1. 1849 Armand Louis Fizeau’s method reflector 86.33 meters away (50 back-and-forth reflections)  8.630 km (5.36 miles) 720 cogs in the wheel which had to turn ~12 Hz to make light vanish measured c = 194,410 mi/sec 313,300 km/sec 1876 Cornu reflector 23 km away measured c = 298,000  500 km/sec 1879 J.B. Léon Foucault rotating mirror reflector 605 meters away measured c = 186,380 mi/sec 299,910  200 km/sec 1926 Albert A. Michelson rotating mirror reflector 22 miles away (Mt. Wilson to Mt. San Antonio) measured c = 186,380 mi/sec 299,774  4 km/sec 299,792,458 m/sec or 186,282 miles per second

2. e–e– A) X-rays which travel mostly in direction 1 B) X-rays which travel mostly in direction 2 C) no electromagnetic waves at all large amplitude small amplitude no wave Remember our picture of a charge moving. The EM wave is emitted perpendicular to the direction of the motion of the charge. By the way, the electrons also lose energy to the phosphor in the screen, which causes it to glow, thusly producing a picture. Electrons in a TV picture tube hit the television screen at a high speed and come to a stop. When the electrons stop in the TV screen they produce

3. E field points down E field points up E field momentarily zero strong weak zero E-field pointing down Oscillating electric charge +q (and the – q its absence leaves behind). Equilibrium position, where all charges could rest stably.

4. Also, this SIMPLE HARMONIC MOTION generates a B-Field! slowing to zero speed maximum speed As this positive charge moves up, the B-field in this region points INTO the screen

5.                                              B field is oscillating, continuously flipping the magnetic field in & out & in & out & in & out & · · · E field is oscillating, continuously flipping the electric field and at the same time up & down & up & down & up & down & · · ·

6. Before the days of cable, televisions often had two antennae on them, one straight, and one circular. One antenna picked up electric field oscillations, and the other picked up magnetic field oscillations. Which antenna picked up the magnetic oscillations? 1) the circular antenna 2) the straight antenna

7. Amplitude Modulation Carrier Frequency

8. Frequency Modulation

9. A changing E field creates a B field Maxwell looked at this table and, appealing to symmetry, postulated... E Field produced by B Field produced by electric charge moving electric charge changing B field changing E field