2veritasium - 2018-04-06
When spun on a screwdriver, magnets climb up its length, but why? This video brought to you by my friend Steve Mould: http://ve42.co/SteveMould This all started with a question on twitter, when someone wanted to know why a chain of neodymium magnets climbs up a screwdriver when the screwdriver is rotated. A search for the explanation ensued, culminating in the stick-slip conclusion presented in this video. Let us know what you think in the comments.
In my head, I was already constructing a complicated device to spin it with a smaller radius at the top. Then Steve just turns the screwdriver upside down. Now i feel stupid 😁
Him turning over the screwdriver proves nothing, still purely in the circular motion and not how he explained it. He is overthinking something so simple
same here.
For those saying "turning the screwdriver upside doesn't prove anything", watch the whole video. He spins it with a drill and it still rose up with no wobble.
Same
same here, your'e not alone.
Why is this on 2veritasium and not on the main channel?
Steve Mould is High quality content!
Exactly, if you want to get people to check out Steve's channel then show this to 4.6 mil people rather than just .5 mil.
@Mabel Shircliff 5 mil. am i missing something here?
@Black Panther .5 mil
half a million
4.6 is bigger than .5
@Mabel Shircliff damn i missed the dot before 5
@Black Panther all good
Marvel: "Avengers Infinity War is the most ambitious crossover event in history"
Veritasium: "hold my beer."
Haha wow I thought exactly the same thing when I saw the title XD
Added Kina we're memers at heart, memers for life
I was literally watching Infinity War videos when I saw this in my Sub.
No Thank You I disagree. Steve Mould is an amazing science guy on YouTube and this is called a collaboration. For main content, you should watch Veritasium not 2Veritasium. However, I do agree that he doesn't seem to give two shits about his content or scheduling these days, just posts when he wants to
It's like Magneto teaming up with Iron Man.
ME "Well that's easy to answer..."
Steve "If you turn upside down, it still goes up"
ME "Alright... I still a dumb mf"
What if the magnets are square?
@Benjamin H Thanks a lot. I was wondering about the square magnets as well (though I believed the hypothesis of Steve) and you are my/our hero.
Even a year later you still are!
@TheSparty301 you'll find the answer along the comments (starting by "thanks for your patience")
@Hoch134 that means a lot to me, thank you ! :)
I'm a science teacher now and I built many of steve things (starting by the laser+speaker+membrane+mirror, it looks so cool) and bruce Yeany is a big inspiration too ! :)
Last project was a stroboscopic fountain that appear to not flow or flow up depending on the relative frequency of water vibrations and ligth turning on and off.
@Benjamin H These are the science teachers we need! Glad that there's another good teacher knowing how to motivate his scholars to learn new things.
Keep going.
@Tim van Akkeren well looks like Monday never came...
I think he should of tried to prove his hypothesis by using square magnets
I would be curious to see if the same affect is observed with a length of all-thread rod.
Someone needs to send this to Destin at SmarterEveryDay so that he can shoot it in slow motion and confirm this theory.
Destin is most likely subscribed to Derek anyway since they know each other.
I was about to say the same thing. A high-speed camera and magnets with a black line on the side to better see the rotation and voila!
Although he'll probably get confused and shoot it with an AK or something.
4 seconds into video... "uhm... centrifugal force? How is that not obvious?"
1:00 into the video... "oh... okay... never mind then..."
5:30 "Ooooh! Because gravity! Okay."
Same. I always thought it was centrifugal force.
I am amazed to be wrong about something so simple.
I thought it was Eddy currents (the same thing that happens when you drop a neodymium magnet through a foil tube or copper pipe)
should've painted the magnets on the sides and made another demo that way.
yes, chequermarked magnets and a high speed camera ought to be able to verify this
i miss you derek
I appreciate you saying...
such a derek
MrChanw 11: Exterminate!
https://www.youtube.com/watch?v=RhEUBgu9j5Y (just a nice dalek compilation) ;)
I miss you too
I miss you derek
Steve could have proved this hypothesis by spinning the magnets around a horizontal screwdriver. The result being they move in neither direction.
if the screwdriver stayed level, it shouldn't move at all
Isn't it general relativity and quantum mechanics that don't get along? I'm pretty sure QFT and even the Dirac Equation are perfectly happy with special relativity...
I was wondering that myself!
Quantum Field Theory (QFT) is the unification of special relativity and quantum mechanics.
The real challenge is unifying QFT with general relativity.
What is the difference between the genral and speacial theorys ??
@Kepler 78b The special theory of relativity deals only with the special case where there is no gravity and the acceleration is not too large. (Any remotely realistic acceleration you might be thinking of is probably not too large.) This is the theory that assumes a constant speed of light and shows famous facts like the equivalence of mass and energy (E = mc²). It assumes that all inertial frames of reference are equally valid (in the sense that they all have the same laws of physics, including the same speed of light) but distinguishes these from non-inertial reference frames. The general theory of relativity deals with gravity and shows that an inertial reference frame in free space is locally indistinguishable from a non-inertial reference frame in a gravitational field. It describes gravity not as a force but as a change in the metric--a curving of spacetime. It makes predictions regarding the shape and future of the universe, the existence of black holes, the lensing of light around massive objects, gravitational radiation, etc.
The basic attempts to formalize quantum mechanics in the curved spacetime described by general relativity or to create a quantum description of gravity have failed. The theories turn out to be mutually inconsistent, and naive calculations often give infinite results, probabilities greater than 1, and other issues. One thorny problem is time. Time is just a scalar variable in quantum mechanics, but in general relativity, it is just a projection of 4-dimensional spacetime, an essential feature if it is to curve. The central problem in physics today is to find a consistent theory of quantum gravity that agrees with both quantum mechanics and general relativity to within the error of our measurements. Some progress has been made in research into string theory, loop quantum gravity, and other contenders, but so far there is no accepted theory of quantum gravity (also known as a "theory of everything").
Special relativity however is perfectly consistent with quantum mechanics, though it still requires a change of perspective. Old quantum mechanics still used classical spacetime, but the fusion of quantum mechanics and special relativity is called "quantum field theory," and this is the theory used today whenever the non-relativistic equations are not accurate enough (like for the nuclei of very heavy atoms or very energetic collisions).
@EebstertheGreat thanks for taking your time to type this.
STEVE MOULD used GRAVITATIONAL WAVE DEMONSTRATION! It's super-effective!
+
FFS I rly thought my headset was broken or smth bcause of the start, you scared the shit out of me, I just bought it a few weeks ago
My headset IS broken, so I couldn't even hear him lmao
WoyablePitt Your keyboard seems broken though, there are letters missing in some of the words...
You think that’s bad?
I was listening on my phone, I thought it had blown the speaker or something... -_-
WoyablePit
It would be cool to send this experiment to the international space station to see if the explanation is wrong
You could just hold the screwdriver horizontal so their is no top or bottom quicker and cheaper.
what a fantastically calming way of speaking
Yep, Steve Mould definitely deserves more subscribers!
You can demonstrate it by drawing a line with a marker over the magnets and do a short spin to check it it rotated the way you predicted.
So what if you use square magnets and keep them perpendicular to Earth's gravitational vector.
No height change then ?
Akitake I was thinking the same
Same but less pronounce, do you not know how magnets work? It probably wouldn't roll as well but the main concept of slipping and sticking is still there.
why didn't he prove his explanation by using square magnets ??
Well, since there's no symmetry and gravity always biases it upwards... And as it moves around the screw driver, gravity is tipping the magnet roll downwards, only the bottom edge makes good contact and the strip rolls around its end. And it'll have a turning radius pointing upwards, since the "inside" of the turn is always pointing up thanks to gravity. Kind of like if you take a core of a toilet paper roll or any other cylinder, stand it up on its end on a flat surface and apply a fake "gravity" to the top, tangential to the flat surface thereby tilting the cylinder... If you then push the cylinder along such that it rolls on the remaining edge, it'll tend to translate on the surface away from the direction "gravity" is pointing in.
That was my thought anyway, before you pointed out the noise -- though I still think it would work just as well even if it could not slip.
Someone please explain what on earth I just read.
It's still just increasing centrifugal force to the top. The magnets hang to the ground, creating a upward 'track' on the axis.
But in order to be certain this theory is correct, it needs to be tested with different variables. For example, magnets with a square cross section instead of a circle, or a change in relative size in either the metal pole (screwdriver) or the magnets to test the "roll and slip" idea.
To prove your theory, I think you should make same experiment with rectangular cuboid magnet.
So for some reason the right channel/side has no audio for your voice during the introduction... Just FYI.
Updated: @ 6:17 it's the same. Apparently either your mic was/is 'jacked' (pun intended) or maybe just some slight technical difficulties....
Again - Just wanted you to know, because I'm certain your going to get other comments on this the more the video is watched.
It's a mono mic, he recorded or imported it as stereo, so just the left channel got a signal. Happens quite a lot somehow. You'd think people would watch their videos before uploading them...
There is actually some sound on the right channel it's just really quiet. Also yeah, this keeps happening and it's quite annoying.
I am actually watching with one broaken earphone so in the part where derek is talking there is almost no audio, there is definately some audio though like Jack Evans said
Yeah, but it was still really quiet... had to turn the volume all the way up to be able to hear him on the right side.
we need a “control” experiment using square magnets 🤔
also: steve’s awesome 👏
derek: some of us kind of miss you 😅
when I started watching this video, I was like, "It's so obvious", but then you turned it upside down .-.
"Grand mysteries, what is dark matter"
Its matter in the dark.... whats so mysterious about that?
Suddenly very aware of Derek's mortality. Looks like he's aged 15 years since his last upload
because it was 15 years ago
Had one headphone in and wondered what the hell happened to the sound...
6:06 Challenge accepted!
the "Steve Mould threw Veritasium a bone" effect?
"PIVOT! PIVOT! PIVOT!! PIVOOOTT!!!"
Great video :D
Now we need someone in the ISS to do this experiment. Logic tells the magnets will just spin around. Probably will move up or down depending on little "vertical" movements if done by hand, since it's rather impossible to keep all axis fixed when done by a human hand.
6:26 Wild MOULD used GRAVITATIONAL WAVE DEMONSTRATION!
It's super effective!
I could not manage for the life of me to watch this at normal playback speed
1:47 in to this video and I had to set up and lean into the screen... the drill
2:48 That's actually a cello ;)
To prove this theory about gravity's role in this mystery, we should recreate it on the International Space Station where the impact of gravity is minimal. Reminds me of the feather and hammer experiment on the moon...
You could just hold the screwdriver horizontal so their is no top or bottom quicker and cheaper.
1:30 makes that explanation a bit questionable to me tho
1:48 I guess you mean general relativity
So, according to the explanation, we deduce that it only works with cylindrical magnets, right?
I like your tone more, I was kind of feeling sleepy, listening to the other person's voice
So... My question is, does this effect work in space? I'd assume not, Since gravity plays a big role in it??
I was fighting with my headphones at the start.
Thank you so much YouTube algorithm for recommending some flat earth proof after a veritasium video. It's very refreshing. Great video.
Before watching:That's centrifugal force!
After watching:
It's sad to find out you were wrong.
I drew a small dot close to the tangent of the circle of the cylinder of magnets and did the same experiment a few times to see if the point shifted proving the cylinder rotates as described. It does.
Look mom, I did actual science!
Is it only me like to broke a looped string with some heave stuff on one end and spin it on my finger and now I understand this thing
Now build one space elevator using that :3
azdgariarada What are you talking about? Spinning the tether would make it more stable, in fact that's how some of the first satellites were launched. https://en.wikipedia.org/wiki/Spin-stabilisation
Spinning a small object like a satellite is entirely different than spinning an enormously long stationary object. Also, it's not exactly a spin. If you'll notice, the screwdriver isn't rotating about it's own axis, it's staying stationary relative to itself and oscillating back and forth, perhaps describing an elliptical path to induce the rotation of the magnets around it's central shaft. Scaled up, this sort of motion on the order of kilometers would be catastrophically destructive to all currently known materials.
Jusore how would you get it down?
Search YouTube for magnet brakes
They're used in some extreme unpowered rides
They didn't spin the satellites, they spun the rockets that carried them to increase stability of the atmospheric flight. Also, you are right about the elliptical path of the tether, but what OP was talking about was this part of the video 1:29 , no elliptical path, the drill was spinning it straight, the difference is you have to use a catching mechanism like the ruler to get the magnets to go up. It would give it gyroscopic stability.
I do agree that the material strength could still be a problem with a many kilometers long tether, and no material we can realistically produce could even withstand it's own weight, but nothing that carbon nanotubes can't solve.
Guys, its simple. He showed us you can do with the rod rotating around its own axis. As for where we get the power to spin such a long rod? Your looking at it the wrong way. We already have the power to spin it. I propose we build an actual North Pole. The earth spins the pole, we just have to spin the elevator in the opposite direction. The elevator would move up and, if the speed in the video is any indication, we would get there in maybe a few years.
The Legondary - 2018-04-06
My left ear enjoyed the start
Dean Su - 2019-11-02
Your comment helped me realise my earphones were flipped
Ob - 2019-12-09
He must have been using cheap headphones when editing
Aaron Mott - 2019-12-10
My right AirPod has been messing up, and I did NOT enjoy that moment of panic
Reno Simpson - 2019-12-13
@Dream Dice Thats a level of sarcasm I can appreciate. You are a wordsmith!
Stan Ervin - 2019-12-13
Effed up audio 4 real!