Page:Benton 1959 The Clock Problem (Clock Paradox) in Relativity.djvu/47

 A study is made to ascertain the limitations and inherent errors present in space-time measuring systems used on high-speed tracks for determining velocity and acceleration. (Space-time systems determine either the instants of time at which a vehicle passes given positions in space or the position of a vehicle for known time intervals). Equations are derived for the errors of velocity, acceleration and the rate of change of acceleration, when the space and time errors inherent in the measuring system are known.

A popular explanation, with illuminating illustrations, directed toward helping the layman understand the apparent slowing up of time.

Illustrates the time-dilatation effect as it affects interstellar flight.

In view of the paucity of experimental tests for the general theory of relativity, it is desirable to consider the uses to which a satellite vehicle could be put. The advance of the perigee is calculated similarly to the perihelion advance of Mercury; it amounts to only 15 seconds of the arc per year. However, the effect on a satellite clock is large and could be measured. With respect to an earth clock it is calculated to be a "red shift" for low-altitude orbits, zero shift for an orbit of one-half the earth's radius, and a "violet shift" for higher altitudes, where it approaches 7 x 10-10. Some experimental schemes for the measurement of the clock shift are discussed; a counting technique seems to be best suited since it is capable of higher ultimate accuracy and avoids signalling problems during intercomparison arising from the motion of the satellite.