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