Hello, everybody. Welcome back to our lecture series. My name is Professor Seungbum Hong, and to my next side, we have our teaching assistant, Melodie Glasser. So, this will be introductory video for our second part of the lectures, namely analysis of electric fields. So, let me introduce ourselves briefly. So, as I mentioned I'm Dr. Hong. I'm professor at KAIST and I'm a KAIST alumni and I used to be a researcher at Argonne National Lab. Melodie Glasser is a Colorado Schools of Mines alumni and she's currently a masters student at KAIST. So, this is the mascot of KAIST and this is the symbol of our university. It is located in South Korea as you can see on the map, in the center part, which is called Daejeon. So, in the first part of our lecture we covered electrodynamics and we give you an introduction to electrodynamics over five weeks and you just completed it. Congratulations. From now on, we will move on to the second part, which is namely the analysis of electric fields, which will be given to you over five weeks. So, if we recap what we have learned in the first part of the lecture, you can see five bullet points, describing the scope of the first lecture series, which includes, Electrical Forces and Quantum Mechanical Effects; Concepts of Field Flux and Circulation; Vector Calculus: Divergence, Curl, Gauss, and Stokes' Theorem; Electrostatics and Gauss' Law, and; Applications of Gauss' Law and Electric Shielding. So, Melodie? Yes. When we learned about the electric shielding, do you remember one-way and two-way shielding? Yes. So, in one-way shielding, it is the case that the electric field outside the metal cavity cannot influence the electric field inside. However, the charge inside the cavity can affect the outside. That's correct. So, what was the way to make sure we have two-way shielding? I think you should ground your metal container. Exactly, you should ground your metal container to have two-way shielding. So, if you don't remember this you can revisit our lecture slides or video and recap what you have learned. Now, we still have things to learn and that includes. We just learned how to visualize vector fields including electric field and magnetic field. We will now learn how to calculate the vectors as a function of space and time. Also, we will cover from microscale to macroscale, so we will have a multiscale knowledge on electrodynamics. So, Melodie, when we learned about this rock salt structure of a salt, we learned that we can have electroneutrality in the macroscale, but what about if we just look at, say, 111 plane. Does the electroneutrality still holds true for each plane? No, because if you get to a small enough scale, or the electroneutrality does hold true for the plane, but if you get to a small enough scale, then you'll be able to see the individual charges, and you can see the electric fields between those charges. Yeah, and in case of this ionic crystals, in fact because they donate electrons to neighboring atoms and become ionized, some of the planes will not be neutral. So, at that scale, you will start to see breaking of those laws. So, in our second part of our lecture, namely Analysis of Electric Fields, we will learn the electric field in various circumstances over two weeks. We'll learn about Electrostatic Energy and we will learn about Dielectrics over two weeks as you can see, then we will expand our knowledge on dipole moment, and see how that works in a solid-state environment. So, with that, I'd like to wrap up our introduction and I hope you enjoy our journey toward the second part of our lecture series. Thank you and have a nice day. Bye.
