Invalidation of the light clock gedanken The following is one of the observations that we have made during our research into special relativity. It is not *the theory* to which several of our postings have referred. SPECIAL THEORY OF RELATIVITY One of the tenets of Albert Einstein's special theory of relativity is its concept of time dilation - 'a moving clock runs slow'. THE LIGHT CLOCK GEDANKEN Some physics textbooks that deal with the subject of special theories concept of time dilation depict this phenomenon using a device known as a light clock. The following is a simplified version of this gedanken (thought experiment). Imagine a very tall glass tube - 300 000 kilometres in height - that has, at its base (A), a light source. From the point of view of an observer (an astronaut) who is standing next to this device a beam of light, emitted by the source, will reach the top of the tube (B) in one second of their time; B * * * * * * * * * * * A diagram 1 However, from the point of view of an observer past whom the device is moving, the tip of the beam moves in this fashion: B1 B2 * * * * * * * * * * * A1 A2 diagram 2 (the asterisks were placed in a straight line from A1 to B2, I hope that they transmitted that way) On the basis of a constant velocity of light it is said that the tip of the beam of light moves from A1 to B2 at 300 000 kilometres a second and, due to the fact that this distance is greater than the height of the tube, it is said that the beam will therefore take longer to make this journey from the point of view of the observer than it does from the astronaut's point of view. If the light clock is travelling at 298 500 kilometres per second past the observer it takes ten seconds of the observer's time for the tip of the beam of light to move from A1 to B2 (3 000 000ks.) so, from the observer's point of view, each of the astronaut's seconds must be equal to ten of their seconds ergo the astronaut has, according to the textbooks, incurred time dilation. Of course it is quite obvious that the same effect (as per dia.2) will take place irrespective of the direction in which the light clock is moving - from the observer's left to right as shown or from right to left. THE HAFELE-KEATING EXPERIMENT In 1971 Hafele and Keating took atomic clocks around the world in the same direction as the Earth's axial spin (i.e. from West to East). It was found that the clocks incurred time dilation - ticking over at a slower rate than the laboratory clock. This was said to confirm special theories concept of time dilation. The clocks were then taken in the opposite direction (i.e. from East to West) and it was found, as anticipated, that the clocks incurred time *contraction* - ticking over at a faster rate than the laboratory clocks - however this was still said to comply with special theory. It is axiomatic (as shown by the HKX) that if we are looking at a clock that is travelling from West to East, the clock will indicate time dilation, compared to our own clock, whilst an identical clock that is moving in the opposite direction will indicate time contraction (of course, we are only talking about nanoseconds therefore we would not *see* these variations however they would, according to that experiment, be taking place). NEGATION OF THE LIGHT CLOCK GEDANKEN If we are looking at a light clock and an atomic clock that are moving from East to West (i.e. in the opposite direction to the Earth's axial spin) at identical velocities the light clock (according to the textbooks) will incur time dilation but the atomic clock *will* incur time *contraction*! Which of those two clocks represent *reality*? The atomic clock experiment *has* been conducted whilst the light clock gedanken is nothing more than a diagrammatical interpretation of a mathematical proposition that - according to Einstein, does *not* refer to reality. The Hafele-Keating experiment proved that the textbook depiction of special theories concept of time dilation as per the light clock gedanken will not take place! (in fact it can be shown that the textbook depiction is misleading however this requires a series of diagrams which would be very difficult to present in this format) The light clock gedanken is acknowledged as being *the accepted* presentation of special theories concept of time dilation. If, as we suggest, the gedanken *is* nullified as indicated by the results of the Hafele-Keating experiment it follows that special theories concept of time dilation will not take place as claimed. Special theories *assumption* of the constancy of the velocity of light is fully dependant on its concept of time dilation. If clocks do *not* slow down and lengths do not *physically* contract as presented by special theory then its concept of light speed constancy cannot be maintained. In our forthcoming theory we show that time dilation *does* take place but not as depicted by special theory - simply as the result of one reference frame moving relative to another reference frame. ............................................ Copyright - Sydney - Australia - 26 June1995 Bill Owen (for: W H & G D Owen (B.App.Sc.Hons.)) wowen@extro.ucc.su.OZ.AU