 Buddy, and welcome back to Super Science Saturday, brought to you by UCAR and NCAR. This is an annual event that is now brought to you virtually this year, and we're all from our own homes. So we hope that you have been enjoying this event if you've been with us since we started at 10 a.m. If not, we will be having every 30 minutes new science activities for you to join and participate in through asking questions through the Slido interface that if you scroll down the page, you can enter Slido and ask us questions. We're also interested in seeing where you all are joining us from. So definitely answer those polls, let us know how many of you are watching and we have with us as well our new scientists who are coming up and that will be Janine Aquino and Tim Barnes for their presentation of rocket propulsion, taking the pulse of the empire. Take it away, Janine and Tim. Hi everybody, my name is Janine Aquino. I'm a software engineer actually with NCAR. So I help the scientists do a lot of math that they need to do to get their work research done. And Tim's gonna join us after our video. So I just have a quick question for you. Who likes Star Wars? If you do, yeah, I do too. If you have a favorite character, maybe Ray or Finn or one of the ones from the recent stuff, I would like you to invite you to join me and pretend that we are part of the Rebel Alliance and we are going to do some reconnaissance and learn something about the empire. So with that, I'm gonna start our video. Remember, you're my new Rebel recruits, okay? This will take me one second. Here we go. Welcome, Rebel fighters. I am General Programma, Supreme Commander of the Resistance. The empire is developing a new fighter for use in the atmosphere of terrestrial planets. I am here to familiarize you, the new Rebel recruits with this technology. In 2B2, display the diagrams that we intercepted from the empire. In a rocket engine, fuel and air are combined and set on fire in a combustion chamber. This causes the pressure to increase in the chamber and the burning mixture is forced out a hole which pushes the rocket in the opposite direction. In a rocket, this happens nonstop. In a pulse jet, this is not nonstop. It happens in short bursts. So after the burning mixture is forced out of the chamber, the air is sucked out of the chamber with it because we're not adding any more air. This leaves low pressure in the chamber. Fuel can't burn without air. So the low pressure sucks the air back into the chamber along with some of the fire and this starts the cycle all over. So recruits, your job now is to let the Rebel Alliance know if you see the empire using this new technology out in the field. Stay safe out there and may the force which you use in times of acceleration be with you. This is Lord Durath Value. You are here for the testing of our new pulse jet engine. Look out for Rebel spies. They could be lurking anywhere. They're testing it again. Let's get closer. And now watch carefully. You will see the whole pulsing burn of the engine again but in slow motion. Notice as the yellow flame is replaced with a blue flame that is the beginning of the fuel burning. And as that fuel near the opening of the bottle combusts that ignition goes all the way down into the bottle and continues until the available oxygen is used up. This reignition happens over and over again when low pressure inside the bottle draws in more oxygen and the heat and vaporized fuel ignite again. We see the blue flame when the reignition happens and then fades and then comes back and fades and comes back over and over again. This technology will defeat the resistance because it's very, very hard to destroy. Wow. That was amazing. Baby Yoda and I are so impressed about how you have managed to fight against the rebels. Hi, Baby Yoda. I'm glad you could join us. So Tim hopefully can join us now too. You saw him. There we go. Durath Value has come to answer some science questions. Here I am. Hi, everybody. We hope you enjoyed that. We had fun making it. That was awesome. And it makes me wonder, that's very dangerous but it looks like the adults were working on that project and there was cameras set up. So even though you said let's get closer, it was probably a camera that was closed because that looks pretty intense. That is correct. We just zoomed in the camera. I actually stayed quite a ways away. And there's so much chemistry going on. And as we're waiting to see as the questions are coming in, I know you explained a little bit more but can you talk a little bit about what it was like to set this experiment up? Well, this is an experiment that we, everything that we do is practiced over and over again after it, any concerns are vetted through our industrial hygienists and our safety people. So they look at everything that we're thinking of doing and then we consider, should something go wrong? How do we manage that? Then the practice begins and all of what could influence the demo is taken into account. So what we're doing is literally vaporizing a fuel in a contained space and finding out exactly what we need to do that was key, that five gallon plastic bottle that we use is the same one, once we find out what works, we stick with that. And there's a specific amount of fuel that we use and a specific admission process. And then we just have to make sure that no one's too close. The closest camera was actually an iPad sitting right next to the bottle even closer than I ever got. Yeah, you had a really long stick to start that flame up as well. Yeah, if I have it here somewhere, it's over a meter long, so it's make sure I can get far enough away. That's good, because some of the other demos, this is not one that you can try at home. That's good to know, because it does definitely look like you had to go through safety inspection prior to getting this together. Thank you so much. And we practice this over and over again, we've been doing this one in practice a long time. That's good, safety first, of course. And we do have a few questions, but before we go to the questions, I wondered Janine and Tim, did you have anything else that you wanted to share about this experiment? I think we can take questions, Tim. Sure, let's go for questions. Okay, awesome. Let's go ahead and put up the questions and see what are people asking. And we have Wallace who's asking, would a pulse jet work in... That's so interesting, we were going to ask that question too. Janine, would you like to respond? Yeah, so that's a really good question. If you remember at the end of the video, when Durth Value was explaining, he was saying that oxygen was getting sucked into his container. So the experiment we did wouldn't work in outer space, there's no oxygen out there. However, a pulse jet used in a rocket is a little different. They can actually inject the oxygen into the combustion chamber along with the fuel, and then you can use it in outer space. And it is actually something that NASA has explored for using for different rockets that they're dealing with. And I'm not sure what else, I'm not very familiar, but I did see that that is something that they have worked on. That's so awesome. So while this particular project wouldn't work directly, there are ways that scientists and engineers have engineered space shuttles and rockets to be able to work in outer space. That's correct. That's awesome, thank you so much, Wallace, for that question. And we have another question from Checho Kai and Amaya. Why were the flames blue and not red or yellow? Should I go ahead and take that one, Janine? Yes, please do. Okay, well, first off, I have to say hi to Kai and Amaya and of course, Checho. They're really good friends and they've been just loving today. So I'm glad that you're still here. And kind of Maya, the flame is blue because the fuel that's burning burns blue and that's methanol. The candle that's on the end of the ignition pole it burns yellow. It's burning different chemicals. It's not burning pure methane or sorry, methanol. So that's why in the description, when I point out the change in color, that's no longer the candle burning and it's the methanol which is vaporized inside the bottle. And liquids aren't gonna burn as easily as, actually liquids aren't going to burn. The methanol has to be vaporized and you might have noticed me shaking in a bit. It was a little cold outside too. We got a slower burn, which was really great. It was more visible. And that blue is the methanol burning with all of the oxygen and it's drawn into the bottle. So that's how the color of methanol. That's so amazing. Cause I was thinking it was just like really, really, really, really, really, really hot. But I'm just wondering. Yeah. Cause the bottle melted. It was so hot. Yes. And I just happened to have the bottle here. In case you are wondering, let's see if we can, I'm not sure my background's blocking that too much, but you can kind of see at the bottom where it melted, yeah. Wow, yes. So definitely glad you were, you were at least six feet away or more. Or more. Or more, yeah. More. Great. Well, thank you so much. And we have another question from T. What makes pulse jet better than regular rocket? So I can take that one. In our video, we actually probably misled you a little. We said this is indestructible and it's the best, but we were having fun doing a little make believe to bring you our experiment. In reality, I don't think one is better than the other. They have different uses. So you can imagine a regular rocket is going to burn consistently. If you can do pulses, maybe you can control your speed a little better or change your angle that you're flying at. So being able to, I imagine different situations would be different uses. And one of the reasons why I said that it's indestructible is taking liberty there, but it's also simpler. If you, when the more complex something is, the more things can fail. And in this case, simplicity is the key of this design, but could it fail as well? Of course, especially if you're using a plastic water bottle. That's awesome. Thank you so much, both of you. And thank you T for that question. We have another question from Chungus. And I apologize if that is not how you say your name. I would love to know how to say that name. Chungus, what was on the end of the long stick? And I think you might've briefly mentioned it. I did. That was a candle. And it's a normal candle that you might use for a birthday cake candle. And it was taped to the end of the stick. So because of how much force comes out of the opening of the bottle when the methanol starts to burn, the thrust from that burn can extinguish the candle before ignition is complete. And the way we found out, of course, was through not being able to ignite the methanol completely over and over again. And finally we realized that a candle will stay lit long enough for the methanol vapors to ignite and continue to burn with the oxygen inside. But then you might have noticed in the video that the yellow flame disappears because the rush of those blue flames does extinguish the candle. So I'm not bringing flame back with me. And what the methanol ignites. So it's just a regular birthday candle duct taped on to the end of the bowl. That's great. It's great to take precautions so it doesn't just keep going up the stick that you are holding. Great. And a comment from Rue. I love it. Thank you Rue. Okay. We do have a question from Max. Is fire a type of matter? So it's a state of matter, right? So you probably hear a lot in school about solid, liquid and gas. Maybe you've come across that in your studies but there's another thing called plasma. And I think that fire is just that state. So it's the gas is burning and that's another state that matter can be in. Well, thank you so much. Thank you everybody for asking all of those great questions. And I am just amazed at everything that you all have done to pull this off with, you even have a mask. I mean, it was Halloween recently and that's the best way to cover yourself with a mask these days. And Janine, I love how you were able to introduce that. Can you, if you have it, can you let us know what was written at the beginning of the video? Cause it went a little fast. It did go a little fast and I'm sorry about that but it was basically the introduction that I gave you that we were new rebel recruits coming to do some reconnaissance on what this new technology was that the empire was gonna do. Great, thank you so much. I just wanted to make sure that I didn't miss anything just cause I, it's hard for me to read slanted words. Yeah, and it was fast. I am, this was my first movie I've made. I'm not very good at it. So that's all I could learn to do a little better. We're always learning and thank you so much. That was amazing, both of you. We do have another question. Hey, let's see, from Chetro Kai and Amaya. How high did the blue flame go when it was out there in the bottle? It came out about the most, the highest flame, it's kind of arch shaped but it came out about eight inches out of the top. And then as we know, the top of the flame is actually hot in the base of it. So at the very tip of it, even though you couldn't see it as well. So it's coming almost a foot out of the top of this bottle at full burn. Wow, like a whole foot? Yes, and that's why we have to make sure that there's nothing over it that will ignite. And we've done this at the Mesa laboratory during Super Science Saturday in our main seminar on move. Of course our safety people looked at it and went up at the ceiling like what's up above that can burn. So that's one of the things you might not notice as dealing is ensuring that there's nothing above it before we ignite it. It's always safety first. Wow, yeah, you did do it outside. So that was great. And there was no tree foliage, no leaves hanging over the street. So definitely glad. And that was Halloween. That was Halloween night when we did it. So the trick-or-treaters got a chance to see. Yes, so there were people there all gathered around. They were the special effects, so they were not with the empire. They were out trick-or-treating. And conveniently, it was dark enough that they couldn't see. Couldn't be seen. That's so great. And that has inspired a lot more questions to come up afterwards. So thank you all of you for asking that question. And Faye is asking a question of why did it not last very long? Why is it that this didn't burn for very long? So why wasn't there a lot of a long burn? So I have, I don't know how well you can see that with all my light in here. I do have the bottle of the fuel. And this was packaged by our safety people, specifically for that with the safety data sheet on the back describing what the health hazards are of this material. And this only had, right now, it's empty because they used it all, but it only had 30 milliliters of methanol in it to start. And for the first, we did it twice. So I only used 15 milliliters of methanol, which vaporized. So with a bottle this big, that small amount of fuel doesn't last very long. And it's burning pretty vigorously with lots of oxygen. So there's just not a lot in there. And that's another one of those safety things. If we wanted to continue the burn, we would have to continue, we'd have to add more fuel safely to the bottle. Great, that makes so much sense. You can't continue without fuel, just like our cars. See, thank you for that question. Karen is asking, how hot does the flame need to be in order to melt the bottle? Well, I'm so glad you asked that question. And I can tell you, I don't know, but it's pretty hot. And you know what? In our next test, we will get a temperature of those flames. And typically the bottle does not melt. The other wizards, as soon as they looked at our video, they were like, why did the bottle melt? And I think part of the reason for the bottle melting in this situation was that the air outside was cold enough that the burn was slower than normal. So when there's a quick burn, the heat, the flame doesn't stay in the bottle as long. So it might not have been how hot the flame was, it was just how long the burn was. So we can do some experiments and find out. Yeah, we've got a infrared gun, we can point at that and see what temperature we get next time. Great, thank you so much. And we have a comment or a question about what if from Checho Kai and Anaya, it is asking, if the bottle was tipped sideways, would it have moved forward? So would it have actually propelled the bottle for movement? Do you think? Yes, with every action is an equal and opposite reaction. So the thrust out of the neck of that should the bottle been laid sideways would have caused the bottle to move away from the thrust and that would have skidded it across the road, which is one of the reasons why it was not laid sideways if I wanted to make sure I knew where the flames were. Great, thank you so much. Maybe next time when you do the temperature reading, you can also see the distance of travel from that. So we have somebody who you might recognize, Megan and Booker, who is saying it was cool to see. Yep, so that's my family right there and they were actually in the background watching it. So anybody who knows my family, you can ask them just how cool it was. They were right there when it happened and yeah, it was super cool. Great, thank you so much. And let's take a question from Wallace, which is about how does the new heavy lift rocket compare to the Saturn V? Jeanine, do you have any input on that one? I really don't, I'm sorry. That's all NASA stuff and we're in cars. So we don't work on all that stuff. We have used rockets, but not for years and years and years. We mostly use airplanes. But that might be something that you'd have to Google and look up at NASA. I just don't know anything about it. I love science because it always leads us to more questions and curiosity to investigate on our own. Maybe with our adults at home or our friends to ask these questions and continue the conversation beyond just this program. So thank you so much for asking that question. Yeah, I love my job because I constantly learn new things. I've been at NCAR for 30 years and every year every new project I learned something new. Great, thank you so much. And we're coming up to almost close to 11.25. So we're gonna just have a couple of more questions and comments and then I will thank you before we head to the next event. But from Juniper, could you do this project or this experiment with a glass bottle? Do you think? I think that could be very dangerous because if it did overheat like that and crack that I could sink glass flying, the plastic melts, but it doesn't go anywhere. So I would be really worried about trying to do it with a glass bottle. Absolutely, it would work with a glass bottle. And that's one of those things our safety people said, not doing a little glass bottle, just to be sure because that one doesn't, plastic isn't gonna shatter. I think it knows. That's great information because if anybody out there ends up doing anything, just be safe and make sure you have adult supervision. This one again is not an experiment that is recommended for at home to try out at home but rather a good experiment to learn about by watching this episode. So thank you so much everybody for all of your great questions that have been coming in. And thank you both Janine and Tim for your great presentation and for answering all the great questions that have been coming to us today. Thanks everybody, I'm glad you could join us. Yeah, we'll see you again at Super Science Saturday. Thank you everybody.