tailieunhanh - The Philosophy of Vacuum Part 6

The Philosophy of Vacuum Part 6. Physicists will find it extremely interesting, covering, as it does, technical subjects in an accessible way. For those with the necessary expertise, this book will provide an illuminating and authoritative exposition of a many-sided subject." -John D. Barrow, Times Literary Supplement. | Reflections on Ether 43 anticipated by Lorentz. However Poincare persisted in regarding the length contraction as a real physical effect and even founded the theory upon this hypothesis Lorentz did not adapt to the changed situation presented by relativity for many years. It was Einstein alone who followed the implications of relativity to their logical conclusion. 4 Special Relativity and the Electromagnetic Field Einstein s presentation of the theory was uniquely his own it rested on two principles 1 The relativity principle The same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good. 2 The principle of the constancy of the velocity of light Light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body. Einstein referred to the special theory as a theory of principle founded on hypotheses that are suggested by For all that the temptation to read into these laws a purely operational significance must be resisted. For example it would be in error to interpret the relativity principle as the assertion that no electrodynamic or optical experiment can distinguish a privileged inertial frame of reference this would permit the interpretation of . length contraction as a real physical effect experimentally undetectable in a co-moving frame because of the contraction of all measuring rods in that frame. This was precisely Poincare s reading of the theory. In what sense is the relativity postulate founded on experience A better reading of Einstein s thinking is that he considered the fundamental equations of electromagnetism and optics as themselves phenomenological in this sense their form invariance may also be considered as a generalization from experience. The main development of Einstein s ideas is as follows. From the two postulates applied to an operational analysis of the definition of simultaneity .