 Hi guys! Welcome to my talk on rocket fuel making hydrogen from home. I'm going to be talking today firstly about a bit of rocket science and rocket fuel and that's what I think. I'm going to talk about that for a little while at the start and then I'm going to move into doing a demonstration where you guys can make your hydrogen at home. So to do the experiment you're going to need these things at the bottom here. We're going to come back to those in a moment but because we're going to talk for a little while first you have a second to gather everything together and then we can do it together. So I'm going to start off firstly by talking, oh move to the next one, talking a little bit about myself. So I unlike the other speakers don't actually do astronomy or astrophysics but I really love talking about it. So I'm a science communicator so that's what I actually studied and it's what I do professionally and I really love talking to people about the stars and about rockets and I think rockets are really great fun. So you can see me on the left there talking about how we do spectroscopy. There's been some talks about that in the past so go back through and check them out and then at the top it's our rocket launcher that I made at home. So rockets are this really great thing that everyone can do together I think in terms of science and it's something that I get really excited about when I talk to people about. So what I'm going to do in this talk the first thing I'm going to do is talk to you about what is rocket fuel and then at the end I'm going to take some questions but I really encourage you to ask questions throughout the talk and then they'll come up and I can answer them either as we go through or answer them at the end. Then I'm going to do the experiment live in front of your eyes and at the end and all throughout it ask questions, send in troubleshooting and we'll try and work through it together and join in in that way and I'd really encourage you if you build it along with me to post a picture in the comments and everyone can see what you've done I'll be posting my picture and I'll take questions all throughout that so ask your questions anytime. Oh there it is and yeah post your results. The other thing is please make sure you have a supervisor with you for this experiment. You can get a bit fiddly and involves a little bit of an electric current, a little one, so make sure you have a responsible adult with you for this experiment. So what are we going to need? The first thing you're going to need is some aluminium foil this is going to be the going to help us with the batteries to kick start the reaction we're going to do. You want to get a clear container this one's mine it's not too big but deep enough that we can put the aluminium foil in it. Get some plastic cutlery so you can put it along the top of your container it doesn't have to be cutlery necessarily wooden chopsticks or plastic chopsticks will work just as long as something you can prop on the top and that is not metal is the main thing so some plastic knives or something is perfect there. Get yourself some sticky tape some salt and some dishwashing liquid you don't have to have the dishwashing liquid but it can be really cool if you have it and yep so the final product is going to look like this just to give you an idea. I'd really encourage you to get a few batteries double A batteries preferably but not more than four. One is probably not enough but um three or four is a great amount not more than four or you might get a zap and that would be sad for everyone. So let's talk about rockets. So getting off the earth is actually really difficult and there's a few reasons why that is the first reason is gravity pulls us down the closer you are to earth the more gravity you feel and it can be a bigger struggle to launch up and away from gravity and the more weight you have on the ship the harder it's going to be to beat gravity so you think well you know if it's so hard to beat gravity we'll just put more fuel in and we'll get a bigger rocket but the more weight you add through things like rockets and fuel the harder it's going to be to beat gravity. The second thing is that getting through the atmosphere can be really bumpy it's a bit like if you've ever been on a plane and they tell you to put your servo outs on because there's going to be some turbulence and it's the most extreme form of turbulence you can imagine on a rocket and they're strapped really tightly in but what that means for a rocket fuel is it's not something that can be very unstable it has to be something that doesn't get bothered by a lot of heat in the atmosphere and something that's not going to be bothered by a lot of bumpiness so that's that's the reason why getting off earth can be hard and we have to really think when we're designing rockets and rocket fuel. We've got two kinds of rockets that we're going to use to get off earth the first one is solid a solid fuel in like a solid rocket so once this fuel is ignited it's just going to go and go and go you can't turn it down or use it to do things like thrust or steer because it's going to just like keep on going once you've ignited it the second type of rocket then is a liquid rocket so you've got much more control over this type of fuel you have you're able to actually use this liquid rocket to um control the speed of the rocket ship and even turn the rockets on and off completely so the two main ingredients then of liquid fuel are hydrogen and oxygen and that's what we're going to be making today so that's also fun so two kinds of of rocket fuel then so what about hydrogen and oxygen so hydrogen is great because it's really really light it's the lightest molecule on earth and it burns really intensely so over 3000 degrees celsius and it's going to be very very hot for that reason and as it burns and explodes it's going to create a lot of energies it's going to push our rocket along it's actually hydrogen so explosive and so bright in its explosion that an example of it is in the sun and in stars and if you go back and have a look george's talk last week talked about how intensely bright and fiery things like stars and supernova can burn and they're also made of hydrogen so that's why we're going to use hydrogen in our rocket the second thing is oxygen now remember we said that hydrogen is so powerful when it burns but this is called a combustion reaction and you need something else in a combustion reaction so planes also use combustion reactions but they are burning fuel to create energy as well that pushes them along just like a rocket but in order to burn fuel the second thing you need is oxygen and the plane luckily can get that oxygen from the air so our air in our atmosphere provides the fuel with the spark it needs to kind of ignite and burn a lot so it can draw in air from the atmosphere space as you might know is in a vacuum that's why we can't necessarily hear things very well in space and why you know all sorts of friggy things can happen when you go out into space in terms of pressure but what that means is that there's no air and there's no oxygen to burn so when we ignite the rocket we need to get that oxygen from somewhere else to get that burning combustion reaction so we actually need to send that oxygen with them on the rocket and it draws it in from the cylinders so if we go back to those two kinds of fuel actually we need rockets with oxygen for both solid and liquid rockets which is an important thing to know because we cannot get that oxygen once we're in space so how does a rocket work so simply our liquid rockets are going to work by burning hydrogen fuel with the oxygen in a high pressure chamber and we can see it here at the end on the right and we've got the hydrogen fuel in one area the oxygen and other they're going to combine in a reaction and bang it comes out the end in my very explosive diagram here and the direct exhaust out of the nozzle is going to propel the rocket along so we're about halfway now so if you've got any questions ask them now and we can answer them toward the end and there's the rocket being propelled along by the the energy of the exhaust so now you must be looking at a lot of these rockets and the kind of trails that they're creating and thinking like wow this must be pretty terrible for the environment and climate change and stuff like that look at all this explosion and this burning and you know the planet must be pretty sad but actually not so much because when we have a plane and a plane is also burning fuel like we talked about and it's a drawing that air in from the atmosphere to burn that fuel the fuel they're burning is not hydrogen it's something called kerosene which is a bit like diesel you guys might put in your car or your truck or your parents maybe if you don't have a car or a truck yet so you might have heard that like a co2 or carbon dioxide or carbon emissions um this is created when you burn a fuel that is carbon based so diesel is made of carbon so when it burns and it combines with that oxygen that we have in the air what you're going to get is carbon dioxide co2 and too much of this is what's contributing to climate change and the planet being sad like we saw in the last slide but luckily rockets don't actually use a carbon based fuel rockets as we've just talked about use hydrogen combined with oxygen and when you combine carbon no sorry when you combine hydrogen with oxygen what you get is H2O H for hydrogen over oxygen so you get water so actually when it burns it's not actually creating those like terrible carbon emissions it's creating just water which is like much better for the environment rockets aren't totally environmentally friendly you know space junk is a growing problem and making the rockets uses a lot of energy resources can be difficult to collect and it can be really difficult to recycle the materials in rockets once we've used them but hydrogen fuel is certainly a way forward and not necessarily bad for the environment especially compared to something like diesel so if we've decided if we've discovered now that water is the product of rocket fuel combining with oxygen we can make this at home by going the other way so splitting the water back up into hydrogen and oxygen for fuel but they're fixed very tightly as you can see in this diagram here they're really stuck together and we need to do something to break up this very very fond band of triplets and what are we going to do we're going to use electricity to break apart the bonds that are holding water together so my why might we actually do this in space so one of the reasons why we're actually going back to the moon even though we've already been there and we kind of want to go to mars is that before we go to mars we have to be able to make sure we have enough fuel to get to mars so remember the more fuel we have the harder it is to get off earth and the more expensive it is to push our rocket gravity is really hard to beat and it's expensive so we know that there's ice on the moon now and we can see in this diagram here the north and the south pole of the moon the south poles on the left and the north poles on the right there and you can see those blue dots are where ice is and they're in the darkest parts of the moon so the the lighter spots are the parts of the room that's the part of the moon that's the warmest and the dark spot are the cold it's in the really cold dark areas of the moon and we also know that there's water detected under the surface of the moon so if we can separate rocket fuel from this ice on the moon we could potentially use it as a source to kind of fuel up and keep going to mars and beyond and that would be really great for us so this is sort of the last bit we're going to go through before we start the experiment so um if you have any final questions go now but what are we going to do to break up water electricity breaks water up so what we're going to need firstly as we talked about is water and that's what we're going to get our fuel from then we need to put in some metal metal is useful because it's a conductor of electricity so if you've ever been told by your parents start to put a fork in the toaster or if you're like um my mom you've actually put a fork in a toaster and had something horrible happen to you um electricity flows through the metal and it doesn't flow so well through other things like plastic or wood so that's why we're going to use electricity and that's why we're going to be putting our props as not um as not metal because you know we don't want to zap ourselves in our props so the metal's going to bring the electricity into the water then we've got batteries batteries are what's going to kick off our current we're going to have a positive and negative side and connect them together so we have the flow going through um through the metal and into the water and then the last thing we've got to do is sit and watch the water break up and create our gas bubbles so the um on the one side we're going to see hydrogen gas coming off and on the other side we're going to see oxygen gas coming off which one is which you might ask you'll have to try it and see or if you're not going to try it you can just watch me do it and I'll show you so but you said I said that we were going to make a liquid rocket and now we're making gas well you know I hear you but you know it's kind of complicated so to make hydrogen into a liquid you're going to need a lot of compression you need to be very cold and you're going to need somewhere to secure and store it that's not going to leak out once you've created it and made it into a liquid and that's kind of hard to do from home much harder than just you know separating water so if you're interested though in um liquid hydrogen into the future um hydrogen is being looked at as an alternative fuel for things like planes and cars because as we talked about we want to move away from those carbon-based fuels and into one that maybe just makes water instead of carbon emissions so if you're interested in you know liquid fuel um that could be a very lucrative career into the future but unfortunately not today so um if there's no questions uh we might press on so next up we're going to need these things so we're going to need the foil the batteries the container the cutlery sticky tape salt and dishwashing liquid so before we begin there's a few warnings that we should go through so make sure you're working in a very well ventilated space because we're going to be adding salt to the mixture a really small amount of chlorine is maybe going to be produced so you don't want to make your bedroom smell like a pool for the rest of the week so go to somewhere i'm outside you don't have to go outside being in a like an open plant area is fine but maybe don't do it in a cupboard so make sure you disassemble the the assembly as soon as you're done or leave it in a well ventilated space outside if you're not able to leave it outside somewhere where you know your cat's not going to eat it or your little sibling's going to knock it over i have an example of one i've done a few days ago so you can see what it's like you're not missing out anything but if you're going to leave it make sure it's somewhere well ventilated don't do it on a metal bench or a metal sink as we said metal conducts electricity you want to zap yourself try to do your experiment and avoid touching the foil and avoid touching the water and make sure your hands are dry before we touch all those things or you might get a zap you might not but you might so don't do it and make sure your responsible supervisor is with you to do this and if you haven't already get the responsible person and i'm going to remind you of all of this as we go through so let's begin so now i'm going to move the camera down so you can see what i'm seeing and this is my workbench move that out of the way so this is what we're going to need here it all is here on the bench my foil i've also got some towels here to make sure my hands are dry nice and safe my container got my triple-a batteries i'm only using three but remember maximum of four and then we've also got our salt over here so let's begin here's my container the first thing i'm going to do is fill the container with water so it gives the salt a bit of a chance to dissolve i'm going to drive because it's easier but water out of the tap is really fine i'm going to take it off it'll go a bit faster now we add our salt again table salt just fine no brand sponsorship here but iodized table salt will do fine and just eyeball like a few tablespoons and then maybe grab one of your little case of cutlery mix it together and that will dissolve while we do everything else so move it to the side if your hands are wet make sure you dry them because we don't want to combine electricity and water on ourselves just in the experiment okay i've got my three batteries double-a's triple-a's will also work if you have a few of them at a stretch you could use a nine volt battery but double-a's are the best so four maximum of these otherwise you know increases your chance of getting a zap so what we're going to do is combine them together in what's called series so i'm going to use my sticky tape here to stick the batteries together smack tag a second but i'll hopefully take as long as you so you don't need to pause at anything and i'm going to go just like this and really pressing them together as we do that because if there's too many gaps then the electricity won't fall flow through it'll just like get stuck so here's the first one i'm going to do another one and holding them really tight see me i'm struggling with the the effort you know this can be a bit fiddly you haven't got your parent or guardian grab them now they'd be really great to help you with the with the batteries especially this next part which can be a bit fiddly and you can see mine are still a bit wobbly we don't want that so we're going to create a bit of a stirrup down here and what we're going to do is press down and pull down here like that and now that's really secure as you can see we don't want much flex at all if any so the next thing we're going to do just putting our batteries to the side for a second is grab our foil don't need too much foil and what we're going to do is oh excuse me is to connect each end of foil to one end of the battery so scrunch it up a bit like this and stick it on and like the other two if you can make sure you get it as tight as possible so grabbing the sticky tape oh it's stuck to my fingers really pressing it on okay so like the batteries we don't want a lot of movement here either so have a look and see if it's wobbling at all but if it's not you might want to like to put some sort of around the sides or maybe even underneath and then we're just going to put the side a little bit so something we don't want is for this to be touching the other bit of foil so make make sure you don't touch this bit of foil to the other bit of foil as we do this so next bit of foil and make sure you're not like clutching both at the same time just be careful you know try and touch hold the battery see I'm just carefully keeping it away you just bump both of them at the same time so I just don't like grab them both at the same time okay here you go very secure on one side very secure on the other side we've made our little thing now so what you probably want to do now is just gently just like open it up a bit make sure the foil is you know it's all clumped together we want as much surface area as possible to be in our salty water and just double check everything's on really securely yep looks good now we're going to grab our salty water back make sure one last time you could even add a bit more water not water salt if you want it you want it to be really salty make sure you're not using the wet implement give everything a bit of a dry dry dry dry my hands okay two just like this over the top remember if you don't have knives you can use cutlery or something or not cutlery not metal use chopsticks whatever and then we're going to put it in here it might only just fit so lucky me the reaction has begun and if you have a look down here you can see it bubbling away on the left hand side now the question we've got is how much hydrogen does it take to blow up a safe like to get money out I assume I'm not sure I think it would depend how robust the safe was but you can collect this hydrogen if you want and I wouldn't recommend you have a go but yes oh sorry I just realized my left your right camera is flipped so yes on the on the right hand side to you guys here it is bubbling away now something you might ask is I told you that it was going to be hydrogen and oxygen and you're saying what I only see the hydrogen what's happening on this side not much well that's because actually the oxygen that's being created is reacting with the salt in there and instead of creating oxygen gas it's creating chlorine gas which is much yakia and unfortunately not super useful for the audience so you might smell a tiny little bit the smell of chlorine a bit like a swimming pool don't stick your face in it chlorine's not very good for you in case you don't know it's usually used to clean things but that's why you're not seeing anything happening on this other side all the actions going on here and you'll see it's beginning to rise up now this is the time you might want to add the dish soap if you want to and you can see some pretty bubbles forming on the top with the dish soap and yeah so that's it and you can see it sticking to all of the crevices here where there's the most exposed parts and there you've got your hydrogen you can collect it and use it to blow up a safe or power your rocket the choice is yours so the last thing I kind of wanted to show you so it's the last thing so if you've got any final questions about safes or otherwise you can send them in now but if not add them to the comments later and we'll answer them for you is what happens when you leave it overnight so fast forward two days and this is one I prepared earlier I'm just going to swap them out here and you can see it's looking very different so we've got here we've still got our fork and the batteries they've been sitting and running you can see down the bottom here we've got this disgusting looking white foam and on the left it's the foil has become completely tarnished and dark and on the right where it was originally the same size oh sorry on your right and my left um on your right and your left it's completely gone it used to be the same size now it is much much smaller and you can see on top as well we've got some delightful looking metallic foam so this is because we've actually created is an electrolytic cell and what's happened here is an oxidation reaction has taken place and it's demolished this this part where the oxygen and the chlorine is being created and at the bottom you see that reaction between the aluminium and the salt to create a bit of our foamy deposit here so if you want to do that then that's that's what it will look like in a few days um we have a question about why does it stick I'm not sure what it is but if you're talking about the bubbles it's because they haven't quite escaped yet so they're going to cling on until they're able to kind of break that surface tension and rise to the top so yeah if there's no more questions you might just wrap up and let you sit and and think about your next rocket adventure you can actually I'm not sure if it's quite enough you can actually hear the bubbles so the last thing is when you're done with your cell if you don't want to leave it overnight like I did which is totally fair enough you know it looks um a bit disgusting if you don't want to leave it overnight then what you can do is just disassemble it straight away so pull apart the batteries and it's okay to just pour it down the sink it's only salty water at this stage so that's fine if you do want to leave it overnight make sure you put it in a well ventilated area somewhere that someone's not going to knock it over or anything like that but yeah thank you so much for joining me and um oh yes and when you're pulling it apart make sure you don't touch the two metal ends together still although you may not have another end as you saw with mine to come back to at all so be careful with that so yeah thank you so much for joining me um I hope you enjoyed it or you can try it yourself if you didn't watch it if you weren't able to watch it live um and do it with me live but yeah it was great to have you all joining me and yes this was luck bye guys