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Author Topic: Have the Pioneer anomalies also affected other probes?  (Read 25618 times)

Sverre Vigander

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Sverre Vigander  asked the Naked Scientists:
   
Have the alledged anomalies of acceleration been observed on Pioneer only, or on Voyager as well?

Any theroetical work to explain anomalies in Pioneer would surely also have to be consistent with the Voyager flights.

If there are no anomalies associated with these, that would seem to me to indicate that the explanation is something mission-specific rather than new physics...

Thanks,
Sverre

What do you think?
« Last Edit: 10/04/2011 18:30:03 by _system »


 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #1 on: 18/04/2011 15:10:50 »
Hi Sverre,

This is my take on the anomaly, I don't believe it is mission specific or involves new physics.  In fact it has been predicted by relativity but apparently ignored.

The Pioneer anomaly is due to time dilation that is caused by the gravity of the Solar
System.  As pioneer leaves the solar System the rate of flow of time increases causing a
doppler blue shift relative to our perspective.  This blue shift reduces the expected red
shift so the red shift is not as far red shifted as expected.  The craft is where it is supposed
to be, it just appears to be closer to us than it is.
Full article here http://vixra.org/abs/1103.0103

Mike
 

Offline yor_on

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Have the Pioneer anomalies also affected other probes?
« Reply #2 on: 18/04/2011 20:02:22 »
There is another, more mundane explanation, that slowly seems to gain acceptance. Here are some other alternative explanations.
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #3 on: 20/04/2011 09:50:49 »
Hi,

Thanks for the links.  I've read most of the other explanations and most of them are just complicated or unlikely or both.  I am not a mathematician so have not done the mathematics but surely the simplest answer (so long as it agrees with known facts) is most likely to be correct?

Gravitational time dilation also explains other anomalies
Galaxy rotation anomaly
http://vixra.org/abs/1104.0041
The Discrepancy in Redshift Between Associated Galaxies and Quasars
http://vixra.org/abs/1103.0113

I suspect it is also the cause of the spacecraft flyby anomalies as well but have not studied that.

Mike
 

Offline yor_on

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Have the Pioneer anomalies also affected other probes?
« Reply #4 on: 21/04/2011 18:48:54 »
Maybe. I don't know Mike. Myself I think there will be several causes building up to the deviation.

"The Pioneer 10 and 11 deep space probes were launched in 1972 and 1973, visiting Jupiter and Saturn before pushing on toward interplanetary space, into the unknown. The Pioneer program really lived up to its name, pioneering deep space exploration. But a few years on, as the probes passed the through the 20-70 AU mark, something strange happened… not suddenly, but gradually. Ten years ago Pioneer scientists noticed that something was wrong; the probes were slightly off course. Not by much, but both were experiencing a slight but constant sunward acceleration. The Pioneer probes had been measured some 240,000 miles (386,000 km) closer to the Sun than predicted. This might sound like a long way, but in astronomical terms it’s miniscule. 240,000 miles is a tiny deviation after 6.5 billion miles (10.5 billion km) of travel (it would take light 10 hours to cover this distance), but it’s a deviation all the same and physicists are having a very hard time trying to work out what the problem is.

That is until NASA physicist Slava Turyshev, co-discoverer of the anomaly, rescued a number of Pioneer magnetic data storage disks from being thrown out in 2006. These disks contain telemetric data, temperature and power readings that both Pioneer probes had transmitted back to mission control up to 2003 (when Pioneer 10 lost contact with Earth). From this, Turyshev and his colleagues teamed up with Viktor Toth, a computer programmer in Ottawa, Ontario, to design a new code designed to extract the vast quantity of raw binary code (1s and 0s), revealing the temperature and power readings from the crafts instruments. It sounds as if the search for the culprit of the Pioneer anomaly required a bit of forensic science.

Now the researchers have a valuable tool at their disposal. Turyshev and 50 other scientists are trying to match this raw data with modelled data in an effort to reconstruct the heat and electricity flow around the craft’s instrumentation. Electricity was supplied by the on-board plutonium generator, but this is only a small portion of the energy generated; the rest was converted to heat, lost to space and warmed up the probe’s bodywork. Heat lost to space and warming of the probe’s instruments are both thought to have a part to play in altering spacecraft momentum. So could this be the answer?

Tests are ongoing, and only a select few simulations have been run. However, early results indicate that around 30% of the Pioneer anomaly is down to the on-board heat distribution. The rest, it seems, still cannot be explained by probe dynamics alone. The team are currently processing a total of 50 years of telemetry data (from both Pioneer 10 and 11), so more simulations on the rich supply of transmissions from the probes may still uncover some surprises."

The Pioneer anomaly by Slava Turyshev from 2010.

It seems as a extensive research.
 

Offline MikeS

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« Reply #5 on: 22/04/2011 09:12:53 »
yor_on

Thanks for your reply.

As I understand it much of the research into a gravitational solution is based on Newtonian gravity.  However, my limited research tells me that the result would not be much different for a relativistic solution.  If that is the case then there must quite obviously be something wrong.  To the best of my knowledge, Newtonian gravity totally ignores relativistic time dilation due to gravity. 

I cannot help feeling that if the gravity of the Solar system is strong enough to stop it from all flying off into space then it is strong enough to marginally dilate time within the Solar System, which is predicted by relativity and is exactly what we see. 

In my research into the anomaly, I have not come across anyone else suggesting the anomaly is due to time dilation within the solar System and yet it seems to me that it is the most likely answer.

As I said before I am not a mathematician and at 67 I am not about to start but I have a very strong feeling that either I or all of the scientific community who have looked at this problem are missing something and I really believe it is them.  I really feel like I am missing something…?

To my mind, the Pioneer anomalies are quite obviously due to gravitational time dilation within the Solar System.  Would I be right in thinking that the Voyager spacecraft may be experiencing something similar?  To my mind all craft leaving the Solar System should experience the same Doppler blue shift.

If anyone can prove to me for certain that the anomaly is not due to time dilation in the Solar System I would be delighted to hear from them.

Mike
 

Offline yor_on

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Have the Pioneer anomalies also affected other probes?
« Reply #6 on: 22/04/2011 10:08:17 »
Well, let me reason around it a little and see what we can agree on Mike? First of all, talking about gravitational time dilation. The greater the invariant mass the larger the time dilation relative some observer being 'at rest' outside that gravity well, right? But Pioneer was on its way out of the 'Solar system'¨as it started to deviate so the gravitational attraction should become increasingly weaker, do you agree?

Then we come to the blue-shift. I'm not entirely sure how you expect a object going away from the observer to be blue-shifted? Think of it as a rope that we arranged as a wave in space. Tie one end to the ship, the other you hold, now let the ship move away. The rope will tighten up right? All troughs and crest we had made will now 'smoothen' out into a 'straight line'. The same can be said for any wave-like radiation it creates, as its telemetry, if anything I would expect it to become red-shifted relative us? Maybe you are thinking that as it gets out of the solar systems gravitational field everything on that ship 'speeds up' in some way?

Maybe I will see your point better after sleeping :)
Let us discuss it tomorrow Mike.
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #7 on: 22/04/2011 11:45:44 »
"Maybe you are thinking that as it gets out of the solar systems gravitational field everything on that ship 'speeds up' in some way?"

Yes exactly, time passes slower in the Solar system because of gravitational time dilation, so it must flow faster outside the solar system.  So relative to us it is blue shifted.  This blue shift reduces the expected red shift.

"But Pioneer was on its way out of the 'Solar system'¨as it started to deviate so the gravitational attraction should become increasingly weaker, do you agree?"

Again yes, as the gravity becomes weaker so the rate of the flow of time increases relative to us.  The signal is blue shifted relative to our perspective which results in an overall decrease in the expected red shift.

"Think of it as a rope that we arranged as a wave in space. Tie one end to the ship, the other you hold, now let the ship move away. The rope will tighten up right? All troughs and crest we had made will now 'smoothen' out into a 'straight line'. The same can be said for any wave-like radiation it creates, as its telemetry, if anything I would expect it to become red-shifted relative us?"

I don't know much about waves but if the rate of flow of time is faster outside the Solar System then the wave length must get shorter, not longer?

Thanks for your input, I find this a fascinating subject.
Mike
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #8 on: 22/04/2011 14:37:28 »
This is just to hopefully clarify the situation.

Nasa speaks of the Voyager spacecraft making an anomalous acceleration towards the sun.  This is gobbledegook for meaning the spacecraft are slowing down.   

Using the same logic, a decrease in red shift can be seen as a blue shift. (or an anomalous acceleration towards the sun)

If this theory of time dilation within the solar System is correct then everything we observe from outside of the Solar System is slightly gravitationally red shifted.  I believe the effect is so small as to be insignificant for anything other than craft we are tracking leaving the Solar System.

All clear?

Mike
 

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Have the Pioneer anomalies also affected other probes?
« Reply #9 on: 22/04/2011 16:45:14 »
Sorry that should read Pioneer not Voyager.
 

Offline yor_on

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Have the Pioneer anomalies also affected other probes?
« Reply #10 on: 22/04/2011 18:25:27 »
What you are suggesting then is that due to a lesser gravity the Pioneer's red-shift, as observed relative earth, will be decreased? That as the gravity-well the light 'climbs' out of will diminish, the further that spacecraft moves from us? It's a cool idea :)

Now let us turn that around. We use red-shift to define astronomical objects, from those red-shifts and other types of triangulations we set their 'distances' relative us. Assume that with different gravity this red-shift will change relative us observing those suns etc. If you would be right you not only found a explanation to the Pioneer anomaly, but also invalidated all definitions we have of redshift, as we then also would need to know the specific 'gravity' involved at their source for defining their speed etc relative us.

I don't know Mike, to me a light quanta/photon will be of a defined energy. If we now translate that into a wave then it follows that this wave also have a 'defined' energy. What the light quanta does, when 'climbing' a gravity well like you sending a beam up from earth into the sky, is following the same path as it takes anywhere in the universe. That means that it does not expend any 'energy'. You need to remember that a photon never lose 'energy'. If it did we could expect all photons/waves to die at some point traveling towards us, but as far as I know they don't.

But when that light climbs the 'gravity well', assuming that we have an astronaut observing it, it will to him seem 'red shifted' meaning that it somehow have 'lost' energy. But as we already have defined it hasn't, not 'really' :). The redshift seen is a effect between the observer and the 'source' and that same 'light quanta' if instead observed outside that gravity well will now be found to be back to normal and no longer red shifted.

And if we assume that the beam is directed at some planet in another solar system, the observer on 'Earth Two' instead will see it as a 'blue-shift' as it 'accelerates' into that 'gravity well'. But from another light-quanta/photon/wave traveling beside our first, always at rest relative it, that light-quanta/photon/wave never changed its 'energy'.

That's how I see gravity's influence on relative red and blue shift. Then we come to relative motion. If you have two flash-lights, their beams pointing at each other and both equipped with detectors of that same beams, we can by setting them into motion towards or from each other get a similar effect. When you let them move apart their 'light-waves' will seem to 'stretch' relative each other, as with that rope I talked about and as long as they are moving apart this 'red-shift' will be true. The opposite, moving towards each other, will produce a blue-shift, relative each other.

Why I keep using 'relative each other' is because this effect seen is 'relative'. Remember that our light quanta/photon/wave have one 'invariant' energy, not many. But depending on whom sees that light, moving towards it or apart from it it will express a different 'energy'. That energy is a true measure of the energy, but only relative the one measuring it.

It takes some thinking around corners to see what I mean here but it falls back on, again as I see it, that lights speed in a (perfect) vacuum only can be of one 'speed'. The only way a 'light quanta' can express relative 'speeds' (motion relative a observer) is by red or blue-shifting where a blue-shift will be two objects moving towards each other, and a red-shift will be the same objects moving apart.

The red-shift seen is primary a Doppler red-shift, same as listening to that ambulances horn, sounding shrilly as it comes towards you, only to change to a deeper 'slower' bass as it later moves away from you, a little part but raising with velocity is the so called Lorentz-contraction that comes into play, noticeably around 0.5 'c' if I remember right and raises to become insurmountable near 'c' contracting the spacecraft in its motion.

Hope I didn't bore you to death here, but to see my points you need to see my premises.
And they are some :) and growing..

1. light is massless
2. light is time less
3. light has no inertia
4. a light-quanta will, from source to sink, be of one same 'energy', until its annihilation.
5. light has only 'one same speed' from, and in, any 'frame of reference' observed
6. The only way you can translate a 'acceleration/deceleration' for light, is in its relative blue or red shift. And that is a relation between the observer and the 'light-quanta/photon/wave'
7. When discussing the 'recoil' of a photon, as observed in some experiments. It has nothing to do with a acceleration. Assuming that the 'system' (source/photon) are at 'rest' before the excitation. The recoil will be a response to the 'demand' that the the final 'total momentum' of the source/photon interaction must equal zero. If we assume a photon to have a certain momentum, then the recoil have to exist to 'counteract/equalize' it. It's a question of the symmetry of our universe, and so make a very weird sense, just as lights 'speed' in a vacuum makes a weird sense.

In a way there are two ways to look at the laws of our universe. From inside where we discus forces and fields. From 'outside' where we talk about 'symmetries'. It's a really confusing place, SpaceTime :)


So the red/blue shift defined relative a gravity well is a 'short range' effect, only existing inside the gravity well. Whereas 'relative motions', moving towards or apart, is 'long range' effects, as I see it. This one is disputable and a sort of hand waving :) But I use it to emphasize a point. Invariant mass and 'gravity' is 'short range effects' as I thinks of it, the gravity-wells strength diminishing rapidly as it's a law squared, as you double the distance you have to quarter the gravity, or expressed differently Gravity Force Coupling Constant.

Those seven goes into each other, defining a very weird 'constant' regulating all life and our whole universe. Light never change its 'speed'.Frozen into a Bose Einstein condensate it will still have the property of 'c', although now in a state, relative us observing, that makes us describe it as being 'still'. As soon at we 'release it' we will find it 'moving at c', no acceleration involved. And what really happened there is that we enforced a new state on the condensate, storing the 'idea' of a photon in it, or if you like, added a energy to it that it couldn't express under those 'chilled' conditions.


Well, that's how I see it. And, as always, I will need to look at it later to see if it makes sense. Coffee usually helps there:) In a way you can see it as 'hand waving' as we only discuss it, not using any math. But I'm pretty sure that I have the idea of it right here. So, getting back to Pioneer, I don't think it is possible myself, although I'm not a hundred percent. Any red-shift expressed (versus us observing from Earth) will be relative its motion apart as I think, and what blue-shift we can expect will be the exact same blue-shift as for all light coming at us astronomically. But I still need to look at it again and see if I made any sense. So bear with me huh :) And let me get my coffee..

Light is so weird.

==

Told you I needed to look at it again :)
I'm the master of rewriting ::))
Ah well :)

But coffee helps, I just need some more..
==

Well, it worked, the coffee that is.
I hope I've corrected most of my misspellings, etc, now?
If I haven't, even coffee has a limit :)





« Last Edit: 23/04/2011 03:06:06 by yor_on »
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #11 on: 23/04/2011 08:44:44 »
“What you are suggesting then is that due to a lesser gravity the Pioneer's red-shift, as observed relative earth, will be decreased? That as the gravity-well the light 'climbs' out of will diminish, the further that spacecraft moves from us? It's a cool idea :)”

Yes, it’s a cool idea but as I understand it, it was Einsteins.  All I have attempted to do is apply the logic of relativity, without the math to the problem.

”Now let us turn that around. We use red-shift to define astronomical objects, from those red-shifts and other types of triangulations we set their 'distances' relative us. Assume that with different gravity this red-shift will change relative us observing those suns etc. If you would be right you not only found a explanation to the Pioneer anomaly, but also invalidated all definitions we have of redshift, as we then also would need to know the specific 'gravity' involved at their source for defining their speed etc relative us.”

The speed of light is a constant in a vacuum (away from anything that upsets it).  As I said everything that we see from outside the Solar System is marginally red shifted.  Light leaving any source that is big or massive enough for us to be able to see is being affected by a gravitational red or blue shift at source.  That’s why the quasar in a galaxy quasar pair always seems to be far red shifted in relation to the galaxy.  The quasar is far blue shifted at source.  Why is it blue shifted you might well ask?  Quasars only appear in the early universe, the first 20% of its age.  Quasars are what built the universe.  They are white holes in our universe; time reversed black holes in the previous antimatter cycle.  However, I digress into another even more fascinating subject.

I am a bit pushed for time at the moment so will keep this short for now.

This is the main thing to remember and people quote it frequently but I suspect seldom stop to really think about it.

“Relativity allows mass to gravitationally dilate time” (not stated but equally valid it allows for negative mass to contract time.  I do not know whether it states this or not but a very large local input of energy can also contract time locally.)

This is probably the main thing we need to remember.

The speed of light in a vacuum is allowed to be a constant because the rate of flow of time is a variable.

This affects all other constants of nature in a way that makes it impossible for us to tell any difference in the rate of flow of time.  One minute to us in our universe could to a hyperthetical observer outside the universe represent one minute or a million years.

So yes, the speed of light is invariant but the rate of flow of time isn’t.
Time flows slower near to the Earth.  Time flows slower in the Solar System.  Time flows slower in the Milky Way galaxy. Time flows slower in our local cluster and so on and so forth right up to intergalactic voids where gravity is at a minimum.  So you can see the one thing that the rate of flow of time isn’t, it isn’t constant.  Now there is good reason to believe that Einstein was correct when he declared the speed of light to be invariant.  However you can see from above that if we decided that the rate of flow of time was invariant then the speed of light would be a variable and variable all over the place.

Clear?

Mike
 

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« Reply #12 on: 23/04/2011 13:48:44 »
Well Mike, we have a divergence there. Time has the same 'rate' everywhere you go as I see it. If you go spacefaring or settle down on a neutron star doesn't matter for that. Time as such do not slow down on any of those places. The time dilation we see is a phenomena between 'frames of reference' not any observable for you. The only way to prove it is to make a so called twin experiment, and only as the traveling twin come home to roost will it be shown.

Imagine yourself having a super telescope following that traveling twin. At no 'time' will you lose sight of him and at no time will you find your 'time' to act funny watching him, and neither will you find his spacecraft slow down as it 'speeds up' relative you. What gravity does is influencing 'time' but in no way perceptible for you. Assume that each human have one million heartbeats before he dies, then that is our measured life span. And it will be so wherever you go, and whatever you do. That the universe dies as you travel near light doesn't matter for this. Your time will be the same, as mine, and as everyone else's. The mistake people make is to assume that as a time dilation exist time isn't of one duration. That's wrong, time is of only one duration, but when comparing between frames of reference we will find discrepancy's. But without a twin experiment you will have a he* of a problem defining how your 'time' fares relative anything else. Time is on your personal plane of only one duration, but on the conceptual plane 'fluid'. You have to see the difference there because that one is important for understanding why there are no pockets of 'slower time' in the universe.

In reality you will never find a place where time change duration.
 

Offline MikeS

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« Reply #13 on: 23/04/2011 16:41:56 »
Ok good now we are making progress.

Well Mike, we have a divergence there. Time has the same 'rate' everywhere you go as I see it. If you go spacefaring or settle down on a neutron star doesn't matter for that. Time as such do not slow down on any of those places.

Relativity tells us that the rate of flow of time can vary. Where is our divergence, do you not believe in Relativity?  Relativity proposes time dilation by massive objects right?  We know this to be correct as it has been shown that atomic clocks in orbit where gravity is less run faster than on Earth.  Also time dilation has to be taken into account for satellite navigation systems. Time dilation caused by the Earth is minute but is the scheme of things the Earth is only small.  Do you agree so far? 

Time dilation is very real.

Lets go back to the Pioneer anomaly again.  The anomaly was signals from the spacecraft were observed to be blue shifted.  This was interpreted as meaning that the spacecraft were slowing down.  The anomaly only became apparent when the spacecraft were leaving the Solar System.  These I think you will agree are known facts.

Relativity states that massive objects can gravitationally dilate time (slow it down).  Still with me?  The pioneer spacecraft outside the Solar System transmit their signal home.  That signal as it enters the Solar System becomes red shifted due to gravity, which is exactly what we see.  From our perspective we see the signal as relatively blue shifted.  As I have said before the red shift is not as far red shifted as predicted.  The spacecraft are where they are supposed to be they just appear to be closer to us than they are.  What is it about this that you either don't agree with or don't understand?

At no 'time' will you lose sight of him and at no time will you find your 'time' to act funny watching him, and neither will you find his spacecraft slow down as it 'speeds up' relative you.

Consider he flies too close to a large black hole and just manages not to get caught.  We would observe him to slow down whilst he was near the event horizon but he would still consider himself travelling at the same speed.  There is a discrepancy in the rate of flow of time between the two twins.

You have to see the difference there because that one is important for understanding why there are no pockets of 'slower time' in the universe.

That's not true we live in one.  If we lived in orbit at the edge of a black hole event horizon we would be living in a very large one.

In reality you will never find a place where time change duration.

The only way you can make a statement like that is if you don't believe in gravity causing a relativistic time dilation.  I guess you don't have to believe in it but it has been proven to be true.  Personally I don't believe in quantum gravity.  However, I suspect you do believe in relativistic time dilation by gravity, in which case I'm not sure what it is we disagree upon?

One of us must have got it wrong.  I don't think it is me and I know I am out on a limb but If you can prove me wrong then fair enough. Hopefully, we will eventually reach a mutual agreement that will entail an increase in knowledge and understanding.

Mike



































 

Offline yor_on

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« Reply #14 on: 23/04/2011 18:49:07 »
No Mike :)

I think I'm right there, and I have no trouble believing in 'time dilation'. It's just that there exist no corners of this universe that will make your time go any 'slower'. As I said, time dilation is a comparison between 'frames of reference', not 'time' slowing down for you.

==

Thinking of it, maybe that 'spaceship' moving apart will 'hang' too? :)
Yep, I think it will. But it doesn't invalidate what I say.
=

You also need to realize that, from the viewpoint of those people inside the spacecraft, their 'time' is as always. They will in a 'time' oversee-able by them pass what we define as the EV and plunge into the singularity. And that 'time' they experience will to them be no different than the 'time' they experienced at home. As I see it :)

I'm not proselyting Mike, this is the opinion I have. You're welcome to yours however. I don't expect you to change your mind here though, so let us merely accept that we have two interpretations of the same phenomena.
« Last Edit: 23/04/2011 18:53:31 by yor_on »
 

Offline yor_on

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« Reply #15 on: 23/04/2011 19:12:36 »
You know, I really need to consider that definition of it 'hanging' there. First I explained as the light being 'delayed' but I took that away as you then would assume that your interpretation of different pockets of 'local time' being true. My explanation was correct but not 'clear'. It is a result of the room time geometry around a black hole. As the spacecraft falls toward the event horizon the 'room time geometry' around that ship warps with the increasing gravity and the photons bouncing of that spacecraft will red shift relative the observer outside the gravity well, as well as take more 'time' to reach him. So it's not photons slowing down as they bounce back from the event horizon, but rather a effect of the room time geometry around it. But it is easy to see that there is no such pockets of 'slow time' if we turn it around. Assuming you to be right you would now find that the speed of light in a vacuum no longer can be called a 'constant' as it then would have to 'slow down' in those 'time pockets'. Quite a nice name btw :)



Hope this one makes better sense :)
==

If you accept that the speed of light is a 'constant' the same everywhere in SpaceTime, then any explanation talking about 'delayed light', propagating inside a vacuum (space) only has one solution. Namely the room time geometry being warped for the light propagating. I use 'room time geometry' instead of 'frame of reference' for defining a 'SpaceTime' as seen from 'first perspective', the one we experience first handedly. 'Frames of reference' is very much about comparisons between frames conceptually, but I find the 'first perspective' to be more of a immediate 'reality' as that is the one we experience ourselves, constantly, until we die.
« Last Edit: 23/04/2011 19:28:12 by yor_on »
 

Offline MikeS

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« Reply #16 on: 24/04/2011 06:23:34 »
Ok, let me try to summarize.  Please correct me if I am wrong.

This is part of what I wrote in my last post and it is in essence what we are disagreeing about:-

"Lets go back to the Pioneer anomaly again.  The anomaly was signals from the spacecraft were observed to be blue shifted.  This was interpreted as meaning that the spacecraft were slowing down.  The anomaly only became apparent when the spacecraft were leaving the Solar System.  These I think you will agree are known facts.

Relativity states that massive objects can gravitationally dilate time (slow it down).  Still with me?  The pioneer spacecraft outside the Solar System transmit their signal home.  That signal as it enters the Solar System becomes red shifted due to gravity, which is exactly what we see.  From our perspective we see the signal as relatively blue shifted.  As I have said before the red shift is not as far red shifted as predicted.  The spacecraft are where they are supposed to be they just appear to be closer to us than they are.  What is it about this that you either don't agree with or don't understand?”

Although you didn’t directly answer the above questions, as I understand it whilst saying that you have no trouble in believing in ‘time dilation’ between ‘frames of reference’ you don’t actually believe in time dilation as being a very real and observable property of the universe, is that correct?

My take on the Pioneer anomaly is it is a real and observable example of time dilation.  Time dilation means that the passage or rate of flow of time is variable.  For the speed of light to be a constant, the rate of flow of time must be a variable.
To summarize my view, the speed of light is a constant because the rate of flow of time in the universe is a variable.  The universe has an average rate of flow of time, however on any local scale there can be deviations from the average.

To me the idea of the rate of flow of time being variable is perfectly reasonable.  It is predicted by relativity, has been proven to be true and is a real and observable phenomenon.  It explains the Pioneer anomaly in very simple terms.

As you say we can agree to disagree because we have two interpretations of the same phenomena.  There probably is only one truth on the subject and it would be good to agree.

You said in a previous post:-
 “What you are suggesting then is that due to a lesser gravity the Pioneer's red-shift, as observed relative earth, will be decreased? That as the gravity-well the light 'climbs' out of will diminish, the further that spacecraft moves from us? It's a cool idea :)”

Yes, that’s it exactly, you initially seemed to like the idea until you thought about it and realized that it implied gravitational time dilation.

Although you say you believe in time dilation, it seems to me you only believe in it in an abstract frames of reference sense.  Why is it so difficult to believe in time dilation as being real and observable as in the Pioneer anomaly?

I do not want to labor the point but where you say:-
“But it is easy to see that there is no such pockets of 'slow time' if we turn it around. Assuming you to be right you would now find that the speed of light in a vacuum no longer can be called a 'constant' as it then would have to 'slow down' in those 'time pockets'.”

If we analize what you are actually saying. 

the speed of light in a vacuum no longer can be called a 'constant' as it then would have to 'slow down' in those 'time pockets'.”

What you are missing here is the speed of light in a vacuum is a constant precisely because the rate of flow of time is a variable.

Mike
 

Offline MikeS

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« Reply #17 on: 25/04/2011 14:50:39 »
In your last post you said:-

“If you accept that the speed of light is a 'constant' the same everywhere in SpaceTime, then any explanation talking about 'delayed light', propagating inside a vacuum (space) only has one solution. Namely the room time geometry being warped for the light propagating.”

Or another way of putting this is:-

“If you accept that the speed of light is a 'constant' the same everywhere in SpaceTime, then any explanation talking about 'delayed light', propagating inside a vacuum (space) only has one solution. Namely the room time geometry being warped for the light propagating.”

"For  room time geometry being warped for the light propagating.
Read, space time geometry being warped by mass for the light propagating.

For space to be warped, something has to cause it to warp.  In this case, we are talking about mass.

Another way of putting this is mass cause’s space-time to dilate (warp).

Another way of putting this is mass causes the rate of flow of time to slow down.

You seem to be in full agreement with me.  Surely, this cannot be?

Mike
 

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« Reply #18 on: 25/04/2011 18:06:08 »
Time is a really weird phenomena Mike, just as 'frames of reference'. Take a look here and see how it is explained in the wiki Relativity of simultaneity. . It's as they say 'counterintuitive' and makes no real sense, well, as we're used to think of it. It's like 'times arrow' as such always is following you keeping the same steady rate, but when comparing between frames we find the opposite being true. There we need to apply mathematical transformations, translating their 'SpaceTime coordinates' to ours before they start to make sense.

You might see it as if 'light' is what gives you the 'whole seamless SpaceTime' whilst 'motion' and 'mass' is what creates the different frames of reference, that's how I see it myself for now. But there is one thing I'm quite sure of and that is that you will find nowhere in the universe where light will slow down, or speed up, in a vacuum. And if you was right then those places should exist relative the observer outside the gravity well. And as far I know they don't. It's a cool idea, 'time-pockets' as I call them but I don't expect them to exist myself. That 'times arrow' differs when comparing is a direct result of the SpaceTime geometry. And as I said, when discussing it from the 'first person' view then I like to call that your 'room time geometry'. And that definition is solely mine :)
« Last Edit: 25/04/2011 18:22:10 by yor_on »
 

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« Reply #19 on: 25/04/2011 20:02:30 »
"But there is one thing I'm quite sure of and that is that you will find nowhere in the universe where light will slow down, or speed up, in a vacuum."

I agree entirely light never slows down or speeds up. It does not have to, the rate of flow of time changes to accommodate it.  As I have been saying all along, the speed of light is a constant because the rate of flow of time is a variable.

Mike
 

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« Reply #20 on: 26/04/2011 01:10:42 »
How Mike?

How does time adapt?
And why would it adapt to a constant?
 

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« Reply #21 on: 26/04/2011 01:42:09 »
A constant is by definition unchanging. You can't have it both unchanging and changing Mike, if you use such a definition then we're not talking about a constant any longer. When we speak about the room time geometry inside a black hole we can define it, depending on whose math we trust and 'mass' as 'infinite'. That doesn't state that time changed its 'speed' to adapt so that we will find the speed of light in a vacuum to fit. It state that the room time geometry is different, the reason why we use room time is because you can't have a 'room' without time and neither can you have a 'time' by itself. But the direct effect for us being inside will be that the room in fact become infinite, not that light as such change speed.

In one way this whole discussion is meaningless as 'speed' is a very shaky definition. The only thing that always seem to have one exact 'duration' when measured by us, invariant in/from all frames, is lights speed in a vacuum. And that goes from anywhere you choose to measure it, inside that black hole or outside it. You can measure it from any frame you like, against any other frame, moving near the speed of light measuring that event horizon for example. You will still find it to have one single 'speed'. But you can have an observer at the same exact 'location' as where you do your measurement, but contrary to you being still relative that black hole. He will be doing the exact same measurement on the same light. And you will both find the speed to be the same, namely 'c'.

The speed of light in a vacuum is invariant. Time does not slow down to adapt the light speed, as shown by our two observers, to fool us. To me it's a question of the geometry of SpaceTime, and it is coupled to mass, motion, and possibly energy?
==

As it seems to me )

In your world everything gets invincible forcefields of 'time' adapting itself so that we won't notice lights speed 'differing' if I understand you right? Whilst in mine there is only one thing that is constant, namely lights speed in a vacuum. I go out from that definition and from there I find the geometry of 'SpaceTime' to change. That also fits with all observation I know of your personal time never differing, no matter if you're at the EV of a black hole, speeding away near light, or just comfortably reclining in your sofa.

Using your definition it becomes trickier it seems.  When it comes to uniform motion you can exchange any motion measured. For example, 'A' will say it moves close to lights speed relative 'B' being still, but, you can as easily exchange that to it being 'B' moving near lights speed relative 'A' being still, or give them both any speeds in between as long as they add up to the number measured relative each other.

In Relativity both statements are true when it comes to uniform motion, and it builds on the equivalence of them, as observed and tested in a 'black box scenario'. If all experiments you can do inside that black box, on each of the ships, gives you the exact same results, then all uniform speeds are the same from that point of view and so speed becomes a meaningless definition. (ignoring tidal forces here)

But it seems to me that if you was right then we would have a way to prove that only one of them was 'moving'. And that would redefine the equivalence principle and theory of relativity to me  :) And as I see it, for Einstein too if he was here.
« Last Edit: 26/04/2011 02:52:09 by yor_on »
 

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« Reply #22 on: 26/04/2011 03:21:31 »
You can, if using my definition, think of time as measured out by lights invariant propagation. Then it will with relative motion (and mass) be found to have different 'distances' to reach. If you're uniformly moving away from the light it will take longer to reach you than if you were moving towards it. That can in a way be translated into time. The geometry you move in is dependent on those light signals, they are the watch that 'ticks', and they 'tick' differently for you moving than for you being still. And they will be normal to you as all 'light ticks' only can have one constant invariant speed, but to the observer being still they will describe another duration as they propagate trough space, moving with you.

And as light is the only true constant, that and the fact that your personal time never changes, then the effect you see in a time dilation suddenly will be found to be placed in the relation between you and the observer. In SpaceTime all time is a definition from lights propagation, and the geometry changes with it too. To you the light clock you have with you always bounce the same amount of 'distance'. But to the observer at rest relative your origin (Earth) that same 'light corn' will bounce a different (longer) path through SpaceTime. And yet you both observe the same light-clock, although it to him will be found to take a longer path through space as you move, but for you, being at rest with it comoving, it will be found to take the exact same path as on Earth.

There is two ways to look at that phenomena, that light will be found to have a 'longer path' from Earth than as what you perceive traveling aside it. Either you define it as the light clock 'slowing down' as observed by the observer on Earth, now saying that light goes 'slower' inside that ship, and that seems to be your interpretation of it, or you define it as light having one invariant speed and the effect you observe being a result of 'different' room time geometries, the observers and yours, aka 'frames of reference'. But as I also see their 'times arrow' as unchanging in both scenarios, which is my interpretation of it :) I state that it is the room time geometry that is different for them. And stating that I define the room time geometry as their 'SpaceTimes' being different. Which in a way make me even more heretic than you as I now define them each one to have a unique, different, SpaceTime :) And that's kind'a weird :) The only thing that I see binding those SpaceTime's together is 'light'. Radiation is what makes this universe seem seamless to us, that and mass, motion, and possibly 'energy'. It both is what shows us that we're in reality 'divided' at the same time as it 'joins us' :) And now I'm afraid we soon will have to move us both to 'New Theories'.

Ahem..

And that's why your personal time always is the same, unchanging, and that's why the observer and you will disagree on the 'time taken'. And that's why a time dilation exist. But it weirder than that :) Because as I said, you can define any uniform motion as being at rest, weightlessly 'drifting', no gravity existent. And that is true, there is no way you will find any gravity inside that black box. And if you measure a light coming from the stern to the aft, it will not 'blue shift' no matter what speed you believe yourself to have relative Earth. Also you can redefine our planetary gravity (Earth) as a constant 'uniform' acceleration at one gravity. And that is the direct equivalence to your spacecraft starting to accelerate a constant one gravity. And if you now watch that light in-falling from the stern you will find it to blue shift, same as on Earth. So it's a tricky business, where it's very easy to get lost in its definitions. But it's a nice idea, although I see it differently.
« Last Edit: 26/04/2011 03:51:38 by yor_on »
 

Offline Geezer

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« Reply #23 on: 26/04/2011 03:42:03 »
Let's try an experiment.

I'm zipping along in my very fast spaceship. So fast in fact that time will be dilated relative to time on Earth. On my spaceship, I happen to have an evacuated tube and a light source that allows me to measure the speed of light in a vacuum. It's really quite a simple setup.

If I understand how this all works, despite any shortening of the tube and local time dilation, the value that I measure in my spaceship will be exactly the same as the value I measure using the same equipment on Earth.

Do we all agree with that, or have I got it wrong somewhere?
 

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« Reply #24 on: 26/04/2011 03:53:53 »
As long as you're uniformly moving that should be correct as I see it :) It will 'zip away' or 'tick' heh :) the same as on Earth.
==

Maybe you are thinking of what will happen if you turn it around? In the direction of the motion '|' as for putting it horizontal '-' to the motion. The Lorentz contraction will equalize the difference as I see it. and so the 'ticks'  will be found, from a thought up observer on Earth, to be the same when measured, all of the same duration. And for you being inside the ship, you will be at rest with your equipment and so notice no difference at all.

In a acceleration it becomes trickier for me as there will be a constant accelerating displacement relative the lights path, with a respective red and blue shift noticeable. But as lights speed in a vacuum is a constant, it shouldn't matter for the 'ticks'. Ah, that is for you being inside, at rest with the light source. For our observer at Earth the acceleration will change the durations measured, well as I think. Acceleration is indeed trickier, and very weird to me.
==

Think of bouncing a tennis ball on the floor of a aircraft at 900 km/h. The ball won't care, it will go straight down on the floor and up. But if the floor was made of glass and someone standing on earth could watch that ball bounce he would swear to it taking a curved path down and then a curved path up. Exchange the ball for light, and define it as a constant, always of the same exact 'speed' in a vacuum. Then try to define the shortest durations we can measure. That will be by that same invariant light, won't it? Radiation is the best 'clock' we have.
« Last Edit: 26/04/2011 04:24:59 by yor_on »
 

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