Measure For the men and women of Hewlett-Packard I APRIL 1977 • New proof of Einstein theory - pages 2-4 • Renegotiation - unnecessary burden - pages 5-7 • New ways of organizing work - pages 8-12 • The great all-Europe HP ski race - page 13 • From the president's desk - page 15 www.HPARCHIVE.com Another proof for Einstein... Lab director Len Cutler and HP atomic clocks help prove general relativity theory o The theories of Albert Einstein are effects would be working against each resonance and measures it so precisely that nearly 75 years old now, and several gener­ other. But, as any science-fiction buff it would take about 30,000 years for the ations of scientists have relied on them. knows, velocities approaching the speed clock to gain or lose even one second. The With the exception of a few skeptics, of light would age an interstellar traveller U.S. Bureau of Standards, the U.S. Naval modern-day physicists and astronomers very slowly in comparison with his friends Observatory, and similar agencies in other generally accept the curvature-of-time­ on Earth. countries rely on HP atomic clocks. In and-space concept as fact. Widely held be­ Experiments conducted in 1971 tend fact, the official definition of a second is liefs about the evolution of the universe to bear that out. Under the direction of now based on the oscillations of the free are based on relativity theory, and Professor Joseph Hafele of Washington cesium atom. Santa Clara Division also Einstein's hypotheses are considered "a University and Richard Keating, an as­ makes rubidium standards, which have dif­ cornerstone of modern cosmological tronomer with the U.S. Naval Observatory, ferent characteristics but are also quite thought," as one scientist put it. HP atomic clocks were flown around the stable and accurate. But can these theories, involving the world in jet airplanes and then compared The experiments in the early seventies effects of velocity and gravity on the pas­ with identical stationary clocks at the ob­ tested the effects of velocity, but the flying sage of time, be proven in a laboratory? servatory. The time differences were as clocks were also subjected to higher gravi­ For Einstein himself it would have been predicted, and although they were infini­ tational potential during the flights. Last impossible, but with today's technology tesimal, it's all in a day's work for an HP year another experiment - set up by Pro­ the effects are definitely measurable. Some atomic clock to measure accurately in fessor Carroll Alley and his associates at experiments using HP's super-accurate nanoseconds - that is, in billionths of a the University of Maryland, and supported atomic clocks support the view most scien­ second. by the U.S. Navy - went a step further tists hold - that the "time-warp" effects These so-called "atomic clocks," made in studying the gravitational effects that theorized by Einstein are very real. by HP's Santa Clara (California) Division, could be predicted by Einstein's general The effect of velocity is to slow down are actually cesium beam frequency stan­ theory of relativity. Again, the Naval Ob­ or stretch time for the object in uniform dards. Since HP introduced the first such servatory participated. The plan was to motion. This is a prediction of "special" instrument in 1964, they have proven so carry the clocks to a high altitude, circle ... relativity. General relativity theory, in ad­ accurate and reliable that they've replaced slowly for an extended period of time, and dition, maintains that clocks run faster in celestial methods for keeping international bring them back to confront the identical regions of high gravitational potential. standards of time. clocks on the ground. Therefore, since the potential increases as The technology is based on the fact Dr. Len Cutler, director of the Physical one moves away from the Earth, clocks that the cesium atom will resonate or oscil­ Research Laboratory of HP Labs, had should run faster in the air than on the late exactly 9,192,631,770 times per sec­ played a role in the earlier Hafele-Keating ground. On a flight into space the two ond. The HP instrument tunes in on that research and was to serve as co-investi- 2 www.HPARCHIVE.com An elaborate "clock box" provided a benign environment for the HP cesium standards used in the University of Maryland experiment. The clocks were protected from vibration, magnetism and changes of temperature to reduce these in­ fluences so they would not mask the effects being looked for - that is, the phenomena predicted by Einstein. gator with Professor Alley. Len was one of the principal designers of HP's first cesium standard, and has been closely in­ volved with the technology ever since. "One of the things I did was help de­ sign a box for the HP clocks," Len said of his association with Professor Alley. "The clocks had to be in a benign environment. The temperature had to be constant within one or two tenths of a degree Farenheit, they had to be isolated from vibration, and they needed magnetic shielding. I also modified the cesium standards, which al­ ready had the new high-beam flux tubes, to further improve their performance." A Navy P-3C aircraft was outfitted for the tests, and the equipment on the ground was installed in a temperature-controlled van. Two hydrogen masers were used in addition to the ensembles of HP clocks. Besides face-to-face comparisons of the clocks, a system for directing laser pulses at the airplane in flight would measure the drift as it occurred. Physicist Len Cutler, director of the Physical Research Labora­ Another major contribution Len made tory of HP Labs and one of the world's foremost authorities to the success of the experiment was for­ on the technology of atomic clocks, has participated in several mulating the best theoretical methods of experiments that tend to confirm Einstein's theories. analyzing the enormous amounts of data acquired. Five fifteen-hour flights were made at an average altitude of 30,000 feet. The flight path was a racetrack pattern flown (continued) 3 www.HPARCHIVE.com proving Einstein Students and scientists worked inside an air-conditioned van (at right) to monitor the experiment and handle the reams of data acquired during the five flights. The Patuxent Naval Air Station (at left), where the aircraft and van are shown side by side, served as home base for the research team. inside an area restricted to military air­ at 186,000 miles per second - moves only results definitely make it more believable." craft, and the plane was tracked by radar one foot in a nanosecond. Preparations are underway for some to measure its position and velocity every Professor Alley reported his findings additional flight experiments supported by second. to a committee of scientists last June. At the United States Navy and Air Force. The distortion in time, or the differ­ the same time, he pointed out that the These will look at other general relativistic ence between the air and ground clocks, importance of these studies goes beyond effects. turned out to be typically 50 nanoseconds the laboratory. "We now have clocks so Both Alley and Cutler hope the Na­ gained from the gravitational effect and stable," he said, "that we have to make tional Aeronautics and Space Administra­ 5 nanoseconds lost due to the plane's allowances for the general relativistic tion will allow additional relativity experi­ velocity. The airborne clocks thus moved effects described by Einstein in normal ments to be conducted aboard Skylab II. ahead 45 nanoseconds - almost exactly human affairs. These views of Einstein are If that happens, it will be the first time HP as predicted using Einstein's hypothesis. not just relevant to theorists, they are now atomic clocks have been carried into outer The precision of the experiment, accord­ becoming relevant to engineers." space, where they can be subjected to ing to Len, was about 1~ percent of the Len Cutler calls the experiment "a both high velocity and high gravitational effect. Since the effect is very small ­ very powerful convincer." The effects of potential. about one part in a trillion - it required velocity, he feels, are generally accepted It may finally put to rest any doubts measurement accuracy and stability of by scientists. "But the general theory of still remaining about Einstein's theories. about one part in 100 trillion. For some relativity is less believable, because the idea of the time interval involved, con­ predictions are unusual and the experi­ sider the fact that light - which travels ments are so difficult to perform. These o 4 www.HPARCHIVE.com D "The proposed Renegotiation Reform Act of 1977 (the so-called 'Minish' bill) Renegotiation Act: poses a very serious threat to the way HP and many other non-defense companies do business. It will give the government the dubious satisfaction of controlling profits and profitability. The price the A wartime necessity becomes a peacetime pain ­ government will pay for this control will and the ache may get much worse be higher prices for the products and services they buy." tor industry and U.S. taxpayers . .. -Jack Beckett, director of government relations, Hewlett-Packard. "There seems to be a naive belief by the proponents of renegotiation that (continued) 7 I-H. R. 4082 1\11\1' 11 \ t 1 I 1~I~d 7 I" 5 www.HPARCHIVE.com Renegotiation Act industry's administrative cost burdens can "Congress and proponents are totally Any legislative act that draws such be absorbed without any impact on the mistaken if they think renegotiation fire and which offers such opportunities economy.