Electrodynamics/Tutorials/5/1/1
< Electrodynamics | Tutorials | 5
- Don't think about magnets as you study magnetism: They're weird (show)
- Kind of like charges: They attract.
- But if you turn one of them around, now they repel!
- It's like a Rubik's Cube: how things were spun affect how things behave.
- ARGH!
- When you get to magnetic fields in matter, IT WILL ALL MAKE SENSE. But you need to master this basic stuff first.
- Think of the magnetic field as the mitigating thing. Don't think of a particle over here moving causing a particle over there to move. It's not intuitive.
- Velocity of the charge is important, both in producing the field and in interacting with it.
- wires moving together attract, opposite repel. Wires try to make a circle? What happens when you loop a wire like this... Hum...
- Stationary charges (electrostatics) neither produce a field nor interact with one, which is why we did electrostatics first. Magnetostatics, on the other hand, has no stationary charges, no electric fields, no coulomb forces.
- Later on, we'll see how the Special Theory of Relativity being true creates magnetism, IE, this is really electrostatic forces caused by the speed of light being so slow. (If it were much faster, the magnetic fields would be much, much weaker.)
- Joke at the expense of Astrophysicists.
- Once you've really comprehended magnetism, you get to call yourself a physicist. No other field that I know of really understands magnetism like we do. (Same is true for rotational mechanics, QM and TD, of course.)
Hand-waving about how the forces works.
Understanding how it works relies, entirely, on understanding the interpretation of the cross-product. Notice that if you use your left-hand consistently, it still works... odd... do cross products include information about which hand was used in addition to the magnitude and direction? HUMMMMM....
Overview of the chapter. Mention A vector.
PARALLEL WITH ELECTROSTATICS.
