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 #38164 - 04/18/11 02:05 PM Re: Light From Distant Galaxies. Bill Megastar Registered: 12/31/10 Posts: 1858 Loc: Oklahoma, USA Bill 6, You pick up on the equivalence principle, but you ignore one of the basics on which Einstein based both SR and GR. The measured speed of light is the same in ANY reference frame. It doesn't matter where the light is coming from or what motion the source may have with respect to the reference frame of the observer it still travels at the same speed. Since the speed is constant the only variable left is the frequency. So it is red shifted if it moving away from you, or is coming out of a gravity well.Remember that one of the problems that Einstein addressed with SR was the failure to detect a change in the speed of light depending on the direction of motion. The Michelson-Morley experiment was expected to find the difference based on the direction of movement of the earth. It failed, and created a significant problem for Newtonian physics. SR, based on the fact that the speed of light is constant for all observers took care of the problem.Bill Gill _________________________ C is not the speed of light in a vacuum.C is the universal speed limit. Top
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 #38167 - 04/19/11 02:04 AM Re: Light From Distant Galaxies. [Re: Bill] Bill 6 Member Registered: 02/28/11 Posts: 74 Loc: Australia Originally Posted By: BillBill 6, You pick up on the equivalence principle, The term 'pick up' implies a surreptitious application. I 'pick up' on the equivalence principle on the basis of its validity and relevance!Originally Posted By: Billbut you ignore one of the basics on which Einstein based both SR and GR. The measured speed of light is the same in ANY reference frame.I previously pointed out that an observer located alongside the black hole adjacent light source (due to the fact that his measuring rods and clocks are physically affected by the gravitational field) will determine constancy for both beams however the far-distant observer will not!Are you of the opinion that the relevant beams in my diagram (depicting an accelerating light source, ref below) will not travel different distances away from their source in a given period of time as determined by your clock?<------------•---->Originally Posted By: BillIt doesn't matter where the light is coming from or what motion the source may have with respect to the reference frame of the observer it still travels at the same speed.It is still measured as traveling at the same speed by the local observer but only due to the fact that his measuring rods and clocks are physically affected by their locations in a gravitational field.Refusing to respond to this point does not invalidate it.GR tells us, and the Wallops Island experiment confirmed, that clocks which are located at various altitudes will tick over at different rates and, obviously, the same thing applies to clocks that are at different fixed distances from a black hole.Depending on their point of attachment - radially orientated measuring rods will either be stretched or compressed in length.A local observer who conveniently chooses to ignore those facts will determine constancy for the respective beams of light.If you agree that the respective beams will travel different distances away from their accelerating source in a given period of your time as per the above diagram - are you of the opinion that the principle of equivalence does not apply in the situation I depicted; that the respective beams will not travel different distances away from their source in a given period of time as determined by your (far distant observer) clock?• <---------------•----->I make every effort to directly respond to all salient points introduced by others and would appreciate reciprocality.You wrote that I "...ignore one of the basics on which Einstein based both SR and GR. The measured speed of light is the same in ANY reference frame." yet you seemingly choose to ignore the fact that Einstein stated in the introduction to GR:-"...daß das Prinzip von der Konstanz der Vakuum-Lichtgeschwindigkeit eine Modifikation erfahren Muß."(...that the principle of the constancy of the vacuum speed of light must be modified.)There are two ways of modifying that principle - 1) The speed of light is not always constant and 2) the speed of light is not constant and, as Einstein points out in his book 'Relativity', the presence of a gravitational field invalidates special theory.To the best of extant scientific knowledge - there is no place in the entire universe that is not permeated to some degree by gravity.The MMX bears no relationship whatsoever to a discussion pertaining to the variable speed of light in a gravitational field ergo reference to same is nothing more than a red herring. Top
 #38168 - 04/19/11 03:09 PM Re: Light From Distant Galaxies. Bill Megastar Registered: 12/31/10 Posts: 1858 Loc: Oklahoma, USA I am of the opinion that when Einstein said that light always travels at the same speed he meant just that. You say that the measuring tools are distorted. I say that they are perfectly correct under any conditions. When I measure a length in a reference frame that is moving or in a different gravitational field with respect to the one I am in I am getting correct measurements, even though they are different from the measurements somebody in that reference frame would get. We are both correct in our measurements, it is just that we are looking at them differently. There is no distortion in any of them. You have to accept that things in a GR world are just not what we intuitively think they are because we live in a world that is very little affected by GR.Bill Gill _________________________ C is not the speed of light in a vacuum.C is the universal speed limit. Top
 #38172 - 04/20/11 12:55 AM Re: Light From Distant Galaxies. [Re: Bill] Bill 6 Member Registered: 02/28/11 Posts: 74 Loc: Australia Originally Posted By: BillI am of the opinion that when Einstein said that light always travels at the same speed he meant just that.I am of the opinion that when Einstein said, in 1905, that light always travels at the same speed he meant just that and when, TEN YEARS LATER, he said it doesn't he also meant just that.I have provided you with reference material to that effect yet you choose to deliberately ignore same. Originally Posted By: BillYou say that the measuring tools are distorted. I say that they are perfectly correct under any conditions.I am obviously wasting my time asking you to respond to my comments or questions as you evidently lack the common courtesy to do so. I have already described the distortion incurred by measuring rods and clocks in a gravitational field but by refusing to respond to my comments you are of the opinion that they never occurred.Turning your back on a legitimate question is a personal insult indicative of an unworthy opponent.Originally Posted By: BillWhen I measure a length in a reference frame that is moving or in a different gravitational field with respect to the one I am in I am getting correct measurements, even though they are different from the measurements somebody in that reference frame would get. We are both correct in our measurements, it is just that we are looking at them differently. There is no distortion in any of them. You have to accept that things in a GR world are just not what we intuitively think they are because we live in a world that is very little affected by GR.Bill Gill According to SR - if I change my location to that of another, previously synchronous, clock I will find that my clock then lags behind that clock due to the fact that my clock has, whilst I was moving, ticked over at a slower rate than the other clock.Whilst I am fully entitled to insist, whilst I am moving, that my clock is ticking over at its 'correct' or 'normal' rate I would be contradicting special theory if I were to insist, whilst I am moving, that my clock's rate of operation has not changed from what it was before I started moving.Oxford dictionary - 'Distorted': changed.Assuming that they have read and accepted SR - somebody in that clock's reference frame will get the same measurements as I do with respect to my clock's rate of operation not different measurements as you state above.It appears that 'what I have to accept' is that you will continue to rudely ignore my questions in your authoritarian ad hominem fashion. Top
 #38178 - 04/20/11 02:31 PM Re: Light From Distant Galaxies. Bill Megastar Registered: 12/31/10 Posts: 1858 Loc: Oklahoma, USA Well, I figure you just need a little education. The fact is that nothing changes in any of the scenarios you suggest, except your perception. Your demonstrations assumes that you are working in space. But in spacetime you have to include the time dimension. When you do that you are actually viewing the projection of the object which is moving partly in the time dimension. This means it is tilted with respect to your view and is thus shortened, as you view it. Just as something that you view at a sharp angle to its length is shortened in your view. Think of an arrow which you look at from almost in front. The view you have makes it look very short. The difference in relativity is that the apparent shortening due to the timelike part of its travels is retained when it returns to a more spacelike frame of reference. And if I really understood what relativity means I would write it up and get me a Nobel Prize. Our minds just aren't really built to correctly visualize the effects of relativity.And of course there are those who will jump on the "it's your fault for not agreeing with me" bandwagon.Bill Gill _________________________ C is not the speed of light in a vacuum.C is the universal speed limit. Top
 #38183 - 04/21/11 07:21 PM Re: Light From Distant Galaxies. Bill Megastar Registered: 12/31/10 Posts: 1858 Loc: Oklahoma, USA Well, I will give one more reply. You suggested that light travels at different speeds, using a diagram to show it. Your diagram doesn't show anything of the sort. It is the same thing that Michelson-Morley experiment tested for and it was found that it didn't happen. If you measure the speed of light in the frame of reference of the source it will be found to be C. If you measure the speed of light from that source in any other reference frame it will be found to be C. The frequency of the light will be different, but there will be no change in speed. This applies whether the two frames are moving with respect to each other or if they are in locations where the spacetime is warped differently (that is they are in places where the gravitational field is different). Since they are in different reference frames their clocks and other measuring tools will give different results, because of the effects of relativity. The tools will still be completely accurate in their own reference frame, it is just that in comparing them between different reference frames they will appear to be different. The predictions of relativity, both SR and GR, have been tested to very high accuracy and they have so far been found to be correct. And in none of the tests has there been found any indication that C changes under any conditions. If you can't believe that I suggest that you get a good book on relativity and study up on it.Bill Gill _________________________ C is not the speed of light in a vacuum.C is the universal speed limit. Top
 #38185 - 04/21/11 09:11 PM Re: Light From Distant Galaxies. Bill S. Megastar Registered: 08/20/10 Posts: 3570 Loc: Essex, UK Fortunately the OP takes no responsibility for the way in which a thread develops. I'm sorry to see the way this is going, though, and without any of the forum's regular "snipers". However, to take a positive from it; it's going to make me take another look at the whole idea of relativity. Just when I thought I was getting the hang of it. _________________________ There never was nothing. Top
 #38196 - 04/22/11 06:31 AM Re: Light From Distant Galaxies. Bill 6 Member Registered: 02/28/11 Posts: 74 Loc: Australia Originally Posted By: Bill S.Fortunately the OP takes no responsibility for the way in which a thread develops. I'm sorry to see the way this is going, though, and without any of the forum's regular "snipers".Perhaps, like me, the forum's regular snipers feel that it's only worthwhile contributing if we've got something to contribute.Originally Posted By: Bill S.However, to take a positive from it; it's going to make me take another look at the whole idea of relativity. Just when I thought I was getting the hang of it. Relativity's 'law' of the constancy and maximum attainable speed of light is a barrier against scientific progress in general and the conquest of space in particular.Whilst SR 'allows' long distance travel based on its time dilation factor neither industrialists nor politicians are keen to approve the expenditure of trillions of dollars on projects that might take millions of years to generate profits.We need to take another look at the whole idea of relativity and if my feeble efforts prompt others to do so then I'll be happy.A major objection to the concept of a variable speed of light in a gravitational field is the fact that it presents a challenge to the basis of the 'big bang' theory - the redshift of distant galaxies.There we go - another quantum thread shift. Top
 #38198 - 04/22/11 02:07 PM Re: Light From Distant Galaxies. Bill Megastar Registered: 12/31/10 Posts: 1858 Loc: Oklahoma, USA Ok, I see. You have unilaterally decided that Einstein is wrong, because you want him to be wrong. Therefore all the research that has shown he is right is also wrong. Since you don't want to be educated I will just stop trying.Bill Gill _________________________ C is not the speed of light in a vacuum.C is the universal speed limit. Top
 #38201 - 04/22/11 11:57 PM Re: Light From Distant Galaxies. [Re: Bill] Bill 6 Member Registered: 02/28/11 Posts: 74 Loc: Australia Originally Posted By: BillOk, I see. You have unilaterally decided that Einstein is wrong, because you want him to be wrong. Therefore all the research that has shown he is right is also wrong. Since you don't want to be educated I will just stop trying.A typical spoiled brat reaction.I exposed the fact that you were starting to agree with me so you spit the dummy.I have never suggested that Einstein was wrong! I happen to agree with Einstein that special theory is invalidated by gravity.In accordance with the scientific principle that no theory can be proven, only disproven, the research that has purportedly ratified SR does not prove SR however people such as yourself find no problem in ignoring such principles when it suits them to do so."By denying scientific principles, one may maintain any paradox." (Galileo)I did not respond to this thread on the basis that I wanted to be educated but if I had I would certainly not accept the words of a biased, deceitful person like you. Top
 #38203 - 04/23/11 01:53 AM Re: Light From Distant Galaxies. Bill Megastar Registered: 12/31/10 Posts: 1858 Loc: Oklahoma, USA As I said, Einstein's theories have been extremely well tested, and they have always passed. Now you say that gravity is wrong in his theories. How do you explain all the times that it has been tested successfully?Originally Posted By: Bill 6"By denying scientific principles, one may maintain any paradox." (Galileo)The devil can quote the scriptures for his own ends.Bill Gill _________________________ C is not the speed of light in a vacuum.C is the universal speed limit. Top
 #38204 - 04/23/11 03:12 AM Re: Light From Distant Galaxies. [Re: Bill] Bill 6 Member Registered: 02/28/11 Posts: 74 Loc: Australia Originally Posted By: BillAs I said, Einstein's theories have been extremely well tested, and they have always passed. Now you say that gravity is wrong in his theories. How do you explain all the times that it has been tested successfully?I made no comment to the effect that 'gravity is wrong' in Einstein's theories.You previously wrote:-Originally Posted By: BillSince you don't want to be educated I will just stop trying.On the basis that you obviously lack the courage of your convictions as well as continue to post comments that you falsely attribute to me I herewith terminate our discussion. Top
 #38209 - 04/23/11 10:26 PM Re: Light From Distant Galaxies. Bill S. Megastar Registered: 08/20/10 Posts: 3570 Loc: Essex, UK Originally Posted By: Bill6I herewith terminate our discussion.Only in this thread, I hope. _________________________ There never was nothing. Top
 #38213 - 04/24/11 03:53 AM Re: Light From Distant Galaxies. Bill 6 Member Registered: 02/28/11 Posts: 74 Loc: Australia Originally Posted By: Bill S.Only in this thread, I hope. In any thread wherein a contributor resorts to deception. Top
 #38217 - 04/24/11 02:44 PM Re: Light From Distant Galaxies. Bill Megastar Registered: 12/31/10 Posts: 1858 Loc: Oklahoma, USA Originally Posted By: Bill 6In the MMX the light source is NOT accelerating relatively to the observer!Then the circular rotation of the earth and its approximately circular orbit around the sun don't produce an accelerated motion. And the experiments operation in the earth's gravitational field didn't cause any relativistic changes.Originally Posted By: Bill 6Relativity's 'law' of the constancy and maximum attainable speed of light is a barrier against scientific progress in general and the conquest of space in particular.Well yes, relativity's law of the constancy and maximum attainable speed of light is indeed a barrier against a lot of things that we wish would happen. Unfortunately, no matter how much we would like to find a way around it so far nobody has found such a way. And wishful thinking doesn't count in science. Unfortunately, we can't just wish away the laws of nature, we have to go ahead and live with them. So buck up and accept the facts, instead of railing against people who point them out to you.Bill Gill _________________________ C is not the speed of light in a vacuum.C is the universal speed limit. Top
 #38220 - 04/24/11 10:29 PM Re: Light From Distant Galaxies. [Re: Bill] Bill S. Megastar Registered: 08/20/10 Posts: 3570 Loc: Essex, UK Originally Posted By: Bill6Imagine that you are looking at a light source located in your reference frame and some distance away from you. The source emits beams of light in opposite directions which, in a certain period of time as determined by your clock, travel identical distances away from that source:-<----------•---------->The source now starts accelerating across your line of vision and again emits beams of light in opposite directions which, in a certain period of time as determined by your clock, travel different distances away from their source:-<---------------•----->From your point of view, as a distant observer, the beams are moving at different speeds relative to you due to the fact that their source is accelerating.Bill6, I know you said you were terminating your discussion in this thread, but I need some help getting my head around this, so I'm hoping you are still there.I have no problem with the above quote up to the last sentence. You say: "...the beams are moving at different speeds relative to you...". My interpretation of your second diagram would be that the two light beams are moving at the same speed relative to the observer, but appear to the observer to be moving at different speeds relative to the source. I'm quite prepared to believe I'm missing something, but I need to know what it is. _________________________ There never was nothing. Top
 #38222 - 04/25/11 02:27 AM Re: Light From Distant Galaxies. Bill 6 Member Registered: 02/28/11 Posts: 74 Loc: Australia Originally Posted By: Bill S.Bill6, I know you said you were terminating your discussion in this thread...I have terminated a discussion in this thread not all of my discussions.Originally Posted By: Bill S.My interpretation of your second diagram would be that the two light beams are moving at the same speed relative to the observer, but appear to the observer to be moving at different speeds relative to the source. I'm quite prepared to believe I'm missing something, but I need to know what it is.Special theory's concept of the constancy of the speed of light applies exclusively to inertial reference frames.In my depiction the light source is accelerating ergo it is not an inertial reference frame thus SR's law of light speed constancy does not apply.In accordance with the principle of equivalence - that law is, as Einstein pointed out in relation to gravitational fields, invalidated by acceleration/gravity.Before the inevitable deceptive response is posted - there has never been an experiment which indicates the constancy of light emitted by an accelerating source.But, thanks to your enquiry, I now realise that I confused the two observers and where I wrote that the beams emitted by the accelerating light source do not travel at the same speeds relative to the distant observer I should have written relative to the local observer; i.e. a person traveling along with the light source.This does not, however, alter the fact that where the light source is at a fixed location from a black hole the respective beams travel at different speeds relative to the distant observer. Top
 #38225 - 04/25/11 05:27 PM Re: Light From Distant Galaxies. Bill S. Megastar Registered: 08/20/10 Posts: 3570 Loc: Essex, UK Originally Posted By: Bill6...I should have written relative to the local observer; i.e. a person traveling along with the light source.I could be getting there - slowly. Correct me if I am wrongly interpreting you, but you seem to be saying that an emitting source that is accelerating relative to a beam of light will observe that light as travelling at less than "c". If that is the case, and the source were able to accelerate to the speed of light, would it not observe the light as stationary? _________________________ There never was nothing. Top
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