5 Advanced Space Drives (That May Or May Not Work) | Answers With Joe

this video is supported by curiositystream last week i talked about some of the most earth-like exoplanets that we found and while it's cool that we found them the bummer of course is that we'll probably never actually get to go see them so instead i talked about some of the next generation space telescope technology that's going to allow us to study them from afar yeah you know all those cool science fiction movies where we just study things from afar i don't either we're humans we want to go we want to see things we want to explore and we can't that sucks at least with current technology of course there's no shortage of ideas to get around current technology and actually make it possible to go see these other worlds some ideas are more plausible than others so this video is going to kind of piggyback off of last week's video and talk about some alternative drive systems that might actually make our sci-fi dreams a reality [Music] chemical rockets have been our ride to space since the 1950s it's proven technology and we understand it really well when i say we of course i mean rocket scientists and engineers and stuff and random nerds on youtube and they work because chemical reactions pack a punch the saturn v rocket that took astronauts to the moon got 7.5 million pounds of thrust out of its five first stage engines the most powerful rocket in current use the spacex falcon heavy produces about 5 million pounds of thrust the earth is a jealous mistress one who does not easily give up our children to escape the surly bonds of earth you need a lot of power thing is once you get up to orbital speed out in outer space all that power almost becomes a problem navigating in a microgravity vacuum is less like flying a plane and more like throwing darts you burn the engines just a few seconds at a time and get up to the speed and the trajectory that you need to go on and then you just kind of glide the rest of the way you could go a lot faster if you could accelerate for longer but chemical rockets tend to burn through their propellant pretty quickly that propellant by the way is super heavy which adds mass which means you need more energy to accelerate that mass which means you need more propellant which adds more mass this is the tyranny of the rocket equation and this is why spacex plans to refuel in orbit before it heads off to mars with the starship because it's actually going to burn through some of its propellant just getting up into orbit and i've heard different estimates as to how many launches they're gonna need to refuel it in orbit all the way up to six you might have noticed this is not how space travel is portrayed in sci-fi movies most of them anyway it's usually more like flying through the air just rockets burning the whole way and that's usually just a flight of fancy on the part of the filmmakers but rocket designers would love to do that too the thing is low constant acceleration can actually push a spacecraft a lot faster over time than chemical rocket burns can so any technology that could provide even a tiny amount of constant acceleration with lighter propellant would be game-changing take ion thrusters for example i've talked about that here on this channel before but they produce acceleration by launching ions charged ions out the back of the engine now that's a tiny tiny amount of mass that produces a tiny amount of thrust but again constant acceleration adds up as you know every action produces an equal and opposite reaction the old newton's third law chemical rockets get their action from releasing that heavy propellant at explosive high velocity out the back which creates a reaction toward the pointy end and ion thrusters work the same way except the propellant is tiny charged xenon atoms which obviously carry very little force but these are flowing out with powerful electromagnetic fields at 90 000 miles an hour and it does it billions of times per second why xenon well scott manley did a great video about it that i'll i'll link up down below but first and foremost xenon is a noble gas which means that it won't react with any of the materials on the engine and of the noble gases xenon has one of the highest atomic masses which gives you at least a little bit more force out of it finally ion engines work by knocking electrons off of atoms by bombarding it with electricity and the more electrons that you have on an atom like a xenon atom has the more opportunities there are to knock an electron free the less energy it takes to create the ion so the propellant is lighter for ion dries but it does still require a lot of electricity which if you're floating around the inner solar system like the dawn spacecraft you can get plenty of it from pv panels but venture out into the outer solar system or beyond you're going to have to carry some kind of power source with you which is going to add mass a future technology might make it possible to power a spacecraft with a laser some kind of fusion technology might make it so you could collect gas from interstellar space there might only be one atom per cubic meter of space but you could take that and make fusion energy with it but still an ion drive would have that xenon in there and that would eventually run out the ultimate solution to long distance space travel would be a rocket that doesn't have to carry propellant mass a racket with this engine would defy the tyranny of the rocket equation it would also define newton's third law producing an action without an equal and opposite reaction which is why they call these kinds of theoretical engines a reactionless drive serious scientists pretty much rolled their eyes at this concept it's basically the holy grail of uh rocket science and it's considered impossible by most people but it has not stopped people from trying first on the list is the dean drive the dean drive is the brainchild of norman l dean who filed patents for this back in the 1950s but they were incomplete so if you wanted to make a dean drive based off of the patents you wouldn't be able to do so which makes it sound super legit dean got some early publicity when his claims were investigated by famous science fiction editor john w campbell of astounding magazine john w campbell's kind of a legend in sci-fi circles unfortunately he was also kind of a fan of segregation and once called slavery a useful educational system so yeah for a futurist he was pretty stuck in the past he was also apparently a sucker because he claimed the dean drive worked in a private demonstration dean claimed that he saw the drive actually reduce its own weight on a scale and thought that dean had created a way around newton's laws in some way and he thought that it was going to revolutionize travel both on earth and off the basic idea behind the dean drive is that it would harness the centrifugal force created by spinning weights now normally this would create a balanced back and forth motion you know action reaction and whatnot but dean claimed that through some kind of complicated mechanism he could basically cut out the reaction part so you would get an action in one direction without a reaction meaning you would get thrust in that direction and he explained this by phrasing it in terms of inertial reference frame so the reaction did happen it just happened in a different frame than the one that we're in somehow so yeah since the reaction is taken out of this frame it creates thrust supposedly now this is nowhere near the only idea involving gyroscopes and spinning weights and stuff like that in fact back in the 90s nasa actually had a program where people would submit ideas for advanced propulsion drives and they got so many involving gyroscopes and oscillating weights and whatnot that they had to produce an internal memo and with guidelines on how to deal with it it was titled responding to mechanical anti-gravity and one of the standout lines was quote about a third of amateur requests nine percent of all submissions display paranoia or delusions of grandeur nasa throwing some shade and they went on to caution sensitivity when dealing with those submissions but also to you know not waste nasa's time now the dean drive does still have its defenders but it has been pretty thoroughly debunked really all you need is a pendulum the notion that dean's drive produces is actually called slip stick motion the the ground itself basically serves as the reaction mass so it's it moves forward by friction basically put the drive on a pendulum where it's not in touch with the ground and the effect tends to go away obviously a drive that only works when it's in contact with the ground is not very useful in a space situation in general there's nothing magical about gyroscopic drives they work off the conservation of angular momentum it's basically it's basically torque being misidentified the mega drive was proposed in 1993 by dr james woodward at the university of california and it takes advantage of a phenomenon known as the mock effect hence the name mock effect gravity assist drive or mega drive but it's not just a clever name this idea is sort of similar to the dean drive and that it steals momentum from an action that should be producing a reaction but doesn't but in the mega drive the back and forth motion is created by piezoelectric disks which charge on one end of the motion and discharge on the other end of the motion so according to woodward when it's charged there's more electrons in there which adds just a tiny tiny bit of mass and then when it discharges on the other end it releases that mass meaning that it actually produces a little bit of momentum in one direction haha clever but does it work scientists are skeptical and even if it does work it would have to be scaled up massively because well electrons don't weigh very much but tests so far have actually been positive last we heard was in 2019 they were able to assure nasa that they got the effects of vibration out of their measurements because the effect is so slight that anything any kind of aberration has to be counted in but obviously fingers are crossed on this one we'll have to see some more tests to figure it out the m drive is something i've covered before you can check it out here if you want to get the deep dive but here's a quick primer on it the m-drive is basically a cone with microwaves bouncing around inside of it and it's a closed cone so there's nothing actually going out the back of this thing and this should do nothing the microwave should just bounce off the inside of the thing off of the walls the walls producing a force equal to that of the the microwaves bouncing against it action reaction and whatnot it's kind of like saying you can move a car forward by pushing on the dashboard but some very smart people have been able to measure a net thrust in one direction they claim that it actually is interacting with the zero point energy in a quantum vacuum but of course other smart people have pointed out that that might just be attributable to thermal heating some gravitational abnormalities or even just the movement of air in the room so it's it's still very much debated but interestingly dr woodward does have a different opinion on how this works he thinks it actually might use the mock effect that we were just talking about to push against the gravitational potential of the universe is the gravity potential of the universe an actual thing no i'm asking i i have no idea i kind of feel like we're never really going to know the answer about the m drive until we can just get one in space and see if it gains momentum over time i don't know maybe starship can just drop one off on the way to the moon or something the helical engine is perhaps the newest concept that i've been talking about today and it works on a similar principle as the mega drive only this one gets relativistic the idea was theorized by david burns a phd in electrical engineering at nasa and before you put him in the wackadoodle pile he did have this to say about his idea quote if someone says it doesn't work i'll be the first to say it was worth a shot probably a good attitude so instead of affecting the mass of oscillating discs by adding and removing electrons like the mega drive this one adds mass by spinning particles up at relativistic speeds according to einstein objects gain mass as they get closer to the speed of light so burns idea is to put a particle accelerator and accelerate the particles through a helix from one side of the engine to the other as they speed through the helix they gain momentum and mass so that they weigh more on one side than they do on the other add to this a well-timed oscillation of the helix and you can get a very small one directional thrust he proposed that a 12 meter ring containing the accelerator helix would suck up about 165 megawatts of power and produce about one newton of thrust how much is one newton of thrust about the same amount of force as this apple against my hand not staggering but not nothing either again that one newton force would add up over time with unlimited power you could get the alpha centauri in 90 years of course power is not unlimited and you're talking about running a small large hadron collider 24 hours a day wouldn't that just be a small hadron collider so yeah that's kind of an issue and that's if the thing works at all which is questionable astrophysicist ethan siegel says in his blog if burns had properly accounted for the total momentum of the box plus ring system he would have noted that the total momentum never changes yeah treating the ring as an independent system is problematic because when you factor in all the forces in the box ring system they kind of cancel each other out and dr brian koblen in an article for universe today pointed out that time dilation and length contraction also add up together to balance out the whole action reaction thing so sprinkling a light frosting of relativity on a deen drive unfortunately doesn't make it not a dean drive and last but not least is the alcubierre warp drive again i've talked about this one before link down in the description but this one is quite a bit different from the others in that it's uh it's not trying to skirt the laws of science it's it's working on proven science this was conceptualized by miguel alcubierre in 1994 and he quickly gained an interest amongst physicists that were fond of the warp drive concept including harold sunny white formerly of nasa's eagle works lab it works by expanding and contracting space-time effectively the spacecraft would create a bubble that shrinks space-time ahead of it and stretches space-time behind it so it's kind of a cheat around the speed of light because it's not actually passing through space it's just warping the space around it el cubiere expected that a crap like this could reach velocities weight faster than light by repeatedly shrinking the space in front of it which sounds great there are a few hangups to do this requires access to exotic matter what is exotic matter well exotic matter is made up of negative mass meaning if you had one pound of negative matter and put on a scale the scale would say minus one pound i'm making that sound ridiculous because it is but the math of physics leaves room for negative mass and white holes in time travel so it could possibly exist out there naturally or we might actually be able to make it in a lab either way it's gonna need a lot of this stuff like according to his original paper more mass than exists in the observable universe sunny white would later propose shaping the warp bubble like a taurus which actually reduced the amount of mass needed from you know the size of the universe down to something about the size of the voyager spacecraft that's that's a tiny jump in mass there but still it's the mass of the voyager spacecraft in a material that doesn't exist a 2019 paper by joseph agnew at the university of alabama did make some advancements in this idea but we really haven't seen much else about this in terms of actual progress on the el cuvier drive probably because of the whole kneading matter that doesn't actually exist thing now someone proposed that there was a fourth spatial dimension that you might be able to use that to expand and contract the space time around the spacecraft that would solve the exotic matter problem other proposals suggest that a warp ship wouldn't actually have to expand the space behind it it would only need to worry about contracting the space in front of it and the space behind would snap back into place automatically this would cut down on the amount of power needed because you're only doing half of it now another interesting theory in agnew's paper is that you could replace the exotic matter with really powerful electromagnetic field emitters but it should be said that this idea so out there they actually call it semi-exotic but it's nice to have alternatives so this is probably not what you want to hear i know you probably clicked on this video thinking oh here's going to be some alternative propulsion devices that are going to get us to the stars and save us and all that and here i am just you know throwing a wet towel on your head i'm the worst but the fact of the matter is interstellar travel on any kind of useful time frame anyway just might be impossible and pursuing technologies like this might just be a total waste of time but then it might not be fans of this channel are probably more than familiar with arthur c clarke's third law which states that any sufficiently advanced technology is indistinguishable from magic while getting to the stars and passing light speed would definitely require some magic i mentioned last week that the parker solar probe in 2025 is going to become the fastest thing that humans have ever created going at 430 000 miles an hour around the sun and even to get to the closest star would take 6 700 years at our current technology the only way we're going to reach any other stars is through generation ships this will be a ship where human beings are born live out their lives and die generation after generation after generation for as long as recorded human history has existed and it would have to be maintained that entire time like imagine if the first pharaoh of egypt built a car and we have to keep that car running and we're living in the car and you can't open the window somebody farts my metaphor is falling apart here life extension technology might be able to cut down on the extreme number of generations it would take to get there but still it wouldn't be you dancing on proxima centauri it would be some long distant descendant of yours who after thousands of years of the extreme environment of space speaks a completely different language is probably a different race than you maybe even a totally different species so you know good for them bummer for you fortunately for us arthur c clarke didn't just stop at one law number three is the famous one there are two others clark's law number one when a distinguished but elderly scientist states that something is possible he's almost certainly right when he states that something is impossible he is very probably wrong distinguished but elderly scientists might disagree with that statement but it's proven true in the past you know we once thought that humans would never fly we once thought that space travel was impossible we once thought that nuclear power was impossible even einstein thought so some of the founders of quantum physics thought that interpreting quantum measurements in reality in the real world was an exercise in futility my point is everything is impossible until it's not or as clark's second law says the only way of discovering the limits of the possible is to venture a little way past them into the impossible and that i feel is a law worth 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nebula and curiosity stream for one price which they're discounting right now at 26 for the yearly subscription which brings it down to 14.79 for an entire year it's like a buck and change month if that sounds good to you just go to curiositystream.comscott or there's a link down in the description and if you're tired of hearing me talk about this then i suggest you go to curiositystream.com joe scott and sign up for a nebula subscription because on nebula the videos are ad free so you wouldn't be hearing me talk about this anymore modern problems require modern solutions big thanks to curiosity stream for supporting this video and a huge shout out to the answer files on patreon that are forming a nice community and being awesome and doing cool things i love all of you there's some new people whose names are going to murder real quick we got chris ferguson david pete ballet bashu william holes andrew hagan sally jenko marco pavlovic no pants mode love it nathan marvy mike myers david coleman otter ruin love that one uh joe rutkowski uh eduardo sadre junior ecken siegick eric roth uh trevor eberil and andrew spencer that almost broke me thank you guys so much if you would like to join them get early access to videos access to me exclusive live streams and other kinds of stuff you can go to patreon.com please do like and share this video if you liked it and if this is your first time here this one is apparently up your alley google seems to think so anyway there's also other videos down here that might have my face on it you can go check those out and if you enjoy them i invite you to subscribe i come back videos every monday all right that's it for now you guys go out there have an eye opening rest of the week stay safe and i'll see you next monday love you guys take care

Channel: Joe Scott

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Id: JgGAauWqFFM

Length: 20min 51sec (1251 seconds)

Published: Mon Sep 14 2020

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