...prelude to the dawn of the quantum revolution,

in the midst of the Industrial Revolution

Age of Light, Electricity and Magnetism


each hot element produces its mysterious, characteristic, sharp

series of line spectra of light...like chords of music

H, He gas discharge

NaCl in flame

see spectra charts

cold gases absorb the same lines

...helium discovered in the atmosphere of the sun before on earth

Fraunhofer lines in sun's atmosphere lines doppler shifted if source moves

electricity comes in 2 "charges"...can separate mechanically

fur + rubbing rubber -

silk - rubbing glass +

charging electrometer

likes repel, unlikes attract

nature asymmetric in charge...

+ is stationary

- "flows"

UV short wavelength, high energy light knocks off - only

does not affect + charged electroscope

only high energy light 1) excites electrons from metal

2) activates lower energy light in dyes

Age of Light, Electricity and Magnetism

IR light does not make the "threshold"

fluorescent beads only absorb UV

while in the citrus groves of Piedmonte, Northern Italy

Volta's "piles" of zinc and copper disks in rain gutters

bathed in lemon juice

lemon clock gives 1 volt

volt...measure of electrical force per charge..up to 1000's

Galvani...galvanizing iron plate with zinc

in the suburbs of Paris

Ampere hooks the batteries to wire,

and the electric currents turn compasses...magnetic "field"

in the labs in Princeton

Joseph Henry moves wires through magnets

....generating electric currents

and in England, Maxwell writes a wave equation, with "c" popping out