Magnetism+and+Electricity

Electromagnetism, Electromagnetic, Electromagnet https://www.youtube.com/watch?v=qhh32JYkQPk What causes Magnetic attraction and repulsion?

All throughout physics, we see things trying to exist in the lowest energy state possible: balls roll down hills, hot drinks cool down, etc. This can be seen on the atomic scale: when uranium undergoes fission or hydrogen undergoes fusion, the atoms that make up the nucleus are arranged into more 'efficient' configurations, reducing the energy per constituent of the nucleus, and forming a more stable nucleus (this is why nuclear bombs work). After such fission or fusion processes, the potential for the same release of energy has been lost, released as heat/kinetic energy/light etc.

While energy is conserved, the Second Law of Thermodynamics tells us that these processes are, on average, one-way (unless you put more energy into the system). Things therefore tend towards a state of //maximum// entropy, and this generally corresponds to a //minimum// potential energy. Magnets attract (or repel) because by doing so, they are moving towards a lower potential energy state, like a ball rolling down a hill. The tiny individual magnetic fields of the electrons (though it applies to every particle with 'spin', including neutrons and protons) in a 'permanent magnet' (your typical iron bar magnet) are aligned. In this state, the electrons have an additive magnetic field, which is strong enough for you to feel. When you put two magnets near each other, the aligned electrons in the two magnets feel each other. If you align the magnets in such a way that the fields all point in the same direction, it is energetically favourable (a lower energy state) for the electrons to be closer together, so there is attraction between the two magnets. If you align the magnets so that the fields are opposed, there is repulsion for the same reason (it's in a higher energy state, and they want to push apart into a lower energy state).

Why electrons have spin in the first place is an extremely fundamental question. I don't think it currently has a satisfactory answer beyond 'that's just the way they are'. They have spin, therefore they have a tiny magnetic moment.

[|Measuring Magnetic Strength Activity]

[|Capture Lightning]

http://makezine.com/2014/10/07/diy-ferrofluid/

http://www.fnal.gov/pub/today/archive/archive_2013/today13-03-29.html http://www.fnal.gov/pub/today/archive/archive_2015/today15-01-22.html

Electrons Repel Each Other http://www.fnal.gov/pub/today/archive/archive_2013/today13-03-15_NutshellReadMore.html

Interesting timelines and lists: http://www.magnetricity.com/DIY/DIY.php

Ferrofluid DIY http://makezine.com/2014/10/07/diy-ferrofluid/

Historical Problem Solving What experiments did Gilbert do? http://www.rare-earth-magnets.com/t-william-gilbert.aspx

http://fear-of-lightning.wonderhowto.com/how-to/measure-geomagnetic-storms-with-diy-magnetometer-0132960/

Magnets Aluminum and Copper http://www.exploratorium.edu/tv/index.php?project=41&program=1231

Hoverboard Maglev http://www.theverge.com/2015/5/27/8665479/canadian-smashes-world-record-for-longest-hoverboard-ride



Dynamo Generator Projects http://www.instructables.com/id/Make-your-own-simple-shaky-generator-to-light-an/ http://www.creative-science.org.uk/gensimple1.html http://mike-thomson.com/blog/?p=9 https://www.kjmagnetics.com/blog.asp?p=shake-flashlight

Cool generator http://www.sci-experiments.com/Electric_Generator/Electric_Generator.html

Radio http://earlyradiohistory.us/tesla.htm