For many years I was confused about electricity and magnetism. I thought they were two separate forces, but it turns out They were unified by Einstein over a hundred years ago and probably Louis Amphor probably tried to explain it I don't know if a lot of people understood him He came up with this Amphor's force law which is a relationship showing how wires with current flowing in them in opposite directions will repel and current flowing in the same direction will attract and That's Amphor's force law and it's described by this equation here Which is the force in Newton's per meter of wire parallel wires is equal to two times the magnetic force constant which is probably just some made-up figure to make this all work and then you have a The current in one wire times the current in the other wire in Amphor's divided by r which is the distance between the two wires and that gives you your force So you can see how if one of these currents up here I1 or I2 Was reversed or negative and that would make the force negative as well, so it would repel That's what's happening here Now the way this behaves it's almost as if the current is warping space and That might not be what's actually happening, but it helps to visualize this to imagine a space warping around the current carrying wires So you can see how current flowing through this diagonal Field would be attracted to the other wire In vice versa and then when these when the current changes in the wire The changes in this field propagate at the speed of light but then when the current is constant then it then the We field gradient is also a constant Now you see if we remove the current from one of the wires and just shut it off That makes both sides of the equation zero, so there's zero force Even though there's current flowing in this wire this wire doesn't really sense any forces on it And over here we have Force being applied to the wire and if we push one wire towards the other one magically this current appears in the wire that we're pushing and We can predict which direction it goes by visualizing the force around the other wire or The the warp field we might call it It's just a handy way to visualize a magnetic field. You don't really need to remember the right-hand rule or the direction of the magnetic field or any of that Because you can just imagine current flowing in the direction of the arrow Now this diagonal field is actually a cone shape So if we wind this wire around into a coil and visualize it in 3D we can see we've got cones on the wire and They line up with letters of the alphabet and an S for north and south and As you can see the way the warp cones line up there is facing the same direction But depending on how you look at it you get either a north or a south pointing electric magnet Let's make a crude electric magnet by wrapping some wire around a chunk of iron and I'll show you what I mean What we have here is one of those old tube type computer monitors and What we're going to do is take take our magnet and We're going to see what happens to the screen when we hook it hook a magnet up and And place it the poles facing the screen Okay Take that out when we hook up power to it notice how the screen twists to the right it Twist clockwise when power is applied See that Let's turn the magnet around See now it twists the other direction Now Don't worry the monitor is not ruined we just push the button and we can degos it