and what was Elon Musk's objection to flying cars oh that's right they make way too much noise I and they make a lot of noise but playing giant rockets all over the planet transport on the planet it was we're gonna fly bfr like an aircraft oh bloody time nah Elon Musk friends fly halfway across the globe in a you'll be on the VFR for a roughly half an hour or 40 minutes and the longest part of that yeah it's so awesome yes which is completely awesome except by the time that becomes practical will all be traveling by personal rocket pack the longest part of that flight is actually the boat out and back I mean Quinn come on this this this is awesome but it's crazy right like this is never going to actually happen oh no it's definitely gonna happen no no it's not going to happen and there's a very good reason for that look there's been a lot of very very smart people working on rocketry over the past 50 or so years there's kind of a practical limit to how safe you can make rocket engines because of the extreme conditions they work under which if you're lucky means that you're going to blow up about one rocket in every hundred that's not really passenger friendly if it really was that easy to make rockets that are hundreds to thousands of times safer what might have worked that out by now um and let's talk a little bit about the business everyone thinks Rockets are really expensive and to a large degree they are and yes they are expensive which is why this is a really stupid idea if only there was some sort of dumb justification when somehow will make this dumb idea even dumber how could we possibly compete with airline tickets here but if you think about it if I can do this trip in half an hour to an hour I can do dozens of these a day right and yet a long-haul aircraft can only make one of those flights a day well yes and if I had transonic solar-powered planes I could do it even quicker and even cheaper so even if my rocket was slightly more expensive and the fuel is a little bit more expensive I can run 10x at least what they're running in a day and really make the revenue that I need to out of that system and claim that these oddly preposterous doesn't even hold up the most superficial of inspections but God Elon Musk fans hate it when you point it out to them always claim that the Hyperloop it's really not that difficult it still sounds pretty complicated Elon it's like a tube with an air hockey table the high pressure air buildup on the nose and pumping it through the air skis it's really I swear it's not that hard I was gonna use for his air bearings yes very high pressure air cold gas thrusters and how far pray tell has Elon Musk's easy idea of putting together the Hyperloop come in five or so years he's no closer to building a Hyperloop thing Gerard ever was when he proposed the concept of the Hyperloop or vacuum train over a hundred years ago but in the wonderful little crossover turns out one of the Hyperloop entries into Elon Musk's Hyperloop design contest used cold gas thrusters not the levitation none of them have managed to do that yet this by Elon saying how easy it would be to just put put little air skis on these things now they used cold gas thrusters for acceleration it works like this to high pressure tanks filled with nitrogen gas empty about 90% of their mass over the course of three seconds as the gas exits it converts thermal and pressure energy into kinetic energy it vented the gas into the vacuum chamber which of course partially destroys the vacuum the happy damn this is more soapbox derby than the future of Transport so here you can see the true power of a cold gas thrusters firing something a little smaller than the Tesla okay a lot smaller than a Tesla so you see the rough size of the tank that gets this thing up to an amazing about 40 kilometers an hour it's less than 30 miles per hour yeah this is also something that drives the Elon Musk fans crazy is when you tell him that he's not the visionary who invented the Hyperloop he just took somebody else's idea that was over hundred years old and gave it a new name I have a name for that neighbor which is for the Hyperloop yeah a whole genius it's almost like the reason that no one has ever built one of these 600 mile Baja vacuum trains the Hyperloop intends to propel passengers through a low pressure vacuum tube at speeds up to 700 miles per hour it's because it's insanely difficult insanely dangerous and even seemingly expensive to do seriously the Hyperloop makes the whole flying car thing seem like a cakewalk Oh in Elon Musk claimed that he with no experience Ducky's first tunnel 100 times cheaper than all of the world's experts could ever have done he's very first tunnel normally it's the tunnels cast like sit on up to a billion dollars so like a discount tunnel would be sort of two hundred million dollars but we're able to build this tunnel for about 10 million dollars so he claimed a bucket for one percent of what it would cost real professional engineers to do it a claim that is preposterous on first inspection and when you take a look at the actual numbers of what it would cost to dig such a tunnel you find that Elon Musk's digging costs were almost exactly the same as everyone else's digging costs now if that must isn't a visionary here he's a Fanta cyst this isn't science it's science fiction the emperor has no clothes on and when you live in a fantasy land she could as well go for the flying cars or the supersonic vertical takeoff and landing electric jet the ideal long-distance transportation mechanism is a supersonic vertical takeoff and landing electric jet nuclear-powered commercial airliners we about to reach new limits with cars we have super cars we have hyper cars is this the start of a new generation of super ultra hyper cars maybe and I couldn't be more excited oh hell let's be real what okay for the thorium powered cars running on solar freakin roadways but if you're willing to suspend your disbelief to this extent I really don't understand why you stopped with masks I mean like I heard of this amazing new invention from a Stark Industries some form of nanotech that allows you to fight space Hovis and fly faster than any of elam masks spaceships you know II love masks Pacers the ones that blow over when it gets a little windy so if you enjoyed this video give it a thumbs up and ring the notification belt and if you really enjoyed it subscribe and maybe consider supporting this channel through patreon because it really does give me the freedom to allow projects like this take shape you [Music]

Channel: Thunderf00t

Views: 360,552

Rating: 4.6250129 out of 5

Keywords: elon, musk, tesla, flying, car, electric, cold, gas, thrust, thruster, spacex, roadster, compressed, compressor, joe, rogan, high, pressure, falcoln, full thrust, hyperloop, hype, vtol, rocket, mythbusters, bottle, cylinder

Id: znv0TQsR5jk

Length: 35min 0sec (2100 seconds)

Published: Sun Jan 27 2019

Reddit Comments

[u/Robbinator]

It's upsetting that one of the only people doing a decent job of talking about Musk is Thunderf00t because he's shit at explaining himself and pads the fuck out of his videos

[u/S-Vineyard]

Makes me think about what Montana Skeptic talked about in a Podcast some weeks ago.

If Musk is just doing this to show Wall Street with how much bs he gets through.

[u/insane_gravy]

Ye gods the fact that someone has to debunk this nonsense should be a searing indictment of the silicon valley techbro cult.

[u/[deleted]]

Makes me wish I could watch this video without YouTube recommending misogynist rants at me for 2 weeks afterwards.

[u/MrZipZap]

Showing a video of a car with a rocket strapped on it crashing to make a point. That's like showing someone a video of a rocket exploding and saying "Well this rocket blew up, guess spaceflight isn't viable let's stick to Earth."

[u/TheRealKSPGuy]

I don't always agree with this guy (ahem, DC-X is landing an orbital booster apparently), but assuming this flying car thing is not a joke, I don't think it is a good idea, especially since Elon said flying cars can fall on your head and kill you. If it is a joke, r/woooosh to everyone. You never know with Ol' Musky.