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Scientists Make Frog Float In Mid-Air
From: UFO UpDates - Toronto <updates@globalserve.net>
Date: Tue, 15 Apr 1997 01:17:59 -0400
Fwd Date: Tue, 15 Apr 1997 01:17:59 -0400
Subject: Scientists Make Frog Float In Mid-Air
From: Stig_Agermose@online.pol.dk (Stig Agermose)
To: updates@globalserve.net
Date: Tue, 15 Apr 1997 04:20:47 +0200
Subject: Re: Scientists Make Frog Float In Mid-Air
Here are excerpts from the webpage of Nijmegen High Field Magnet
Laboratory - http://www-hfml.sci.kun.nl/hfml/levitate.html - and a
picture of the frog:
Molecular Magnetism and Levitation.
(The Frog Which Learned to Fly)
Seeing is believing:
A little frog (alive!) and a water ball levitate inside a =D840mm
vertical bore of a Bitter solenoid in a magnetic field of about 16
Tesla at the Nijmegen High Field Magnet Laboratory. =20
=20
=20
The image of a high-temperature superconductor levitating above a
magnet in fog of liquid nitrogen can hardly surprise anyone these days.
It has become common knowledge that superconductors are ideal
diamagnetics and magnetic fields must expel them. On the other hand,
the enclosed photographs of water and a frog hovering inside a magnet
(not on board a spacecraft) are somewhat counterintuitive and will
probably take many people (even physicists) by surprise.
=20
This is the first observation of magnetic levitation of living
organisms as well as the first images of diamagnetics levitated in a
normal, room-temperature environment (if we disregard the tale about
Flying Coffin of Mohammed as such evidence, of course).
=20
In fact, it is possible to levitate magnetically every material and
every living creature on the earth due to the always present molecular
magnetism. The molecular magnetism is very weak (millions times weaker
than ferromagnetism) and usually remains unnoticed in everyday life,
thereby producing the wrong impression that materials around us are
mainly nonmagnetic. But they are all magnetic. It is just that magnetic
fields required to levitate all these nonmagnetic materials have to be
approximately 100 times larger than for the case of, say,
superconductors.
The water and the frog are but two examples of magnetic levitation. We
have observed plenty of other materials floating in magnetic field -
from simple metals (Bi and Sb), liquids (propanol, acetone and liquid
nitrogen) and various polymers to everyday things such as various
plants and living creatures (frogs and fish). We hope that our
photographs will help many particularly non-physicists to appreciate
the importance of magnetism in the world around us. For instance, it is
not always necessary to organize a space mission to study the effects
of microgravity. Some experiments, e.g. plants or crystal growth, can
be performed inside a magnet instead. Importantly, the ability to
levitate does not depend on the amount of material involved, V, and
high-field magnets can be made to accommodate large objects, animals or
even man. In the case of living organisms, no adverse effects of strong
static magnetic fields are known. After all, our frog levitated in
fields comparable to those used in commercial in-vivo imaging systems
(currently up to 10T). The small frog looked comfortable inside the
magnet and, afterwards, happily joined its fellow frogs in a biology
department.=20
A.K. Geim, J.C. Maan.=20
The work is featured in: Physics World, April 1997, p. 28. A.K. Geim et
al, Molecular Magnetism and Levitation, in Proceeding of European Low
Gravity Association (ELGRA), Biannual Meeting, Paris, 17 March 1997.
=20
Last updated on 25-mar-97. =20
=20
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