Maxwell’s equations

Plane waves in a vacuum

Galileo attempts to measure the speed of light by a lantern relay between distant hilltops. He gets a very large answer.

Albert Einstein, when asked to describe radio, replied: "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat."

There was a young lady named Bright, Whose speed was far faster than light; She set out one day, In a relative way, And returned home the previous night.

one dimensional wave equation x y z EyEy

x y z EyEy

MOST GENERAL SOLUTION!! E y = a F(z - ct) + b G(z + ct) = a F  b G  where F & G are arbitrary functions that depend on the excitation

Q. E. D. E y = a F(z - ct) + b G(z + ct) = a F  b G  is a solution of the wave equation!!! 

E y = aF(z - ct) + bG(z + ct) = aF  bG  z EyEy t = T z EyEy t = 2T

E y = aF(z - ct) + bG(z + ct)

z E y = aF(z - ct) + bG(z + ct) = aF  bG  Let c = 2  z - ct =  z + ct =  t z   z        5 t

z E y = aF(z - ct) + bG(z + ct) = aF  bG  Let c = 2  z - ct =  z + ct =  t z   z        5 t

perturbation transverse to the direction of propagation “transverse waves”

“trajectory” z t * * * *

the flood

whips and chains

“the slinky wave”

perturbation is in the direction of propagation “longitudinal wave” sound waves--compression & rarefaction of air

ion acoustic wave in a plasma

nerve propagation test for MS

Pulse generator

general properties of linear waves

soliton - soliton collision

Twinkie shortage looms March 21, 2000 PORTLAND, Maine (AP) - A Teamsters strike against a bakery company is creating shortage of Twinkies across parts of the Northeast. A Philadelphia bakery was shut down after pickets appeared Monday, and Teamsters planned to set up pickets in Buffalo, N.Y., as well. A New York City bakery also was shut down over the weekend. "It's a wave that's going to go right across the country," said Richard Volpe, director for the union in the United States and Canada.