Word: spectra
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...even losing its supremacy in high-technology goods. Its trade surplus for these products, including computers and telecommunications gear, has dropped from $25.5 billion in 1980 to $17 billion last year. Spectra-Physics, a San Jose, Calif.-based manufacturer of laser equipment, says that its share of the world market for some products has fallen from 75% to 50% in only three years...
...found that it was split into a rainbow of colors, a spectrum. Newton's successors discovered that any material heated to incandescence not only produces a spectrum but one so distinctive that it could be used like a fingerprint for identifying the substance. Astronomers soon found that the spectra of distant stars yielded all manner of information, including the star's composition, age, temperature, motion, magnetic field, even whether it was a single or double star...
...spectra can also be created by directing a light beam or, say, X or gamma rays at an object. As the radiant energy strikes the atoms, their electrons hop from one orbit (or, in the language of quantum mechanics, one energy level) to another, absorbing or emitting light at specific frequencies. Such spectra yielded invaluable data about atomic and molecular structure...
...onto a photo-imaging tube akin to the night-vision devices used by the military in Viet Nam. This electronic gadgetry strengthens the signals and then stores them as electronic data in a computer, while it subtracts any disturbing background glare. Eventually the astronomers accumulated enough light to produce spectra, or light signatures, for all four galaxies, but that took considerable doing. The image of just one of the galaxies, known as 3C 427.1, required 40 hours of telescope time on 23 separate nights over a period of three years...
...especially after Einstein went into full operations on January 15, the X-rays really have been "coming down the pipe," and from a wide spectra of sources...