cool magnet stuff

[skadistic]

Can someone explain how these work?
http://www.metacafe.com/watch/20901/metal_gun/

And this is just plain cool!:
http://www.metacafe.com/watch/55826/who_can_explain_this/

 

[Perfection]

Can someone explain how these work?
http://www.metacafe.com/watch/20901/metal_gun/

Think of it this way:
before you have this OOOOM and one O really far away
After you have this OOOMO and one O really far away
So this is in effect is transfering the energy gained from moving the farthest one closer to a sphere very far away.

I had a few friends who built one not too long ago.

And this is just plain cool!:
http://www.metacafe.com/watch/55826/who_can_explain_this/

Yeah, that's superconductor crap. The superconductor will mirror the magnetic field keeping it afloat.

 

[Urederra]

It is a pity they have to use liquid nitrogen to make the black piece diamagnetic. What it would be really cool is to reproduce the superconductivity properties at room temperature, that could be one of the most important scientific advances ever.

I wouldn't play with magnets that way, if you dip your finger in liquid nitrogen by accident, then say goodbye to your finger.

 

[Zelig]

I wouldn't play with magnets that way, if you dip your finger in liquid nitrogen by accident, then say goodbye to your finger.

I've seen people splash their fingers through liquid nitrogen, and not lose any of them...

 

[thetrooper]

I've seen people splash their fingers through liquid nitrogen, and not lose any of them...

Yeah, with cryogloves and not for too long...

 

[Bartleby]

I poured N2 down my sleeve once. My Arm didn't fall off or anything but I got a big blister.

 

[CoolioVonHoolio]

this is pretty cool. is there anything else for me to say? no.

 

[Cheezy the Wiz]

magnets are fun. they say that if we CAN create a Fusion reaction, that magnetic fields will play a big part in controlling it or something like that

 

[Urederra]

I believe there is a difference in english between splash, pour and dip, but anyway, I have never had an incident with liquid nitrogen, nor with liquid helium when refilling the NMR. I try to be carefull when handling those things. With solid CO2, on the other hand, I am pretty careless, I hold it with my bare hands.

N2 Splash shouldn't be so bad, nitrogen would evaporate before doing much damage, pour must be more dangerous, dip your finger would be crazy.

 

[MrCynical]

I believe there is a difference in english between splash, pour and dip, but anyway, I have never had an incident with liquid nitrogen, nor with liquid helium when refilling the NMR. I try to be carefull when handling those things. With solid CO2, on the other hand, I am pretty careless, I hold it with my bare hands.

N2 Splash shouldn't be so bad, nitrogen would evaporate before doing much damage, pour must be more dangerous, dip your finger would be crazy.

It is actually possible to stick your finger in liquid nitrogen without injury to yourself. I've seen it done a few times, and I've done it myself once. The liquid nitrogen boils before it actually comes into contact with the skin, and so there's a layer of N2 gas preventing the liquid from coming into direct contact. In effect you get a shield of N2 gas around your finger, thermally insulating it from the liquid. It is inadvisable to leave your finger in there for very long, as this shield isn't perfect and things become rather chilly quite rapidly, but you're in no imminent danger of losing fingers.

Similarly if you spill liquid nitrogen over yourself it's unlikely to do you any real harm unless it's in very large quantities, or something forces the liquid into direct contact with the skin. Spilling it up your sleeve would be dangerous, since the weight of the fabric will force the liquid against your arm, which can cause serious burns.

I'd have thought a similar effect would occur with liquid helium, but I wouldn't try it myself. Helium acts in curious ways, so I certainly wouldn't rely on in acting in the same way as nitrogen. In any case I've never had the opportunity to handle liquid helium, since the closest I've got to it is using NMR spectrometers.

 

[Urederra]

WOW... there are a lot of OT posters who uses NMR spectrometers.