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Rember that there is no such thing as a frame of reference whose velocity is absolute zero. All inertial frames are equivalent.
Strictly speaking, they don't "slow down" at all. "Slow" implies a change in speed, but there is no speed change because speed is a function of time. Assuming the clocks are good timekeepers they are both correct, even though they may differ. Time is purely local and it controls all processes.
and clocks really do run slow if they are not stationary within that preferred frame
Quote from: David Cooper on 26/07/2012 19:18:51and clocks really do run slow if they are not stationary within that preferred frameThe word "slow" does not really apply in that context. The clock, is simply measuring time at its location. Unless the clock is defective in some way, it is neither slow nor fast.
Imagine a clock which uses sound in open air as part of its mechanism. If you move the clock at high speed, it runs slow, and if you move it at the speed of sound, it stops. Exactly the same thing happens with clocks using components governed by the speed of light: they run slow as you move them around, and if you could get them to the speed of light they would stop. The difference is that we can use the speed of light to help us determine what's going on with a sound clock, but it doesn't give us any answers when looking at a light clock. The fact that we can't work out whether a clock is moving or not does not justify making assertions that there is no such thing as stationary - Einstein got that bit wrong (as I demonstrated in my previous post). His maths works, but his interpretation most certainly does not.
The fact that we can't work out whether a clock is moving or not does not justify making assertions that there is no such thing as stationary . . .
That's all based on an assertion (Einstein's) which is demonstrably wrong. There has to be a preferred frame of reference, and clocks really do run slow if they are not stationary within that preferred frame.If you send a photon away from the Earth and bounce it back off a mirror half a lightyear away such that it gets back to the Earth a whole year later, no time has passed for that photon, if you believe Einstein's interpretation of relativity. During that time, a whole year has passed on the Earth. The photon supposedly takes a shortcut into the future by getting there instantaneously, if we ignore the tiny delay at the turn-around when it hits the mirror. [It supposedly also does the trip by covering zero distance, but we needn't go into the details of that here.]
Quote from: David Cooper on 27/07/2012 17:26:18The fact that we can't work out whether a clock is moving or not does not justify making assertions that there is no such thing as stationary . . .That's precisely what it does justify if you confine yourself to working within space and time. We're pretty sure we know what a stationary reference frame would look like within our universe, and we have experimentally and observationaly ruled it out.
You can always make the argument (which you did above) that our theories are currently limited to the universe, and there might be some reference frame beyond it. (After all, as you say, something had to 'build' our space-time.) That's in the realm of philosophy, though, since you aren't offering any testable predictions. It's always possible to say "outside the scope of this theory, this theory doesn't apply."
I'm always skeptical of claims that something had to create the universe and thus exists outside of it. The idea of creation and outside require space and time as well as our familiar laws of physics to exist outside the universe. But the universe contains all space and time (so far as we know), so there's no good reason to justify assuming that something exists outside the universe.
This above paragraph which seems to unpin your ideas is completely wrong. Your assertion that time is frozen for a photon is baseless and certainly does not flow from E's relativity.
Similarly the assertion that the distance is infinitely contracted. These come, I guess from an application of a time dilation factor and length contraction factor but using v as equal to c. This is completely impossible within SR .
SR is premised on the fact that physical laws are identical between inertial frames of reference.
Quote from: imatfaal on 27/07/2012 19:57:40This above paragraph which seems to unpin your ideas is completely wrong. Your assertion that time is frozen for a photon is baseless and certainly does not flow from E's relativity.I didn't say it was frozen for a photon, so you're attacking a straw man. Time passes for the photon, so on the trip I described a year goes by for it while it travels a lightyear. A photon doesn't do anything while travelling, so you could describe it as being frozen in one sense, but it's actually doing a lot: i.e. moving a very long way at a very high speed. But with Einstein's interpretation, no time passes for it at all on that trip.
QuoteSR is premised on the fact that physical laws are identical between inertial frames of reference.And yet, it falls short straight away. Let's take a look at the popular thought experiment involving twins. One of them goes away in a rocket at 87% the speed of light and then returns at the same speed. She (let's make her female and her stay-at-home twin male so we can use the words "he" and "she" and know which is which) is away on her rocket trip for ten years according to her watch, while her twin brother who has stayed on the Earth records her trip as lasting twenty years.What has happened here? Time has run in the rocket at half the rate it did on the Earth, on average, although there's no way of knowing that it didn't run faster on one half of the journey and a lot slower on the other half - the Earth could be moving such that throughout the first half of the rocket trip the rocket may have been stationary and resulted in its clocks running twice as fast as clocks on the Earth, but once it turned round and raced to catch up with the Earth, they would have run much slower than those on the Earth, to the point that by the time it got there only ten years would have been recorded on the rocket's clocks. The way relativity works makes it impossible to find out whether clocks are running faster or slower relative to each other while they are in different frames - all we can measure is the average difference when clocks are separated and then reunited.
Now, if all frames have identical laws, there can be absolutely no mechanism there to allow for the travelling twin's clock to run at a different rate from her brother's, so they must be running at the same rate. The same applies to the return trip as there is no mechanism to allow them to run at different rates. There should therefore be no difference between the amount of time that's passed for the twins - they should still be the same age. But that's not how it is: there is a difference between frames which allows the clocks to run at different rates. You can treat any frame as if it is the preferred frame and the maths will then work out perfectly, allowing him to age twice as much overall as her while she is away. It requires a preferred frame to provide the mechanism, but it does not allow you to work out which frame is actually the preferred one. Because you can pick any frame to use as a preferred frame, that makes them all seem equal, and yet they cannot be - if there is no preferred frame, there is simply no mechanism there to enable the clocks run at different rates, unless you want all of them to be preferred frames at the same time and to determine that the clocks in the rocket were running both slower and faster than the ones on the Earth at the same time, but that's adding an infinite amount of unnecessary complexity to something which can be accounted for much more simply. What we actually have is a theory which depends for its functionality on a mechanism provided by something which the theory then denies - a preferred frame.
Now, let's do an extreme version of the twins experiment. Let's make the rocket move at a fraction less than the speed of light on both halves of the trip such that it makes the whole trip in one second if you measure it by its clocks. On the Earth, twenty years have gone by. From the female twin's point of view, all the events of those twenty years must have gone by in a single second. Imagine these events being generated, the results of earlier ones having causal inputs into the events which follow them - the generation of these events must happen strictly in sequence, so while they are being generated, the events in the rocket have to be generated much more slowly. Move the rocket at even higher speed and only a tenth of a second would go by during its trip, by its clocks. At even higher speeds, it's a single millisecond, or a microsecond, or nanosecond, etc. - it's heading for zero time, and if it could move at the speed of light it would clearly be zero time. We have a clear difference in the rates of time for different players. When you look at it from the point of view of a preferred frame though, time doesn't vary for any frame of reference - only apparent time varies, but real time is passing at the same rate for all frames. Clocks run slow, but their components are still running at full speed - they just have further to go to complete circuits, so you get an apparent slowing and a reduction in apparent aging.
I have moved David's sidebranch dealing with Einstein's assertion which is demonstrably wrong to it's own thread in New Theories.please can we keep this thread and others on the main boards restricted to mainstream ideas? many thanks
Quote from: JP on 27/07/2012 19:13:55Quote from: David Cooper on 27/07/2012 17:26:18The fact that we can't work out whether a clock is moving or not does not justify making assertions that there is no such thing as stationary . . .That's precisely what it does justify if you confine yourself to working within space and time. We're pretty sure we know what a stationary reference frame would look like within our universe, and we have experimentally and observationaly ruled it out.No it does not justify that - if you live inside a universe which you can't see out of such that you can't detect anything outside of it at all, to conclude that there is nothing outside the universe would be sheer stupidity. The only valid conclusion you can come to in such a situation is that you don't know if there's anything outside - not that there's nothing there.
Quote from: David Cooper on 28/07/2012 23:27:01Quote from: imatfaal on 27/07/2012 19:57:40This above paragraph which seems to unpin your ideas is completely wrong. Your assertion that time is frozen for a photon is baseless and certainly does not flow from E's relativity.I didn't say it was frozen for a photon, so you're attacking a straw man. Time passes for the photon, so on the trip I described a year goes by for it while it travels a lightyear. A photon doesn't do anything while travelling, so you could describe it as being frozen in one sense, but it's actually doing a lot: i.e. moving a very long way at a very high speed. But with Einstein's interpretation, no time passes for it at all on that trip."But with Einstein's interpretation, no time passes for it at all on that trip.""no time has passed for that photon, if you believe Einstein's interpretation of relativity"These are the straw men to end all straw men! I apologize if I didn't understand your theory (which lets be honest you have exactly expounded in detail); you terribly misreprented SR (which is well documented) and I assumed that your mistaken theory included rather than denied the misrepresentation
Twin paradox is not unexplained, nor a logical flaw in SR. Read Physics Faq - the Doppler Shift Explanation will deal with your exact problem of what is happening THROUGHOUT the voyage
One twin accelerates - frames are no equivalent, can tell the difference and calculate which ages.
Heading for does not equal reaching.
SR does not breach causality - quite the oppposite in fact. There is great experimental evidence for this stuff - and whilst I am sure you won't admit it - it is clear that your understanding of Special Relativity is lacking. You are attacking the ideas on the bases of incredulity and misunderstanding.
Mod note:David, the moderators are happy to review rulings if you keep it civil. Reporting the post or politely asking us to review it is enough. Telling a moderator that they just "displayed the most extraordinary amount of ignorance" is not civil and is a quick way to get the thread locked without review.
You are proposing a new theory. Relativity theory works within our universe, and our universe includes all space and time. Relativity theory also specifies that within this framework (our universe) there is no single preferred reference frame. Relativity doesn't describe what there might or might not be outside of our universe. This is primarily because science requires testable hypotheses and we don't know how to test this yet.
Your claim seems to essentially be that since relativity doesn't outright forbid a preferred reference frame outside the universe, then one exists.
This is a new theory on two counts. First, you're proposing the existence of "stuff" outside our universe.
Second, you're calling it a "reference frame" which is defined in relativity to mean exclusively things within our space-time, i.e. within our universe.
If I'm misinterpreting you on this, let me know. If you are working within the framework of relativity and your theory isn't proposing any add-ons to it, then it certainly can be moved back into the mainstream fora, provided this discussion remains civil.
The preferred frame of reference is in the universe - fine. It doesn't actually need to be, but that's another discussion entirely which can bring in ideas of things outside of the universe. I didn't bring that up because it's completely superfluous to the argument.
Quote from: David Cooper on 29/07/2012 20:52:05The preferred frame of reference is in the universe - fine. It doesn't actually need to be, but that's another discussion entirely which can bring in ideas of things outside of the universe. I didn't bring that up because it's completely superfluous to the argument."The universe" is not a reference frame within special relativity. Reference frames are defined within spacetime. All spacetime itself is not a reference frame.
To manufacture a block universe you actually have to build it up from one end (the past) to the other (the future), and that necessarily involves a kind of time that runs. This is absolute time, and the only frame which records absolute time is the preferred frame - all other frames will record a slower apparent time.
Geezer, he's talking about an interpretation of relativistic effects that does involve keeping an "aether" but making it undetectable. If we can't detect the preferred reference frame in any way, then all our experimental results will look the same as if there is no preferred reference frame. This has fallen out of favor mostly because it is experimentally indistinguishable from special relativity (which has no preferred reference frame) and introduces extra complexity.
Since thinking about "building" a universe requires that you somehow exist outside of it. Your argument with imatfaal appears to be about Lorentzian relativity. I've responded to that on the more mainstream thread.
This has fallen out of favor mostly because it is experimentally indistinguishable from special relativity (which has no preferred reference frame) and introduces extra complexity.David, if both interpretations are equivalent in terms of predictions, then you can't make the claim that Einstein's is somehow scientifically flawed. If either is to be discarded, it's Lorentz's interpretation, since it adds complexity without adding any new predictions, which is generally frowned upon in physics. In fact, you can always take an existing theory and add some undetectable feature to it to make a new theory, so the simplicity test is a pretty useful feature in science.
and then denies that that mechanism exists, leaving it all to happen by magic instead.
Quote from: David Cooper on 29/07/2012 22:16:47 and then denies that that mechanism exists, leaving it all to happen by magic instead.Yes, you mentioned that already. What's the magic trick? Is it that c is invariant?
Coming out of the gate insisting Einstein's theories are wrong and involve "magic," doesn't help your argument.
It also amounts to essentially arguing against a widely-accepted century-old theory because you don't care for the philosophical interpretations.
Also, coming up with pejorative names for the theories you disagree with ("magic") and name-calling doesn't help.
As I mentioned above, you can create an infinity of relativity theories by introducing undetectable features. In science, we don't choose one from among those because it happens to be the most comfortable to our preconceptions of how the universe should work. We choose one by (generally) using Occam's razor to remove all unnecessary features. We then worry about the interpretation of what's left.
If we're going to start introducing undetectable features because we feel more comfortable with them in the theory, who decides which features to allow and which to reject?
Edit: official complaint sent and copies of both threads stored.
David, starting new topics to continue an argument that was moved to new theories is a quick way to get your posts removed. I've unlocked this thread so you can continue the discussion here if you want, but please keep it on topic and don't bring it back to the mainstream boards again.