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Why in the world would Einstein suggest... 2

 
 
layman
 
  2  
Reply Thu 7 May, 2015 11:56 am
@Olivier5,
Quote:
That diagram does not speak of simultaneity, and Poincare never said that time was not intuitive....How obtuse can you be?


What Poincare did say about time (among other things) was:

Quote:
We have not a direct intuition of the equality of two intervals of time. The persons who believe they possess this intuition are dupes of an illusion
.

He mentions purely subjective notions of time, but says they CANNOT be taken into the external world as minkowski diagrams purport to do.

I guess you also forgot that, eh?

layman
 
  2  
Reply Thu 7 May, 2015 11:58 am
@Olivier5,
Quote:
Some people just can't understand some stuff. That stuff is beyond you, period.


Yeah, sho nuff. And some people don't have any clue about what the significance of what is said would be, eh? And that includes the significance of their own statements, unfortunately.
layman
 
  2  
Reply Thu 7 May, 2015 12:12 pm
@Olivier5,
Quote:
That diagram does not speak of simultaneity

Yeah, right, eh?:

Quote:
A particular Minkowski diagram illustrates the result of a Lorentz transformation. The horizontal corresponds to the usual notion of simultaneous events, for a stationary observer at the origin. The Lorentz transformation relates two inertial frames of reference, where an observer makes a change of velocity at the event (0, 0). The new time axis of the observer forms an angle α with the previous time axis, with α < π/4. After the Lorentz transformation the new simultaneous events lie on a line inclined by α to the previous line of simultaneity


http://en.wikipedia.org/wiki/Minkowski_diagram

If you want to actually see what one looks like, they have it at that site, eh?
Olivier5
 
  0  
Reply Thu 7 May, 2015 12:14 pm
@layman,
You misunderstand Poincare, as you misunderstand me and everybody else. You're putting words in his mouth. He is saying that simultaneity and duration measurement are not intuitive, but that we DO have a powerful intuitive notion of time.

These are complicated subjects where a degree of care, concentration and precision is required.
layman
 
  2  
Reply Thu 7 May, 2015 12:19 pm
@Olivier5,
These are complicated subjects where a degree of care, concentration and precision is required.

OK, Ollie, great. Why don't you read them with great care and precision, then? If you do that, you might understand what he said about time when I get back.

Gotta go. Later.
0 Replies
 
Olivier5
 
  0  
Reply Thu 7 May, 2015 12:42 pm
@layman,
Quote:
And some people don't have any clue about what the significance of what is said

And some other people make much hay of insignificant details.

When they size on some concept or another which for some obscure reason pike their interest (the value of Pi, the Holocaust, Jesus, climate change, the Jews, relativity...), they will suddenly pull out of their rear end all sorts of massively significant meanings... They over-interpret the world, and see significance even where there is none...

They will tell you that, since they have seen some puff of smoke come out of some WTC windows on some crappy videos, then it follows that the CIA is behind 9/11.

They will tell you that that since the ancient Egyptian word for "dung" also means "alien", it must follow that all the world's **** must come from outer space.

They will argue that since the King James Bible contains 985439865938465 letters in total, it follows that YHWH must be yellow.

Or they will tell you that, since accelerating an object does not seem to result in time dilatation, then it follows that all frames of reference can somehow be considered inertial...

And if you fail to see the significance in puffs of smoke, hieroglyphic etymology or the number of letters in a book, they will treat you as the worse idiot ever, because you failed to see the magic meaning that they magically "see" springing everywhere.
Olivier5
 
  1  
Reply Thu 7 May, 2015 05:41 pm
@layman,
Yeeeaah... These pesky lines. I've always found odd to speak of simultaneity about them. They are the envelop lines, the limits of the past and future of an event.

In a classic representation of time, these lines are the same unique line separating the past from the future. We call it 'the present', in an absolute sense: the same present at the same time everywhere in the universe.

In relativity and in its representation through the Minkowski diagram, these lines are distinct, and relative to one's location: one line defines the limit of the past of one particular 'event', another line defines the limits of an event future, but they leave out a huge chunk of events out there which are neither past nor future but outside of both. In this view, there is no simultaneity anymore, other than local, and as a convention. Everything else is past or future. So the term 'simultaneity' there refers to something entirely different from classic simultaneity. It means: things that LOOK simultaneous.

When Tycho Brahe first saw that supernova, the forming of the mental image of this "new star" in his conscience was not simultaneous with the stelar explosion phenomenon that he saw. The star had exploded (event A) centuries before that, in the distant past of Brahe seeing it (event B). And yet if one would plot these two events on a Minkowski diagram, A lies precisely on the envelop line (so called 'line of simultaneity') of the past of B... That's a misnomer, an undue reference to a foregone classic notion.
layman
 
  3  
Reply Thu 7 May, 2015 06:35 pm
@Olivier5,
Quote:
They are the envelop lines, the limits of the past and future of an event.


Heh, speaking for myself, I always suspect that anybody who gets a sense of "meaning" from a minkowskian piece of graph paper must be on an acid trip.
Olivier5
 
  0  
Reply Fri 8 May, 2015 06:04 am
@layman,
It's a nice infographic, mislabeling aside.
0 Replies
 
layman
 
  2  
Reply Fri 8 May, 2015 07:24 am
@Olivier5,
Quote:
And if you fail to see the significance in puffs of smoke, hieroglyphic etymology or the number of letters in a book, they will treat you as the worse idiot ever, because you failed to see the magic meaning that they magically "see" springing everywhere.


Yeah, you just keep telling yourself that, Ollie. Best tell it to Poincare and the many other brilliant scientists and philosophers of science who didn't get sucked in by SR, then and now, eh? Surely you would convince them that they are just "conspiracy theorists," ya know?

Why is it, I wonder, that you seem almost religiously devoted to SR, even though you clearly don't understand many of it's physical and philosophical implications? Some "emotional" commitment, maybe? Like, being a member in good standing with what you perceive to be the "mainstream physics" club, or is it more than that?
Olivier5
 
  0  
Reply Fri 8 May, 2015 07:34 am
@layman,
Quote:
Yeah, you just keep telling yourself that, Ollie. Best tell it to Poincare and the many other brilliant scientists and philosophers of science who didn't get sucked in by SR, then and now, eh? Surely you would convince them that they are just "conspiracy theorists," ya know?

Plus I am accusing YOU and only YOU of reading too much in a little detail.

Poincare almost invented SR. He's like Moses who could lead his people to the promised land, but could not enter it. At the time, these ideas were quite radical and he had an attachment to intuitive truths, which apparently worked against him in some cases.

Among modern scientists, pray tell who denies relativity?
layman
 
  2  
Reply Fri 8 May, 2015 10:13 am
@Olivier5,
Quote:
Among modern scientists, pray tell who denies relativity?


No doubt a lot more than would ever admit to it. Read the stories of guys like Louis Essen (aka, the father of the atomic clock and the foremost expert on time measurement in his day), and Herbert Dingle to see what happens to the careers of anyone who openly questions SR. Nobody who doesn't want his career ruined is likely admit to any such disbelief. Karl Popper didn't buy it, but he was primarily a philosopher of science. Many highly respected scientists through the years have denied SR (read some history, if you doubt it) but more recently such denial became virtually equivalent with career suicide.

Of course some do, but most of them or retired, or else live in countries other than the USA where the SR dogma is not so vigorously enforced. They are all called "cranks" of course, no matter how lucid their arguments. That said, it's easy to "read between the lines" sometimes. For example, in the old thread, I provided several excerpts from a Havard physicist who has written highly acclaimed textbooks on SR (David Morin), where he pretty expressly says it is not believable.

The better question might be this: On what conceivable grounds can the scientists who "believe in" SR, but reject LR, justify their allegiance? Certainly not on any empirical grounds.

Since Dingle's time another Havard professor (can't remember who right now) did his best to make a completely impartial review of all the aruuments made by scientists against Dingle as they destroyed his character and blacklisted him. His conclusion was that NONE of them actually responded to the questions which Dingle was seeking answers to. Instead, they just gave evasive, or irrelevant "responses" that claimed Dingle was "completely wrong."
Olivier5
 
  0  
Reply Fri 8 May, 2015 01:49 pm
@layman,
Dingle was an old fool who ate crow more than once. Hardly current anyway. Karl Popper, from the same era, never doubted relativity any more than any other theory. In fact he had a lot of respect for Einstein, and only disagreed with his determinism. Louis Essen published The Special Theory of Relativity: A Critical Analysis, in 1971, around age 63. He retired one year after that in 1972, and later claimed that "I was warned that if I persisted I was likely to spoil my career prospects". His career was pretty much a done thing by then, so this claim cannot be taken seriously.

Quote:
The better question might be this: On what conceivable grounds can the scientists who "believe in" SR, but reject LR, justify their allegiance? Certainly not on any empirical grounds.

The absence of aether is one ground, the lack of evidence that molecules and inter-atomic spaces are physically contracted by movement is another, and finally there is the elegance of SR.

Your question could be asked in reverse, and in fact I have asked it several times: on what conceivable grounds can you "believe in" LR, but reject SR? Certainly not on any empirical grounds.
layman
 
  2  
Reply Fri 8 May, 2015 02:14 pm
@Olivier5,
Quote:
The absence of aether is one ground


Heh, and you want to talk about straw men, eh? How many times have you been shown that the existence of an "ether" is completely irrelevant to LR?

I have stated the reasons for my objections, many time over, in the old thread. I don't want to do it all over again.

Briefly, I only object to it insofar as it's advocates claim that it represents "reality." Accepting that claim requires one to accept utter solipsism, to disavow logic, to disregard known laws of physics (such as the law of intertia), etc.. And students are indeed browbeaten into accepting such things. There are other reasons, but those are at the top.
Olivier5
 
  0  
Reply Fri 8 May, 2015 02:32 pm
@layman,
Quote:
How many times have you been shown that the existence of an "ether" is completely irrelevant to LR?

You haven't shown any such thing. Lorentz clinched to the end to the idea of an aether, as that was the main difference between his theory ("Lorentz Ether Theory") and SR. That theory was abandoned because there was no evidence of an aether whatsoever.
layman
 
  2  
Reply Fri 8 May, 2015 02:57 pm
@Olivier5,
Quote:
That theory was abandoned because there was no evidence of an aether whatsoever


You again show your ignorance, and show your disregard of what it presented to you. Poincare said it didn't matter in the least if the ether existed, for just one thing, and I quoted that for you. He further said that he expected it to be discarded in the future.

The ether is NOT essential to the concept of absolute simultaneity. Lorentz "clung" to it for other reasons--as a medium to propogate light waves, etc. Newton himself clearly stated that there was no possible way to prove that some motionless point existed (as did Lorentz). Yet Newton said that, in theory, time was absolute. His view was accepted for centuries, and it still is accepted by many. (Newton did say, that for practical purposes in the solar system and on earth, the frame of the "fixed" stars was suitable as a "close approximation" of a motionless frame).

Lorentz was trying, and came close to succeeding, to posit a PHYSICAL theory which would explain time dilation. Al said he tried the same for years, but felt science had not advanced far enough to justify such a theory.

He therefore, he said, proposed SR out of "desperation." He was NEVER satisfied with the theory because it was not a "constructive" theory, but merely a "piniciple" theory, which was clearly deficient and inferior in his view.

In his later years (post GR) Al was back to saying there MUST be some kind of aether. He said his "rejection' of it had been mistaken and premature.
Olivier5
 
  0  
Reply Fri 8 May, 2015 03:19 pm
@layman,
You want to re-invent the L.E.T., tweak it here or there, replace "aether" with "cosmic background", find new ways to justify simultaneity, etc... Go ahead by all means, but don't tell me that this is the same theory as Lorentz'. THE L.E.T. WAS HISTORICALLY DISCARDED based on the absence of evidence for aether, etc. It ended up being a mere stepping stone to SR, itself a mere stepping stone to GR, etc.

Quote:
In his later years (post GR) Al was back to saying there MUST be some kind of aether. He said his "rejection' of it had been mistaken and premature.

Evidence for that???
layman
 
  2  
Reply Fri 8 May, 2015 03:21 pm
@Olivier5,
It gets extremely tedious repeatedly showing you the same quotes, over and over again, only for you to completely "fail to see the significance" of what you are reading. But, once again, from wiki:

Quote:
The introduction of length contraction and time dilation for all phenomena in a "preferred" frame of reference, which plays the role of Lorentz's immobile aether, leads to the complete Lorentz transformation (see the Robertson–Mansouri–Sexl test theory as an example)


Are you even capable of understanding what's being said there? At all? It is a "preferred frame" NOT an "immobile aether" that generates an AST.

Both Newton and Lorentz said that it was not important that a motionless point actually be DETECTED, but that, as a theoretical matter, one must exist. Poincare, being the conventionalist that he was, went further, and said it didn't even matter if it existed:

Quote:
"Whether the ether exists or not matters little – let us leave that to the metaphysicians; what is essential for us is, that everything happens as if it existed, and that this hypothesis is found to be suitable for the explanation of phenomena. After all, have we any other reason for believing in the existence of material objects? That, too, is only a convenient hypothesis; only, it will never cease to be so, while some day, no doubt, the ether will be thrown aside as useless."


Poincare saw it as essential to providing a coherent theory of physics. I do too (as do many others).
0 Replies
 
layman
 
  2  
Reply Fri 8 May, 2015 03:26 pm
@Olivier5,
Quote:
Evidence for that???


Google it and find out for yourself. About time you did something like that.

Quote:
You want to re-invent the L.E.T.,


Will you EVER understand what you read? Such as this (which I have shown you before):

Quote:
What is now often called Lorentz ether theory (LET) has its roots in Hendrik Lorentz's "theory of electrons", which was the final point in the development of the classical aether theories at the end of the 19th and at the beginning of the 20th century.


The ether was essential to his theory of ELECTRONS, get it? It was NOT essential to his theory of relative motion. He did "associate" his "preferred frame" with the aether, but that was strictly incidental to his theory (which was about ELECTRONS).


layman
 
  2  
Reply Fri 8 May, 2015 03:56 pm
@Olivier5,
Quote:
Quote:
Dingle was an old fool...


Yes, of course he was. You know that because, well, uh, because you have been told so. As I mentioned, Dingle's questions were never properly addressed, according to modern analysis.

I noted one of his questions in an earlier post. As with virtually everything I post for your consideration, you completely ignored the post. But, here it is again:

Quote:
If you had ever read it, you might recall that Einstein, in his original 1905 paper, said that a clock at the north pole would run faster than a clock on the equator. Why? Because the clock on the equator is moving in a circle at a constant rate, whereas the other is not. It is, after all, the (faster) moving clock that runs slow.


It is also worth noting that Einstein here posits an absolute difference between the clocks, and presumes to know WHICH one is ACTUALLY MOVING (relative to the other).

These days, the relativists like to pretend that such things are "unknowable." Go figure, eh?


Dingle's question was: if motion is relative, how can you determine this (he asked the same question in connection with the twin (or clock) "paradox" which Al himself set out in his 1905 paper).

Do YOU have an answer to Dingle's question? I mean, one that makes sense? One that doesn't duck the issue. Can you give a response that even shows you understand the question?

I have an answer (but it is not even my answer, it is merely one that makes sense) and I have given it here many times. Do YOU have an answer?
0 Replies
 
 

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