quantum electrodynamics
Where does this leave us What is light We can describe very precisely what it does:
1. It has wave-like properties that give very exact answers according to the classical theory of interference.
2. It has particle-like properties that give very exact answers in collision processes between photons and particles.
3. It travels through a vacuum at the constant speed of light.
4. It has the same constant speed in a vacuum no matter how we look at it, be it in a laboratory frame of reference or from a space ship moving close to the speed of light.
5. The particles of light have no mass. . . .
To describe these properties quantitatively we need the theories of relativity and quantum electrodynamics, we need the theories of relativity and quantum mechanics. These are combined in a quite superb theory known as quantum electrodynamics, which can describe very beautifully all of these properties and is the most precise theory that has been tested in the whole of physics.
—Malcolm Longair in Light and Colour, an essay in Colour: Art & Science, edited by Trevor Lamb and Janine Bourriau, 1995.
lemon yellow, pale blue and pearl grey
Do you know a painter called Van der Meer . . . the palette of this curious painter consists of blue, lemon yellow, pearl grey, black and white. In his very few paintings there is in fact the whole richness of a complete palette; but the combination of lemon yellow, pale blue and pearl grey is as characteristic to him as the black, white, grey and pink are to Velazquez.
—Vincent Van Gogh in a letter to Bernard, quoted by Bridget Riley in Colour for the Painter, an essay in Colour: Art & Science, edited by Trevor Lamb and Janine Bourriau, 1995.
Prussian Blue
In terms of painting materials, the modern era began in 1704, with the invention of Prussian Blue. . . .
The precise dating of pigment inventions gives us a formidable weapon in the matter of determining authenticity. A number of apparently old paintings have been betrayed by the presence of Prussian Blue.
—David Bomford, from The History of Colour in Art, an essay in Colour: Art & Science, edited by Trevor Lamb and Janine Bourriau, 1995.
violettomania
Coloured shadows in Impressionist paintings generally contained blue/violet tones as the complementary to yellow sunlight. Much fun was had at their expense, and the derisive term violettomania was coined to describe their collective sickness.
—David Bomford, from The History of Colour in Art, an essay in Colour: Art & Science, edited by Trevor Lamb and Janine Bourriau, 1995.
the metallic sheen of a mallard ducks blue speculum
In Nature, colour may be a source of great beauty to the beholder, but to a plant or an animal it is most often a means of survival. . . . Natural colour arises from a diversity of mechanisms, often associated with distinct functions. Dyes and stains are used by many creatures, frequently for camouflage. Structural colourtypified by the metallic sheen of a Mallard ducks blue speculumis generally used for the intense colours that announce the presence of an individual, as for example in a mating display. Colour can also be used for warning, as in the poisonous fire-bellied toad, or even for mimicry. Less commonly, animals can dispense with colour altogether and become transparent, or, as in the squid, they can actively control skin colour for the purpose of camouflage, or for attraction and mating.
—Trevor Lamb and Janine Bourriau, from the introduction to Colour: Art & Science, edited by Trevor Lamb and Janine Bourriau, 1995.
bioluminescence.
Some animals give off bioluminescence. Some contain bacteria, which they stimulate chemically to glow, and some use filters to modify this light. Others produce their own alchemy of compounds, which when allowed to mix give off light. . . . Some bioluminescence has a sexual function. Fireflies certainly atract mates with their light displays, and several species of deep-sea squid and fish would appear to use bioluminescence in their courtship displays.
—Peter Parks, from the essay Colour in Nature, from Colour: Art & Science edited by Trevor Lamb and Janine Bourriau, 1995.
once in a blue moon
Blue is always different from yellow, for example: depressed (the blues), where yellow is gay, loyal (true-blue), where yellow is cowardly, and the like. Blue has a similar meaning to yellow about once in a blue moon.
—Marshall Sahlins, quoted by John Gage in the essay Colour and Culture, from Colour: Art & Science edited by Trevor Lamb and Janine Bourriau, 1995.
acira.
A Sanskrit word for diamond, meaning fire or sun.
—The Book of Diamonds by Joan Dickinson, 1965.
arkansas.
The only state in the U.S. where diamonds of any amount have been found. . . . Altogether four pipes have been found, the principal one being called the Crater of Diamonds in which the public may search for a fee.
—The Book of Diamonds by Joan Dickinson, 1965.
arkansas diamond.
Watch out! This is usually rock crystal from Arkansas.
—The Book of Diamonds by Joan Dickinson, 1965.