Holy floating mice!

headscratcher4 · 9th September 2009, 03:02 PM

http://news.yahoo.com/s/livescience/...faGVhZGxpbmVfb

Cool.

Dr Adequate · 9th September 2009, 03:40 PM

They've had that for decades, how do you think they faked the moon landings?

Olowkow · 9th September 2009, 07:09 PM

Originally Posted by Dr Adequate

They've had that for decades, how do you think they faked the moon landings?

Dr. A has a knack for repartee that defies comment.

Good grief, now we have the "mousers".

iMaGiNaTioN · 10th September 2009, 05:35 AM

This is amazing, science is awesome.

McHrozni · 10th September 2009, 07:09 AM

Very nice indeed

It would be nice to know how much power such magnets require

McHrozni

quixotecoyote · 10th September 2009, 07:25 AM

That thing says it levitates the water inside tissue. I don't quite get it.

McHrozni · 10th September 2009, 07:27 AM

Originally Posted by quixotecoyote

That thing says it levitates the water inside tissue. I don't quite get it.

Simply put, hydrogen in water is magnetic, and the magnet repulses it. This works on all hydrogen in the body, but the majority of it is in water.

McHrozni

Madalch · 10th September 2009, 02:52 PM

Originally Posted by McHrozni

Simply put, hydrogen in water is magnetic, and the magnet repulses it. This works on all hydrogen in the body, but the majority of it is in water.

McHrozni

Um...no.

Water, like almost all simple molecular compounds with no transition metals, is diamagnetic- this is not a function of containing hydrogen, but a function of having no unpaired electrons. This means it's weakly repelled by a magnetic field (many of us chemists are still scarred from trying to do measurements on a Guoy balance to try to measure the repulsion and thus calculate the number of unpaired electrons in a sample....urgh). Thus, the mouse, frog or strawberry (a Dutch university has had, on their website, clips of levitating frogs and berries for the past five or six years...here: http://www.hfml.ru.nl/levitation-movies.html ), which is mostly diamagnetic compounds (water, carbohydrates, etc) will float away from the magnetic field.

One common material that is paramagnetic is oxygen- if you pour liquid oxygen onto an extremely powerful magnet, it will stick (until it boils away).

McHrozni · 11th September 2009, 12:04 AM

Originally Posted by Madalch

Um...no.

Water, like almost all simple molecular compounds with no transition metals, is diamagnetic- this is not a function of containing hydrogen, but a function of having no unpaired electrons. This means it's weakly repelled by a magnetic field (many of us chemists are still scarred from trying to do measurements on a Guoy balance to try to measure the repulsion and thus calculate the number of unpaired electrons in a sample....urgh). Thus, the mouse, frog or strawberry (a Dutch university has had, on their website, clips of levitating frogs and berries for the past five or six years...here: http://www.hfml.ru.nl/levitation-movies.html ), which is mostly diamagnetic compounds (water, carbohydrates, etc) will float away from the magnetic field.

One common material that is paramagnetic is oxygen- if you pour liquid oxygen onto an extremely powerful magnet, it will stick (until it boils away).

I see. Thanks for the explanation

McHrozni

Madalch · 11th September 2009, 12:26 AM

Originally Posted by McHrozni

I see. Thanks for the explanation
McHrozni

Any time. You were probably thinking of magnetic resonance, which does rely on the magnetic properties of the hydrogen nucleus. But that's a much weaker magnetic property.

McHrozni · 11th September 2009, 12:30 AM

Originally Posted by Madalch

Any time. You were probably thinking of magnetic resonance, which does rely on the magnetic properties of the hydrogen nucleus. But that's a much weaker magnetic property.

In all likelyhood, yes.
It's been years since uni, and I now work much closer to biology than chemistry

McHrozni

sphenisc · 11th September 2009, 08:49 AM

You see, they really are particularly clever hyperintelligent pan-dimensional beings.

BNRT · 11th September 2009, 08:59 AM

Originally Posted by McHrozni

Very nice indeed

It would be nice to know how much power such magnets require

McHrozni

A lot. I once did a high school experiment involving superconductivity using the magnets at the High Field Magnetics Laboratory Madalch mentioned. I've also had a tour there, both are quite some time ago. I think those magnets used a tenth or more of the power of a small city. They used to do the big experiments at night, when electricity was cheaper. I still remember the on switch made quite a loud bang, as it was just a big piece of metal touching another big piece of metal.

The exact numbers were too mind boggling to remember. Also, I think they didn't use superconducting magnets. Just normal coils, with a lot of water pumped through.

Mashuna · 11th September 2009, 09:00 AM

Originally Posted by sphenisc

You see, they really are particularly clever hyperintelligent pan-dimensional beings.

Even cleverer than the dolphins.

quixotecoyote · 11th September 2009, 09:30 AM

Originally Posted by Madalch

Um...no.

Water, like almost all simple molecular compounds with no transition metals, is diamagnetic- this is not a function of containing hydrogen, but a function of having no unpaired electrons. This means it's weakly repelled by a magnetic field (many of us chemists are still scarred from trying to do measurements on a Guoy balance to try to measure the repulsion and thus calculate the number of unpaired electrons in a sample....urgh). Thus, the mouse, frog or strawberry (a Dutch university has had, on their website, clips of levitating frogs and berries for the past five or six years...here: http://www.hfml.ru.nl/levitation-movies.html ), which is mostly diamagnetic compounds (water, carbohydrates, etc) will float away from the magnetic field.

One common material that is paramagnetic is oxygen- if you pour liquid oxygen onto an extremely powerful magnet, it will stick (until it boils away).

Since you seem to know what you're talking about:

When I think of this, I think of the water and oxygen in my (or a mouse's) body being moved and tearing out of the containing tissue leaving a dehydrated corpse with millions of tiny preforations.

Why doesn't that happen?

cwalner · 11th September 2009, 09:37 AM

my favorite line from the article

Quote:

The researchers first levitated a young mouse, just three-week-old and weighing 10 grams. It appeared agitated and disoriented, seemingly trying to hold on to something.

To reference hitchhikers again, this part of the experiment was funded by the IFSWOTPO (Institute for slowly working out the painfully obvious)

Madalch · 11th September 2009, 12:27 PM

Originally Posted by quixotecoyote

Since you seem to know what you're talking about:

When I think of this, I think of the water and oxygen in my (or a mouse's) body being moved and tearing out of the containing tissue leaving a dehydrated corpse with millions of tiny preforations.

Why doesn't that happen?

For one thing, most of the tissue is also diamagnetic, and thus is also repelled by the magnetic field. The only paramagnetic stuff in the body would be dissolved oxygen and some transition metal-containing compounds (a tiny percentage of the body).

For another thing, the short-range intermolecular forces between the water molecules and the molecules surrounding it are a lot stronger than the magnetic forces- you only observe motion due to the magnetic forces because it's the sum of all of them, and they're all pushing in one direction.

If you had a small bag of iron filings, and held a powerful magnet up to it, would you expect the whole bag to lift up and stick to the magnet, or would you expect the iron filings to tear tiny holes in the bag?

RSLancastr · 11th September 2009, 12:31 PM

Squeeeeeeek!

Ziggurat · 11th September 2009, 12:36 PM

Originally Posted by Madalch

Um...no.

Water, like almost all simple molecular compounds with no transition metals, is diamagnetic- this is not a function of containing hydrogen, but a function of having no unpaired electrons.

Close, but not quite. Ordinary diamagnetism applies to every material, whether or not it's got any unpaired electron. If there are any unpaired electrons, the resulting paramagnetic susceptibility is frequently much larger than the diamagnetic susceptibility, but the diamagnetism is still there.

quixotecoyote · 11th September 2009, 01:24 PM

Originally Posted by Madalch

For one thing, most of the tissue is also diamagnetic, and thus is also repelled by the magnetic field. The only paramagnetic stuff in the body would be dissolved oxygen and some transition metal-containing compounds (a tiny percentage of the body).

For another thing, the short-range intermolecular forces between the water molecules and the molecules surrounding it are a lot stronger than the magnetic forces- you only observe motion due to the magnetic forces because it's the sum of all of them, and they're all pushing in one direction.

If you had a small bag of iron filings, and held a powerful magnet up to it, would you expect the whole bag to lift up and stick to the magnet, or would you expect the iron filings to tear tiny holes in the bag?

Thanks. I was imagining a bag of iron filings and lead weights held up to a powerful magnet.

Madalch · 11th September 2009, 01:37 PM

Originally Posted by quixotecoyote

Thanks. I was imagining a bag of iron filings and lead weights held up to a powerful magnet.

But since most of the mass of the living thing is actually water, skip the lead weights.

Soapy Sam · 12th September 2009, 08:13 AM

Surely this is the ultimate "better mousetrap"?
We need upscaling though. The implications for crowd control are entertaining. Imagine a bunch of would-be rioters, floating two feet off the ground...

INRM · 13th September 2009, 09:35 AM

But if you levitated the fluid in someone's eardrums using a magnetic field like that wouldn't they get far more disoriented than if they were in no gravity?

McHrozni · 13th September 2009, 12:50 PM

Originally Posted by BNRT

A lot. I once did a high school experiment involving superconductivity using the magnets at the High Field Magnetics Laboratory Madalch mentioned. I've also had a tour there, both are quite some time ago. I think those magnets used a tenth or more of the power of a small city. They used to do the big experiments at night, when electricity was cheaper. I still remember the on switch made quite a loud bang, as it was just a big piece of metal touching another big piece of metal.

The exact numbers were too mind boggling to remember. Also, I think they didn't use superconducting magnets. Just normal coils, with a lot of water pumped through.

Interesting - do you remember what did that particular magnet do?

McHrozni

Ziggurat · 13th September 2009, 01:10 PM

Originally Posted by INRM

But if you levitated the fluid in someone's eardrums using a magnetic field like that wouldn't they get far more disoriented than if they were in no gravity?

Nope. The fluid in the ear will have a diamagnetic susceptibility very close to that of the body as a whole (both are mostly water), and so will "float" within the ear in a manner very similar to what would happen in free fall.

Ziggurat · 13th September 2009, 01:15 PM

Originally Posted by McHrozni

Very nice indeed

It would be nice to know how much power such magnets require

McHrozni

Superconducting magnets require zero power to maintain a field. It takes power to ramp the field up, but how much depends on how fast you want to ramp the field.

But they do require power, because they require cooling (usually liquid helium) to stay cold. I'm not sure what the refrigeration power requirements would be, but probably not more than a few thousand watts for a closed cycle system, and if it's not closed cycle (just let the helium boil off), then the power wouldn't even be spent at the magnet, but wherever the helium was liquified.

McHrozni · 13th September 2009, 01:28 PM

Originally Posted by Ziggurat

Superconducting magnets require zero power to maintain a field.

Unless the field is required to do actual work - in this case, lifting a mouse - right? That will degrade the field eventually.

McHrozni

Ziggurat · 13th September 2009, 01:37 PM

Originally Posted by McHrozni

Unless the field is required to do actual work - in this case, lifting a mouse - right? That will degrade the field eventually.

No work is required to keep the mouse suspended, any more than work is required for a spring to keep a hanging mass from falling. If the mouse is suspended (ie, stationary), then the displacement is zero, so work (which is force x displacement) is zero as well. Work can be done inserting into or removing the mouse from the field, but not much, on the order of what it would take to lift the mouse into and out of its cage.

CelticRose · 13th September 2009, 01:57 PM

Oh, the images floating through my brain...

(to the tune of the Blue Danube Waltz, of course

)

alexi_drago · 13th September 2009, 02:16 PM

Could this be used as artificial gravity in space?

Audible Click · 13th September 2009, 02:22 PM

Originally Posted by CelticRose

Oh, the images floating through my brain...

(to the tune of the Blue Danube Waltz, of course

)

Now I'm thinking of that movie, the ending was, to me, mysterious. The article about the mice was facinating BTW.

BNRT · 13th September 2009, 04:38 PM

Originally Posted by McHrozni

Interesting - do you remember what did that particular magnet do?

McHrozni

We used it to test what it would take for a superconducting compound (ceramic?) to lose their superconducting properties. I think we went right up to about 20 Tesla.

Ziggurat · 13th September 2009, 11:58 PM

Originally Posted by alexi_drago

Could this be used as artificial gravity in space?

In principle, yes. In practice, no. What determines the net diamagnetic force is not actually the field strength itself, but the field gradient (how quickly it changes). We can get a large enough field gradient over a volume that can hold a mouse, but you'd need a simply ginormous magnet with a far bigger maximum field to get the same gradient over the size of a human body. We can't even do that on earth, let alone aboard a space ship.

McHrozni · 14th September 2009, 03:37 AM

Originally Posted by BNRT

We used it to test what it would take for a superconducting compound (ceramic?) to lose their superconducting properties. I think we went right up to about 20 Tesla.

Ouch

It's no wonder they need a small dedicated power plant for each

McHrozni

BNRT · 14th September 2009, 09:54 AM

They didn't use dedicated power plants. I even believe it recently became too expensive to do much testing. Not sure though.

Ziggurat · 14th September 2009, 10:05 AM

Power is not the limiting factor for high-field steady-state superconducting magnets.

For destructive pulsed magnets (which can reach the highest obtained fields, and are called destructive because the field is so large it rips the magnet itself apart in the process), the pulse power is very large, but the pulse duration is short, so the total energy isn't that huge. You don't need a power plant, what you need are lots and lots of capacitors to store the energy over time and release it very rapidly.

9th September 2009, 03:02 PM	#1
headscratcher4 Philosopher Join Date: Apr 2002 Location: USA Posts: 6,424	Holy floating mice! http://news.yahoo.com/s/livescience/...faGVhZGxpbmVfb Cool.
	__________________ Weaseling out of things is important to learn. It's what separates us from the animals ... except the weasel. -- Homer Simpson

9th September 2009, 07:09 PM	#3
Olowkow Graduate Poster Join Date: Oct 2007 Posts: 1,548	Originally Posted by Dr Adequate They've had that for decades, how do you think they faked the moon landings? Dr. A has a knack for repartee that defies comment. Good grief, now we have the "mousers".
Olowkow Graduate Poster Join Date: Oct 2007 Posts: 1,548	__________________ It's not that I'm so smart, it's just that I stay with problems longer. --Albert Einstein Our remedies oft in ourselves do lie, which we ascribe to heaven. --Shakespeare

10th September 2009, 05:35 AM	#4
iMaGiNaTioN Scholar Join Date: Nov 2007 Posts: 65	This is amazing, science is awesome.
iMaGiNaTioN Scholar Join Date: Nov 2007 Posts: 65

10th September 2009, 07:09 AM	#5
McHrozni Muse Join Date: Jun 2009 Posts: 691	Very nice indeed It would be nice to know how much power such magnets require McHrozni
McHrozni Muse Join Date: Jun 2009 Posts: 691

10th September 2009, 07:25 AM	#6
quixotecoyote Howling to glory I go Join Date: Jun 2006 Posts: 6,300	That thing says it levitates the water inside tissue. I don't quite get it.
	__________________ Ladewig: I'll start worrying about the media's liberal bias the day I hear of labor negotiations described as management demands and union concessions. Thank you for the avatar xkcd.

9th September 2009, 03:40 PM	#2
Dr Adequate Banned Join Date: Aug 2004 Location: Waiting Long Enough By The River Posts: 17,902	They've had that for decades, how do you think they faked the moon landings?

10th September 2009, 07:27 AM	#7
McHrozni Muse Join Date: Jun 2009 Posts: 691	Originally Posted by quixotecoyote That thing says it levitates the water inside tissue. I don't quite get it. Simply put, hydrogen in water is magnetic, and the magnet repulses it. This works on all hydrogen in the body, but the majority of it is in water. McHrozni
McHrozni Muse Join Date: Jun 2009 Posts: 691

10th September 2009, 02:52 PM	#8
Madalch The Jester Join Date: Nov 2006 Location: The wet coast. Posts: 4,810	Originally Posted by McHrozni Simply put, hydrogen in water is magnetic, and the magnet repulses it. This works on all hydrogen in the body, but the majority of it is in water. McHrozni Um...no. Water, like almost all simple molecular compounds with no transition metals, is diamagnetic- this is not a function of containing hydrogen, but a function of having no unpaired electrons. This means it's weakly repelled by a magnetic field (many of us chemists are still scarred from trying to do measurements on a Guoy balance to try to measure the repulsion and thus calculate the number of unpaired electrons in a sample....urgh). Thus, the mouse, frog or strawberry (a Dutch university has had, on their website, clips of levitating frogs and berries for the past five or six years...here: http://www.hfml.ru.nl/levitation-movies.html ), which is mostly diamagnetic compounds (water, carbohydrates, etc) will float away from the magnetic field. One common material that is paramagnetic is oxygen- if you pour liquid oxygen onto an extremely powerful magnet, it will stick (until it boils away).
	__________________ As the size of an explosion increases, the number of social situations it is incapable of resolving approaches zero. -Vaarsuvius Last edited by Madalch; 10th September 2009 at 02:56 PM. Reason: Found the link.

11th September 2009, 12:04 AM	#9
McHrozni Muse Join Date: Jun 2009 Posts: 691	Originally Posted by Madalch Um...no. Water, like almost all simple molecular compounds with no transition metals, is diamagnetic- this is not a function of containing hydrogen, but a function of having no unpaired electrons. This means it's weakly repelled by a magnetic field (many of us chemists are still scarred from trying to do measurements on a Guoy balance to try to measure the repulsion and thus calculate the number of unpaired electrons in a sample....urgh). Thus, the mouse, frog or strawberry (a Dutch university has had, on their website, clips of levitating frogs and berries for the past five or six years...here: http://www.hfml.ru.nl/levitation-movies.html ), which is mostly diamagnetic compounds (water, carbohydrates, etc) will float away from the magnetic field. One common material that is paramagnetic is oxygen- if you pour liquid oxygen onto an extremely powerful magnet, it will stick (until it boils away). I see. Thanks for the explanation McHrozni
McHrozni Muse Join Date: Jun 2009 Posts: 691

11th September 2009, 12:26 AM	#10
Madalch The Jester Join Date: Nov 2006 Location: The wet coast. Posts: 4,810	Originally Posted by McHrozni I see. Thanks for the explanation McHrozni Any time. You were probably thinking of magnetic resonance, which does rely on the magnetic properties of the hydrogen nucleus. But that's a much weaker magnetic property.
	__________________ As the size of an explosion increases, the number of social situations it is incapable of resolving approaches zero. -Vaarsuvius

11th September 2009, 12:30 AM	#11
McHrozni Muse Join Date: Jun 2009 Posts: 691	Originally Posted by Madalch Any time. You were probably thinking of magnetic resonance, which does rely on the magnetic properties of the hydrogen nucleus. But that's a much weaker magnetic property. In all likelyhood, yes. It's been years since uni, and I now work much closer to biology than chemistry McHrozni
McHrozni Muse Join Date: Jun 2009 Posts: 691

11th September 2009, 08:49 AM	#12
sphenisc Master Poster Join Date: Jul 2004 Posts: 2,290	You see, they really are particularly clever hyperintelligent pan-dimensional beings.
sphenisc Master Poster Join Date: Jul 2004 Posts: 2,290

11th September 2009, 08:59 AM	#13
BNRT Scholar Join Date: Jul 2009 Location: The Netherlands Posts: 111	Originally Posted by McHrozni Very nice indeed It would be nice to know how much power such magnets require McHrozni A lot. I once did a high school experiment involving superconductivity using the magnets at the High Field Magnetics Laboratory Madalch mentioned. I've also had a tour there, both are quite some time ago. I think those magnets used a tenth or more of the power of a small city. They used to do the big experiments at night, when electricity was cheaper. I still remember the on switch made quite a loud bang, as it was just a big piece of metal touching another big piece of metal. The exact numbers were too mind boggling to remember. Also, I think they didn't use superconducting magnets. Just normal coils, with a lot of water pumped through.

11th September 2009, 09:00 AM	#14
Mashuna Ovis ex Machina Join Date: Jan 2006 Location: Welsh Wales Posts: 4,122	Originally Posted by sphenisc You see, they really are particularly clever hyperintelligent pan-dimensional beings. Even cleverer than the dolphins.
	__________________ By the time I was 14 I was too smart for my own God. - Terry Pratchett Mashuna, you are the king of all awesomosity - Hokulele

11th September 2009, 09:30 AM	#15
quixotecoyote Howling to glory I go Join Date: Jun 2006 Posts: 6,300	Originally Posted by Madalch Um...no. Water, like almost all simple molecular compounds with no transition metals, is diamagnetic- this is not a function of containing hydrogen, but a function of having no unpaired electrons. This means it's weakly repelled by a magnetic field (many of us chemists are still scarred from trying to do measurements on a Guoy balance to try to measure the repulsion and thus calculate the number of unpaired electrons in a sample....urgh). Thus, the mouse, frog or strawberry (a Dutch university has had, on their website, clips of levitating frogs and berries for the past five or six years...here: http://www.hfml.ru.nl/levitation-movies.html ), which is mostly diamagnetic compounds (water, carbohydrates, etc) will float away from the magnetic field. One common material that is paramagnetic is oxygen- if you pour liquid oxygen onto an extremely powerful magnet, it will stick (until it boils away). Since you seem to know what you're talking about: When I think of this, I think of the water and oxygen in my (or a mouse's) body being moved and tearing out of the containing tissue leaving a dehydrated corpse with millions of tiny preforations. Why doesn't that happen?
	__________________ Ladewig: I'll start worrying about the media's liberal bias the day I hear of labor negotiations described as management demands and union concessions. Thank you for the avatar xkcd.

11th September 2009, 09:37 AM	#16
cwalner Graduate Poster Join Date: Aug 2008 Location: Deepest Darkest Indiana Posts: 1,354	my favorite line from the article Quote: The researchers first levitated a young mouse, just three-week-old and weighing 10 grams. It appeared agitated and disoriented, seemingly trying to hold on to something. To reference hitchhikers again, this part of the experiment was funded by the IFSWOTPO (Institute for slowly working out the painfully obvious)
	__________________ Vecini - Inconceivable! Inigo - You keep on using that word. I do not think it means what you think it means.

11th September 2009, 12:27 PM	#17
Madalch The Jester Join Date: Nov 2006 Location: The wet coast. Posts: 4,810	Originally Posted by quixotecoyote Since you seem to know what you're talking about: When I think of this, I think of the water and oxygen in my (or a mouse's) body being moved and tearing out of the containing tissue leaving a dehydrated corpse with millions of tiny preforations. Why doesn't that happen? For one thing, most of the tissue is also diamagnetic, and thus is also repelled by the magnetic field. The only paramagnetic stuff in the body would be dissolved oxygen and some transition metal-containing compounds (a tiny percentage of the body). For another thing, the short-range intermolecular forces between the water molecules and the molecules surrounding it are a lot stronger than the magnetic forces- you only observe motion due to the magnetic forces because it's the sum of all of them, and they're all pushing in one direction. If you had a small bag of iron filings, and held a powerful magnet up to it, would you expect the whole bag to lift up and stick to the magnet, or would you expect the iron filings to tear tiny holes in the bag?
	__________________ As the size of an explosion increases, the number of social situations it is incapable of resolving approaches zero. -Vaarsuvius

11th September 2009, 12:31 PM	#18
RSLancastr Philosopher www.StopSylvia.com Join Date: Sep 2001 Location: Los Angeles Area Posts: 8,572	Squeeeeeeek!
	__________________ Who is "Kaz?" Read about her at www.StopKaz.com. Curious about Sylvia Browne? Read about her at www.StopSylvia.com. Ever wonder "What's the Harm?" with psychics, alternative medicine, etc?

11th September 2009, 12:36 PM	#19
Ziggurat Penultimate Amazing Join Date: Jun 2003 Posts: 13,873	Originally Posted by Madalch Um...no. Water, like almost all simple molecular compounds with no transition metals, is diamagnetic- this is not a function of containing hydrogen, but a function of having no unpaired electrons. Close, but not quite. Ordinary diamagnetism applies to every material, whether or not it's got any unpaired electron. If there are any unpaired electrons, the resulting paramagnetic susceptibility is frequently much larger than the diamagnetic susceptibility, but the diamagnetism is still there.
	__________________ "There is certainly not one government in Europe but is now watching the war in this country, with the ardent prayer that the united States may be effectually split, crippled, and dismember'd by it... We are all too prone to wander from ourselves, to affect Europe, and watch her frowns and smiles. We need this hot lesson of general hatred, and henceforth must never forget it. Never again will we trust the moral sense nor abstract friendliness of a single government of the world." - Walt Whitman, 1864

11th September 2009, 01:24 PM	#20
quixotecoyote Howling to glory I go Join Date: Jun 2006 Posts: 6,300	Originally Posted by Madalch For one thing, most of the tissue is also diamagnetic, and thus is also repelled by the magnetic field. The only paramagnetic stuff in the body would be dissolved oxygen and some transition metal-containing compounds (a tiny percentage of the body). For another thing, the short-range intermolecular forces between the water molecules and the molecules surrounding it are a lot stronger than the magnetic forces- you only observe motion due to the magnetic forces because it's the sum of all of them, and they're all pushing in one direction. If you had a small bag of iron filings, and held a powerful magnet up to it, would you expect the whole bag to lift up and stick to the magnet, or would you expect the iron filings to tear tiny holes in the bag? Thanks. I was imagining a bag of iron filings and lead weights held up to a powerful magnet.
	__________________ Ladewig: I'll start worrying about the media's liberal bias the day I hear of labor negotiations described as management demands and union concessions. Thank you for the avatar xkcd.

11th September 2009, 01:37 PM	#21
Madalch The Jester Join Date: Nov 2006 Location: The wet coast. Posts: 4,810	Originally Posted by quixotecoyote Thanks. I was imagining a bag of iron filings and lead weights held up to a powerful magnet. But since most of the mass of the living thing is actually water, skip the lead weights.
	__________________ As the size of an explosion increases, the number of social situations it is incapable of resolving approaches zero. -Vaarsuvius

12th September 2009, 08:13 AM	#22
Soapy Sam NLH Join Date: Oct 2002 Posts: 18,092	Surely this is the ultimate "better mousetrap"? We need upscaling though. The implications for crowd control are entertaining. Imagine a bunch of would-be rioters, floating two feet off the ground...
Soapy Sam NLH Join Date: Oct 2002 Posts: 18,092

13th September 2009, 09:35 AM	#23
INRM Illuminator Join Date: Jul 2002 Posts: 3,573	But if you levitated the fluid in someone's eardrums using a magnetic field like that wouldn't they get far more disoriented than if they were in no gravity?
INRM Illuminator Join Date: Jul 2002 Posts: 3,573

13th September 2009, 12:50 PM	#24
McHrozni Muse Join Date: Jun 2009 Posts: 691	Originally Posted by BNRT A lot. I once did a high school experiment involving superconductivity using the magnets at the High Field Magnetics Laboratory Madalch mentioned. I've also had a tour there, both are quite some time ago. I think those magnets used a tenth or more of the power of a small city. They used to do the big experiments at night, when electricity was cheaper. I still remember the on switch made quite a loud bang, as it was just a big piece of metal touching another big piece of metal. The exact numbers were too mind boggling to remember. Also, I think they didn't use superconducting magnets. Just normal coils, with a lot of water pumped through. Interesting - do you remember what did that particular magnet do? McHrozni
McHrozni Muse Join Date: Jun 2009 Posts: 691

13th September 2009, 01:10 PM	#25
Ziggurat Penultimate Amazing Join Date: Jun 2003 Posts: 13,873	Originally Posted by INRM But if you levitated the fluid in someone's eardrums using a magnetic field like that wouldn't they get far more disoriented than if they were in no gravity? Nope. The fluid in the ear will have a diamagnetic susceptibility very close to that of the body as a whole (both are mostly water), and so will "float" within the ear in a manner very similar to what would happen in free fall.
	__________________ "There is certainly not one government in Europe but is now watching the war in this country, with the ardent prayer that the united States may be effectually split, crippled, and dismember'd by it... We are all too prone to wander from ourselves, to affect Europe, and watch her frowns and smiles. We need this hot lesson of general hatred, and henceforth must never forget it. Never again will we trust the moral sense nor abstract friendliness of a single government of the world." - Walt Whitman, 1864

13th September 2009, 01:15 PM	#26
Ziggurat Penultimate Amazing Join Date: Jun 2003 Posts: 13,873	Originally Posted by McHrozni Very nice indeed It would be nice to know how much power such magnets require McHrozni Superconducting magnets require zero power to maintain a field. It takes power to ramp the field up, but how much depends on how fast you want to ramp the field. But they do require power, because they require cooling (usually liquid helium) to stay cold. I'm not sure what the refrigeration power requirements would be, but probably not more than a few thousand watts for a closed cycle system, and if it's not closed cycle (just let the helium boil off), then the power wouldn't even be spent at the magnet, but wherever the helium was liquified.
	__________________ "There is certainly not one government in Europe but is now watching the war in this country, with the ardent prayer that the united States may be effectually split, crippled, and dismember'd by it... We are all too prone to wander from ourselves, to affect Europe, and watch her frowns and smiles. We need this hot lesson of general hatred, and henceforth must never forget it. Never again will we trust the moral sense nor abstract friendliness of a single government of the world." - Walt Whitman, 1864

13th September 2009, 01:28 PM	#27
McHrozni Muse Join Date: Jun 2009 Posts: 691	Originally Posted by Ziggurat Superconducting magnets require zero power to maintain a field. Unless the field is required to do actual work - in this case, lifting a mouse - right? That will degrade the field eventually. McHrozni
McHrozni Muse Join Date: Jun 2009 Posts: 691

13th September 2009, 01:37 PM	#28
Ziggurat Penultimate Amazing Join Date: Jun 2003 Posts: 13,873	Originally Posted by McHrozni Unless the field is required to do actual work - in this case, lifting a mouse - right? That will degrade the field eventually. No work is required to keep the mouse suspended, any more than work is required for a spring to keep a hanging mass from falling. If the mouse is suspended (ie, stationary), then the displacement is zero, so work (which is force x displacement) is zero as well. Work can be done inserting into or removing the mouse from the field, but not much, on the order of what it would take to lift the mouse into and out of its cage.
	__________________ "There is certainly not one government in Europe but is now watching the war in this country, with the ardent prayer that the united States may be effectually split, crippled, and dismember'd by it... We are all too prone to wander from ourselves, to affect Europe, and watch her frowns and smiles. We need this hot lesson of general hatred, and henceforth must never forget it. Never again will we trust the moral sense nor abstract friendliness of a single government of the world." - Walt Whitman, 1864

13th September 2009, 01:57 PM	#29
CelticRose Muse Join Date: May 2009 Location: Mesa, AZ Posts: 555	Oh, the images floating through my brain... (to the tune of the Blue Danube Waltz, of course )
	__________________ Be who you are & say what you feel, because those who mind don't matter & those who matter don't mind. - Dr. Seuss I yam what I yam. - Popeye Be yourself no matter what they say. - Sting

13th September 2009, 02:16 PM	#30
alexi_drago Muse Join Date: Oct 2006 Posts: 503	Could this be used as artificial gravity in space?
alexi_drago Muse Join Date: Oct 2006 Posts: 503	__________________ Thank you for flying Delta Business Express. We hope you enjoyed giving us the business as much as we enjoyed taking you for a ride. Remember, nobody loves you, or your money, more than Delta.

13th September 2009, 02:22 PM	#31
Audible Click The gap in the plot Join Date: Jul 2008 Location: BFE Posts: 2,037	Originally Posted by CelticRose Oh, the images floating through my brain... (to the tune of the Blue Danube Waltz, of course ) Now I'm thinking of that movie, the ending was, to me, mysterious. The article about the mice was facinating BTW.
	__________________ A great many people think they are thinking when they are merely rearranging their prejudices.-William James. www.StopVisionFromFeeling.com

13th September 2009, 04:38 PM	#32
BNRT Scholar Join Date: Jul 2009 Location: The Netherlands Posts: 111	Originally Posted by McHrozni Interesting - do you remember what did that particular magnet do? McHrozni We used it to test what it would take for a superconducting compound (ceramic?) to lose their superconducting properties. I think we went right up to about 20 Tesla.

13th September 2009, 11:58 PM	#33
Ziggurat Penultimate Amazing Join Date: Jun 2003 Posts: 13,873	Originally Posted by alexi_drago Could this be used as artificial gravity in space? In principle, yes. In practice, no. What determines the net diamagnetic force is not actually the field strength itself, but the field gradient (how quickly it changes). We can get a large enough field gradient over a volume that can hold a mouse, but you'd need a simply ginormous magnet with a far bigger maximum field to get the same gradient over the size of a human body. We can't even do that on earth, let alone aboard a space ship.
	__________________ "There is certainly not one government in Europe but is now watching the war in this country, with the ardent prayer that the united States may be effectually split, crippled, and dismember'd by it... We are all too prone to wander from ourselves, to affect Europe, and watch her frowns and smiles. We need this hot lesson of general hatred, and henceforth must never forget it. Never again will we trust the moral sense nor abstract friendliness of a single government of the world." - Walt Whitman, 1864

14th September 2009, 03:37 AM	#34
McHrozni Muse Join Date: Jun 2009 Posts: 691	Originally Posted by BNRT We used it to test what it would take for a superconducting compound (ceramic?) to lose their superconducting properties. I think we went right up to about 20 Tesla. Ouch It's no wonder they need a small dedicated power plant for each McHrozni
McHrozni Muse Join Date: Jun 2009 Posts: 691

14th September 2009, 09:54 AM	#35
BNRT Scholar Join Date: Jul 2009 Location: The Netherlands Posts: 111	They didn't use dedicated power plants. I even believe it recently became too expensive to do much testing. Not sure though.