# Tag Info

22

You would feel weightless if every part of your body of mass $m$ would be subject to an upward force equal to $m$ times the local gravitational acceleration $g$. Such an exact part-by-part cancellation is not going to happen via diamagnetic levitation as utilized on the frog in your example. Not only does this levitation couple according to magnetic ...

6

Water is a diamagnetic material and like most other non-ferromagnetic materials it does interact with magnetic fields but with much weaker interactions than you are used to from fridge magnets and the like. However, if you crank up the field to something like hundreds of thousands of the Earth's magnetic field - about 10 Tesla will do - then you do get ...

5

This is simply a matter of force balancing. The only forces on each magnet are gravity and the magnetic repulsion from the neighbors. The top magnet must be repelled from below with a force equal in magnitude to the force of gravity on it. The next magnet down has not only its own weight pushing down, but the weight of the one above it as well. This is an ...

5

As lurscher mentioned in a comment, you're using the wrong units for magnetic susceptibility. $\chi$ is actually a dimensionless number that is related to the magnetic permeability of a material relative to that of a vacuum. I think you were mixing it up with the molar magnetic susceptibility, which is $\chi_\text{mol} = \mathcal{M}\chi/\rho$, where ...

5

This paper describes the effect in some detail. Stable levitation is caused by a combination of the Meissner effect, and of flux pinning in Type-II superconductors. The Miessner effect is the property of superconductors which prevents magnetic flux from penetrating the superconducting material (beyond the penetration depth). It occurs because the applied ...

4

The feeling of weight is caused by contact forces acting on only parts of your body: forces like the pavement pushing on your feet, air rushing past certain parts of your body as you fall at terminal velocity, the floor of an elevator pushing with reduced force on your feet as the elevator starts its downward trip. Basically you feel one part of your body ...

3

The video here on YouTube has some more information as well as video of the effect. The puck is a layer of sapphire crystal 500 microns thick which is coated with a 0.5 micron later of superconductor and then gold. The whole thing is wrapped in cling film/plastic wrap. The locking is explained at 1:52 to 2:09 and has to do with the magnetic field being ...

3

In short, no, at least not at this point. Unfortunately I was not able to read the entire article, but what I understood from the abstract is that it was only meant for very small volumes and masses, but if they did manage to levitate a cup of coffee, that is a step in the right direction. But there's another problem with this method - it uses ...

3

There's a lovely children's novel in which much the same idea is employed for building a "perpetumobile", something that cannot be possible for all we know about physics. The easiest law stating that it can't work is Newtons third law: for every force (like the one that levitates the human) there must be an equal and opposite counter force, in this case ...

2

Sadly the Meissner effect can't be used as an anti-gravity device. If you lay under the magnet and put the 3mm superconducting disk and car on top you would indeed be squished. The presenter does use the words "in my hand", but I suspect this is just poor phrasing and I'm sure he is not suggesting he could lift a car in one hand using a superconducting ...

1

What you want to investigate is called a Halbach array. You will still need a guide rail for the train, but it will pick up off the track at very low speeds. See http://en.wikipedia.org/wiki/Inductrack for an example.

1

Using electromagnetic flux to generate enough momentum to cause "spinning" or speeds of greater then 20 rotations per minute, can be accomplished easily using rotating fans or other objects that act as a base and move independently of the surrounding mass. but hypothetically lets say that we desire the pen to move independently of the base or the 'levitating ...

1

The Title of the video is misleading. What Boaz Almog is demonstrating is not at all levitation. The disk is not pushed away from the magnet, and it does not levitate. It is fixed or trapped in the magnetic field, by an effect refered to as "Quantum Locking" or "Flux Pinning". This can be demonstrated by locking the disk in space underneath the magnet, which ...

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