# Tagged Questions

The tag has no usage guidance.

7k views

### Can lasers lift objects?

I have been fascinated by a very intriguing question - Can lasers push objects up? I have done the below math to find out Lets say we have a $1000~\text{mW}$ laser and we would like to lift an ...
2k views

### Explanation for this type of (magic-trick) suspension? [closed]

Well let's start off with that I'm not a physicist but I'd like some thoughts on something I came across in my hometown. This guy: Is it possible that due to the electrical charge of magnets this ...
1k views

### Does a magnetically suspended frog feel weightless?

Magnetic levitation has been used to suspend frogs in midair. I was wondering: Does the animal still feel gravitational pull? I mean: Does the frog feel like an astronaut on the ISS, or does he feel ...
26k views

### How does Hendo hoverboards achieve the self-propelling motion? What is the MFA?

From what I understand of the idea behind Hendo hoverboards, they use four disc shaped hover-engines to generate a self-propelling motion. I also understand that it uses Lenz's law and eddy currents. ...
6k views

### How do superconducting materials float in magnetic field?

The movie Avatar got me interested in the subject, but so far I only found sophisticated articles loaded with unfamiliar words. Is there a simple way to explain how magnetic field affects ...
5k views

### Can I levitate an object without using an electromagnet?

I know that it's possible to make an object levitate using an electromagnet to hold it up. But is it also possible to do this with regular magnets? Is there a special kind of magnet I need in order ...
2k views

### Is it possible to levitate a toy maglev train using only permanent magnets as long as the train stays in motion?

I am fascinated with magnets, and specifically the idea of magnetic levitation. I recently purchased a Levitron toy maglev train and have enjoyed finding the perfect sweet spot at which it levitates, ...
8k views

### Can superconducting magnets fly (or repel the earth's core)?

If a superconducting magnet and appropriate power supply had just enough $I\cdot s$ (current $\cdot$ length) so that when it was perpendicular to the earth's magnetic field, the force of the ...
344 views

### What is the exact physics behind sonic levitation

Me and a group of friends decided to choose sonic levitation as our research topic. However, after looking up the theoretical background, we hit a roadblock: (Here is an image of a standing sound ...
2k views

### Is magnetic levitation a good way to vibrationally isolate a speaker from its support?

I recently heard about this company planning to sell a magnetically levitating bluetooth speaker. I understand that the levitation is partly motivated by visual aesthetics, but on the website the ...
6k views

### How does quantum trapping with diamagnets work?

I just saw this demonstration by someone from a Tel Aviv University lab. What they achieved there is mind blowing. I myself own a levitron that uses the Hall effect to levitate a magnet, the problem ...
468 views

### Can molten metal be suspended in air?

I wondered if magnets could be used to hold a drop of molten liquid metal in air (not for any particular reason just because it could be done), but was disappointed when a quick Google search showed ...
240 views

### Flywheel energy storage: Why not use room temperature diamagnets instead of superconductors?

Flywheel energy storage has garnered some interest from academia and industry for its potential to store surplus electrical energy efficiently in kinetic form. Modern designs use magnetic bearings ...
2k views

### Can water be magnetized?

This may be a stupid question, so feel free to shoot it down. Assuming all atoms have a magnetic moment, I would assume the water molecule too would have a resultant magnetic moment; ergo, it may be ...
751 views

### Physics of donut magnets levitating vertically on a pencil?

When you put identical donut magnets on a pencil horizontally, the magnets all repel from each other in a way that creates equal spacing between each magnet. However, spacing is not equal when the ...
973 views

### Magnetic Levitation : Confusion with Lenz's Law

Considering the above diagram, I am failing to see why the aluminium ring floats upwards rather than oscillates. I understand Faraday's law, but I am struggling with Lenz's law - as there is an ...
4k views

### Quantum levitation (locking) 3mm thick disk could carry 1000kg small car claim

I watched this TED presentation: http://www.ted.com/talks/boaz_almog_levitates_a_superconductor.html It is about superconductivity and quantum levitation. It tells that super-thin, three-inch disk ...
596 views

### What is the missing proportionality constant in the magnetic levitation formula?

The formula for magnetic levitation is $$B \frac{dB}{dz} = \frac{ \rho g }{\chi}$$ but as always, I have a hard time figuring the units in SI. The left hand side is $\mathrm{T^2 /m}$, while $\chi$ ...
1k views

### How can I cause a levitating magnet to rotate?

I have a device like this one: http://www.youtube.com/watch?v=kA_hw_lY-OY (All of them work the same) Here's an image: I want to make it spin without touching it with hands. I tried using magnets ...
272 views

### Magnetic Levitation For Space Travel

At 1 G, we feel at home. At 5 G's, normal people can stay awake. At 9 G's, trained pilots with G-suits can stay awake. At 25 G's, R.I.P. Unfortunately, these numbers are limiting for space travel, ...
975 views

### How do magnetically levitated trains (maglevs) stay on the tracks?

Just went on one yesterday, and had a bit of a thrill. And I was musing on the fact that electromagnetic forces are so strong, that they can keep a whole train up in the air. But then, wouldn't ...
462 views

### Can we use radiation pressure to push/levitate a human?

I want to know, at least in theory, are there any safe em wavelength that could affect human body as net force and do no harm? To put it bluntly I want to know is it possible for levitate a human on ...
2k views

### What is “Quantum Levitation”?

I just found this video Controlled Quantum Levitation on a WipeOut Track and I'm having a hard time finding the term "Quantum Levitation" used except in reference to the video. What is the proper ...
2k views

### How much magnetic field will be required to levitate a human? [duplicate]

According to this video: http://www.youtube.com/watch?v=BqKeiiezqzc it should be possible to levitate humans because the water in our bodies is diamagnetic - but it is stated (at 1:14) "although ...
76 views

### Lifting capacity of superconductors

How does the strength of the magnetic field the superconductor is exposed to affect its ability to levitate/lock heavier objects? Or is there no relationship (for superconductors) between magnetic ...
490 views

### A correct explanation for the levitation of a superconductor above a magnet [duplicate]

I teach high school physics and I'm trying to put together a correct explanation for the levitation of a superconductor above a magnet without a high level of quantum mechanics (but consistent). I ...
54 views

### Is this a possible monopole setup, or will it cancel out? [duplicate]

Suppose you have a ball that is covered in magnets, in which the North Pole of every magnet faces outward. Is this a monopole? Or at least "functions" as a monopole? And what will happen if you placed ...
127 views

### Can I levitate soon?

Whereas I have seen frogs fly in high magnetic fields and Sumo ringers stand on high-temperature superconductors it seems that these are not the only forms of levitation. Recently a group of ...
90 views

### Why does this 'Quantum Pinned' superconductor allow easy repositioning

I'm confused by videos such as this (popular demonstration of 'Quantum Levitation'): https://www.youtube.com/watch?v=Ws6AAhTw7RA So my current understanding of superconductors is that when in the ...
131 views

### Bottom magnetic levitation

There are many decorative devices, that keep a small metal sphere levitating in air by attracting it to a top electromagnetic coil while monitoring their height by optical sensors. There is also the '...
652 views

### Magnetic levitation frog example

I'm trying to figure out the strength of the magnetic field needed to levitate the frog, assuming it's spherical, has mass $5$kg and diameter $20$cm. I also assume $\vec{B}$ is uniform. Since it's ...
412 views

### How to figure out the magnets needed to repulse a given weight?

Given a weight. Is it possible to determine what strength of magnet and what width, length and thickness would be needed in order to repulse that weight a given height? If so, how? To be clear: Two ...
66 views

### Energy conservation in diamagnetic levitation

How do we account for conservation of energy in diamagnetic levitation when no external energy is required?
30 views

### Levitation inside a solenoid

Is it possible to levitate something inside a solenoid? If yes, is it possible in any direction (horizontal, vertical)? Also, is it possible when an object is traveling through? Thanks in advance!
294 views

### Repulsive Force between two Electromagnets

This question might seem a bit too basic(or advanced!), but it is the one to which I'm really desperate to find a simple enough explanation and solution. Ok, So here's the problem, I have two ...
686 views

### Why is the Meissner effect not used for levitation in MagLev trains?

The Meissner effect does not seem to be used as primary source of levitation in MagLev trains, instead, electromagnetic and electrodynamic syspension are mainly used. Why is this? Could it be that the ...
451 views

### How do you levitate a foam rock? ('Endless Second' artwork)

I saw this in an art museum: How is this possible? The materials used to make this were foam, wood, stone dust, paint, electromagnets, and metal. I would like to know how this was make and how I ...
52 views

### Could a man float in a large enough magnetic field to simulate zero gravity?

I know the magnetic field would need to be very large, but if an organisation like NASA with huge funding and resources could build a large enough device, could a man float in that magnetic field to ...
70 views

### Could I pick up a human with a strong enough magnet? [duplicate]

Could I pick up a human with a strong enough magnet? Humans contain magnetic materials, such as iron.
80 views

### Magnets levitation stability

I'm willing to make a levitating stand based on standard magnets. Both the stand itself and the levitating object would have magnets attached, of course the same poles heading each other. I have two ...
38 views

### Superconductors and hoverboards

We know that superconductors are repelled by magnetic fields. The earth has a magnetic field of about $10^{-5}$ Tesla. I just want to know if it is possible to use this property of earth to make hover-...
45 views

### Question about Meissner Effect video

In this video, what material is on top of the superconductor disk that keeping it cold? Is it just a circular chunk of dry ice? http://www.youtube.com/watch?v=Ws6AAhTw7RA I'm planning on recreating ...
220 views

### Remotely changing superconductor levitation height?

I want to be able to modify the height of a quantum locked superconductor. My original plan was to levitate the superconductor over an electromagnet and modify the current to said magnet (increase the ...
753 views

### Can effect of gravity be broken (counteracted) by electric force?

Can we make a jacket using an electronic circuit that uses electric force to cancel the effect of gravity so that we get lifted in air.
372 views

### What gives Maglev trains forward horizontal motion?

Maglev trains have superconductors which are immune to magnetic field lines with low enough temperature. Due to this property, they levitate on magnetic rails as magnetic field lines are bended below ...
54 views

### Can Acoustic levitation be used to contain antimatter?

Can Acoustic levitation be used to contain antimatter? To me, It sounds like an obvious use of the phenomenon, but I didn't find any documentation about anyone trying this on the web, which could ...
60 views

### How does the levitating water illusion work?

After watching a movie in which levitating water was used as an illusion, I was curious to discover how it works. Unfortunately I cannot find any great explanations of the science behind the effect, ...
338 views

### How possible is liberal human flight using a flying superconductor bed?

I saw a video by Michio Kaku, showcasing levitation of a small object with a superconductor cooled by liquid nitrogen. It's the same technology used by some trains. Hypothetically, how possible is it ...