m. electromagnet. and i can kind of show you that over here. here, i have a whole lot of coils or wires. see all those wires, those green coils? it's coiled around, around, around, around, around. when i pass an electric current through here, guess where the field is gonna be concentrated, inside or outside? begin with i. inside. inside. --be concentrated in there. and furthermore, what i'm gonna do is i'm gonna induce the magnetization of this piece of iron core. i can show you that. right now, this does not pick up the clips. why doesn't it pick up the clips? it doesn't pick up the clips because right now, it's not an electromagnet. why is it not an electromagnet? what are the two ingredients you gotta have for electromagnet? electro, right? i've gotta put some electricity. i gotta put some current through here. and i can do that by simply plugging into a power source here. can you hear that little hum? it turns out this is an alternating current. but let's watch this, gang. it turns into a magnet. guess what kind of magnet? electromagnet, ge

m. electromagnet. and i can kind of show you that over here. here, i have a whole lot of coils or wires. see all those wires, those green coils? it's coiled around, around, around, around, around. when i pass an electric current through here, guess where the field is gonna be concentrated, inside or outside? begin with i. inside. inside. --be concentrated in there. and furthermore, what i'm gonna do is i'm gonna induce the magnetization of this piece of iron core. i can show you that. right now, this does not pick up the clips. why doesn't it pick up the clips? it doesn't pick up the clips because right now, it's not an electromagnet. why is it not an electromagnet? what are the two ingredients you gotta have for electromagnet? electro, right? i've gotta put some electricity. i gotta put some current through here. and i can do that by simply plugging into a power source here. can you hear that little hum? it turns out this is an alternating current. but let's watch this, gang. it turns into a magnet. guess what kind of magnet? electromagnet, ge

electromagnetic levitation. how come that thing is levitating? why? this becomes a what when i plug it in? beginning with m. magnet. magnet. and this is levitating, so this must become a-- magnet. it's aluminum, but it's a closed loop aluminum. yeah. oh-- it's a closed loop aluminum in a changing-- starting to get it, starting to get it. let's see, this is a changing magnetic field 'cause it's ac. right. and there's some connection between the changing magnetic field and a closed loop. you guys be getting it? no, i guess there's no connection, or is there? how many know why this thing was levitating? did you ever see one magnet repel another? what did you just see now? you saw one magnet repel another. and why did it fly off when it was way down here? here's a question you can all answer. every one of you guys can answer this. this thing weighs an eighth of an ounce. i'm making that up. an eight of an ounce. what is the strength of the electromagnetic force pushing up on that ring? check your neighbor. what's the answer, gang? eighth of an ounce. an eighth of an ounce. that's old mechanics, right? if there'

m radiation. it doesn't have any charge just like light ray doesn't have any charge. it's just pure energy, pure energy of electromagnetic fields, okay? and your beta particle is just electrons. and your alpha, helium nuclei. now those helium nuclei-- an alpha particle and a beta particle brought to rest will make up what's called a helium atom because this is the nucleus, this is the orbiting electron. and so the next time you see a kid walking by with a balloon filled with helium, tell the kid's mother, "hey, kid, you know what's in that balloon?" and just tell the mother, that's radioactive debris from uranium and radium and dangerous things like that. true or false? true. that's true. that's true. but these particles now have lost their energy. if you walk by an old historic site and you see an old cannon and you see some of these cannonballs all sitting, all piled up. do you get scared when you walk by those cannonballs? you don't get scared when you walk by those cannonballs. they have no more energy. not the energy they had when they were projectiles in some war or something. so just as those cannonballs don't-- a