1. 8/5/08Lecture 2 Part 21 Maxwell’s Equations of the Electromagnetic Field Theory Gauss’s Law – charge makes an electric field The magnetic field is solenoidal (no monopole sources). Faraday’s Law of electromagnetic induction -- E curls around a changing B. Ampère’s Law – current makes a magnetic field Maxwell’s “Displacement Current”

2. 8/5/08Lecture 2 Part 22 Theory of Electromagnetic Waves

3. 8/5/08Lecture 2 Part 23 Theory of Electromagnetic Waves

4. 8/5/08Lecture 2 Part 24 Theory of Electromagnetic Waves

5. 8/5/08Lecture 2 Part 25 Photon Energy Frequency Wavelength Applications Each part of the electromagnetic spectrum has important applications!

6. 8/5/08Lecture 2 Part 26 With our modern technologies, we use all parts of the electromagnetic spectrum. But how do we create the different electromagnetic waves?

7. 8/5/08Lecture 2 Part 27

8. 8/5/08Lecture 2 Part 28

9. 8/5/08Lecture 2 Part 29 Radiance = Power per unit area per unit wavelength Photosphere

10. 8/5/08Lecture 2 Part 210 Blackbody Radiation Radiance = Power per unit area per unit wavelength