Safety warning?!!! ;)

[Don Klipstein]

In article <9jek40dggabd98d8k47nj5o20ovmpt4g2q@4ax.com>, DarkMatter wrote:

On 4 Mar 2004 19:37:27 GMT, "Walter Harley"
walterh@cafewalterNOSPAM.com> Gave us:

"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:bbre409vedrcika1fmv4cda081cqplbo5f@4ax.com...
The 1.4 megagauss number is absurd; kilogauss, maybe. I seriously
doubt the part about separating the iron out from one's blood, too;
superconductive MRI magnets are far more powerful than any PM can ever
be, and have no such problems.

They're also farther away. Inverse cube law, right?

No. Magnetic flux dissipates at the square of the distance.

But "pull" on small objects is the derivitive (with respect to position)
of the sqaure of flux, and that normally falls off faster than
inverse-square of distance from the source.

- Don Klipstein (don@misty.com)

 

[John Larkin]

On Sun, 7 Mar 2004 04:55:35 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:

(Oh, need I repeat - whatever "magnetic sense of direction" I actually
have/had, to whatever extent it actually exists, had damage from DC
magnetic fields nonexistent enough or short-term enough for me to newly
suffer impairment of such a "sense of direction" every time that I
delivered to the buildings in question!)

I sometimes meet with people in a conference room that has a chain of
paper clips that stick to one wall and protrude into the room about 45
degrees from the vertical. There's an NMR magnet in the adjacent room,
and all the furniture is wood.

John

 

[Don Klipstein]

In article <YG0z3KFPMlSAFw4o@jmwa.demon.co.uk>, John Woodgate wrote:

I read in sci.electronics.design that DarkMatter <DarkMatter@thebaratthe
endoftheuniverse.org> wrote (in <scek40d33f7b9cuq49mpmouejm9cic1ppn@4ax.
com&gt about 'Safety warning?!!! ', on Sat, 6 Mar 2004:

Does anyone here even know where the
iron molecules are in the bloodstream?

In the middle of each haemoglobin molecule. I can't remember the
oxidation state (2?), but I doubt that it has an unpaired electron, so
presumably no magnetic moment.

I think iron in its "+2" oxidation state (which I think is what
hemoglobin has) has its two easiest-to-grab electrons (from the 4s
subshell, and an s subshell only has two) grabbed. Makes no difference
from iron in a zero oxidation state. Either way, iron has 3 unpaired
electrons in its "3d" subshell (if I get it right).
What matters is paramagnetic vs. ferromagnetic. Iron is ferromagnetic
if not diluted too much, and if diluted much (as in most of its compounds)
it is paramagnetic.
The difference is that "paramagnetic" materials have a permeability only
a fraction of a percent greater than that of vacuum, while "ferromagnetic"
materials have permeability in the 10's to 100,000's that of a vacuum
along with nonlinearity and a tendency to "saturate" at field intensities
in or near the .2-2 Tesla range.
I suspect that hemoglobin is paramagnetic, and I suspect that as a
result magnets have some very slight, requiring extreme conditions to
measure, pull on hemoglobin molecules that I would expect to be a
similarly slight pull on entire red blood cells.
I expect a more extreme case on magnetic field pulling on red blood
cells would be within a couple millimeters of smaller rare earth magnets,
as opposed to just outside the cavity of an MRI unit where the field
gradient is much lower even though the field intensity is similar or
somewhat greater. Also, I expect pull on red blood cells to be comparable
to or less than that on similar size particles of copper sulfate (a
notably paramagnetic compund) - which is not much! Paramagnetism tends to
involve permeability being in the general ballpark of around a hundredth
of a percent to a few hundredths of a percent greater than that of a
vacuum!

As for people having a "sense of direction" that is based magnetically
and screwed up when near an MRI unit: That would be due to ferromagnetic
iron particles postulated to exist in special sensors in such
postulations, as opposed to hemoglobin or anything else known to exist in
the human body for any reason other than this! (I have heard of birds
being "screwed up" by having magnets attached to their heads - this is
some but maybe not conclusive evidence that at least some animals have
some sort of "magnetic compass" that I believe relies on some special
sensor in the head relying on maybe these postulated special ferromagnetic
particles.)
(FURTHERMORE - I have worked a job as bicycle messenger and delivered to
places with MRI units and places having steel beams trucked into "the
location" via streets adjacent to MRI units. I have sensed a "screwing
up" of my "sense of direction" when I delivered to these places. But such
a screwup, if it actually happened, is not some permanent or long term
damage [maybe no damage at all] to any "magnetic sense of direction" that
I have, since it happens newly all over again when I deliver again to such
places!)
(Yes, I did take along a compass that I pulled out of my pocket to look
at when I got to a location where I usually made a wrong turn. An
alternative hypothesis is that where I often made the "wrong turn"
navigating the building in question, most hallways were at 45 degree
angles to the streets. The compass did indeed turn two full rotations in
2-4 meters (7-13 feet) as I walked through a region where I was prone to
making wrong turns. I do admit that this is merely a bit of evidence, not
conclusive proof of one hypothesis over another, and even maybe a little
short of being substantial enough to elevate one hypothesis and not
another to the level of "theory".)
(Oh, need I repeat - whatever "magnetic sense of direction" I actually
have/had, to whatever extent it actually exists, had damage from DC
magnetic fields nonexistent enough or short-term enough for me to newly
suffer impairment of such a "sense of direction" every time that I
delivered to the buildings in question!)

- Don Klipstein (don@misty.com)

 

[Don Klipstein]

In art. <c2dqr1$1s9193$1@ID-193109.news.uni-berlin.de>, Ray Drouillard wrote:

"DarkMatter" <DarkMatter@thebarattheendoftheuniverse.org> wrote in
message news:scek40d33f7b9cuq49mpmouejm9cic1ppn@4ax.com...
On Thu, 04 Mar 2004 09:57:30 -0800, John Larkin
jjlarkin@highSNIPlandTHIStechPLEASEnology.com> Gave us:

On 4 Mar 2004 05:36:25 -0800, billb@eskimo.com (William J. Beaty)
wrote:

A bit of humor:

1.5" supermagnet : safety sheet
http://www.houseofscience.com/ouch/ouch.html

The 1.4 megagauss number is absurd; kilogauss, maybe. I seriously
doubt the part about separating the iron out from one's blood, too;
superconductive MRI magnets are far more powerful than any PM can ever
be, and have no such problems. And no small magnet is going to affect
a color TV from three feet away.

This guy sounds like a fathead, hardly a humorist.

We are working on a single pass PET scanner with Philips that makes
an image in a single pass under the detector array, as opposed to the
older method of making passes for each detector cell.

One's blood does not separate. Does anyone here even know where the
iron molecules are in the bloodstream?

The iron atoms are part of the hemoglobin molecule. Hemoglobin is used
inside the red blood cells.

Interestingly enough, hemoglobin is similar in structure to chlorophyll.
Chlorophyll is built around a different metal, however. I can't
remember if it's Mn or Mg. I think it's Mg.
Ray Drouillard

Chlorophyll is built around Mn or maybe Cr, definitely not Mg.

I do remember that chlorophyll is similar to hemoglobin, and different
from hemoglobin mostly by being built not around Fe but around a nearby
metal on the periodic table.

Also note: There are two types of chlorophyll. Biggest difference:
ability to utilize wavelengths of red light around 675-695 or maybe
680-700 nm. One but not the other is good for a roughly 200 nm wide range
around 680-690 nm. Both are good at utilizing wavelengths in the
mid-600's and maybe low 600's, as in wavelengths red or reddish and about
670 nm or shorter but red/reddish (low-mid 600's nm). Neither is good at
utilizing wavelengths much above 700 nm.

- Don Klipstein (don@misty.com)

 

[John Woodgate]

I read in sci.electronics.design that Uncle Al <UncleAl0@hate.spam.net>
wrote (in <404A66F9.59B9D937@hate.spam.net&gt about 'Safety warning?!!!
', on Sat, 6 Mar 2004:

Christ... nobody is keeping it a secret.

I didn't imagine it was, but I don't have your expertise in
biochemistry.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[John Woodgate]

I read in sci.electronics.design that Don Klipstein <don@manx.misty.com>
wrote (in <slrnc4lcnj.n9g.don@manx.misty.com&gt about 'Safety warning?!!!
', on Sun, 7 Mar 2004:

Chlorophyll is built around Mn or maybe Cr, definitely not Mg.

Check your facts. You *usually* get things right.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Phantom]

On Sun, 7 Mar 2004 05:28:19 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:

In art. <c2dqr1$1s9193$1@ID-193109.news.uni-berlin.de>, Ray Drouillard wrote:

"DarkMatter" <DarkMatter@thebarattheendoftheuniverse.org> wrote in
message news:scek40d33f7b9cuq49mpmouejm9cic1ppn@4ax.com...
On Thu, 04 Mar 2004 09:57:30 -0800, John Larkin
jjlarkin@highSNIPlandTHIStechPLEASEnology.com> Gave us:

On 4 Mar 2004 05:36:25 -0800, billb@eskimo.com (William J. Beaty)
wrote:

A bit of humor:

1.5" supermagnet : safety sheet
http://www.houseofscience.com/ouch/ouch.html

The 1.4 megagauss number is absurd; kilogauss, maybe. I seriously
doubt the part about separating the iron out from one's blood, too;
superconductive MRI magnets are far more powerful than any PM can ever
be, and have no such problems. And no small magnet is going to affect
a color TV from three feet away.

This guy sounds like a fathead, hardly a humorist.

We are working on a single pass PET scanner with Philips that makes
an image in a single pass under the detector array, as opposed to the
older method of making passes for each detector cell.

One's blood does not separate. Does anyone here even know where the
iron molecules are in the bloodstream?

The iron atoms are part of the hemoglobin molecule. Hemoglobin is used
inside the red blood cells.

Interestingly enough, hemoglobin is similar in structure to chlorophyll.
Chlorophyll is built around a different metal, however. I can't
remember if it's Mn or Mg. I think it's Mg.
Ray Drouillard

Chlorophyll is built around Mn or maybe Cr, definitely not Mg.

It is, in fact, magnesium.
See: http://en.wikipedia.org/wiki/Chlorophyll

I do remember that chlorophyll is similar to hemoglobin, and different
from hemoglobin mostly by being built not around Fe but around a nearby
metal on the periodic table.

Also note: There are two types of chlorophyll. Biggest difference:
ability to utilize wavelengths of red light around 675-695 or maybe
680-700 nm. One but not the other is good for a roughly 200 nm wide range
around 680-690 nm. Both are good at utilizing wavelengths in the
mid-600's and maybe low 600's, as in wavelengths red or reddish and about
670 nm or shorter but red/reddish (low-mid 600's nm). Neither is good at
utilizing wavelengths much above 700 nm.

- Don Klipstein (don@misty.com)

 

[Uncle Al]

John Larkin wrote:

On Sat, 06 Mar 2004 16:04:09 -0800, Uncle Al <UncleAl0@hate.spam.net
wrote:


OTOH, intense high divergence magnetic fields have a distinct affect
upon mental function. There is a old (magnet poorly shielded)
multi-nuclear 360 MHz NMR in the basement of the UVic chemistry
building. One must bloody crawl under the supercon magnet with one's
head pushing against the bottom of the armored dewar to get at the
probe switchbox for changing nuclei. That is the field divergence
sweet spot. Everybody who goes underneath comes up giggling - even
the flesh-eating NMR lady. Uncle Al was careful never to be checked
out on that machine.

Maybe it's the helium boiloff that got'em. Or maybe there's a really
good Dilbert pasted to the bottom of the dewar.

I'll ask my buddies at Varian NMR if the magnets make them goofy;
they've got 900 MHz magnets with spiral staircases wrapped around the
outside.

Won't do it. Modern magnets are actively and passively shielded. It
only works at the sweet spots - maximum field divergence at the top
and bottom of the solenoid. The 360 MHz magnet in particular was
poorly designed in this regard. It is the same magnet that an Eastern
European emigree char lady pushed a steel mopehead under. WHAM!!!!
The gal went into hysterics. The the NMR lady had to unpower the
magnet to get the mop loose, repower, and wait a week for it to
stabilize. She went into hysterics, too. The side field is less than
100 gauss and flat.

Now in addition to a whole door covered with warnings in every obscure
language from Pashto to Quebecois to Tagalog (Canukistan only has 50
White people, and they pay all the taxes), the janitorial staff is
excluded.

If you Google it, the hot new anti-depression treatment is pulsing
brains with high divergence magnetic fields. Uncle Al is a
traditionalist - either chromed hammers whacking a depressed head or
gold-plated icepicks lobotomizing the uninterestingly unpleasant.

--
Uncle Al
http://www.mazepath.com/uncleal/qz.pdf
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)

 

[Uncle Al]

Don Klipstein wrote:

In art. <c2dqr1$1s9193$1@ID-193109.news.uni-berlin.de>, Ray Drouillard wrote:

"DarkMatter" <DarkMatter@thebarattheendoftheuniverse.org> wrote in
message news:scek40d33f7b9cuq49mpmouejm9cic1ppn@4ax.com...
On Thu, 04 Mar 2004 09:57:30 -0800, John Larkin
jjlarkin@highSNIPlandTHIStechPLEASEnology.com> Gave us:

On 4 Mar 2004 05:36:25 -0800, billb@eskimo.com (William J. Beaty)
wrote:

A bit of humor:

1.5" supermagnet : safety sheet
http://www.houseofscience.com/ouch/ouch.html

The 1.4 megagauss number is absurd; kilogauss, maybe. I seriously
doubt the part about separating the iron out from one's blood, too;
superconductive MRI magnets are far more powerful than any PM can ever
be, and have no such problems. And no small magnet is going to affect
a color TV from three feet away.

This guy sounds like a fathead, hardly a humorist.

We are working on a single pass PET scanner with Philips that makes
an image in a single pass under the detector array, as opposed to the
older method of making passes for each detector cell.

One's blood does not separate. Does anyone here even know where the
iron molecules are in the bloodstream?

The iron atoms are part of the hemoglobin molecule. Hemoglobin is used
inside the red blood cells.

Interestingly enough, hemoglobin is similar in structure to chlorophyll.
Chlorophyll is built around a different metal, however. I can't
remember if it's Mn or Mg. I think it's Mg.
Ray Drouillard

Chlorophyll is built around Mn or maybe Cr, definitely not Mg.

[snip]

Magnesium, Mg(II).

--
Uncle Al
http://www.mazepath.com/uncleal/qz.pdf
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)

 

[Uncle Al]

John Larkin wrote:

On Sun, 7 Mar 2004 02:00:12 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:

The main magnetic field is achieved with a supercunducting
electromagnet.

And by the way, do not ever hit one of those emergency shutoff switches
for the main magnetic field unless there is some real emergency requiring
this. I am under the impression that restoring the main magnetic field
involves more than just moving that switch back to its normal position,
and that the main magnetic field is not turned off for nights, weekends,
holidays, or whatever.

The field persists as long as the magnet stays cold; no power supply
is needed.

If it quenches, a lot of helium will boil out pronto. It will have to
be refilled with liquid nitrogen and liquid helium, and it will have
to be recharged with a power supply. The charging supplies are usually
brought in, and are not kept on site.

Liquid helium has no specific heat. If a supercon magnet quenches it

is auto-dumped into sacrficial resistor bank to collapse the field in
a quick ramp. If the magnet died and the field collasped all at once,
yu'd ave to clear shrapnel and rebuild the room.

Repowering is no big deal, but it takes a few days to a week to
stabilize good enough for NMR or MRI specs.

[snip]

My wife had an MRI when she had braces on her teeth. The MRI was
almost useless, terribly distorted, but she didn't have any associated
discomfort. She got them removed and it worked better.

The field inside the bore is flat to ppm or better. The field at the
ends is highly divergent and very dangerous for sucking in
ferromagnetics (Canadian nickels are nasty). Transition metal oxides
used in traditional tattoo pigments are sufficiently paramagnetic to
ruin MRIs. Nipple rings can be interesting with the modulated RF
field. Break the conducting ring with a dielectric bead or wear
barbells. Wear plastic.

--
Uncle Al
http://www.mazepath.com/uncleal/qz.pdf
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)

 

[Uncle Al]

John Woodgate wrote:

I read in sci.electronics.design that Uncle Al <UncleAl0@hate.spam.net
wrote (in <404A66F9.59B9D937@hate.spam.net&gt about 'Safety warning?!!!
', on Sat, 6 Mar 2004:

Christ... nobody is keeping it a secret.

I didn't imagine it was, but I don't have your expertise in
biochemistry.

5 credits of Moo U Biochem at 0800 hrs winter term. I am scarred for
life.

--
Uncle Al
http://www.mazepath.com/uncleal/qz.pdf
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)

 

[John Larkin]

On Sun, 07 Mar 2004 08:59:43 -0800, Uncle Al <UncleAl0@hate.spam.net>
wrote:

John Larkin wrote:

On Sat, 06 Mar 2004 16:04:09 -0800, Uncle Al <UncleAl0@hate.spam.net
wrote:


OTOH, intense high divergence magnetic fields have a distinct affect
upon mental function. There is a old (magnet poorly shielded)
multi-nuclear 360 MHz NMR in the basement of the UVic chemistry
building. One must bloody crawl under the supercon magnet with one's
head pushing against the bottom of the armored dewar to get at the
probe switchbox for changing nuclei. That is the field divergence
sweet spot. Everybody who goes underneath comes up giggling - even
the flesh-eating NMR lady. Uncle Al was careful never to be checked
out on that machine.

Maybe it's the helium boiloff that got'em. Or maybe there's a really
good Dilbert pasted to the bottom of the dewar.

I'll ask my buddies at Varian NMR if the magnets make them goofy;
they've got 900 MHz magnets with spiral staircases wrapped around the
outside.

Won't do it. Modern magnets are actively and passively shielded. It
only works at the sweet spots - maximum field divergence at the top
and bottom of the solenoid. The 360 MHz magnet in particular was
poorly designed in this regard. It is the same magnet that an Eastern
European emigree char lady pushed a steel mopehead under. WHAM!!!!
The gal went into hysterics. The the NMR lady had to unpower the
magnet to get the mop loose, repower, and wait a week for it to
stabilize. She went into hysterics, too. The side field is less than
100 gauss and flat.

They do have some 500 MHz unshielded magnets, and you have to crawl
around underneath and grunt a lot to change or tune a probe. I'll ask.
Better yet, maybe they'll let me try it.

Now in addition to a whole door covered with warnings in every obscure
language from Pashto to Quebecois to Tagalog (Canukistan only has 50
White people, and they pay all the taxes), the janitorial staff is
excluded.

All the folks who work in NMR use expensive beryllium copper tools and
leave their wallets in their offices. I'd guess an NMR facility is a
pickpocket's paradise. All the scopes and monitors are now LCDs, as
the CRT displays were always twisted and weird colors. Relays are a
problem sometimes too... they pull in once.

If you Google it, the hot new anti-depression treatment is pulsing
brains with high divergence magnetic fields. Uncle Al is a
traditionalist - either chromed hammers whacking a depressed head or
gold-plated icepicks lobotomizing the uninterestingly unpleasant.

If it's all the same to you, I'll stick to coffee and chocolate. I
like my meds to taste good.

John

 

[William J. Beaty]

Uncle Al <UncleAl0@hate.spam.net> wrote in message news:<40475AB2.E5643DD@hate.spam.net>...

Why would one fabricate a rare earth dipole magnet as sphere?

No earthly reason. But the guys at wondermagnet.com had some small
spheres made up.

They sold. You can form them into little chains. Then they started
selling large 3/4 inch supermagnet spheres. A discovery! While two
cylindrical 0.75" supermagnets, if they slam together, will grab
the edges of finger tips and leave blood blisters, the spheres tend
to push the flesh out of the way as they come together. ALso, two
cylinders will spall off little chips which travel at eye-piercing
velocity, while the spheres do this only rarely. Sometimes the
cylinder magnets even shatter. The spheres never do (not so far
as I've experienced, and I have lots them here.)

So now an unskilled adult can play with the larger supermagnets
without experiencing unexpected violent pain. Don't worry, it
still takes plenty of skill to handle the 1.5" spheres. Even the
experts have scars and stitches. Don't leave them out on your desk,
or you'll be performing some inadvertant Selection upon curious
passersby. Plus erasing all their credit card stripes. I leave
mine stuck to a nitrogen cylinder chained to the wall. Most
people can't even figure out how to pull them loose.


Then the guy at engconcepts.net started selling 3/8" supermagnet
beads at very low quantity prices (like $.30 each.)

The things are VERY COOL in quantity. Long chains of them act
like biology: rings will merge or peel apart like bacterial plasmids.
You can spiral the chains up to make spiral-phase nanotubes or tobacco
mosaic viruses. Take 60 beads, make twelve rings of 5 magnets each,
then merge them into a pseudo-buckyball (4 bonds per atom, with
squares instead of hexagons!) SOmeone needs to make some beads
with quadrupole magnetization rather than dipole, so true buckyballs
can easily be made.

After a couple of hours I was able to simulate a buckyball orgin:
two hemispheres of 30 magnets each, which when brought together will
suddenly knit up into a 'buckyball' (and entrap any ions which happen
to get between 'em. Always wondered how that occurred.)

The girlfriend likes chains of alternating gold and black beads.
Make nice looking spiral-wrap bracelets, *or* play with dipole-chain
pseudo-biomolecules when bored at work.

It's a great price for the big one! The obvious thing to do is to order
two and see how the pair is shipped. Kinda hard to envision a "keeper"
to lessen field decay/time.

Put them in a thick styrofoam box. The fields at the box surface are
low. Then wrap the box in thin iron sheets. The iron doesn't
saturate. Or, if you bought a bunch of the things, they can be
shipped formed into a ring where the field is internal to the ring
and only 'leakage' fields escape. A single enormous magnet is
harder to ship. Two of them can be rotated oppositely to mostly
eliminate the distant dipole field.

"House of science" supermagnets (note the 1.5" sphere)
http://www.houseofscience.com/is/mag/mag/mag.html

"Force field" supermagnets
http://www.wondermagnet.com

"Mr. George" supermagnets
http://www.engconcepts.net/



(((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))
William J. Beaty SCIENCE HOBBYIST website
billb@eskimo.com http://amasci.com
EE/programmer/sci-exhibits amateur science, hobby projects, sci fair
Seattle, WA 206-789-0775 unusual phenomena, tesla coils, weird sci

 

[John Larkin]

On Sun, 07 Mar 2004 09:08:33 -0800, Uncle Al <UncleAl0@hate.spam.net>
wrote:

Liquid helium has no specific heat.

Huh?

John

 

[Spehro Pefhany]

On 7 Mar 2004 11:14:02 -0800, the renowned billb@eskimo.com (William
J. Beaty) wrote:

Put them in a thick styrofoam box. The fields at the box surface are
low. Then wrap the box in thin iron sheets. The iron doesn't
saturate. Or, if you bought a bunch of the things, they can be
shipped formed into a ring where the field is internal to the ring
and only 'leakage' fields escape. A single enormous magnet is
harder to ship. Two of them can be rotated oppositely to mostly
eliminate the distant dipole field.

For mail, magnets are included in USPS Pub 52, Hazardous, Restricted
and Perishable mail.

http://www.usps.com/cpim/ftp/pubs/pub52.pdf

See: USPS Packaging Instruction 9B (page 328)

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Uncle Al]

"William J. Beaty" wrote:

Uncle Al <UncleAl0@hate.spam.net> wrote in message news:<40475AB2.E5643DD@hate.spam.net>...

Why would one fabricate a rare earth dipole magnet as sphere?

No earthly reason. But the guys at wondermagnet.com had some small
spheres made up.

They sold. You can form them into little chains. Then they started
selling large 3/4 inch supermagnet spheres. A discovery! While two
cylindrical 0.75" supermagnets, if they slam together, will grab
the edges of finger tips and leave blood blisters, the spheres tend
to push the flesh out of the way as they come together. ALso, two
cylinders will spall off little chips which travel at eye-piercing
velocity, while the spheres do this only rarely. Sometimes the
cylinder magnets even shatter. The spheres never do (not so far
as I've experienced, and I have lots them here.)

So now an unskilled adult can play with the larger supermagnets
without experiencing unexpected violent pain. Don't worry, it
still takes plenty of skill to handle the 1.5" spheres. Even the
experts have scars and stitches. Don't leave them out on your desk,
or you'll be performing some inadvertant Selection upon curious
passersby. Plus erasing all their credit card stripes. I leave
mine stuck to a nitrogen cylinder chained to the wall. Most
people can't even figure out how to pull them loose.

Then the guy at engconcepts.net started selling 3/8" supermagnet
beads at very low quantity prices (like $.30 each.)

The things are VERY COOL in quantity. Long chains of them act
like biology: rings will merge or peel apart like bacterial plasmids.
You can spiral the chains up to make spiral-phase nanotubes or tobacco
mosaic viruses. Take 60 beads, make twelve rings of 5 magnets each,
then merge them into a pseudo-buckyball (4 bonds per atom, with
squares instead of hexagons!) SOmeone needs to make some beads
with quadrupole magnetization rather than dipole, so true buckyballs
can easily be made.

After a couple of hours I was able to simulate a buckyball orgin:
two hemispheres of 30 magnets each, which when brought together will
suddenly knit up into a 'buckyball' (and entrap any ions which happen
to get between 'em. Always wondered how that occurred.)

The girlfriend likes chains of alternating gold and black beads.
Make nice looking spiral-wrap bracelets, *or* play with dipole-chain
pseudo-biomolecules when bored at work.

It's a great price for the big one! The obvious thing to do is to order
two and see how the pair is shipped. Kinda hard to envision a "keeper"
to lessen field decay/time.

Put them in a thick styrofoam box. The fields at the box surface are
low. Then wrap the box in thin iron sheets. The iron doesn't
saturate. Or, if you bought a bunch of the things, they can be
shipped formed into a ring where the field is internal to the ring
and only 'leakage' fields escape. A single enormous magnet is
harder to ship. Two of them can be rotated oppositely to mostly
eliminate the distant dipole field.

"House of science" supermagnets (note the 1.5" sphere)
http://www.houseofscience.com/is/mag/mag/mag.html

"Force field" supermagnets
http://www.wondermagnet.com

"Mr. George" supermagnets
http://www.engconcepts.net/

"Ultimate Ring Magnets - 4.25" OD - Nickel Plated N45 - 1.75 inch ID
and 0.70 inch thick - these will seriously crush body parts that get
between two of them." $125.00 each

Oh god oh god oh god oh god oh god oh god! With things like that in
the univesre, how can anybody commit suicide? You cannot have an
atomic nucleus of Z larger than the Fine Structure Constant reciprocal
because it would spark the vacuum and inverse beta-decays. There is
no limit to how intense a magnetic field can be obtained. BRING IT
ON!

--
Uncle Al
http://www.mazepath.com/uncleal/qz.pdf
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)

 

[Uncle Al]

John Larkin wrote:

On Sun, 07 Mar 2004 09:08:33 -0800, Uncle Al <UncleAl0@hate.spam.net
wrote:

Liquid helium has no specific heat.

Huh?

You've never transferred liquid heium.

http://hyperphysics.phy-astr.gsu.edu/hbase/imgmod/helambda.gif

For He gas,

Cp=5.193 J/g-K

For liquid He,

T, K Cp, J/g-K
----------------
4.5 4.9
4.0 3.8
3.5 3.0
3.0 2.5
2.5 2.2

/_\Hvap of He is 20 J/g-K.
/_\Hvap of H2O is 2257 J/g-K.

If you add a little heat to liquid He bathing a supercon magnet, you
get an explosion of gas.

--
Uncle Al
http://www.mazepath.com/uncleal/qz.pdf
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)

 

[Don Klipstein]

In article <dvuidgAlTtSAFwat@jmwa.demon.co.uk>, John Woodgate wrote:

I read in sci.electronics.design that Don Klipstein <don@manx.misty.com
wrote (in <slrnc4lcnj.n9g.don@manx.misty.com&gt about 'Safety warning?!!!
', on Sun, 7 Mar 2004:

Chlorophyll is built around Mn or maybe Cr, definitely not Mg.

Check your facts. You *usually* get things right.

OK, I tried a little web searching...

(My newsreader required me to split this into two lines)

http://highered.mcgraw-hill.com/sites/0073661759/
student_view0/chapter21/chapter_quiz.html

Oops! It is magnesium.

- Don Klipstein (don@misty.com)

 

[DarkMatter]

On 7 Mar 2004 03:26:11 -0600, Phantom <phantom@aol.com> Gave us:

It is, in fact, magnesium.
See: http://en.wikipedia.org/wiki/Chlorophyll

Ruh Roh, Rasroh!