Word: reflectors
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...turn the interest back on. The N.S.F. conference last week took place at the site of one model program. Set in 145 rolling acres in Decatur, Ga., the Fernbank Science Center boasts a 65-acre nature forest, a 500-seat planetarium, a collection of dinosaurs and a 36-in. reflector telescope that has been used to track Apollo space missions. Students from all over the surrounding DeKalb County school district use the facility. Each quarter, for example, 60 ninth-graders are bused in for a nine-week program in which they study math, physics, seismology, meteorology and chemistry for five...
...small reactor to build two or three bombs of the type dropped on Nagasaki. The plutonium would be formed into a hollow sphere containing a small neutron source that might be made of radium and beryllium. The plutonium itself would be wrapped in a beryllium or uranium reflector, which helps contain neutrons and prolong the chain reaction. This shield would in turn be covered by a layer of TNT charges, the most critical aspect of the design. The charges would have to be so carefully shaped that the detonation would direct their force largely inward, crushing the plutonium into...
...observations came from the 120-in. reflector at the University of California's Lick Observatory, enhanced by computer technology. To study such extremely faint objects, astronomers had to focus their light 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...
...Most reflector telescopes, including the smallest backyard instruments, play a kind of Ping Pong with light entering the open end of the tube, and so does the space telescope. Light strikes the primary mirror, and then is focused and bounced back to a small secondary mirror (12 in. in diameter) directly in front of it. Rebounding off this mirror as well, the captured light will be funneled through a central hole in the principal reflector and onto a bank of scientific instruments: two cameras, two spectrometers (for analyzing light) and a photometer (for measuring its intensity). All the information from...
...exterior gives an impression of lightness. Inside it is the model of a modern hall. Bulky chunks protrude from the walls in surprising places; neat rows of little mounds trim the loges and balconies. From the ceiling hang adjustable panels, and above the stage are 24 clear acrylic sound-reflector disks. From many locations the audience can see the orchestra mirrored in them. As an image it is not bad, for halls like the Davies are really a kind of musical instrument constructed and tuned by acousticians. Although they can improve or "tune" their work to a degree, acousticians...