http://videosift.com/video/Liquid-Helium-And-Party-Balloons
>> ^brycewi19:

I've heard that helium is getting quite expensive. Something about supply being limited.
Wouldn't that have to factor in to the feasibility of this being financially practical?

I'm not going to dive down the rabbit hole of researching this right now, but the wiki page for Helium seems to agree with me (extraction from natural gas is done,
and entertainment balloons aren't noted as a major user.

It does however note that entertainment balloons are a waste made possible by artificially low prices. These artificial low prices for helium grades probably mean many natural gas producers simply vent it away, which will change as the commodity rises in price.

>> ^deathcow:

>> ^bamdrew:
I'm very, very skeptical that party balloon use is the major user of helium gas. Sure, its "wasted" on entertainment, but there are industrial uses for large amounts of helium (MIG welding and such).

ALSO, I was under the assumption that Helium can be pulled down from natural gas production (if there is money in it).

Dunno, think about the MASSES of people with balloons. Sure someone is welding in every city, but balloons are just everywhere.

>> ^bamdrew:

I'm very, very skeptical that party balloon use is the major user of helium gas. Sure, its "wasted" on entertainment, but there are industrial uses for large amounts of helium (MIG welding and such).

ALSO, I was under the assumption that Helium can be pulled down from natural gas production (if there is money in it).


Dunno, think about the MASSES of people with balloons. Sure someone is welding in every city, but balloons are just everywhere.

Your video, Liquid Helium And Party Balloons, has made it into the Top 15 New Videos listing. Congratulations on your achievement. For your contribution you have been awarded 1 Power Point.

Thanks, I'll check it out. Read some stuff about it, it's bizarre. Hope this sheds some light on it.

In reply to this comment by mauz15:
Since you posted http://www.videosift.com/video/Liquid-Helium-II-the-Superfluid-a-Physics-Demonstration I thought this http://www.videosift.com/video/Bose-Einstein-Condensate-The-Coldest-Matter-in-the-Universe would interest you.

Since you posted http://www.videosift.com/video/Liquid-Helium-II-the-Superfluid-a-Physics-Demonstration I thought this http://www.videosift.com/video/Bose-Einstein-Condensate-The-Coldest-Matter-in-the-Universe would interest you.

I found the full version
http://www.videosift.com/video/Liquid-Helium-II-the-Superfluid-a-Physics-Demonstration

Found the full version
http://www.videosift.com/video/Liquid-Helium-II-the-Superfluid-a-Physics-Demonstration

In reply to this comment by Fade:
um...any chance of finding the full version?

It hasn't even been started yet dude. Last time, some super heated mag failed because of a liquid helium leak. We still have a chance to blow ourselves up! heheh


Feb 2009 sometime, though I expect another mishap. It is one of the most complicated machine ever made after all, I would expect several years of kinks.

As an MR researcher, the 'Why don't you just turn off the magnet' complex is a safety issue we battle everyday. It's easy to make mistakes , even if properly trained, because you can't see the magnetic field, and by the time you feel it, it's often too late. Almost every MR researcher I know has had their credit cards wiped (at least once) by forgetting their wallet in their pockets when they go grab something from the MR suite. This case is more serious but luckily it looks as though no one was injured.

To clear things up, clinical MRI's use Superconducting Electromagnets. After installation, the current is slowly ramped up until the desired field strength is reached but they *DO NOT* require additional power to keep them running. There is NO power cord for the magnet and the current will run FOREVER so long as the coil is kept cool enough to remain superconducting (usually using liquid helium as mentioned previously).

An enormous amount of energy is released when a magnet "Quenches" i.e. heats up and becomes non-superconducting. Once the coil has non-zero resistance a ton of heat is generated, the liquid helium boils off, and the coil can expand causing permanent damage to the magnet. Furthermore, when the helium gas boils off it can displace all the oxygen in the room creating another hazard: asphyxiation.

While most systems have a "Quench" button which has been engineered to be as friendly as possible to the magnet, it is a costly and risky maneuver which is reserved for cases when human life is in danger i.e. someone walks in with a non-MRI safe gurney which pins someone to the magnet... It has happened.

The point is, this is not a magnetic field that can switched off easily/cheaply and turned back on quickly/cheaply!!

As for metal implants, it is important to remember not all metals are magnetic, and most implants are made of MRI Safe materials i.e. won't rip out of your skin in the presence of a strong magnetic field. However, most are not "MRI Compatible" meaning they will cause image artifacts in a small area around their location.

MRI is safe, working with humans around an MRI is the dangerous part.

Well charliem, those MRIs are cooled with liquid helium which is quite expensive and it would take some time to warm up and cool down again. this will probably have to be done slowly to prevent fracture.

So, the big silver thing is a dewar. It most likely contains liquid helium.

I am not sure how much NMR has to do with it, but there are NMR based qubits...The decoherence term, which came from NMR, is the same effect, but not actually the same phenomenon that is going on here, I don't think.

Most quantum qubits that I have heard of are made out of low temperature(Type I) superconductors, like niobium. The qubit itself is a Josephson Junction, which is a entirely too long discussion to go into too much detail.

But the basic idea is that if you get two superconductors close together, but separated by an insulator, they will quantum mechanically link. So the state of one describes the state of the other(e.g. entanglement).

*Warning, a more technical explanation is below.

You can exploit this entanglement and by systematically rocking the potential that describes the coupling between the two states with a microwave signal. Eventually you can get the system into the ground state. Now the flux quanta which couples the two systems, exist as discreet energy levels. By injecting that flux into the system, you excite the system into it's first energy eigenstate. At this point the system is effectively described by the Bloch equation. This two state system is your quantum qubit. Which you can use to make calculations, the easiest of which and first test is to factor numbers or seek prime numbers. The problem, as I alluded to earlier, is that as the system evolves in time some of the energy escapes into other energy eigenstates, it is no longer |Q>=a|1>+b|0> but now it is |Q>=a|1>+b|0>+c|2>... and so on. The time the state can be described by |1> and |0> is referred to as the coherence time.

http://en.wikipedia.org/wiki/Josephson_junction
http://en.wikipedia.org/wiki/Quantum_computer

How was that rbar?