- Hello, I'm Scott Manley. And today I'm responding to my top 1000 YouTube comments. [upbeat music] The following comments came from the most popular video on my YouTube channel. What video is it? I think it's Your Physics Have No Power Over Me. Oh, this is a marvelous video. This was a very early Kerbal Space Program video where in the early game they would optimize it in such a way that some of the parts had essentially no physics mass. Now the thing to notice is they're all flying at exactly the same speed despite this one having a bunch of stuff on it, it's traveling the same speed as the unencumbered one, in fact, the unencumbered one overheats and explodes. Kerbal Space Program is this video game where you can build rockets. And it's really a simulator for rockets, aerospace and other things. And yeah, it came out of nine years ago. I got into it because I was an astronomer and therefore it was one of the few people that was a gamer who could also do orbital mechanics. And somehow I got popular playing this game and yeah, with physics, I was always trying to find ways of breaking the engine and pushing the engine. And this was one extreme version of it. And I made a demonstration about how you could bolt these on and it wouldn't change the acceleration or the drag or anything. And then I demonstrated those one thruster, you could put as many of these on, and it wouldn't increase the mass. So you could accelerate at ridiculous rates and do stupid things. And it got really popular because I linked it and that sort of became the standard. It has always led on my viewings ever since then, what I remember of making it was basically I tried to ram a planet at maximum of speed. We crossed the star system in Kerbal Space Program, like spaceships in the expanse doing full burn. And I decided to try ramming a planet. It was a gas giant. And again, due to glitches in the physics, we actually bounced off even faster than we came in. And I just remember collapsing in laughter and that is straight in the video there. Here's one of the first comments on that most viewed video, try to get to speed that will let you fly through Jool's atmosphere without thrusting once you enter and escape. [laughs] I think we tried that and we bounced off. This is not time accelerated. This is the real thing that actually greeted me as I flew towards the Planet Jool, just wait... You see I even get an encounter with Tethy for about a second, but here we go. And we bounce off and fly away at about 15 times the speed of light. I did not expect that at all. Really though, if you wanted, you could push the physics engine, so you skip through the entire planet in one physics tick, please reply to these comments from that video. This doesn't work in the latest version of real life, God patched it. And it's such a shame because I would really like to be traveling to Jupiter in a few days, rather than several years. physicists I'm sure would love to find a way to exploit this again. If you could play God and patch any part of the physics of reality, what would you adjust? Whoa, that's a scary one because I know all about false vacuum collapse and the anthropic principle. And every time I look at the way the universe works, I find that any even slight change will probably result in humanity not existing. So I would actually stay well away from modifying the laws of physics. Why did I decide to make videos about Kerbal Space Program? Because I'd been making videos about other games and it just happened to come along. And I was sort of rare as being a video game player or streaming on the internet who also knew orbital mechanics and just enough rocket physics to get me into trouble. The following comments came from the second most popular video on my current YouTube channel. What video is it? That one's a little bit harder. Is it the terminable video? Oh wow. Yeah, Faster, Higher, and More Secret Than The SR-71 Blackbird. The A-12 Oxcart, which I loved recording this video. This was us driving back from Southern California last year. And I sort of... One of the people had mentioned in one of the comments I made that by the way, if you're driving back this way, you can stop and see the only place in the world where they have an SR-71 Blackbird and an A-12 Oxcart sitting next to each other. Oh, it's Scott Manley here in Palmdale, California, because this is the only place I knew of where they have an A-12 next to an SR-71, which is pretty amazing. The SR-71 was the well known it was a two-seater, it was longer. And it was operated by the Air Force. Whereas the A-12 was shorter and lighter therefore it could fly higher and faster, and it was operated by the CIA, but most importantly, politicians are flown in the back of the SR-71, 'cause only real pilots are flown in A-12. We had like one hour before an appointment to see the spaceship company, Virgin Galactic. And so I was driving there down the highway and my wife was sitting in the passenger seat and I was asking her questions and she was checking the answers so that when I got there, I jumped out the car, held the camera on my selfie stick and pretty much recorded the video in more or less one take. And I just love the fact that it gives so many views because it was put together in such a slap dash fashion, but it's a subject that I really, really love. What's the most surprising aspect of this plane having been developed 60 years ago? Can you speculate what the Air Force is up to now that we might not know about? Oh, well I'm not really great at speculating, but obviously we did a lot of speculation as to what was happening with the X-37B, which is the reusable space plane. That's been flying into orbit and sitting there doing stuff mysteriously for years on end. It just recently won a prize for innovation. And yet we know very little about it because well, it's just very, very classified. I don't know if the Air Force is building anything faster, but I think they are looking at things that are less observable and perhaps more automated, I think is where the Air Force is really going I guess. Please reply to these comments from that video. They couldn't think of a better name for this ultra supersonic aircraft? Oxcart. Yes. I believe the original code name for the project was Archangel, hence A-12, but it's a really bad idea to have your super secret projects have names that can give you a clue as to what they do. So generally names get very much decoupled from secret projects. This is one of my first videos, four Year Old Sky Playing EVE Online. Wow. Yes, those were the days. There you see it jump through the gate. I think you missed it. Try again, there. Wow. Okay. Now we've got four gates to go. The story behind this video was I was a big fan of EVE Online at the time I wasn't really doing YouTube videos, anything more than what I could post from my phone cam, which I just got an iPhone and I could post direct to YouTube, but I was a big fan of EVE Online. And I had been working really hard in that building out my empire of SARS. EVE Online is an MMO space game. And it's famous for having almost no rules in the system it's also famous for having a player driven economy and giant sovereignty wars as in thousands of players battling for control of space, that they can access the resources and get space rich. And yeah, as a result there's a pretty, very much an uncompromising game, which is filled with drama that is driven by real world interactions between people. And sure, it's very nice to go in and get a big, fancy blinky spaceship, but it's even nicer to take that spaceship and destroy your enemies stations and drive them out of their space. But I was always on the forums, reading posts from people saying, "This game is too complicated. "This game is too hard." So I thought for fun, let's have my four year old daughter at the time playing EVE Online just to how anybody can really understand this game.

- The lights are blue also.

- Yes very pretty sun, isn't it? She sat down and she played and she flew with a fairly large expense of cargo from one station across space to another. It was a relatively easy video to record. And progressively, we went and did harder and harder things until we had Sky sitting on gate camping and killing freighters or haulers. So that was actually how I ended up starting my YouTube channel about gaming because I liked the fact that people watch those and then people would follow up my sign up link. And I eventually became space rich as a result. This is the first comment on my channel. It's probably from my mum and nobody has reported you for giving your child her first addiction. [laughs] EVE Online, the new learning aid. Let me tell you, I have learned a lot of economics from exploiting the markets in EVE Online. The gold magnet was the rare less ship in the game. Originally there was only one and then it could destroy it. And then a few years ago they brought five of them back and they were given out as prizes in a particular tournament, three of those have been destroyed because people take them out and the fight in them. So there's two left and I bought one off them and it's sitting in a hanger, in a space station in low security space. And I've not quite plucked up the courage to fly out of there because as I said, it's the most expensive thing. And people would really like to get a kill meal with that on it. But yeah, thankfully Sky does not touch EVE Online anymore. She stays away from it. She does her own things. She's currently addicted to Gore makeup and things like that. The next video, is one of my earliest hits and would inspire you to create multiple follow-up videos in the same vein. Do I know what it is? I think my earliest hit video is my asteroid discovery video, where I took some work from my PhD era and created a cool animation of the discovery of asteroids. Let's see if I'm right. [laughs] Asteroid Discovery from 1980 to 2010. [dramatic music] Yeah, this was posted back in 2010. I took data from the Lowell Observatory. They create this list of every single asteroid that's known and it includes all the positions, all the orbits. And I basically would plot these out and figure out when they were discovered. I created the Asteroid Visualization series because I had previously worked in asteroids in my post-graduate work. And I wanted to just create a new visualization of this. And I wrote some code and seed that would this data file from the Lowell Observatory. And it printed out, it created these frames, which would then be included. And I realized that when I did it over time, that the actually created a really nice animation when you started plotting the discovery locations, because by plotting the discovery locations you start to see patterns, you start to see that most of the discoveries happen opposite to the earth. You see little bursts when there are observations looking for moons around Jupiter, and you see this pulsing evaded me originally but then I realized that the pulsing was when the moon is full. There's not many discoveries. And when the moon is new, then the skies are darker and we see much more discovery. So there's this pulsing that's built into it. There's so many cool patterns that showed up in that. When I created this, was it planned to be part of a series? Honestly, I just wanted to post definitive version because I thought it looked cool. In fact, the version that was posted wasn't even my final version. That was an interesting thing. 'Cause I originally wanted to set it to music and I sort of posted to my friends and then they started posting it round. And the next thing you know, it's on Slashdot before I finished it. And so I thought, "Oh, it really need some music." So I just went into the YouTube music library, added a piece of music by a band called Tripsonic, who I sort of liked and they ended up making all the money from the video. But I thought the music fit perfectly because the tempo on it exactly matched the lunar cycle, which affects the discovery rate. So yeah, it was never planned as part of a series, but it's one of these things that is continually needing to be updated because we are finding new asteroids all the time. Please respond to these comments from that series. Hey, I'm an intern at NASA JPL and they showed frames from this video at a talk for interns. I recognize your name on the slide of the presentation, which brought me here. Saw many of your KSP videos back in the day, which inspired me to get into engineering and eventually led me to this internship. And that is the best type of comment ever. I love it when I hear real people that are inspired by Kerbal Space Program or a video I made. I'm doing a sort of tech job in the Bay Area because that's what pays the bills, but these people are going off and they're doing science and they're becoming space people. And I'm pretty sure I'm gonna have a few viewers that might well be astronauts in the next few years. How do I feel about my videos being shown to NASA hopefuls? Yeah, it's fantastic. It's the best thing ever to inspire and to educate people I guess it's very, very special. With the shear amount of stuff getting flung around the inner solar system, I'm kind of surprised we're not all dead. Tell that to the dinosaurs. They couldn't see it. That was part of the problem. We are in this unique position as being the first species on Planet Earth that not only can see the asteroids, but we're now at the position where we understand the threat and we're actually figuring out ways to potentially avert the threat in the future. So that is a pretty amazing time to be alive on Planet Earth. Tell us a story behind this video and to the Interstellar Quest series. Are you ready? Three, two, one. And we have liftoff off the first Kerbal adventurer. Kerbal Space Program it had the ability to add mods and there was a mod called Interstellar. And what it did was it took your basic chemical rockets and then on top of that, it added a series of increasingly tech propulsion systems, things like resisto- jet, plasma thrusters you could get up to you nuclear pulse thrusters and eventually warp drive. And so I'm started this series where I just wanted to build and work my way through the tech tree and go to every single planet in the Kerbal system and eventually reach warp drive and sort of, as we were going along, I'm telling the stories of these technologies, but I'm also sort of weaving a narrative about these different characters. And I think Episode 10 is when it starts to get interesting because it was one character who was flying around the planet on the nuclear powered plane and he stopped at this sort of hidden space center. And I was like, "Oh, this is a big mystery." And I decided that I was too lazy to actually fly them all the way around the world. So I created this fake accident where he gets zapped by an energy beam. And then later he comes back as a raw Kerbal. So yeah, we ended up having this story. And then right at the very end of the series, we had been hacking on the game so much. We ended up with a bug queered the fuel quantity in one of my spacecraft became NAN right? Not a number. That's an internal floating point number. Basically it says there's been an error in the calculation. You've tried to divide by... Or you've tried to take a square root of a negative number. And when I would transfer that fuel round, it would infect the other fuel tanks. So the story ended up with this rogue spaceship that was carrying the none or virus. [laughs] And so we want to destroy it. We had the Kerbals trying to escape on a Warp-Drive Ship and they end up landing on real size Earth because we went to real size solar system. And that was supposed to be how the Kerbals find their new earth, a real size planet, which was much harder and more difficult. It was a really interesting series and ultimately kind of experimental, but it ran for a 100 odd episodes. This comment came from that video. Scott, I really appreciate your science videos. I know they get a lower view count than KSP videos, and you've obviously spent a lot of time putting these together. So I understand if they have lower YouTube yield, that is a shame I've learned much about physics and astronomy through your videos, keep up the great work. And I'm gonna say that is from 2015. How times have changed? Are you thinking at all about what will gain views versus what interests you when coming up with ideas for videos and series? I'm absolutely thinking about what people will be interested in. And sometimes I get an idea, which is perhaps really complicated or really silly, but I know people will be interested in and I will absolutely jump on that concept. Frequently, I am wrong, but yeah, I'm definitely interested in what gets people viewing me. The following is your earliest posted accident investigation video explaining the CRS-7 launch failure. At Monday Elon Musk basically held the conference call to explain the status of the investigation and the preliminary findings, which they pretty much think are the reason behind what happened, but they're not willing to say 100% just yet. This was fascinating because the SpaceX failures have all been really interesting in their own way. SpaceX has been very forthcoming with details about what happened and how these failures happen and what this was was CRS-7 was carrying a dragon cargo spacecraft to the space station and partway into the second-stage burn, there was just a clone of liquid oxygen and the spacecraft was lost. And we actually saw the capsule falling away, but it wasn't set up to use as parachutes in that. So it was lost. I wanted to give more details on this after SpaceX came out with it. So I wanted to explain the exact details of how this failure happened using the power of Microsoft Paint. And in this case, what happened was the second stage was obviously accelerating under thrust and to pressurize the tanks on that second stage they have helium tanks inside what are called COPVs, this are composite overwrapped pressure vessels, and they have to be strapped the intro side of the tanks. So they're under the liquid oxygen to keep them cool. The strut holding it in place failed, and it bulb to the surface. And it did so so quickly that it hit the top of the tank. It knocked a hole. It started releasing all this liquid helium and the tank just exploded. So yeah, I wanted to explain this because I thought it was an interesting interaction between buoyancy, rocket thrust and how rockets work. I think one of the best ways to explain some of the minutia of rockets and aerospace in general is explaining how they can go wrong. And this lay should get into really subtle systems that nobody would ever think about. These comments came from that video, please respond. All problems can be solved with more struts and boosters. Oh, this is a classic Kerbal Space Program trope. You can solve all your problems, more boosters, more stress. There's actually a great little flowchart that says, is your rocket moving? If not, you need more boosters. If it's not supposed to move, you need more struts. Do I agree with this? Yes, if you're playing Kerbal Space Program and truthfully, if you're playing real life, you can solve a lot of problems with boosters and struts. So none of the programmers of the rocket thought, "What will we do if the large container of explosive propellant somehow explodes?" When you're designing these things, you generally wanna make sure that you don't make failures happen. Having the parachutes locked out does make a certain amount of sense. The following comments came from the most viewed Going Nuclear video posted on my YouTube channel. What video is it? Chernobyl. I shouldn't have said that with a smile. Should I? When the reactor power crashed all the way down, the washer wasn't being boiled. And that means it was absorbing even more neutrons than normal. So under pressure from the lead engineer, the controllers attempted to restore the reactor to a power level where the test could occur, which meant they had to reduce the neutron absorption. And of course they did this by pooling control rods further and further out of the core. The real physics behind the reactor, I always felt that the real physics had never been done particularly well. In fact, most of the videos on Chernobyl were really bad. The story behind this video on your history with the interest in nuclear energy. My history with nuclear energy actually goes back to when I was a teenager and I got a summer job working at a nuclear power station. You had to sort of learn nuclear physics as part of my undergraduate degrees in physics. We'd go in and we'd be calibrating radiation alarms, and figuring out ways to improve processes because I had to calibrate the alarms, I was cleared for like all of the radiation layer. So I had to get training in the self-contained suits to go in to scary, scary areas, but I knew enough of the physics to be completely cool with where I went. I mean, there was a couple of places in there where you were sort of like, "Okay, this is not a fuel area. "I shall walk swiftly through here." You're not gonna run because you don't wanna fall and potentially contaminate your clothes. You're just gonna walk briskly past this. Distance is very important. And if there's contamination involved, you have to make sure you are not bringing anything out. I started really talking about it during the Interstellar Quest series, because a lot of the spacecraft have nuclear reactors and there's many different fuel cycles to talk about, but Going Nuclear as a series actually started when North Korea exploded their largest test and lots of overly dramatic people were claiming that it was demonstration that they had developed a thermonuclear device. And most of the smart people were saying, it's just a boosted fission weapon. I decided to make a series talking about the design and development of nuclear weapons, because again, there weren't many good series about that. And then Chernobyl was a huge hit and I was watching the TV series. And I sort of mentioned to the guys, if you do a good job on this I wouldn't make my video. But in the end, I felt there was enough room for my real physics behind Chernobyl. And I think the TV show did a really good job of sort of explaining it to the layman. And then I decided to try to do one step a little further. Speed round, answer the following comments as quickly as possible because otherwise we'd be here all day. Scott, can you do a video about the most badass function-over-form plane to ever fly, the A-10? I should do a video about that. I saw one when I was in Utah, like up close, and I love the fact that the gun is off center because the barrel that fires sits along the central line of the aircraft. Thanks Scott for reminding everyone not to point those lasers at aircraft. You'd be amazed at how often is it still happens, especially on approach. Yes, please do not point lasers at aircraft. It is the dumbest thing to ever do. And it's the dumbest reason to end up in prison. Scott, have you ever tried to chat to the ISS on HAM radio? No, HAM radio is one of these things I would love to have time to work on. I have like a million different hobbies, but I would love to spend the time to try that. How about antimatter rocket propulsion? Any thoughts? Well, antimatter is great if you can manufacture it and contain it, but once you do, you get probably the most efficient rocket pound for pound, but yeah, you still have to figure out how to create it. To conclude, we found these comments on a video from last year. Why I have a real planet named after me, 33434. The thing I'm most proud of right now is I now have a planet named after me. Out there in the middle of an asteroid belt there's a minor planet called 33434 Scottmanley. And it's about a five kilometer object in an orbit that will takes about 5.2 years. Very low inclination, very low eccentricity. Just a bit as boring as it comes. I am Scott Manley. Me, the man or the planet. Yes, yes, I'm the man. Do I have mining rights on it? If I can get there before anyone else. Thanks, not only for the asteroids animation, which indeed I've used in my conferences like many other astronomers, but also and mainly for the YouTube channel. In Europe, at least it seems science communication and vulgarization is not done on TV anymore, but now on YouTube. You are doing an important work. The thing I looked to see was at your asteroid number and what surprise you didn't have one. So now it's done. Very, very well deserved. And this is by Alain Maury, who is the person that actually discovered the asteroid and had naming rights and he named the asteroid for me. And I'm so grateful for that. It's really nice to be out there. And one of these days, I hope to get a picture of it. It's really, really cool thing. How'd you feel about your videos providing such a positive impact on people? It's the best thing. I mean, it is the thing that keeps me making videos more than anything else. It's certainly not what I do as a day job, but it's very much a hobby. But it's the best thing in the world. When I went to the East Tech Open Day in Europe last year and I gave a talk and the security basically had to usher me at the back after I was there for half an hour, signing things and taking pictures with people. 'Cause there's so many people just wanting to have a little bit of time. And I always have time for people, it is a great, great feeling to get asked good questions and find that people have moved and done things perhaps in a small part because you inspired them. Final questions, which has been your favorite series and why? I have to say, I really liked Interstellar Quest because it was just playing games and enjoying it. And it didn't feel like work at the time. And we had just a lot of fun stories that naturally evolved out of it. Naturally rose because of problems with the game or dumb mistakes I made. How does it feel looking back on your career and do you have any final messages for fans who have supported me? Fly safe. No, seriously, that's my message to fans, but I don't see that I'm looking back. I see that I'm still looking forwards. I've a million different plans. I've got like half a dozen books now that I wanna write. What's really come out of it though, is that YouTube has become this platform where you can teach very, very high level stuff and people will watch it. And people that perhaps didn't have a background in physics can come to me and learn just enough that they can understand why Chernobyl exploded. And it is not a simple process to talk about the whole xenon poisoning, the xenon pit and nuclear physics. I think the fact that I can teach rocket science is... I don't think I'm teaching at university level, but I think that I'm doing it at a level where I've never seen anything outside of YouTube that does anything at this level. It's great. This has been Scott Manley answering my personal history. Fly safe.