Word: radar
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...ingenious experiments by other scientists anxious to test its validity. Although no experimental results have contradicted the theory, they have not been precise enough to rule out opposing theories that differ in small but significant details. Now a new technique has been used to check out Einstein: interplanetary radar. Preliminary radar tests also have failed to find a flaw in general relativity, a scientist from Massachusetts Institute of Technology's Lincoln Laboratory announced last week, and radar soon should provide results accurate enough to help confirm the theory-or to seriously undermine...
Last year, during two intervals when Mercury and Earth were on opposite sides of the sun, a team led by Physicist Irwin Shapiro bounced high-frequency signals from M.I.T.'s exceptionally precise Haystack radar antenna off the planet Mercury. On their way to and from Mercury, the signals, which travel at the speed of light, had to pass close to the sun. During these passages, according to the Einstein equations, solar gravity should have actually slowed them down, lengthening their 23-minute round-trip time to Mercury by one five-thousandth of a second...
Eight Gigahertz. The M.I.T. team also had to design a new radar transmitter that would operate at eight gigahertz (pronounced with hard gs), which is 8 billion cycles per second. Radar beams of lower frequency would be significantly slowed down by electrons in the solar corona, making it difficult to separate out the delay actually caused by the sun's gravity. Corrections for Mercury's surface irregularity had to be calculated; round-trip time to a Mercurial valley would be longer than to a mountaintop. It was also essential for the researchers to screen out any extraneous radio...
...first that the equipment "consisted in essence" of normal radio receivers that gave the ship "added capacity" to detect indications of possible attack. In testimony released at week's end, however, he admitted that, far from being routine, the electronic gear was designed to somehow "trigger" North Vietnamese radar so that the U.S. would know the frequencies of Northern radar installations. Then, in an amazing turnabout, the Navy disputed its chief, insisting that the equipment was indeed only standard gear...
When the blips were about three miles off, Turner Joy began firing, using her radar as guide, since nothing could be seen. Maddox followed suit-though her radar showed no target at all. Says Lieut. Raymond Connell, in charge of Maddox's guns: "I recall we were hopping around up there, trying to figure out what they [Turner Joy] were shooting at. We fired a lot of rounds, but it was strictly a defensive tactic." It could also have been a malfunction on the radar screen. Aircraft from the carriers Ticonderoga and Constellation were overhead by this time...