Magnetism-The Magnetic Field

Magnetic dipole

fundamental unit of magnetism; both a north and south pole together

Magnetic field lines

come out of the north end and go into the south end

Ferromagnetic

describes a material that become permanent magnets when exposed to a strong magnetic field; ex. iron, nickel

Paramagnetic

describes materials that can become magnetized only as long as there is a surrounding magnetic field

Magnetic fields

produced by moving electrically charged particles

Hans Christian Oersted

noticed that a wire with current running through it would deflect a compass

Right-hand rule

thumb points in direction of current, fingers curl in the direction of the magnetic field

Magnesia

coastal district in Greece where iron-attracting lodestones were found

Compass

points north due to Earth’s magnetic field, usually consists of a small piece of magnetic iron floating in a liquid

Dynamo effect

the Earth generate electric currents through its molten core as it spins

Reversal of polarity

magnetic poles switch every 1k or 100k years; can be seen in alternating patterns in the magnetism of the seafloor

Plasma

gas so hot that the nuclei cannot hold onto any electrons, creates strong electric currents and strong magnetic fields

Sunspots

cool spots of the Sun that are formed when the Sun’s magnetic field gets twisted and cuts off patches of its surface from the rest of it

Polarity reversal on the sun

happens every 11 years, causes lots of sunspots to appear

Coronal mass ejections

when chunks of the Sun’s surface are ejected due to its magnetic field getting so twisted and stretched out

Carrington Event

a particularly big CME that created extremely bright aurora activity and global electrical disturbances

Solar wind

individual protons and electrons that are released from the Sun; get deflected by the Earth’s magnetic field

Aurora

forms when solar wind breaks apart atoms into ions that then capture stray electrons, releasing energy in the form of light (O glows green, H glows purple)

Neutron stars

exposed cores of very massive collapsed stars, have the most extreme magnetic fields due to their rapid rotation

Mars’ magnetic field

incredibly weak, couldn’t protect Mars from solar wind, causing it to lose its atmosphere and water