Is Artificial Gravity Really Achievable? | Answers With Joe

I'm about to show you something that can only be done right here on earth as far as we know there is no other planet in the entire universe where you can do what I'm about to do are you ready it's pretty amazing so hold on your butt's here we go huh I mean in order to have combustion you need oxygen now we found oxygen on other moons in our solar system like your OPA Ganymede and Rhea around Titan but earth is the only place that has it in the pressures necessary to make this happen and we of course are evolved to breathe oxygen we're also evolved for the specific air pressure that we have here on earth air pressure that's remarkably rare Mars only has 1% the air pressure that we do and Venus is air pressure is so strong it would crush you like a tin can Titans atmosphere comes close at 1.5 bars but it's at a sunny negative 180 degrees Celsius we are not evolved for that the fact of the matter is we are evolved for the specific conditions of this extremely weird planet that we live on which means that if we want to travel outside of Earth around the solar system or beyond whatever we have to be able to simulate those conditions and bring it with us things like a pressurized oxygen-rich environment in about a 50 degree temperature range but there is something else unique to earth that we're specifically adapted to something that we're just not gonna find anywhere else nearby and something that's not remotely is easy to simulate and that's gravity space is a dangerous unfriendly place at least according to the NASA human research program website and adjusting to different gravitational environments is one of the biggest challenges that astronauts face here on earth every single part of our bodies is being pulled downward at a constant rate of 9.8 meters per second squared with variations due to elevation we measure this as a gravitational force equivalent or a g-force well you're experiencing right now is a g-force of 1 or 1g unless you're watching this from the International Space Station in which case one awesome and two dude get back to work astronauts in low Earth orbit experience zero-g not because the earth has stopped pulling down on them but because they're falling in sync with their spacecraft this is a common misconception that a lot of the general public has and I'll confess I had the same misconception for a large part of my life as well but when you're up in space Earth's gravity is still working on you if you flew straight up to the height of the ISS you would fall right back down with almost the same amount of force as if you're standing on the ground the only reason astronauts on the ISS or wait list is because they're traveling horizontally at 17,000 miles an hour it's traveling fast enough that it's velocity basically matches the force that's pulling down on it so you're basically constantly falling and this has nothing to do with like outer space if you went fast enough off the top of a tall building you would go all the way around the world just the same way the problem is you can't do that because atmospheric friction would slow you down and a lot of people don't realize that the only reason we go up is to get out of the atmosphere the entire thing about going into orbit is the horizontal motion now this is also an argument against space planes because if you travel horizontally through the atmosphere to get in outer space you lose so much energy just pushing against the atmosphere then it's actually more energy efficient to use rockets and go straight up out of it that was a bit of a rabbit hole now if you would have just traveled directly away from earth and not going to orbit you would still have to deal with microgravity because the g-force would fall away in accordance to the inverse square law as you travel further away so either way whether you're going into orbit or traveling out to Mars and beyond weightlessness is an issue you're gonna have to contend with or microgravity I know somebody's writing that in the comments right now now the thing about weightlessness is it sounds fun especially you know once you get used to it but it actually has some advantages as well especially in the you know cramped quarters of a spaceship or a space station because you can actually use all the space like seriously look around at whatever room you're in right now even if you're just like sitting on a toilet in the bathroom look at how much empty space there is in the room that you're sitting in and how much we're not using how much is completely wasted because we're stuck on one plane thanks to gravity imagine if you were able to just sit on the wall or up in the corner over there imagine how much storage space you could have you could put shelving all along the ceiling in fact being in a big room and space might actually be a problem because you might get stuck floating in the middle of it with nothing to grab on to the problem of course is that this is not built for our bodies contain up to 5.7 liters of blood that moves nutrients around to give our various organs energy and they work in that needs the most energy in our body is the brain which is way up here but blood is a liquid and gravity is constantly pulling this liquid downward so without a circulatory system our blood would all just pool down around our feet not good for the old power hungry brain but luckily we have all the circulatory system one with a powerful pump and valves in the veins to constantly force blood up to the head obviously this is great here on earth it helps with that whole you know staying conscious thing but up in space without that downward force it just adds up to a whole lot of unnecessary pressure pressure that adds up to vision problems obviously circulatory problems and your body actually compensates for this by making less blood and then there's the fact that muscles and bones aren't constantly working to hold yourself up even as you're sitting there right now watching this there are hundreds of muscles activated and working against bones to keep you from collapsing to the floor and without that going on your body starts to atrophy it begins to basically consume itself astronauts spend hours a day exercising to try to compensate for this but even still astronaut scott kelly after his year in space experienced all kinds of dizziness and trouble with his equilibrium as well as foot pain and leg pain that lasted for months afterwards but as I said before Kelly is one year in space would have nothing compared to a Mars trip astronauts will spend up to nine months just getting to Mars and then be on Mars for at least three months before leaving for another nine-month trip back to home in other words your body would have to adjust to 0g then 2.3 g then back to zero-g before finally coming home to the crushing discomfort of 1g we're talking aching joints weakness like you've never felt before in your life constant vertigo and dizziness as your body tries to refigure out how to pump that dangerously low amount of blood up to your head it's like imagine the worst hangover you've had in your life while having the worst flu you've ever had in your life for months I hope you have a comfortable bed now to be fair astronauts will be totally into it they're not normal people and they're perfectly fine risking their life and limb in the name of science and the possibility of maybe doing a TED talk or two but if we really are going to colonize other places in our solar system at some point regular people are gonna have to make this journey and we're gonna have to start getting serious about the idea of artificial gravity and they don't take it from me Andy we're the author of the Martian agrees with that most of the effects of being in long-term zero-g go away in time but exactly as you say in your video yeah okay so you just spent several months in zero-g and now you're suddenly in point four G's you know on Mars you just react Foom yeah you can't just have a Mars mission start with like two weeks of recovery so I honestly believe the solution is just artificial gravity now before you say anything I know a lot of you guys out there right now are like oh my god he's really gonna milk this Andy we're interview for all it's worth and my response to you is yes yes I am expect more of it all right so if we're gonna get serious about artificial gravity in the near term there's really only a couple of options for us imagine you're an astronaut floating in orbit at a steady speed and then you fire the engines and accelerate the rocket forward you would get pushed back against the back of the rocket similarly if you fired the engines in the other direction and slowed the rocket down you'd get pushed down by that as well this is the idea behind the 1g rocket it accelerates at 1g for half the trip and then decelerates at 1g for the second half of the trip this works in accordance to Einstein's equivalency principle which basically means that gravity by acceleration is indistinguishable from the real thing so boom problem solved except there's a lot of problems with this for one thing this means that the engines have to fire for the entire trip and this immediately rules out chemical rockets examle burned for a couple of minutes at a time which leaves us with ion drives our nuclear propulsion neither of which can get anywhere close to 1g of acceleration of course we don't have to travel fully at 1g to avert the worst effects of weightlessness but even to reach some significant percentage of 1g you'd have to scale these engines way up and besides that there's the issue of fuel ion and nuclear drives are efficient but you do still require fuel and at a certain point the fuel gets so heavy that it can't accelerate its own mass even the Orion boom boom machine concept well you can reach some insane speeds you still at some point would run out of nuclear bombs plus there's a problem that when you flip around to decelerate at 1g you would be flying directly into nuclear explosions so not ideal the possibility of flying at 1g is pretty interesting though because after a few months of that constant acceleration it adds up and you can actually reach relativistic speeds and by relativistic I mean you know a significant percentage of the speed of light and as we all know when you start reaching those kinds of speeds time starts doing some interesting things one gene nuclear rocket could reach nearby stars easily in fact theoretically we could span the entire width of the Milky Way galaxy in 12 years of constant 1g acceleration that's 12 years on the ship back here on earth for the rest of us 113,000 243 years of pass a 1g ship could reach the current edge of the observable universe in a human lifetime of course by the time you got there that edge would have receded quite a bit and the earth would be gone as well as the Sun the Milky Way most things really but ultimately it's the fuel that's the problem with the 1g accelerating rocket even if we had an engine that could perfectly convert matter to energy say through an antimatter matter annihilation engine it would still takes 62 metric tons of fuel per one kilogram of mass to reach the black hole at the center of the Milky Way galaxy for reference the SpaceX starship is expected to weigh 120 thousand kilograms drive with no fuel or cargo or anything that ship would require seven billion 440 million kilograms of 100% perfectly efficient fuel to make that trip and that's with perfect efficiency which of course doesn't exist now there are some ideas like the boussard ramjet that would use a giant electromagnetic funnel 6000 kilometers wide to scoop up errant hydrogen in the interstellar medium and then use that to drive a fusion engine so you don't have to carry it all with you needless to say there are a number of design challenges for something like that not to mention you would still have to perfect fusion energy so unless we have some kind of massive breakthrough and plasma drive technology a 1g accelerating ship is really more science fiction than science future which brings us to the other possible approach for creating artificial gravity which is the OL you spin me right round baby right round like a record baby right round round round approach today's physics lesson brought to you by Pete burns it's far more efficient with current technology anyway to simulate a g-force by spinning a spacecraft a rotating body can provide artificial gravity by changing the direction of an movement rotationally and what's another word for a change in direction of a moving object acceleration so you experience constant acceleration in directions that add up to feel as if you're being pushed away from the rotational axis emphasis on the word feel because rotational gravity isn't exactly the same as regular gravity like in a 1g ship the downward force of acceleration would feel exactly like the gravity that you and I experience every day not exactly the same on a rotating habitat when the most extreme and popular proposed habitats that use rotational gravity is o'neil cylinders physicist Gerard O'Neill first proposed this design suggesting it be 20 miles long with a four mile diameter which would require 28 rotations per hour to target 1g but even at this insane scale that rotational gravity would still feel different from what we're used to especially to a nun a climatic visitor just standing still you might be fine you might be okay you might not really feel any difference but as soon as you turn your head the fluids in your ear would slosh around differently than they normally do thanks to that rotational angular momentum meaning best case scenario you might lose your balance worst case scenario you might lose your lunch even nodding might be enough to disturb your equilibrium but if you really want to get weirded out try tossing a ball to somebody or juggling when you throw the ball up in the air closer to the axis it picks up on that horizontal momentum which is a fancy way of saying you throw the ball straight up it will still curve and land to the side of you this is from the Coriolis effect and again these are the effects that you feel with a four mile diameter rotation which is a ridiculously huge structure go smaller and the effects get even worse rotational gravity drops off in proportion to how far away it is from the center of rotation which means that in any kind of structure that we could build with current technology the gravity at your feet would be different from the gravity at your head basically your head would feel like a balloon tied to a concrete block regardless there are a lot of speculative designs online including one called Agamemnon interplanetary ship with unrealistically beefy ion drive and telescoping arms that could rotate at an angle so you could get both linear and rotational gravity nASA has a design that spins a small habitat around a central axis balanced by a counterweight called the Nautilus X design it was imagined as a stopover station where astronauts could refuel and get some exercise on the way to the Mars I'd like to say that private companies are taking up this challenge but any plans that they have right now are just really far in the future even though Jeff Bezos was a student of Gerard O'Neill at Princeton he's talked about using Blue Origin to build rotating structures and o'neil cylinders in space but they seem more aspirational and generational and timescales on the SpaceX side there are some designs and ideas out there for using the starship to do some kind of rotation to create gravity on there but none of them are actually from SpaceX that I've been able to find and of course doesn't stop the speculation of SpaceX fans like blogger Chris Pete barons and YouTube or small stars both of whom have ideas for tethering multiple starships together to create artificial gravity barons basically wants to rotate two ships who have docked in the refueling configuration small stars wants to attach to by a truss to a third central unit small stars did the math and proposed a 100 meter radius that would provide 1g at three rotations per minute but is that big enough to avoid the worst of the orientation issues does this introduce a lot of failure points where things could go wrong I have my concerns but it is a cool idea it's possible the SpaceX is working on stuff like this behind closed doors but in the past Elon has been pretty dismissive about the gravity problem as for Space Station's there is one private company is working on a rotational 1g design called the Gateway foundation their eventual goal is to build a large spaceport called the Gateway but before that they aim to build a much smaller orbital hotel called the von Braun rotating Space Station what's kind of unique about their approach is they want to play with different rotational velocities to create variable gravity and then eventually on the gateway spaceport they want an inner ring to provide lunar gravity and an outer ring to simulate Mars gravity so far their plans only amount to a couple of cool conceptual videos and a Kickstarter program but hey if nothing else at least they're starting the conversation about orbital gravity reality is so boring can't we just build a machine that just turns gravity on and off no we can't but what if we could actually manipulating gravity itself would solve a lot more than just the weightlessness problem it would be the holy grail of propulsion like say you were flying through space and you could create a gravity well about a kilometer in front of your ship your ship would be drawn toward that gravity well and if you can manipulate it so that it stayed about a kilometer in front of your ship like a carrot being dangled in front of a horse you would just constantly be falling toward it and be propulse that way or what if you could create anti-gravity like that would be an easy way to just get off of Earth whether you're going up into space or just taking a hop across town this obviously is in the realm of science fiction but science fact has a few tricks up its sleeve scientists have been able to levitate small objects including frogs and mice living creatures just by using really powerful electromagnetic fields Belgian theoretical physicist Andre Foofa proposed a method for warping space-time in a gravity like manner using electromagnetism back in 2016 though this is untested and also expected to produce only a very small effect and then there's antimatter we know how regular matter interacts with gravity would antimatter react the same way or would it have an anti-gravity effect in theory antimatter is basically just matter with a few properties flipped like spin and charge but we've never been able to actually ascertain how an anti-gravity particle reacts to gravity I mean you're strictly speaking we don't know how an antiproton or a positron might fall would it go up or down how fast we don't really know right now there is a project at CERN right now called the Alpha G experiment that intends to find out it's designed to precisely measure the gravitational effect on antimatter this could lead to a whole new understanding of gravity which could force us to reevaluate gravity's position in the standard model which it was kind of shoehorn into anyway all the other fundamental forces have a carrier particle associated with it but gravity has always eluded us the theoretical particle name is a graviton if it exists it would be so weak that no detector that we could even imagine would be able to pick up on it but if we saw anti particles behaving in a strange way that might prove the existence of gravitons and maybe give us a way to bend them to our will over the centuries science has been able to figure out how to manipulate the other fundamental particles to our benefit like for the fact that we can create photons by using electrical currents if we could do the same thing with gravitons we'd be able to just turn off and on gravity whenever we wanted to this would be a game-changer right now this all sounds like science fiction but who knows what the future will hold right now gravity remains a mystery but if we can unlock its secrets it could open up the entire universe to us let's see where things take us alright thanks for watching this video and a huge shout out real quick to the patreon supporters that support this channel my answer files who are helping me a build a team and build a huge community around this thing I love you guys thank you so much I got a shout out some people who just joined recently live a murder their names real quick we got monkey Zachary Edwards Paul Shattuck David Ward Patrick Shirley Kerry bald Anu Matthew Shepard - Morris Hunter coffin dick Kiefer Seeger snare Ericson Alexander Stross Nicholas V Lynn Jensen brig Vincent lots of Scandinavians in this month Doug cam chor born Krogh Taryn Lexton Steve Saxton Lex PI grant Shatford Alex Brightman Pam sharp and Pete V guitar he said it was Betar like guitar so thank you guys so much if you would like to join them get early access to videos and just join an awesome community you can go to patreon.com/scishow please do like and share this video if you liked it and if this is your first time here maybe check out this video Google thinks you'll like that one or any of the others along the sidebar over here and if you like them I do invite you to subscribe I'll come back with videos every Monday and every Thursday t-shirts available at stores answered with Joe calm / shirts go check them out thanks again for watching you guys go out there now have an eye-opening rest of the week and I'll see you on Monday love you guys take care

Channel: Joe Scott

Views: 1,347,728

Rating: 4.902153 out of 5

Keywords: answers with joe, space travel, artificial gravity, science fiction, andy weir, rotating habitats, 1G ship, equivalency principle, effects of weightlessness, von braun space station, gateway spaceport, SpaceX Starship, travel to mars, gravity, graviton, O'Neill cylinders

Id: wYDJ0vxg1lU

Length: 19min 4sec (1144 seconds)

Published: Mon Oct 28 2019

Reddit Comments

[u/y9807047]

Ehm, we could reach the edge of the galaxy in 12 years with constant 1g speed?

[u/y9807047]

What sort of speed generates 1g? Would it take the Roci like 5 min to go from Earth to Pluto?