Defect of Illumination
Defect of illumination is the maximum angular width of the unilluminated part of a celestial body seen by a given observer. For example, if an object is 40 seconds of arc across and is 75 percent illuminated, the defect of illumination is 10 seconds of arc.
Read more about this topic: Angular Diameter
Famous quotes containing the words defect of, defect and/or illumination:
“Well, I had gone and spoiled it again, made another mistake. A double one in fact. There were plenty of ways to get rid of that officer by some simple and plausible device, but no, I must pick out a picturesque one; it is the crying defect of my character.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“A weak mind is the only defect out of our power to mend.”
—François, Duc De La Rochefoucauld (1613–1680)
“When we want culture more than potatoes, and illumination more than sugar-plums, then the great resources of a world are taxed and drawn out, and the result, or staple production, is, not slaves, nor operatives, but men,—those rare fruits called heroes, saints, poets, philosophers, and redeemers.”
—Henry David Thoreau (1817–1862)