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The Munsell Color Wheel


Color Wheels

Such systems were devised to meet the demands of an expanding economy that needed precise color notation.

The industrial economy included more fabrics, dyes, etc., than ever before.

Such systems use a notation of Letters & Numbers,
seen on the dial at left, in order to ensure accuracy.

A Variety of Colorwheels at FeedBlitz

Newton's Color Wheel at
University of Virginia

Origins of the Color Wheel at
Dimensions of Color



EM spectrum

Review of the Visible Spectrum

This diagram shows the small area our visible spectrum
occupies within the electromagnetic spectrum.


The Electromagnetic and Visible Spectra at
The Physics Classroom

Additive theory explained

Additive Color Theory

This picture clearly illustrates the process of matter absorbing
some light rays & reflecting others


Additive Color at University of California, Santa Barbara


Introduction to the Electromagnetic Spectrum:

Discovery of infrared (1800 by Sir Frederick William Herschel) and ultraviolet rays (1801 by Johann Ritter)

from gamma rays to radio waves

Discovery of Infrared at The Infrared Processing and Analysis Center

Johann Wilhelm Ritter and UV Rays at Universal Design Consortium

William Herschel at



Kelvin Scale

Introduction to the Kelvin Scale

(Lord Kelvin, 1848) concept of 'absolute zero'; explanation of black-box radiation.

The Kelvin system of light measurement,
based upon the light that would be emitted by a "black body "
heated to various temperatures.

Used in the physical sciences as well as photography
to indicate color temperature.


Kelvin Scale at School of Digital Photography

Black Body Radiation at Georgia State University

Lord Kelvin at The Scottish Science Hall of Fame


The Speed of Light

eclipse of moon of Jupiter
oil painting


1610 - Galileo discovered that what were previously thought to be stars were actually moons of Jupiter -
proving that earth & it's moon were not the only "planetary system".

1676 - The eclipse of Jupiter and its moon Io gave Danish astronomer Olaus Roemeran (Ole Rømer; also Roemer) an opportunity to estimate the speed of light.
His observation was that the same eclipse was seen later or sooner, depending on earth's proximity to Jupiter. This demonstrated that light had a finite speed.
Rømer had measured celestial angles in order to use triangulation to determine an estimate of the distance between Earth and Jupiter.
Accounting for the time discrepancy in observation of the same phenomenon, based on the distance between the two points,
he was able to provide the speed of 186,000 mile
s per second, an incredibly close calculation.

Galileo and The Moons of Jupiter at Rice University | The Moons of Jupiter at | Galileo at Stanford University

Ole Rømer at The Museum of Natural History | Rømer's Determination of the Speed of Light at Wikipedia



"Newton's Rings"

"When a convex lens is placed on a flat glass plate, light is reflected by the plate & by the lower surface of the lens.
The two groups of rays interfere with each other to produce 'Newton's Rings.'
These are named after Sir Isaac Newton (1642-1727),
who first investigated this effect" - David Burnie

Newton's Rings
Time-Life Books

Description of how "interference" can cause "iridescence" and why the wave nature of light creates this effect,
based on the relationship of the wave length of light rays and correspondingly tiny spaces between matter,
such as between two pieces of touching glass (where the colors produced are called "Newton's Rings")
or in between the ridges of a peacocks feather:


Here, due to their microscopic spacing,
tiny "rods" of the feather create "interference" with the light rays

peacock feather

It is actually a reverberation effect,
similar to the breaking of waves upon each other at different angles.

Newton's Rings at:

City Collegiate | The University of Adelaide | School Physics

Isaac Newton at:

The Isaac Newton Institute for Mathematical Studies | University of Virginia |
Virginia Commonwealth University: Principia | Optiks


lecture contents