How many say, oh, that Magnetic Field is probably very, very steady . How many of you know the Magnetic Field changing . Whats a changing Magnetic Field induce . Begin with ef. Electric field. Electric fields. Whats a changing electric field induce . Begin with mf. Magnetic field. How many are starting to catch on . What does this changing Magnetic Field induce . Begin with ef. Electric fields. What does the changing electric field induce . Begin with an mf. Magnetic field. How many are getting the idea . Okay. It turns out these waves will regenerate one another. So if you have a shaking charge, honey, you get electromagnetic waves throughout space. Where the electric field makes the magnetic the electric, magnetic at the speed of light thats what light is. Thats what light is. Light is electromagnetic wave generated from a shaking charge. If i take this stick and i put it in the water, and i shake it back and forth, wont i disturb the water . Wont water waves travel out . You can und
And the lamp lit, and held it like this and it didnt light. Surrounding that dome is an alteration of space. And that space is said to contain an electric field, a force field. And you can tell cause when you walk by this, you can feel your hair stand up a little bit on that. Space is different with all that charge there. And it turns out the force field is stronger in here and weaker, weaker as you go further and further away. In fact, it behaves as an inverse square law, when you have all your charge localized at one place like this. It keeps petering out with the inverse square of distance, just like gravity does. And when i held the lamp like this, it lit. You know why . Thats because this part here was in the stronger part of the force field than here. We say that theres more energy on the charges here than here, which introduces a concept, i wanna see if you can get into, the idea of energy per charge, and we call that voltage. Let me define that. Energy per charge. Thatd be ener
Heavy or light . Begin with the h. No, no, h okay. That is heavy, okay . If that anvil, all of a sudden, started like scooting across the table, you will look for some reason for that, wouldnt you . Maybe youll look for maybe a rope that you cant see or maybe a magnet or something. This is just not gonna move of itself, is it . Theres gonna be a reason for it to move. Hey, this is the 20th century, we know there are reasons for things, right . I take this ball, okay . This ball. Put this ball. That ball starts all of a sudden going up in the air. You will look for maybe a string that you cannot see or something, right . Things dont move of themselves, do they . Or do they . Poltergeist. Yeah, or do they . Okay. Were gonna talk about that. A fellow by the name of aristotle, who was a giant for the human intellect and the advancing humankind, way back fourth century b. C. Classified many things and brought knowledge to a very, very high point. But aristotle made some mistakes and not to
We say temperature. Whats that mean . Something different at the atomic level, hot cup of coffee, cold cup of coffee. In the hot cup of coffee, theres more activity. The molecules are jiggling faster. They have more energy of motion. We got a name for energy of motion. What do we call it . Kinetic energy. Kinetic energy. Theres more Kinetic Energy in the molecules in a hot cup of coffee than a you know that. Thats what it means to say that somethings hot, that it has more energy. We might say more thermal energy. More strictly speaking, well say more internal energy, more energy internal to the system. So theres much more internal energy in a hot cup of coffee than a cold cup of coffee. Whats got more internal energy, a hot cup of coffee or an iceberg floating down at the antarctica . Check your neighbor for an estimate. A humongous iceberg or a small hot cup of coffee which has the more internal energy . All the energy combined what would it be, gang . Yeah, the iceberg is frozen. How
Lets suppose, i take a boulder and i take a sledgehammer, and i, boom, i smash the boulder, boom, i smash the boulder down into what . Rocks. Then i take those rocks, boom, boom, i smash them down into. Stones. Stones. Now, i take that sledgehammer, bam, bam. I smash those stones down into. Gravel. Come on, lets be a little imaginative here. And i take that gravel, unh, smash, smash, i break that gravel down into. Sand. Pebbles. Sand. Fine gravel. I take that fine gravel, i smash that down into, begin with an s, ends with and, try it. Sand. Now, id be taking that sand, honey. I take that sledgehammer and i smash that sand down into. Dust. Dust, powder. And i take that sledgehammer and whomp. I smash that dust down to. Pebbles. Powder, fine dust. Fine dust, all right, all right. All right, lets take that fine dust and i smash that down into, begin with c, r, y, s, t, a. Crystals. And i take those crystals and i smash those down into. Molecules, or begin with a and guess what were gonna