It makes you wonder… Once you realise that E = MC ^2 is a transform it inevitably leads to the conclusion that it is simply a derivative with respect to acceleration. On a mundane level, say, for an astronaut within an orbiting space craft the Relative result has to reflect the fact that the observer is weightless despite the acceleration of gravity and since weight = ma then the Relative acceleration (or the Relative mass) must equal zero. Now, as I’ve pointed out before, the observer can feel acceleration but only see velocity… so, since the observer cannot feel any acceleration what can he see? If the craft has windows (not Microsoft’s) then he can see his velocity with respect to the planet below but he is always the same distance from it and so he sees his velocity as Forward… if it helps you can imagine that the craft is stationary and so the planet is rotating beneath him and hence there is no acceleration simply relative velocity. Since a relative Forward velocity is constant, as it is not changing speed or direction, then it has no acceleration and this explains why there is no apparent weight. If we now take Einstein’s advice and imagine a thought experiment: A space craft is accelerating in a straight line away from one sun toward an identical sun and its velocity reaches a significant fraction of the speed of light. An observer aboard the space craft can feel the acceleration and see its velocity relative to both planets – the observer can SEE that essentially he is moving away from one with the same velocity he is moving toward the other. The observer can see the light shifting red from the sun he is leaving and shifting blue for the sun he is heading toward. What difference does the acceleration make to the Relative Doppler shifts? If we imagine that the craft has accelerated well past far enough toward the sun so that its gravity would be several times that of the sun the craft has left behind and the pilot decides to coast in using the sun’s gravitational attraction… Well, the craft will still be accelerating but will the observer feel the acceleration? Einstein tells us that a man in a falling lift will not feel the acceleration of gravity if the lift is free to accelerate downward with no resistance… so, even though the craft is accelerating - since the observer is ‘falling’ toward the planet within the craft - does he feel any acceleration or is he weightless? Whatever the answer is I believe it demonstrates that gravity must directly affect the mass (and hence the nucleus’s) of matter rather than the ‘frame’ which all the other forces seem to interact with. I planned to point out that relativity would require a direction and hence it should be the velocity of light not the speed that was used in the transforms but it has since occurred to me that you might get away with giving time a direction hence space-time… however I can’t see that it is a legitimate assumption. If you consider light from the two suns the velocity of the craft would shift the sun the craft is leaving Red and the sun it is approaching Blue; since Blue light has more energy than Red it is easy to see that the energy is related to the relative direction. It is less easy to imagine the time dilation as the craft approached a velocity that was close to C - relative to the sun it was approaching – because surely any time dilation would affect the frequency of the light from the two suns. ‘So what?’ you might say... but how could the observer aboard the craft recognize the resultant frequency shifts and differentiate the different elements of velocity, acceleration and time dilation? Since we have no idea what velocity we are moving at on our tour of the Universe and no more idea of the velocities of the stars that are on journeys of their own then how is it possible for astronomers to tell us how far suns are away, how fast they are moving etc. especially with things like gravitational lensing and Black Holes bending the light??? Astronomers tell us that suns at the edge of the Universe are travelling ‘outward’ at, or above, the speed of light… I’d love an explanation of how they can know!
Posted on: Wed, 05 Jun 2013 04:12:05 +0000