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ArcticMyst Security by Avery

Levitating frogs and humans

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It takes 10 teslas to levitate a frog. I wonder how many teslas it takes to levitate a human?....................



 





HIMNL9

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Uhm ..... someone asked the frog about the effects of 10T on it ? :p :D

And about the "flying dutch" (lol), look a how is bent the pole where he have the hand ..... and also, stop it at 15 seconds, and you can clearly see the plate where it's sit, on his right side (and i will call this a fail, LOL)
 
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^ Wow, that's very disappointing. I thought it was real. :p

Seriously though, I wonder how much energy would be required to levitate a 150 pound human? I'm not sure what type of energy conversion is needed for 10 teslas into other measurements to make that calculation. Watts? Joules? etc.
 

HIMNL9

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Well, that experiment use "diamagnetic levitation", and it depend from the "diamagnetic susceptibility" (i hope it's the right translation in English) of the target, from its mass and density, magnetic field intensity, and ofcourse from the gravitational acceleration that you need to win (G on earth surface is approximatively 9.8 m/S per S) ..... same principle that you can use for "levitate" a superconductor on a magnet.

The problem is that the "diamagnetic susceptibility" of a superconductor is -1, where instead the "diamagnetic susceptibility" of living bodies is approximatively -0.00001 :p ..... also, the magnetic fields decrease with the square of the distance, not linearly, so you need to pump much more energy in the coil for generate the needed field, if the coil is large enough for contain a human body ..... so, it's discretely easy to float a small frog in a magnetic field from 10 to 15 Tesla inside a small space like that Bitter coil (and, if i recall correctly, that thing was still using some MW of energy and a lot of watercooling :p), but for a mass of a human being, and considering also the necessary space around it for build a coil, you probably need to generate 500.000 to 1.000.000 Tesla, for have some effect ..... and you will end burned, fried and toasted much much before the levitation starts :p :D
 

HIMNL9

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It's all matter of how strong you can get the magnetic field ..... unfortunately, for hobbysts, except some decent neodymium magnets, there's not too much things to do (well, at least, i supose there are not too much hobbysts that have available science labs apparates for free ;))

Otherwise you can also levitate water, but you need that 16 Tesla coil.
 

Benm

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so, it's discretely easy to float a small frog in a magnetic field from 10 to 15 Tesla inside a small space like that Bitter coil (and, if i recall correctly, that thing was still using some MW of energy and a lot of watercooling :p), but for a mass of a human being, and considering also the necessary space around it for build a coil, you probably need to generate 500.000 to 1.000.000 Tesla, for have some effect ..... and you will end burned, fried and toasted much much before the levitation starts :p :D

I must say i have my doubts on this caculation. Why would it take a larger field strength to levitate a human, or an elephant? I'll just assume that all animals have similar composition here, and other than that mass doesn't play a role.

The magnetic field gives a force per unit of mass, and so does gravity. Levitation occurs when they cancel eachother out.

By that logic, the field strength would be equal regardless of the size of the animal levitated. The problem is the scale: The bore of the magnet they levitated the frog in is just a few cm in diameter. Its located in Nijmegen, and requires megwatts of power and cooling as you describe. Scaling that up to a bore of a meter would scale up the power and cooling requirements enormously, and would complicte construction of the magnet coil too.
 

HIMNL9

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^ yes, but also remember that the magnetic field decrease with the square of the distance, not linearly ..... if i recall correctly, that tube where they levitate the frog was 30 or 35 mm diameter, for have like 15 or 16 Tesla in the center ..... and, ofcourse, the mass of the frog was few grams, maybe 3 or 4 grams.

Also, as you've said, the magnetic field gives a force per unit of mass, but is also true that for levitate an object you need to balance the gravitational acceleration with an equal amount of force, and as you probably know, you need to use different force for lift a few grams and for lift, say, 90 Kg, cause if the gravitational acceleration is a constant, the mass of the levitating object change with his weight, so, more it weight (and more it have mass), more magnetic field you need for balance G attraction with the applied force.

Then first you need a magnetic field strong enough for lift the mass of a human body (assume a 90Kg mass for a medium human body weight), so the original magnetic field must be multiplied for that factor (just saying it empirically, say 4Tesla for each gram, you need 360.000 Tesla, for levitate a 90 Kg human body diamagnetically ..... then you need a tube where a human body can stand inside, and this means the coil must be much more large, so need to generate much more magnetic field (considering the strenght decrease with the square of the distance), for have this intensity in the equilibrium point of the coil assembly ..... i see, my estimation was also too much optimistic, you can need much more than 1.000.000 of Tesla, at the end.
 

TTerbo

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....Who is stupid enough to not already know what He was actually doing :p
 
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Benm

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^ yes, but also remember that the magnetic field decrease with the square of the distance, not linearly ..... if i recall correctly, that tube where they levitate the frog was 30 or 35 mm diameter, for have like 15 or 16 Tesla in the center ..... and, ofcourse, the mass of the frog was few grams, maybe 3 or 4 grams.

Also, as you've said, the magnetic field gives a force per unit of mass, but is also true that for levitate an object you need to balance the gravitational acceleration with an equal amount of force, and as you probably know, you need to use different force for lift a few grams and for lift, say, 90 Kg, cause if the gravitational acceleration is a constant, the mass of the levitating object change with his weight, so, more it weight (and more it have mass), more magnetic field you need for balance G attraction with the applied force.

Then first you need a magnetic field strong enough for lift the mass of a human body (assume a 90Kg mass for a medium human body weight), so the original magnetic field must be multiplied for that factor (just saying it empirically, say 4Tesla for each gram, you need 360.000 Tesla, for levitate a 90 Kg human body diamagnetically ..... then you need a tube where a human body can stand inside, and this means the coil must be much more large, so need to generate much more magnetic field (considering the strenght decrease with the square of the distance), for have this intensity in the equilibrium point of the coil assembly ..... i see, my estimation was also too much optimistic, you can need much more than 1.000.000 of Tesla, at the end.

I think i'd have to disagree on that.

Lets consider the device used to lift the frog: It would also lift 2 identical frogs as long as they fit in the bore of the magnet. It would still lift those 2 frogs if you taped them together.

Another thing: They made fame with levitating the frog, but trey tried with various different objects. Those include a strawberry, but also droplets of water. Those droplets would just bounce around in there (as they do in space), and on occasion fuse or split. Regardless of the size of the droplets, they all stayed stationairy in the vertical direction.

The reason a magnet that could lift a man would be bigger, is because it needs a bigger bore. The magnetic fields in Tesla would be equal to that for the frog, but this field would have to cover a lot more area, so the total magnetic flux (in Weber) would have to be larger.

To get some perspective on it: Lets say the bore has to be 20 times the diameter to fit a man in a standing position. Its area would be 400 times that of the frog levitating magnet, and i presume it would therefor take 400 times the energy to maintain the field. Considering the frog levitator used 6 MW of power, that would scale to whopping 2.4 GW, equivalent to the electrical output of a large nuclear plant.
 

HIMNL9

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Uhm, are you sure ? ..... remember that G act on the mass (weight) of the target, and it must be compensated, for levitate it.

And for compensate G attraction on more mass, there's only one way, to apply more force ..... energy, also in form of magnetical force, does not magically appear, you need to apply it in some way ;)
 
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Gravity scales linear with mass, but so does the magnetic force. As Benm stated, put two frogs in (double the mass), and both still levitate in the same field because on both frogs is acting the same force, proportional to the magnetic field. One frog does not suck up the field for the other.
 
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I remember a show on the discovery channel in which the guy talked about these experiments. He said in order to levitate a human, would cost a half billion dollars, and enough power to run a small town.

Boyd Bushman has already created a relatively small device which can levitation a human being by entering within it's directed path. He talks about it here in this interview -
November 4, 2007 — Boyd Bushman | The Paracast

I believe it might involve his patent here-
Apparatus and method for amplifying ... - Google Patent Search


Here he talks about sound levitation-
Boyd Bushman Interview on Vimeo

Corresponding patent..
Thrust producing apparatus - Google Patent Search

This guy is deep in the streets.. :shhh:

Here's another interesting Bushman interview -
 
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HIMNL9

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Gravity scales linear with mass, but so does the magnetic force. As Benm stated, put two frogs in (double the mass), and both still levitate in the same field because on both frogs is acting the same force, proportional to the magnetic field. One frog does not suck up the field for the other.

Uhm, but mass isn't dependent from density/volume report too ? ..... and the density (general density, anyway) in a human body is not the same as in a frog body (that is around 1,03g/cc, almost the same of water), it's bigger (as far as i remember, around 1,4 g/cc), and afaik, density is one of the factors took in the diamagnetic levitation equations too (as density * volume * gravitational acceleration) ..... i never remember equations at mind ..... need to find them somewhere for give exact data ..... anyway, a bigger density still require a stronger field.

So, also if two frogs in the tube can levitate with the same field (cause they have the double of the weight, but also the double of the volume for interact with the field), if you place in the tube something with the same volume of one frog, but with the double of its density (and consequentially the double of its weight to lift with the same volume of a single frog that interact with the field), you need the double of the field strenght, for levitate it, imho .....


EDIT: i realized that i had not exposed it in a correct way, before, mentioning only weight and not also density, giving this as a known fact ..... sorry for that.
 
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density * volume * gravitational acceleration is correct, you know why?
density * volume = mass
whether a frog breathes in or out, magnetism acts on an atomic level, not caring much about the distance between the atoms. It does depend on the magnetic properties of a material, but I'd guess frogs and humans are close enough.
 




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