You want real time communication at relativistic speeds? It's pretty easy, you see here is the crux of the issue.
I have never heard any "believer" in Special Relativity admit that the doppler shift you will get as a body proceeds away from you can be calculated and removed to find the true rate of time dilation and yet logically any analysis of actual reduction in the rate of time must remove this artifact. There are many ways to remove this artifact (and it must be removed because treating it as real is not only dishonest but inconsistent due to the vast difference between sound and light doppler) but here is a fun thought experiment. To make things simple let's slow the speed of light down significantly to 1 meter a second and let's propose we can see a ball of light as it bounces between 2 mirrors half a meter apart orientated vertically. Not let's propose that you are moving at .95 meters per second relative to the earth and so are experiencing significant time dilation. Now the speed of light from your perspective must still be 1 meter per second as it travels from the surface of one mirror to the next half a second has passed to traverse this half meter. However from the perspective of the earth the ball of light has not just traveled directly up half a meter but has also moves .95m / 2 = .475m to the side for a diagonal distance exceeding half a meter. Now lets propose you are doing this experiment on an open train carriage, and a parallel train track on one side has a stationary train with observers, they can see your light clock and indeed various passengers have their own identical model. As you pass by them you can even hold a very brief conversation which is unaffected by any doppler shift much like a car passing by with the horn on the pitch is raised on approach and lowered as it flies off into the distance but for a moment it is the same pitch for both observers. So as you and a stationary light clock owner passes since there are not really meant to be any preferred reference frames each must see the other as subject to time dilation! >From the perspective of the "stationary" observer his mirrors and your mirrors are the same distance apart and you agree as it is length contraction not height contraction. As you pass by each other each of you sees your own ball of light travel from the bottom mirror to the top, but each of you sees the others light path as longer than his own so each of you must as predicted by time dilation see the others light clock experience less than half a second in the time it took for your own light clock to measure half a second. To put it another way even though both of you may agree that both of your light clocks had the ball of light leave the bottom mirror in sync each of you disagrees and claims that the ball of light in his own light clock reached the top mirror first, the problem is that both of you are over this entire half second right next to each other and can hold an essentially heal time conversation. In case you doubt this let's change your course and put a bend in the the track, now over several light seconds you can hold communication potentially entirely unencumbered by and doppler effect, communication that would be real time if not for time dilation. Now you must severely disagree with each other as the light clocks register several seconds on each observers frame but each must (for time dilation and "the speed of light ball") see the other has having had fewer seconds pass. In fact if we want we can bend the track into a circle and put the "stationary" observer in the middle, now you can have years of utterly disagreeing on what constitutes reality in fact if we started with twins each could be near death seeing the other as still young, we can then stop the train and how are these different expectations each expecting to find the other twin much yonger than they going to be met? If you argue that this circular motion somehow changes things then consider that we can just as well have a straight near light speed train going in the same direction at near the same speed pass by part of our circular track and they can ensure that they share essentially the same rate of time and must share essentially the same observations of the "stationary" frame. Also consider that the placement of the stationary observer in the middle of the track while useful does not really change anything because we can't have the train passenger see the rate of time for someone in the center of the track as and different to a stationary observer outside the track, sure they can only have short bursts of communication uninterrupted by doppler effects with them directly but if they saw a different rate of time for them .vs the centered observer they would get a surprise when they stopped. Also consider that in such an arrangement you could have a communication cable go from the train to the centered stationary observer and out to any other stationary observer to again establish communication anywhere on the earth frame without any doppler effect. Indeed next to or if you like above that tain could be another train on a parallel track, all passengers get on the the train and all carriages start to play a music track with synced light flashes and so the stationary observers don't get left out they too have a music and light display and everyone agrees that it's all finely synchronized over both trains and all carriages. Then we start these train (on circular tracks) in opposite directions and get each of them up to 99% of the speed of light as measured by the earth frame. Each can see the hear the music and light flashes from not only their own frame but also the other 2. If SR is correct each must utterly disagree and insist that their own reference frame is the only one that is playing the music or flashing the lights ant anything light the right pitch/tempo. And yet hasn't all this become just far too ridiculous for anyone to stomach? Clearly Special Relativity is just a game and the rule is that you can't use logic but must accept only what you can observe and it presupposes that the only way to observe something is to have it move directly away from you but I have not even heard anyone claim that the raise in frequency as something approaches means that time has speed up for the frame you are viewing. Special relativity only survives due to a huge lack of imagination and intellectual dishonesty. An entrainable aether theory however explains all experiments and has similar predictions to SR for most all experiments except it has no inconsistencies and allows travel at any speed provided you take you take spatial environment with you, something a space ship likelt would do with little effort but a particle in a particle accelerator accelerated by the earth frame would be unlikely to do and hence would experience the length contraction and time dilation which was indeed predicted by Lorentz to occur when moving through the aether. Einstein said he believed in an aether and said that he didn't understand his own theory once the mathematicians were done with it. On Thu, Nov 5, 2009 at 6:00 AM, Horace Heffner <hheff...@mtaonline.net>wrote: > > On Nov 4, 2009, at 5:10 AM, OrionWorks - Steven Vincent Johnson wrote: > > From Abd >> >> ... >> >> FTL travel would have to involve something different than ordinary >>> acceleration; therefore, why bother with acceleration at all? >>> >> >> Is this premise seriously being discussed? >> >> I confess that I haven't been following all the technical specifics in >> this >> thread line-by-line but... let me get this straight. Have there actually >> been Vort individuals who have been speculating that FTL velocities could >> eventually be achieved simply by applying constant acceleration to a >> space-ship such as from a device like from a supped-up reactionless drive? >> >> If so, how quaint. I guess Neutron would be proud! Einstein might sigh, >> however. ;-) >> >> Granted, I myself am a firm believer that FTL travel may eventually be >> achieved through clever physics trickery, but I seriously doubt such >> cheating will be achieved by brute force acceleration technology >> techniques. >> For my money, the often discussed worm-hole theory seems to be the best >> candidate. Others have speculated that warping the immediate surroundings >> of >> the fabric of space might be another viable candidate, but again, >> acceleration by itself would not be responsible for achieving FTL speeds, >> as >> I understand it. >> > > That is only true if reaction mass is required, or equivalently, a lot of > energy is required for each increment of momentum, as in the photon thrust > rocket, which requires 2.94x10^9 watts per kgf of thrust, and fuel must be > carried to produce that energy. If either (1) vacuum energy can be tapped > for a large thrust photon rocket, or (2) vacuum fluctuation particles can be > pushed on as a reaction mass, then the limitations to which you refer are > gone. You can accelerate continuously at g or multiples of g, from the > passenger perspective, with the appropriate technology. > > As a passenger in a 1 g ship, it would appear you can effectively go faster > than c because the distances appear to shrink. If you could ride on a > photon how long would it take you to travel a light year? Zero seconds. > From the viewpoint of the folks at home, you never go faster than c. That > is because the information about you, your messages, your telescope image, > arrive back on earth at c. Further, as you approach c, the quality of the > information about you degrades as you depart, it drops in frequency. If > instant quantum communication can be sustained through acceleration, then it > is a whole new ball game. Relativity is out the window. The folks at home > can watch the whole journey from your perspective. More importantly, you > don't even have to go. You can just send robots and stay home and watch. > > If you can go across the galaxy at what appear to you to be multiples of c, > or compress the distance by a comparably large fraction, and actually arrive > somewhere, it shouldn't matter what the folks at home think they know about > your progress. That doesn't change the fact you arrived. > > > Best regards, > > Horace Heffner > http://www.mtaonline.net/~hheffner/ > > > > >
