Lenz's Law
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- čas přidán 13. 09. 2024
- Lenz's law, named after the physicist Heinrich Friedrich Emil Lenz who formulated it in 1834, states that the direction of the current induced in a conductor by a changing magnetic field is such that the magnetic field created by the induced current opposes the initial changing magnetic field. Or as informally, yet concisely summarised by D.J. Griffiths: 'Nature abhors a change in flux'. [Wikipedia]
In this video, Tim demonstrates a variety of Lenz's Law demonstrations. At its simplest, you can just drop a magnet down a metal tube, maybe made of copper or aluminium, and be surprised at how slowly it descends, despite the fact that copper and aluminium are not attracted to magnets.
Very recently Tim came across an unusual demonstration, involving a large block of aluminium with a slot cut along its length. Dropping a spherical neodymium magnet down the length of the slot produces some interesting and unexpected effects, depending on the orientation of the magnet at the point at which you let it drop.
1:32 - Flawless recovery preventing that lozenge from falling off of the table.
Lol I thought the same thing
This dude can explain what a chair is for hours and I'd still love to hear it till the end
@chi sam don't forget the word -> EXTRAORDINARY
@@broz3998 and couple of heh
Same!! x3
And when he came to the end, he still wouldn’t know 🤪
He is like the one high school science teacher who always brings interesting props to class LOL
Never had that teacher 😔 wish I did.
Never learn physics, wish i did
@@zulfikaralfarisi2609 its not that fun when you have to do millions of equations that needed to memorize alien language
@@mont9150 that's why i never learn it
@@mont9150 The thing is you have to go through millions of irritating problems to get to the interesting stuff which is basically after your bachelor's degree. You have to go through that dreaded mechanics and thermodynamics to get to interesting stuff like quantum theories and beyond (which is even more mind boggling). I might learn it on the side for fun, but I can not imagine doing that stuff for a living. You really have to have the passion to get through "basic physics".
I've seen this before but never this many versions. Very interesting! Thanks for collecting and sharing :)
Tim is just the best 🙏i watch him for hours on end
@Cedric Cameron get lost dude
What's amazing with Tim is that, even tho you know the effect / toy he will be demonstrating, he always comes over with something you've never seen and amazes you...
Whipsy whopsy
I'm worried CZcams might demonitize Tim for sorcery.
*demonize
@@hanihooper *demonetize
Kane O it was a joke u goose
@@hanihooper goose u joke a was it
@@frederico8065 Tim is the devil and we're all in Hell
I have no idea how this guy appeared on my recommended but Im absolutely in love, such a wholesome dude
0:28 2:15 3:18 4:34 4:47 5:03 EXTRAORDINARY
HAHA this is brilliant
What's most extraordinary, is that you went to the trouble of finding each timestamp :'D
Hasol Im you're providing a valuable public service. 🙏
Eschodenerie !
It is!
1:33 "But this one, being a very slow one, goes very, very slowly."
Science, ladies and gentlemen.
r/technicallythetruth
It took me awhile to understand what he was saying, then I did and🤯
Vay vay slower indeed !
@@rchaykovskiy r/thisisnotredditboi
Ah yes, the floor is made out of floor
Answer to why it rotates..... The block is open on one side so the drag is strongest where the pole of the magnet has a surface to impart a current.... Whereas the pole on the opposite side has no such surface and starts to fall faster imparting a rotation of the magnet until it would rotate enough to then be on the closed side and would get slowed down and it would then repeat :) as magnetic field lines are more concentrated at the poles.
if that is the case, why does the ball rotate when magnetic pole is pointed upwards, and the other pole downwards? logically both poles have no surface in front of them to allow eddy currents, so the ball should fall straight without any rotation.
@@kurian2012 the field lines of the magnet go from pole to pole but are concentrated at the poles so they go fully around the magnet and that will induce a small field in the side that is closed and with the ball dropping it will naturally try to rotate the magnet because it's the combination of gravity pulling it down and the small amount of eddy currents acting as friction on the magnet...... This effect works on a flat plate of non Ferrous metal and a magnet passing by it...... Some fair ground rides use it as a break because it's got no wearing moving parts and is practically fail safe. Also the hoverboard that was inspired by back to the future.
Right hand rule.
This explanation does not explain why the magnet moves away from the wall and then back towards it.
yes, it does. the moving magnet creates a current in the block. this means that the block becomes an electromagnet. because you only have the one pole interacting with the block, it interacts with the field but the free pole does not. the pole near the block has friction applied, plus is being pushed/pulled by the induction EM field of the block.
also, the reason the effect can still work with windows cut into the tube is because the tube is still one piece of material. i dont think the effect would work well, if at all, if the tube were not a single piece of material.
1:32 i love how he subtily catches it with his elbow Lol !
Tovarășul Lenin // thanks you for that
Thank you tovaras
@@yaboiaugust8766 vai mersi ! :3
thank you, stranger
Marvelous
0:56 the ball falling exactly in the middle of the rope mat thingy is just pure bliss
My man said “Wipsy whopsy” and I felt that
Magnets: Work
Tim: Extraordinary!!!!
By the way, one of the best channels I have accidentally stumbled upon.
It's not just "magnets: work", it's eddy currents. Magnets only stick to ferrous metals, this is to do with electricity. It's why it took a while for a scientist to notice it.
You're missing the point that the tubes themselves are non-magnetic, but conductive to electricity.
The reason it dances is because there is an opposing current generated on one side rather than two (when the poles each have a metal face to trigger Lenz Law with the ball is slowed equally on both sides, thus an even slow fall with no dance) so it slows down on the back and not the front, ultimately causing it to tip forward and swing around performing its "dance"; If the Aluminum section were longer the ball would probably repeat it's dance with some distortion.
Physicists hate him!
This man can defy gravity with ONE easy trick!
I don't think so
@@ayushkumarsingh616 r/wooosh
All magnets can defy gravity.....magnetic force is stronger than gravity.
Magnetic force is 10 to the power of 36 times stronger than the force of gravity.
A small magnet can levitate metal off the ground against the entire gravitational force of the earth.
Try it with a small magnet on metal paper-clips.The paper-clips fly UPWARDS....magnetism trumped gravity.
@@petergibson2318 Did you get the joke though?
@@petergibson2318 Thanks for this, honestly. The power gravity is not very intuitive. It can be defeated by simply lifting a finger yet it holds vast systems of massive planets, planets and moons together over vast distances. That a force which holds planets in orbit can be defeated by a fridge magnet is verging on the amusing but all calculations and observations match predictions. There are vast differences in scale between a fridge magnet stuck in place and a solar system with planets but the laws of gravity hold their predictive power. Beautiful stuff. Edit to add - Whether or not Peter got the joke at least he was talking sense about something interesting.
If you add a battery and put a magnet on either end it shoots out the copper tube like a rail gun.
Solder Joe I don’t know what to say, what you said was a good thing
Works better if you shoot in the battery first
I will make a note of this.
Yes that’s how they work it’s called electro magnetic propulsion
Like a rail gun? More like a gauss cannon, amirite, boys? ;)
I forgot about this channel but it just popped up in suggested videos. Good stuff. Gotta love Tim and his curios.
1:31 Let us all just admire the skill on the way he stopped that Lozengier, with his elbow! Or it was on the floor, spoiling the presentation. What a pro!!
That was smooooth
Ha! I ate the ball 2 years ago and it hasn't come out yet.
Any of you are magnetic?
Looks more like both
🤔
Way too much copper in your poop chute
Where are you guys in life now?
@@kaical8273 im home :D
If CZcams bans Tim we riot.
i wish youtube was as unregulated as it once was...now its ran by communists, along with google, facebook, etc
I've had the torches and pitchforks ready just in case "Them" tube wants to try us.....
If you think giant corporations like Google are communists I don't think you know what a communist is.
Man I wish google was actually communist.
Zo Mana how would communist understand fun if they keep trying to censor everything people see and say?
First I would like to say, your personality is perfect for the subject of the videos you choose to make. I truly enjoy all I have watched, thank you. I think it would be very interesting to see these experiments repeated with a wire on the copper pipe and aluminum connected to ground, and then again connected to each other.
I've recently found this channel and found so much joy in watching these videos. Just Subscribed and now I have to go back and watch all 800+ haha
I don’t know why this was in my suggestions but I’m honestly enjoying it tbh
I am actually almost done with my second calculus based physics course and we recently learned the math behind this. Super cool to see a physics property in real life that I have studied
It becomes a bit of a power trip, you just start looking around and saying "I can explain all of this.".
If you have a large motor and turn it slowly by hand you’ll find that it has some resistance at certain places. Place a wire between the cathode/anode to allow electromechanical energy to be released by the system and the motor will turn easier by hand as well as causing a small amount of heat in the wire. This is the same thing as the magnet travelling through the copper tube. the movement of the magnet induces a Lorenz force inducing an electrical current that cannot go anywhere (in the tube) but the effect disappears when the electrical current is allowed to disperse. ❤️🧐
I really enjoyed this video Tim! Was fun and educational at the same time! Shows a different side to you from your other fun toys and oddities you find! More videos like this would be awesome!
I love how excited he gets, don't take me wrong it is definatly EXTRAORDINARY
Magnets. How do they work?
It's an attractive subject.
_"karl you're an idiot, play a record"_
Philipp.... look up "insane clown posse - magnets" pretty sure that's the reference/joke >_>
@Anym Look up Richard Feynman magnets to see Philipp's reference. :) czcams.com/video/fZjNJy9RJks/video.html
look up Karl Dilkington Lord of house Gervais
I am a senior physics student. When there is relative motion between charged particles and a magnet, there will be a change in flux. This change in flux according to faradays law, will produce an emf. Since the pipe is a charged substance, the induced emf will setup a current in the form of eddy currents. These eddy currents will try and oppose the original change that produced them (Lenz's Law), and thus, the magnet travels slower. :)
4:58 Whipsy Whopsy
msky42 extraordinary
3:45 Alum - ineeum
@@ViewThis. That's how aluminum is pronounced in the UK.
@@HereComesWheely DUH ! Tell us something we don't already know.
@@ViewThis. I was born in November
I can sit here all day, not getting bored at anything he says
Even though half of the time I genuinely don't understand what he is saying
Absolute legend.
I love you and your videos Tim!
As someone who has done inspections using eddy current this is a fascinating video thank you
I'll quote a clown and just say: "fucking magnets, how do they work"
I had to click on this. Fifty years ago two of us built a Lenz's law demonstrator as a senior project at university. It consists of two concentric coils resting on a series of laminated cores wired in parallel with a number of oil filled capacitors. The whole thing was tuned to resonate at 60 Hz. If you rested an alumin(i)um dish on it and then turned on the power the dish would float about six inches (15 cm) in the air. The varying magnetic field produced by the coils would induce a current in the dish that *opposed* the field produced by the coils. That is what Lenz's law is all about.
If his videos are always ASMR like, he'll be so famous right now
Extraordinário ! Obrigado por nós trazer esses eventos e nos demonstrar.
Whipsy Whopsy from the Nile
newman
I love the way he presents all the objects!
A conductor inside a moving magnetic field, will induce a current inside of the conductor. A current trough a conductor will on the other hand induce a magnetic field. In these toys they attract one another which slows it down. Ofcourse it needs movement to power the second magnetic field, which it gets out of the ball falling. If it doesn"t move, there isn't a magnatic field so it will fall. If you would use a battery to power the magnetic field it would stay static and get it's energy somewhere else. These phenomenons are the basis of the induction motor. This motor also uses some power of the main rotating magnetic field to power the magnetic field in it's core, making magnetic field losses.
Thanks for the Wikipedia excerpt.
@@usa-pi9cl no problem, I wrote that all by myself xoxo.
Why doesn’t it happen when it’s on the outside of the tube and he drops it? Genuinely curious.
No it's the wipsy wopsy effect
to all who might be interested this principle is used in waste recycling. they take in your recycling and sort out the cardboard/paper/large plastics using various methods to create a metal stream, this stream will have ferrous metal, non ferrous metal and non metallic materials, on a conveyor belt a magnet will first pick up the ferrous metal, and then at the end of the belt a drum magnet will roll around inside another drum are an eccentricity, this induces an eddy magnetic current at the end of the belt the aluminium will shoot off instead of just falling off, effectively sorting it from the non metallic stream, of course you can adjust this process slightly to get higher purity levels in the recycling stream but this is the general principle of why u can put everything in cone can.
if you look up Master Magnets Eddy Current Separator (PVC Recycling) you will find a good video showing the result.
His voice is so cultured and high class.
What happens at the end with the large aluminum piece is that the current generates a field that will force the ball's field to orient in the most energy-efficient angle. Without the dots you would have thought that the ball was always falling the same way and not orienting itself because it looks the same all around. That was a nice demonstration.
This makes me forget all the troubles in life
Tim is honestly one of the best youtubers
"Huh" - Tim, Grand Illusions, 2018
I wanted to know if the Lenz effect required a closed tube and here is the video showing me that no, it does not, with no effort other than watching the results. Thankyou so much.
Can't imagine this old man will be angry 😂
When that happens is when daybreaks literally
Is it just me, or is this rather extraordinary?
0:00 Ahoy, you! (This video literaly starts off the same was Vsauce‘s video on Lenz‘s Law.)
August Schroeder i think thats this one czcams.com/video/gTKeB8BnzPY/video.html
Just found this video. What's happening is called magnetic alignment. As it drops the current produces an oscillating pattern because one pole is facing the metal which does create a magnetic flux but the other pole is facing the air.
So you have this repetition of repulsion as it is magnetized and then when the other side faces the already magnetized there is acceleration due to opposing charges which causes it to speed up and this speed up cause an induction of current because of the magnetic flux. This repeats and causes this amazing oscillating motion.
Can't we make a elevator with that concept? For example, make it out a giant magnet - the elevator itself and put it inside a big copper tube, and then if you want to descent it from a certain height you just release it and it will come down slowly, without falling and crashing on the ground. Just a ideia, maybe it is impractical..
You have to remember that they would have to get it back up again.
It's fairly impractical, since magnetic materials are pretty fragile. A magnetic elevator would have to have cables to lift the elevator back up. Although, that feature is already present in current elevators. Magnetic elevators are definitely possible, they're just, as I said before, impractical.
@@torin1006 yes i tought this would be a problem
it would cost a shit ton and it could only go down
It also would mess with people's electronics and pace-makers.
Dear Tim.
The principles behind magnetic Eddie currents is fairly well understood. There is a really advanced research and development company that has even learned how to make programmed magnets. They can educate you on the visualization of the currents.
I'm having flashbacks to physics class and drawing magnetic fields.
The way it works is that current is produced in circles around magnetic field lines, and that induces a force opposing the change causing it (Lenz's law). With the channel, having the poles face towards the sides means there is an eddy current generated (and thus there is an opposing force from Lenz's law) on both sides, while facing it with one pole towards the opening means there's only a force generated on one side, which acts on the magnet's closer side the most, and causes it to spin around. I would reckon the circular motion seen is caused by the simple case of perpendicular forces, fields, and currents that makes an electron beam trace a circular path inside the constant magnetic field of a cyclotron, or a motor's coil spin.
Hey, VSauce, Tim here!
That slow descent of those round magnets through the metal rods reminds me of those times when I had mistakenly swallowed a hot potato or egg and it slowly went down my food pipe.
Who wants to bet Michael from Vsauce gonna make a vid about that last one
It seems like the "dance" is related to the rotation of the ball as it falls and the fact that flux is concentrated at the poles, so when a pole comes quickly rotating toward the conductor a strong opposing field is created that pushes the ball away from the surface. I think of the ball as having a couple of large "cushions" of flux coming off the poles and we are just seeing it ride them as it comes tumbling down.
Greetings from New Zealand Tim
Nicola Elizabeth Ann Morete More boss baby fan
And thank you for the demonstration! That is really cool.
its like 4 in the morning here lol
Makai Clendening dont you mean 46 like?
I agree with Ian Sheppard's comment but feel a need to suggest that the electric field generated also generates a magnetic field that is more effective when the poles r not facing the opening. Thanks for the video made me think. I love that!
3:25 "Oh shiagee"
You are totally right about the eddy current going round the pipes, but the window is so narrow on the pipe with a window that the strength of the current isn't greatly reduced. The eddy current, like all currents, produces its own magnetic field, pushing the magnet up and makes it fall slower.
I'd never seen magnetic field paper, amazing! Also: Obligatory eddy currents in the Nile comment.
You are dealing with the same principle of why electric motors have copper windings. Fascinating to see the reaction between copper and magnets, even though copper is not magnetic.
It's more interesting with his british accent for sure
You always post the most interesting things. This is definitely something I did not know.
The day tim stops uploading is the day i uninstall youtube.
I've always be fascinated by that effect. Thanks for the video.
Lenz's Law.... of the nile..
unfunny meme from the nile
Cole's Law - shredded cabbage mixed with salad dressing
Tim you need a piece of magnetic view film. It is a plastic card that will form iron-filing-like visuals of any magnetic field behind the card.
Magnets from the nile.
Altair Ibn La'ahad your profile picture is 3D man!! Just kidding
You are a very nice man Tim. Thank you for showing us these interesting devices!
We all love you Tim
Guillaume Maille yep Boss baby is a good movie but this video about his old toy and have nothing to do with that movie
The coolest way I've seen this displayed is by putting a giant block of copper into an MRI machine and tilting it over. The block of copper called over extremely slowly as if it was in zero gravity. It also proves that the copper is what is effected by the magnetic field, and not the other way around. The magnet also doesn't need to be inside the copper or aluminium. The copper only needs to be surrounded by a magnetic field.
But the question is - will it fly ??
Can it run Crysis?
if memory serves me correct, the metal platform that the magnet is interacting with becomes slightly charged in the presence of the magnet, and that charge is enough to create it's own magnetic field, which is why the magnet does the little jaunt when the poles are placed front and back or top and bottom.
It's that slight magnetic field that the magnet creates in the copper and aluminium pipes that slows it down and pushes if out of a direct path.
Probably not the best explanation, but its pretty close.
Magnetic fields from the nile.
STOP IT GET SOME HELP
It's magnetic friction... the molecular results of aligned dipolar charges over enough surface area creates enough drag and draw to slow the magnets descent. Much like how water can accumulate on sheer surfaces. Think of it as the magnet responding to relative distance and the other materials innate electro magnetism. If you could form pour a piece of bismuth into the space between one crucible inside a larger one. You should be able to manufacture a bismuth tube relatively easy for more advanced experimentation. Bismuth is diamagnetic and will repel magnetic fields. You could also create a bottom cap for such a tube. And in practice you might see other applications using increases of magnetic pressure field collapse and rebalancing distortions. Most simply observable by using weight or downward pressure upon magnets dropped into such a tube it flattens and expands outward. Some examples of useful devices might include exterior coil interactions disconnecting switches or interlocks or perhaps controlling/assisting another adjacent field manipulation. What you decide to do with magnetic field expansion and how to control it is entirely up to your creativity and design. Using the containment the magnets and the peripheral devices.
Great!
The reason it turns around its axis when the poles are facing up and down is because the magnetic field is strongest near the poles. When you start dropping the ball eddy currents are created around the bottom pole but much less on the side of the open channel. This means the channel creates an uneven drag on the ball causing it to rotate. This effect is always the case but extremely noticable when the poles are in essense ‘almost’ perfectly alligned with the top and bottom of the channel because in that case the biggest difference in ‘drag’ is achieved.
When the pole nears or hits the part of the channel which is full material it does the wobble because the countering magnetic field caused by the Eddy currents inside the aluminium is strongest at that point and there is less force to counter it on the other side.
When you drop the ball with its poles pointed towards the sides of the channel the much weaker magnetic field ‘lines’ in a plane perpendicular to the poles are causing the difference in ‘drag’ (I keep putting drag in between accolades because ofcourse it isn’t drag in the classic sense of the word). This results in a much less noticable rotation of the ball if any. You can test it with some lines running from pole to pole.
If the channel were much longer the ball would end up spinning really fast when the poles are facing the sides aswell... as the rotation would slowly speed up during its descent.
Or so I believe :-)
I somehow got attracted to this video
@Nik Tim too! Huh!
This is extremely calming to watch
This guy talks like he’s typing with sausages for fingers but I can understand everything he says
Extraordinary
I think a good way to describe edicurrents is imagine 2 examples and combine them as a 3rd conceptualizing example.
First take magnetic waves like a ripples in water... drop a pebble into the ripples will deconstruct certain sections but those cancelling waves kinda warp together the two instances and thus u get a jagged kinda pattern.
Second consider in a deeper pool and repeat the previous example taking note that the initial rippling effect is jagged through the depths only at the edge of the sources influence would have a smooth pressure wave down there. And when dropping the pebble... The depths jagged waves are straightened by the new influences progress as water moves from underneath it filling those gaps. Thus the greater influence creates a brief instance of stability of no ripples on entry.I
Thirdly imagine each ripples walk of pressure to be like a string of better yet a membrane to its layers.
Finally combining these concepts to create a 3D interpretation the membrane is the Edis the Edicurrent is the pressure. When dropping the magnet through the pipe it moves pressure and reshapes each edi as it progressed and the warping like water is only bending the strings it can't cut through them.
Aligning the poles to the sides means the edi is passing through the magnet.I
Any other alignment will cause the magnet to pass round the edi as it's impossible for the object to cut the membrane just rolling through the warp that it's own edis create.
As the electro magnetic property is a sub atomic quality there's nothing that isn't magnetic... Only the classification of magnetic levels could be described as pitiful magical and extreme in my opinion.
Pitiful being non magnetic levels of edis
Magical being normal levels
Extreme being high levels.
The Reason for why the magnet rotated with poles being perpendicular to the surface: is in the principle that because of the movement of the magnet current is produced in the conductor, which as per the Lenz's law opposes the magnetic field, but as in this case there are to opposite poles creating effect on a single side, creating two different flow of current as the direction of magnetic filed is opposite at both poles. So because of two opposite poles the induced opposite currents is repelling one pole and attracting the other creating a torque in the magnet.
3:35 a little bit of drunkenness?
This is a fascinating effect and I wonder if it is in practical use anywhere, perhaps as a buffer or shock absorber or just to slow down falling things without the use of springs or air compression?
This is cool and all but
*Water From The Nile*
So you let the balls fall down the pipes because.. they go through slower? What is the use for this besides showing people the unusualness?
Loved watching this! The ball with the poles displayed was really cool! As a bonus it also triggered my asmr been a while since that happened thank you
Idk why but this guy makes me so happy
The magnetic field opposes the field of motion. In this case the ball is moving down and the magnetic field pushes up, causing the ball to slow down. If you attempt to push the ball through the tube horizontally, you'll feel the same force against your movement, instead of gravity. The field lines look like the earth's and are strongest at the poles, and although called lines, they are actually curves so they move into the object as well. If you have a stream pushing up on one side of a ball, it will, in most instances, move away from you. In the last toy, the red pole indicates positive, blue is negative, and this can be observed in that the magnet is pushed away when the dot is exposed and the negative pole is facing the metal. The negative pole facing the metal side gets pushed up and in, while the exposed pole receives no such force. The groove is deep enough to hold the ball through this effect and is rewarded when the positive side begins to attract right in the between the poles because its had the positive pole facing it for longer.
When you have a magnet, you think of its magnetic field as one large thing, but it's actually the sum of a huge number of small "domains" all doing the same thing.
Similarly, you think of the eddy current as flowing all the way around the circumference of the tube, but it's the sum of lots of little currents all doing the same thing.
So transformer cores are laminated to reduce eddy current losses.
It turns because one pole is facing the back of the groove and the other is facing open air. The pole facing the back is slowed down while the pole in front is not, so it's pulled around the horizontal axis. You could put the dots anywhere on the ball actually. Whatever dot is facing the back will be spun around upward due to drag.
Yes I thought that, but you will also notice that it moves in and out on its way down. I can imagine why it would move away from the back, but not not towards it again...?
In that last couple of scenarios where the ball rotates, I think it''s because the poles have asymmetrical distance to the aluminium. Thus, there is a different drag on each pole, which rotates the ball.
Dropped with the N-S axis vertical, it's pretty random which way it tilts, but once an orientation eventuates, there will only be drag on the pole facing the interior of the groove, and a resultant rotational force.
Dropped with the N-S axis horizontal but pointing in-out of the groove, it instantly becomes a case of the previous, same result.
Not only a fun thing to play it has also practical usage: recycling facilities separate aluminium or copper from the waste and of couse breaking systems for roller-coasters or trains (the German ICE for example) work that way since there is no wear compared to disk breaks