How Does The Anti-Gravity Wheel Work?

hey everyone today i'm going to be showing you an anti-gravity wheel this wheel actually weighs less when it's spinning what i have here is a device called maxwell's wheel it's just a metal disc with a rod going through it and at the ends of the rods it's connected to two strings that's just connected to a base that holds the whole thing up this is frequently used in classrooms to show the conversion between potential energy and kinetic energy for example i can wind up the string on these rods here get it all the way to the top and then if i just let it go you can see that it unravels but then it ravels back up and bounces almost to the same height that it started at now it'll bounce back and forth like this for a long time so what's happening is the potential energy that it has to begin with gets converted into rotational energy and as it unravels it goes faster and faster than it hits the bottom but it has a lot of rotational energy still so it winds it back up and converts it back into potential energy at the top the only reason it eventually stops is because some of the energy gets converted into frictional energy and heat and sound and so it loses some of that potential energy that it had to start with so it never gets back up to the same spot that it was originally at so this wheel can teach us a lot about the conversions of different types of energies but for me this isn't the interesting thing about this wheel the interesting part comes from when we weigh it so i put this on here and zeroed my scale when i got this i initially put it on the scale to see the jerk or the amount of force that was applied when it hit the bottom and then rolled back up but then i discovered something really interesting about this so notice it says zero grams right now i've zeroed out the weight of the entire device so as i lift up on the wheel you can see the weight go down it goes negative here so that means i'm lifting it up so what i've done is i've put a mirror here so you can see the reflection of the scale because it's aimed the other way so you can see it and i'm just going to flip it over digitally so it's not reversed a mirror direction but watch this i'm going to do the same thing now where i wind up the wheel i'm going to hold it at the top now watch what happens when i release it it says negative 6 grams and it literally stays at negative six grams the entire time this is bobbing up and down it'll kind of bounce around negative six grams but on average it's at negative six grams you can see it bouncing going around to negative five five up to negative seven but right around negative six grams as its home point so this isn't just fractions of a gram this is six grams of weight that's not registering on the scale right now you can see that when i completely stop it it's back at zero again so when i first saw this i was really confused and i thought okay maybe it's just the scale's kind of shaking so it's kind of going all over the place but you can see that if i shift it around or do anything even get it swinging like this you can see that it doesn't get to negative six grams when i get this wiggling around you can see that it doesn't come anywhere near this negative six gram range it bounces between positive and negative because you're kind of shifting the weight all around but it doesn't keep an average lower weight but as soon as i get the spinning even if i don't do it very high just around let's just start at around this high as soon as it starts spinning it drops to this negative six grams again isn't that crazy we're registering less weight as long as this will is spinning and i should mention this because i know someone's going to mention in the comment section i'm measuring the force in grams this is gram force we're not measuring the mass we're measuring the force so one gram on here is the force that one gram would put on the scale so for some reason when that wheel starts spinning it's the equivalent of removing about this much mass from the wheel that's a significant amount that's around one percent of the mass of this wheel here when i first saw this it brought to mind a famous video by eric lathway at the imperial college in this video he shows that he has this 40 pound wheel with a rod through it and the wheel can spin when he spins up the wheel he's able to lift that 40 pound weight easily over his head he says that it was light as a feather you've also probably seen this recreated on veritasium's video and he said that it actually feels very light when he lift it up over his head so i thought that maybe it was due to some gyroscopic action here so do gyroscopes actually weigh less when they're spinning well let's find out here so i've zeroed this at zero grams now let's start the spinning and sure enough it doesn't weigh any less even as it kind of precesses through here you can see that the weight doesn't change so why is it that this wheel weighs less but this one doesn't when it's spinning so how is professor latheway able to lift this heavy weight over his head he was actually helping it process and when you push the gyroscope in the direction that it's processing it actually wants to lift up on its own so instead of having to lift it up over his head he was just pushing in the direction it was processing and it's way easier to push it around in a circle than lift it up over your head so it felt lighter but if you had a scale underneath him you would see that his weight didn't change the whole time so that doesn't help us understand why the maxwell wheel weighs less as it's bobbing up and down so let's go back to some basic physics we know that when something is accelerating downward it actually weighs less i can show this by standing on a scale and then letting myself fall so i start to accelerate downward obviously my weight goes down so when you accelerate downward your weight decreases so we can apply this to maxwell's wheel like this let's say that i were to cut both of these strings here we know that the second that i cut these strings it's going to weigh less by the weight of this disc because this is accelerating downward now the weight decreased by the entire weight of the disc but then when it hits the bottom it's going to weigh the same as it did before but in the case of the maxwell's disc we didn't just snip the strings and let it free fall but we actually let it slowly fall so the acceleration downward was very slow it was only being accelerated at a fraction of the percent that it would accelerate if you just let it fall so because of the downward acceleration the wheel weighs less as it's falling down so that explains that as it's falling it weighs less but what about when it bounces back up well surprisingly even when it's rising back up it's still being accelerated downward remember acceleration is not the direction of the velocity acceleration is the thing that's making the velocity change now we know that the acceleration is still downward because even as this is moving upward it's slowing down its velocities the velocity is slowing because the acceleration is pointing downward so whether or not it's bobbing up or down it's still always being accelerated downward it's easiest to think about this in terms of a bouncing ball so let's go back to our experiment where i snip both these strings and let's say that this is able to bounce so when i initially snip the strings you can see it goes down by 727 grams the full weight of the disc but as it falls and then hits the ground it's going to increase in weight but as it bounces back up you'll see that it decreases by the entire weight again so the only time we actually register the weight of it is when it's bouncing and hitting the bottom any time it's up in the air you're not going to register the weight of the disc so even if it's bouncing up and down no matter what you don't register the weight of it as it hits the bottom we should be able to measure a force that goes up and down as it bounces off the bottom but the refresh rate of the scale isn't enough to measure that sharp force so the more this approach is a regular free fall the less weight we're going to register on here so let's try to make it accelerate faster by having less wind so it can fall faster and have less rotational energy so you can see we're down at like negative 20 grams now then when it finally stops it says zero grams again the reason i was able to get it to weigh less now is because i was able to get it to have more downward acceleration so that decreased the weight even more now before we end i'd like to thank notion for sponsoring this video notion is a tool that helps you take notes plan collaborate and get organized all in one place you can collaborate in real time with other people and organize information in a really easy to use format with nested folders like this that keep everything really clear you can even turn any page into a website in just a few simple clicks what's really nice is that it syncs everything in the app and browser so no matter what you're using you can keep all of your work updated i've been using notion for almost a month now and i've really enjoyed using it to keep my video ideas in order and also collaborate with my wife who has now become my safety inspector due to some undisclosed incidents you can see i can create video plans and assign the different tasks here then i share the document with my wife or other team members and you can easily communicate with your team members on each specific task and even attach documents or pictures or whatever you need to move forward with that specific task i love how easy it is to organize and keep things clear because i have so many things going on at once usually also notion is very customizable and it fits your needs so you can change it to meet whatever organization goals you want so if you want to try out notion for yourself click the link in my description today and thanks for watching another episode i hope you enjoyed it if you did don't forget to subscribe if you haven't yet and check out the actionlab.com we have some experiment boxes for cell there and also we have a really cool black hole painting there that my wife painted the black hole is actually painted with musso black the world's darkest paint so it gives it a really cool look and thanks for watching and we'll see you next time

Channel: The Action Lab

Views: 934,868

Keywords: angular momentum, gyroscopic precession, anti gravity wheel, anti gravity, rotational motion, the action lan, maxwells wheel

Id: pwx12kwgOAM

Length: 10min 19sec (619 seconds)

Published: Sat Jul 16 2022