Stephen A. Lawrence wrote: ... time dilation isn't really just a simple number.
Hi All, 6-8-09 Here are some thoughts on time dilation. Jack Smith ----------- Quoting from "Relational Mechanics" by Andre K. T. Assis, 1999 (This book can be purchased at Amazon.com.) p. 132 "It is usually stated that this dilation of the proper time of a body in motion has been proven by experiments in which unstable mesons are accelerated and move at high velocities in particle accelerators. In these experiments it is observed that the half-lives ... of these accelerated mesons are greater than the half-lives of mesons at rest in the laboratory. But this is not the only interpretation of these experiments. It can be equally argued that these experiments only show that the half-lives of the unstable mesons depend on their accelerations ... An analogy ... Suppose two identical pendulum clocks at rest on the earth, marking the same time at sea level and running at the same pace, We then carry one of them to a high mountain, keep it there for several hours, and bring it back to sea level at the location of the other clock. Comparing the two clocks it is observed that the clock which was carried to the top of the mountain is delayed relative to the one which stayed all the time at sea level. This is the observational fact. It can be interpreted saying that time ran more slowly for the clock at the top of the mountain. Or it can be interpreted by saying that time ran equally to both clocks, but that the period of oscillation ... depends on the gravitational field of the earth ... As the gravitational field is weaker at the top of the mountain than at sea level, the clock which stayed on the mountain is delayed as compared with the one at sea level ..." ------------------- http://metaresearch.org/cosmology/gps-relativity.asp What the Global Positioning System Tells Us about Relativity Tom Van Flandern, Univ. of Maryland & Meta Research >From the book 'Open Questions in Relativistic Physics' (pp. 81-90), edited by Franco Selleri, published by Apeiron, Montreal (1998) ... Another clue came for De Sitter in 1913, elaborated by Phipps [3], both of whom reminded us that double star components with high relative velocities nonetheless both have the same stellar aberration. This meant that the relative velocity between a light source and an observer was not relevant to stellar aberration. Rather, the relative velocity between local and distant gravity fields determined aberration. In the same year, Sagnac showed non-null results for a Michelson-Morley experiment done on a rotating platform. In the simplest interpretation, this demonstrated that speeds relative to the local gravity field do add to or subtract from the speed of light in the experiment, since the fringes do shift. The Michelson-Gale experiment in 1925 confirmed that the Sagnac result holds true when the rotating platform is the entire Earth's surface. ------------------------ GPS Evidence Against the Relativity Principle, by Thomas E. Phipps, Jr.; Infinite Energy, Issue 67; May 2006; p. 22 and following. ``The Global Positioning System (GPS) compensates the running rates of its atomic clocks for their orbital motion by speeding them up so as to cancel the relativistic time dilatation. Such compensated clocks, when in orbit, run in step with each other and with an earth-surface Master Clock ... The relativity principle ... demands ... the clocks of two ... observers [to be] each running slower than the other. To avoid an inifinite logical regression to nonsense, SRT [Special Relativity] therefore needs clock rates to be appearances. Whereas to earn extra credit for predicting the observed asymetrical aging of muons (circling and stationary in the laboratory) SRT needs clock rates to be real ... SRT's event calculus [is used] to show that clock phase jumps properly account for the asymetry ... Neither actual clocks ... nor biological processes behave discontinuously in nature. The stay-at-home twin cannot reset his biological clock to accommodate the phase jumps ... A clock of the GPS when in orbit is in free fall ... Two independent relativistic effects on such clocks are recognized and compensated for by the GPS. There is an effect of location in the gravity field and a separate motional effect of "time dilatation" by a factor gamma = 1/(1-V^2/c^2)^0.5 ... This means that, when a GPS clock is moved from the earth's surface into orbit, it runs slower due to time dilatation but faster due to location change (being less deep in the earth's gravity field) ... Attention will be confined here exclusively to the phenomenon of time dilatation produced by clock motion ... Confining attention to the GPS atomic clocks, we note that in such clocks a cloud of cesium atoms is irradiated so as to stimulate in some of the atoms a ... transition at frequency No cycles per second ... The GPS engineers reasoned that if this same cloud of atoms were placed in orbit at speed V relative to ... the mass center of the earth ... then those atomic oscillations would be slowed by the time dilatation factor gamma = 1/(1-V^2/c^2)^0.5 due to the relative motion. To correct for this anticipated slowing, they pre-compensated this motional effect by speeding up the clock to be orbited. That is, they set it to run at a rate increased by the factor gamma. This was done in the simplest way by redefining the "second" to be a reduced number No' = No/gamma of oscillations of the cesium resonance. For purposes of discussion, we could picture the "clock" as serving a dual purpose -- containing two counters of the basic oscillations, one set to register a "natural" ... second ... and the other set to register a "compensated second" ... Each clock "sees" all the others as running in step with itself ... the GPS is telling us that the slow-running of orbiting clocks is not an "appearance" nor a "perception" of the earth-surface observer, but a fact verifiable by any observer ... By means of its event calculus, introducing clock phases and the Lorentz contraction of lengths, SRT correctly predicts elapsed times but leaves aside rates. If rates are considered unobservable, the relativity principle [RP] is obeyed. My claim of RP violation is based on the counter proposition, that clock rates are in fact physical observables in their own right ... SRT says explicitly that the clocks of two relatively-moving inertial observers run slower than each other. It mitigates this logical contradiction not a bit to say that reversing the motion of one of the observers and applying the event calculus resolves the "twin" problem. This does not resolve, it evades. If no turn-around event occurs, the contradiction persists indefinitely ... SRT ... as an event calculus, will give a coherent ... accounting of the GPS situation ... not only by fiddling phases but by contorting space (Lorentz contraction of the orbiting light-speed measuring apparatus) ... No experimental measurement of the Lorentz contraction has ever succeeded ... The objective reality of time dilatation [Jack writes: There are alternative explanations], indicated by the GPS evidence demands a matching objective reality of the Lorentz contraction ... To test the issue in a simple manner, it would be desirable to construct a dual-purpose clock, as defined above, put it into orbit, and use it in a suitable apparatus to measure light speed with each of the two clocks ... If the orbiting uncompensated [clock] measured c, this would be seen as confirming the objective physical Lorentz contraction of the measuring apparatus in orbit ... If the compensated [clock] measured c, this would indicate invariance of length and invalidity of the metric statements of SRT ...'' ------------------- Jack writes: Somewhere I think I read that Domina Eberle Spencer has the Hafele-Keating airplane data and has concluded that it was faked. Jack also writes: Time, like truth, is subjective; it is a feeling about something. In terms of natural selection, it is to our advantage to be able to predict what is going to happen; and time is a series of events, heart beats or sunrises, that lets us keep track of things.
