A natural Magnet, magnetite or Lodestone Fe3O4
Chinese South Pointer
Circa 1100 A.D.
Earth Globe with
strong magnet
inside.
The staples align
with the field.
Gilbert made a
sphere of magnetite
and used small iron
rods to explore its
magnetic force.
He discovered that
the reason magnetic
compass needles
pointed north was
that the earth was a
magnet.
Here the equator is
vertical.
Magnetic Sand
on
Radar Magnets
made of
AlNiCo
Text
Black magnetite sand follows magnetic field lines.
Field lines Michael Farady
Magnetic Bacteria navigate using the Earth’s magnetic field
Magnetotacticum Aquaspirillum
Black crystals are magnetite.
The
magnetic
field of the
earth
deflects
ionic
particles in
the solar
wind.
Earth, north and south aurora
Jupiter Aurora
Saturn Aurora
Solar Magnetic field lines.
Plasma follows the field lines.
The magnetic field lines that come up out of the center
magnet curve around and down on its sides exerting an
upward force on the adjacent magnets.
Iceland, Ingolsfjall moberg, a volcano born inside a
glacier.
Iceland, Ingolsfjall moberg, Top 1/2 current magnetic field
Bottom half reversed.
Antarctic lava flow
Near Mt. Morning.
Geologist marks
magnetic north on a
bedrock sample
Theoretical model of a possible flip of the earth’s field.
Pieces of magnetic cassette tape record magnetic
fields
Magnetic stripes in ocean floor lavas.
USGS Menlo
Park magnet
laboratory.
Magnetic stripes on Mars
What is magnetism?
Electric charge at
rest Electrostatics
Electric charge:
Constant speed
Magnetism
Electric charge:
Accelerating
Electromagnetic
Radiation
An Electromagnet.
All magnetism
comes from
moving electric
charges or
changing electric
fields.
Every iron atom is a magnet. Atoms align in domains. In
a nonmagnetic piece of irons the direction of domain
magnetization is random.
See Magnetic domains
Grapes are Diamagnetic, repelled by both magnetic
poles
Oxygen in the air is paramagnetic, attracted to a
magnet.
The flame is low in oxygen and experiences a bouyant
force away from the magnet.
A ball of water (with green dye added) is diamagneticaly
suspended in a magnet.
QuickTime™ and a
YUV420 codec decompressor
are needed to see this picture.
A magnetically levitated frog.
QuickTime™ and a
YUV420 codec decompressor
are needed to see this picture.
A human in a magnetic resonance imager.
Whole Body MRI
Graphite levitated over a strong magnetic track.
A magnet
guided down
a track.
A NIB magnet
falling between
two aluminum
plates falls
slowly due to
electromagnetic
induction.
Drop Zone
Cars are stopped by magnet induced eddy currents.
Electric Guitar