Magnetism & You

The Magnetic Earth

Ferro, Para and Diamagnetism.

The Aurora Borealis.

Magnetic levitation.

The Sun’s magnetic field.

Solar Flares & Communication.

Consider The Following: (Discuss your responses with you partner)

The Magnetic Earth

The Earth's magnetic field reaches 36,000 miles into space. It is surrounded in a region called the magnetosphere. The magnetosphere prevents most of the particles from the sun, carried in solar wind, from hitting the Earth.

Some particles from the solar wind can enter the magnetosphere. The particles that enter travel toward the Earth and create auroras.

The Sun and other planets have magnetospheres, but the Earth has the strongest one of all the terrestrial planets. There is evidence of the Earth's north and south magnetic poles reversing at irregular intervals of hundreds of thousands of years.

Is the Earth’s North geographic pole the same as the North magnetic pole?

Ferromagnetism

Ferromagnetic materials, such as iron, are strongly attracted to both poles of a magnet. In atoms of iron, cobalt, and nickel, electrons in one atom will align with electrons in neighboring atoms, making regions called domains, with very strong magnetization. These materials are ferromagnetic, and are strongly attracted to magnetic poles.

While grazing, cows eat everything from grass and dirt to nails, staples and bits of bailing wire. This ferromagnetic metal tends to lodge in the honeycombed walls of the reticulum, threatening the surrounding vital organs and causing irritation and inflammation.

Cow magnets help prevent this irritation by attracting stray metal from the folds and crevices of the reticulum. One magnet works for the life of the cow!

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Ferromagnetism

Ferromagnetic materials, such as iron, are strongly attracted to both poles of a magnet. In atoms of iron, cobalt, and nickel, electrons in one atom will align with electrons in neighboring atoms, making regions called domains, with very strong magnetization. These materials are ferromagnetic, and are strongly attracted to magnetic poles.

While grazing, cows eat everything from grass and dirt to nails, staples and bits of bailing wire. This ferromagnetic metal tends to lodge in the honeycombed walls of the reticulum, threatening the surrounding vital organs and causing irritation and inflammation.

Cow magnets help prevent this irritation by attracting stray metal from the folds and crevices of the reticulum. One magnet works for the life of the cow!

Continue

Paramagnetic materials, such as aluminum, are weakly attracted to both poles of a magnet.

Atoms and molecules that have single, unpaired electrons are paramagnetic. Electrons in these materials orient in a magnetic field so that they will be weakly attracted to magnetic poles.

Hydrogen, lithium, and liquid oxygen are examples of paramagnetic substances.

Paramagnetism

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The vector sum of magnetic domains has a magnitude much

smaller than ferromagnetic materials.

Diamagnetic materials are weakly repelled by both poles of a magnet.

Because diamagnetic forces are thousands of times weaker than ferromagnetic forces, superconducting electromagnets are needed to levitate this strawberry.

Water, a main component of strawberries, is diamagnetic. Every electron is a tiny magnet as well as the current electrons create. Electrons are charges that spin about a central axis and maintain motion within an atom’s energy levels .

This strawberry is using diamagnetism to levitate in a magnetic field created by a super conducting coil with a huge current.

Diamagnetism

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Magnetic levitation

The frog levitates in a magnetic field generated by a series of super conducting coils of wire.

The “electromagnet” produces a field of about 10 Tesla. Compared to the strength of the Earth’s magnetic field, this electromagnet is almost 2 million times stronger. The levitating frog is another example of diamagnetism.

Every atom in the frogs body feels an attractive force due to gravity and a repulsive force due to magnetism. The net force is zero and the frog levitates as though there are no forces acting on it.

Magnetic levitation continued…

Is this drop of water ferromagnetic, diamagnetic or paramagnetic?

What creates the enormous magnetic field acting on the drop?

The Sun’s Magnetic Field

This image captures a sweeping prominence -- Prominences are huge clouds of relatively cool dense plasma suspended in the Sun's extremely hot, thin corona.

Spectral emission lines indicate the upper chromo sphere’s temperature = 60,000 Kelvins.

Every feature in the image traces magnetic field structure. The hottest areas appear almost

white, while the darker green areas indicate cooler temperatures.

Solar Flares and Communication

This image of the solar corona in 1996 shows an inner streamer belt along the Sun's equator. Here low latitude solar winds originate and are accelerated outward. Near the polar regions plumes are visible racing to the edge of the field of view. The field of view of this coronagraph encompasses 8.4 million kilometers (5.25 million miles) of the inner Helios sphere. Solar storms can increase the intensity of the solar wind and damage Earth orbiting communication satellites.

Yikes!

This Sumo wrestler is

levitating in a magnetic field.

Is it magic or magnetic?

Consider The Following

• Since every iron atom is a tiny magnet, why aren’t all iron materials themselves permanent magnets?

• Why will a magnet attract an ordinary nail or paperclip, but not a wooden pencil?

• The North pole of a compass is attracted to the north pole of the Earth, yet like poles repel. How can you resolve this apparent dilemma?

• When iron naval ships are built, the location of the shipyard and the orientation of the ship while in the shipyard are recorded on a brass plaque permanently fixed to the ship. Why?