Full transcript of “What It Means To Be Weightless”. Click a timestamp to open the video at that moment. Need another video? Use the YouTube transcript generator.
0:00 Chuck I got something I got to explain okay I mean if you feel the need to unburden yes thank you please that is exactly how I feel okay I think hardly anybody understands what it means to be weightless well with the amount of weight I have gained recently you wish I'm in that camp it's sufficiently subtle that most people who think they understand it don't okay therefore I felt they needed an explainer [Music] uh you're standing on Earth all right I can put you on a scale okay and in a
0:45 traditional scale it have Springs and depending on how much you squeeze the spring right the the the the meter will tell you how much your the little thing so I get on it and the little thing goes up and it says badass you have wait because Earth is pulling on you and the ground is pushing back okay if the ground were not pushing back what would happen to you you would just you would fall down through the ground right so it's the fact that the ground is pushing back that's squeezing that scale if you in freef Fall you are weightless of course period right you are weightless because gravity is acting on you and there's nothing pushing against you Isaac Newton knew that objects fall
1:31 okay and then he's sitting near his Apple Tree in his country home in Lin sing a little song Under theone else I don't think anyone else sit under the apple tree but anyone else but me going to find out some Physics today he's sitting there and he sees the apple fall it's in free fall right until it HS the ground good so if the Apple fell with a scale the scale would be zero okay then hit the ground then he looks up at the moon and it's floating and he says hm I wonder if the same Force that's pulling an apple to the ground is keeping the moon in its orbit who thinks this how long ago was
2:16 that like 400 years ago he would have thought this in the 1660s oh my God yeah come in his 20s oh he's in his 20s that's amazing okay by the way all evidence shows he died a virgin so don't be so envious of his circumstances I'm envious of of his brain not his [Music] genitals okay cleared that up yeah all right so he in his greatest work called the mathematical principles of natural philosophy realizing that no one's going to read this except his colleagues right why doesn't he write a popular version of it yeah the summary of this greatest of his works and he called it the system
3:04 of the world oh gosh that's an aggressive T that's that's badass yeah it really is AR many people who could write a book with the title system of the world system of the world and it's a condensed version in English no math no math and in it he tells you why a falling apple is the same as the Moon the Moon he illustrates in a diagram the four form of an orbit and for me it's the most brilliant scientific illustration there ever was here's how he does it he draws Earth M at the top he puts a little mountain okay okay so now you have like a cannon or some thing that can send a projectile a projectile and you spew it out and it lands at some
3:52 distance from the cannon mhm and you give it a little more motion and it goes a little farther and even farther and even farther and so he's reasoning that if I keep shooting this faster and faster this Cannonball is going to come all the way around the earth and there must be a speed where it comes all around and then I duck and it keeps going and sustains the path that would be orbital speed for this Cannonball and if you hit that speed you don't have to maintain it right it's just moving there's nothing to slow it down unless it's air friction dude above the air there's nothing to slow it down and by the way the Cannonball is always falling it's always Falling Towards Earth it's not hitting Earth how come because uh
4:39 gravity is acting on it to keep it just circling Earth Earth happens to be round right okay there you go circling but yes it's round yeah Earth happens to be round so as you fall towards Earth you going down range so fast so far that every foot you fall Earth curved the foot right so you're just falling around the Earth around the earth therefore objects in orbit are weightless because they are in free fall around towards Earth when you put astronauts in orbit and they are weightless half of everybody said oh they've left Earth's gravity no they haven't it's because of Earth gra gra okay so the energy of a rocket launched from a Launchpad you say oh the Rocket's
5:26 going up into space that's primarily not it's doing no you ever see the roll program that it goes into go like this turns and it goes horizontal yes so the energy of the rocket is to give it the speed necessary to go so fast that when it falls a foot Earth curves a foot and that speed is 17,500 mph if you go less than that you'll just fall back to Earth you'll go a long way around but you still fall back to back you're going to fall back in look at that somehow I ended up in the Indian Ocean what the hell called suborbital suborbital flight yes so the moment you hit orbital speed shut off the engines you're weightless you're weightless there it is okay on route to
6:11 that point the engines are on they're they're pushing against you if you stood up in the spacecraft I can't get up so you you could in fact walk around the bottom of that spacecraft because it's pressing against you just the way the floor is pressing against you when you're standing on a scale you could you could stand in the bottom while you accelerating the orbit but the moment the engine's cut off you're weightless okay so now watch we want to go to the Moon they leave Earth's orbit and head towards the moon they give themselves just enough speed to reach the gravitational midpoint at that gravitational midpoint the gravity of the Moon becomes stronger than the gravity of the earth so if I
6:57 send you off in that Direction with enough speed I don't need engines right you're coasting to that point you're slowing down as it cuz Earth is please come back come back don't leave me but you reach the midpoint uhhuh before Earth successfully pulls you back now the moon pulls you in welcome to the dark St while your engines are not firing right now this will get a little weird but it's mathematically correct you are in free fall right away from Earth and towards the Moon no that makes perfect sense and you're under the influence of gravity the entire time that makes sense it's just so it's basically the if you look at it like an attraction it's like you're leaving the
7:43 Earth and you're resisting its attraction you're like I used to like you but I don't like you no more cuz you know you just don't treat me the way you used to however if you don't have enough speed to get to that crossover point you falling back to Earth I don't know why I keep coming back to you and and that whole time you be weightless exactly okay in the film Ad Astra they always got the engines going and you see looks makes cooler and while the engines are firing you look inside and they're floating it's like no saying no no it's all wrong you know who gets it right most of the time the expans the expands always they they they had some physicist in in in the house yeah if you ever have engines firing you will feel what you would think is a force of gravity right
8:29 the acceleration provided by the engines if there's no engines firing you are coasting somewhere under the influence of somebody's gravity and you will be weightless there you go can't be weightless without gravity that's correct there you go that's every that's everything I know about weightlessness everything top to bottom starting with my man uh Isaac Newton Isaac Newton who clearly was tripping I don't know what was in that Apple there been another start talk explainer on weightlessness as always keep looking up unless you're weightless [Music]
