Word: x-rays
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...escape from the bizarre objects, how can astronomers prove that they really exist? The answer may lie in the constellation Cygnus (The Swan), where scientists are now almost certain that they have located a black hole. Its presence was hinted at in 1971 by the first earth-orbiting X-ray satellite Uhuru, which detected a strong and widely fluctuating flow of X rays from Cygnus. Scientists suspected that the radiation source, which they named Cygnus Xl, was a pulsar, or neutron star, the result of a different form of stellar collapse. But the uneven fluctuations bore no resemblance...
...those gases spiraled toward the black hole, they would collide, compress and heat up to as high as 100 million degrees-enough to produce an intense flow of X rays. Recent findings by NASA'S new Copernicus earth satellite strongly support this scenario. Cygnus X-l shows a sharp decrease in X-ray emissions every 5.6 days. That, according to optical astronomers, seems to be the time it takes the bright star's unseen companion to make one trip around it. In other words, every 5.6 days the black hole passes behind the visible star. Thus, the supergiant...
...test in the light of the previous experience of the person entering the test situation: his mood, attitudes, motivations, anxieties affect his performance and depend on emotional and cultural factors which are almost never properly evaluated. The test itself is no more than a diagnostic, a sophisticated kind of x-ray; and even the most "objective" x-ray plate is interpreted differently by different experts...
...X-ray examination showed that she had broken her right forearm; the discovery of spots in her left lung confirmed that she had had tuberculosis; and an examination of her gall bladder disclosed several gallstones. Her digestive tract showed that she had eaten melon shortly before her death; 138 melon seeds were found, all undigested...
...first bout with breast cancer seven years ago, her doctors knew exactly what to do. Following the accepted procedure, they performed a radical mastectomy, removing the affected breast, the underlying muscle tissue and the nearby lymph nodes. Then they subjected her to intensive radiotherapy, hoping that the X-ray bombardment would kill any residual cancer cells. But when cancer recurred at the operation site two years ago, and raised reddish, golf-ball-sized lumps on the flat area where her left breast had been, the doctors were stymied. Surgery was out of the question; the lumps were evidence that...