Power in Optics
In optics, or radiometry, the term power sometimes refers to radiant flux, the average rate of energy transport by electromagnetic radiation, measured in watts. In other contexts, it refers to optical power, the ability of a lens or other optical device to focus light. It is measured in dioptres (inverse metres), and equals the inverse of the focal length of the optical device.
Read more about this topic: Power (physics)
Famous quotes containing the word power:
“...I am who I am because I’m a black female.... When I was health director in Arkansas ... I could talk about teen-age pregnancy, about poverty, ignorance and enslavement and how the white power structure had imposed it—only because I was a black female. I mean, black people would have eaten up a white male who said what I did.”
—Joycelyn Elders (b. 1933)