2. What is Light

A historical approach illustrating how the ideas of science change.     

A historical view that shows how scientific models change over time.

1700 Newton thought that light was a particle, Huygens thought it was a wave.
1750’s Benjamin Franklin said: ”About light, I am in the dark.”
1801 Thomas Young did a two slit experiment to show light was a wave. (I’ll do the two slit experiment),
1817 August Fresnel found the mathematical description of a light wave.
1864Maxwell showed that light was a wave in the electromagnetic field.
1905 Einstein showed that light energy was quantized.
1926 Schrodinger showed it was a wave of probability, the probability of detecting the quantum of light.
1954 Feynman showed how to trace paths through space to calculate probability. 


Electromagnetic waves come in a spectrum of wavelengths and frequencies.  (The electromagnetic spectrum chart) The regions of the electromagnetic spectrum are named by their affects: radio. Microwave, infrared, visible light, ultraviolet, x-ray, and gamma ray



Pinhole in a film can

Diffraction grating ( CD minimag spectroscope)

Phone cord waves

Tape electromagnetic wave


Scientific Explorations with Paul Doherty

© 2011

18 October 2011