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Re: When a black hole moves: The incompatibility between gravitational theory and special relativity

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  Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-05-22 16:53 -0500
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-17 07:20 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity dancouriann@gmail.com - 2017-07-17 12:54 -0700
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-07-18 00:38 -0500
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-31 06:43 -0700
          Re: When a black hole moves: The incompatibility between gravitational theory and special relativity dancouriann@gmail.com - 2017-07-31 11:26 -0700
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-08-08 14:21 -0700
          Re: When a black hole moves: The incompatibility between gravitational theory and special relativity dancouriann@gmail.com - 2017-08-08 16:21 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity xxein1x1@gmail.com - 2017-07-17 13:26 -0700
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-07-17 20:32 -0500
          Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Ustin Veterre <utve@nauoe.ct> - 2017-07-18 16:50 +0000
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity "Dono," <sa_ge@comcast.net> - 2017-07-17 14:20 -0700
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2017-08-06 10:50 -0700
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-08-06 13:38 -0700
          Re: When a black hole moves: The incompatibility between gravitational theory and special relativity "Dono," <sa_ge@comcast.net> - 2017-08-06 18:01 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-07-18 00:14 -0500
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Ustin Veterre <utve@nauoe.ct> - 2017-07-18 16:55 +0000
          Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-07-18 12:04 -0500
            Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Ustin Veterre <utve@nauoe.ct> - 2017-07-18 17:15 +0000
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-24 15:24 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Poutnik <poutnik@privacy.net> - 2017-07-25 11:28 +0200
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity mlwozniak@wp.pl - 2017-07-25 03:02 -0700
          Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Ernard Hevalier <adrdo@tarlaab.lr> - 2017-07-25 11:11 +0000
            Re: When a black hole moves: The incompatibility between gravitational theory and special relativity mlwozniak@wp.pl - 2017-07-25 04:30 -0700
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Ernard Hevalier <adrdo@tarlaab.lr> - 2017-07-25 10:40 +0000
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-08-06 14:51 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-04 11:35 -0400
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-06 16:01 -0500
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-24 15:26 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-06 16:05 -0500
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-24 15:32 -0700
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-24 15:34 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-06 16:10 -0500
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-24 16:08 -0700
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-24 16:11 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity "Dono," <sa_ge@comcast.net> - 2017-07-30 19:31 -0700
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2017-08-06 10:25 -0700
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-08-06 15:27 -0700
          Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-06 20:34 -0500
            Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-08-14 15:37 -0700
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-24 16:12 -0700
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-24 16:16 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Ernard Hevalier <adrdo@tarlaab.lr> - 2017-07-25 11:16 +0000
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity mlwozniak@wp.pl - 2017-07-25 04:33 -0700
      Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-06 16:21 -0500
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity mlwozniak@wp.pl - 2017-08-06 23:24 -0700
          Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Earline Loar <ureoo@wwarao.ei> - 2017-08-07 08:38 +0000
            Re: When a black hole moves: The incompatibility between gravitational theory and special relativity mlwozniak@wp.pl - 2017-08-07 02:05 -0700
        Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-08-14 12:52 -0700
          Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-15 22:01 -0500
    Re: When a black hole moves: The incompatibility between gravitational theory and special relativity Eric Baird <erkdemon@gmail.com> - 2017-07-24 16:23 -0700

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#426046

Dne 25.7.2017 v 00:24 Eric Baird napsal(a):
> On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
>> On 5/19/17 5/19/17 - 6:56 PM, Eric Baird wrote:
>>> Just a short post to let you know that I've uploaded something to
>>> ResearchGate. [...]
> ...
> ...
> 
>>> It's tempting to react to this by deciding that it doesn't matter, since SR
>>> only claims validity for cases in which gravity is considered negligible.
>>
>> Yes, of course.
> 
> Follow the logical chain. Invalidation of the SR relationships for a strong-gravity star leads to a general invalidation of those relationships for all bodies, including those in which gravitational effects would normally be considered negligible.

Why, when even the first chain ring is broken ?

Physics is not math, even if advanced math is often used.

Physical theories are just models of reality behaviour.
While their residual error is below  of experimental resolution,
they are fine.

SR has limited domain of validity
as well as the Newton mechanics has.

Did you stop using the famous formula F = m.a
as it is invalidated for NOT ( v << c ) ?

Or pendulum based clocks,
as both gravity and inertia models of classical mechanics
are invalidated for strong gravity or speed ?


-- 
Poutnik ( The Pilgrim, Der Wanderer )

A wise man guards words he says,
as they say about him more,
than he says about the subject.

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#426047

W dniu wtorek, 25 lipca 2017 11:28:15 UTC+2 użytkownik Poutnik napisał:

> Physical theories are just models of reality behaviour.


They were. Now they are just models of sick imagination 
of some insane halfbrains.

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#426054

mlwozniak wrote:

> W dniu wtorek, 25 lipca 2017 11:28:15 UTC+2 użytkownik Poutnik napisał:
>> Physical theories are just models of reality behaviour.
> 
> They were. Now they are just models of sick imagination of some insane
> halfbrains.

You both are fucking wrong. You guys are forcing people using profanity. I 
take the bet, none of you can define "reality".

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#426057

W dniu wtorek, 25 lipca 2017 13:11:35 UTC+2 użytkownik Ernard Hevalier napisał:
> mlwozniak wrote:
> 
> > W dniu wtorek, 25 lipca 2017 11:28:15 UTC+2 użytkownik Poutnik napisał:
> >> Physical theories are just models of reality behaviour.
> > 
> > They were. Now they are just models of sick imagination of some insane
> > halfbrains.
> 
> You both are fucking wrong. You guys are forcing people using profanity. I 
> take the bet, none of you can define "reality".

How fortunate you can't define "define".

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#426048

Poutnik wrote:

> Physical theories are just models of reality behaviour.
> While their residual error is below  of experimental resolution,
> they are fine.

You have it upside down. There are no errors in theories and laws of 
Nature. You are just using pompous words without having a brain.

> Or pendulum based clocks,as both gravity and inertia models of classical
> mechanics are invalidated for strong gravity or speed ?

"Strong speed"?? No, those are not invalidated in any way. You just need 
to take care.

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#427477

On Tuesday, 25 July 2017 10:28:15 UTC+1, Poutnik  wrote:
> Dne 25.7.2017 v 00:24 Eric Baird napsal(a):
> > On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
> >> On 5/19/17 5/19/17 - 6:56 PM, Eric Baird wrote:
> >>> Just a short post to let you know that I've uploaded something to
> >>> ResearchGate. [...]
> > ...
> > ...
> > 
> >>> It's tempting to react to this by deciding that it doesn't matter, since SR
> >>> only claims validity for cases in which gravity is considered negligible.
> >>
> >> Yes, of course.
> > 
> > Follow the logical chain. Invalidation of the SR relationships for a strong-gravity star leads to a general invalidation of those relationships for all bodies, including those in which gravitational effects would normally be considered negligible.
> 
> Why, when even the first chain ring is broken ?
> 
> Physics is not math, even if advanced math is often used.

But theoretical physics //is// largely logic-based.

Without logic, we don't know how to construct experiments properly, or properly understand the significance of the results. 
 
> Physical theories are just models of reality behaviour.
> While their residual error is below  of experimental resolution,
> they are fine.

Not if you're a theorist and you're actually talented.

The talented guys are the ones who nit-pick the tiny details and logical discrepancies that others ignore, until they come up with a better logical structure than what came before. That can give us a hell of a lead on what the experimenters can manage on their own.

For instance, John Michell not only predicted gravitational shifts and the r=2m gravitational horizon radius back in the 1780s, he also suggested measurement hardware and an astronomical survey project to get an estimate of the amount of additional unilluminated matter in the universe by compiling statistics on double stars, and noting the cases where one partner wasn't visible.

He was trying to work out the details of experimental techniques in gravitational physics about 150 years before the real hardware became available.
 
> SR has limited domain of validity
> as well as the Newton mechanics has.
> 
> Did you stop using the famous formula F = m.a
> as it is invalidated for NOT ( v << c ) ?
> 
> Or pendulum based clocks,
> as both gravity and inertia models of classical mechanics
> are invalidated for strong gravity or speed ?

Actually, somewhere in Principia or Opticks, Newton points out that pendulum clocks are expected to tick at different rates as a function of where you put them in the Earth's gravitational field, and cites someone's experiment (where they'd had an expedition up a mountain?) that had verified the existence of the expected variation.

So a theory of these pendulum variations had already been worked out in the Seventeenth Century, and also experimentally tested. Newton was a nit-picker, too.

Also Einstein. That's why he was able to derive the existence of gravitational time dilation, while all the really clever math guys before him missed it. Einstein spotted a logical discrepancy that couldn't be resolved unless timeflow was a function of gravitational field strength. Earlier guys probably spotted the same discrepancy, but thought, "oh well, its such a tiny mismatch that it's probably not that important" ... or "Well, logically the only way to solve this would seem to be by making the rate of timeflow a variable, and THAT can't be right..." 

Also, with Einstein and E=mc^2, he already knew about the anomalous energy-output of radium, but measuring the associated predicted weight-loss E/c^2 of a speck of radium may not have seemed a credible experimental proposition. This research was not motivated by a desire to create jobs for experimenters!

If you want to produce a new theory, and you don't have access to new experimental data that wasn't available to your predecessors, then quite a good way to get the jump on everyone else is to focus on small logical "kinks" in existing theory that your rank-and-file physics person would simply ignore. If you're //not// unreasonably demanding as to what you expect a theory to do, then you're unlikely to develop a better theory than what we already have.

If we have a bunch of physics guys arguing that the current system is just fine, and that we don't need/want anything better, then we risk never //getting// anything better.
  
The price of constant progress is eternal dissatisfaction.

Eric Baird 
https://www.researchgate.net/publication/316981511_When_a_black_hole_moves_The_incompatibility_between_gravitational_theory_and_special_relativity

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#427205

On 7/24/17 7/24/17   6:24 PM, Eric Baird wrote:
> On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
>> On 5/19/17 5/19/17 - 6:56 PM, Eric Baird wrote:
>>> Just a short post to let you know that I've uploaded something to 
>>> ResearchGate. [...]
> ... ...
>>> It's tempting to react to this by deciding that it doesn't matter, since
>>> SR only claims validity for cases in which gravity is considered
>>> negligible.
>> 
>> Yes, of course.
> 
> Follow the logical chain. Invalidation of the SR relationships for a
> strong-gravity star leads to a general invalidation of those relationships
> for all bodies, including those in which gravitational effects would normally
> be considered negligible.

Nonsense. Invalidation of SR IN A REGIME WHERE SR DOES NOT APPLY does nothing at 
all.

> What you're doing by setting arbitrary domains of applicability is responding
> to a logical contradiction by compartmentalising.

No. Not at all. THIS IS PHYSICS, NOT LOGIC.

In physics, every theory includes a domain within which it is valid, and outside 
of which it is either invalid, or at least not known to be valid. In the 
presence of gravity, SR is KNOWN to not be valid.

This is very basic, and fundamentally simple: SR is based on some postulates, 
and in regimes where those postulates do not hold, SR simply is not valid. That 
is, the mathematical derivation of its equations are IRRELEVANT because in that 
physical regime the postulates don't hold.

> * https://en.wikipedia.org/wiki/Compartmentalization_(psychology)

Completely irrelevant -- this is PHYSICS. Applying theories ONLY within their 
domain of applicability is MANDATORY.

> The only way that you can avoid having the two sets of arguments flatly
> contradicting each other in some situations where we have //both// inertial
> physics and gravitational physics operating is by setting up artificial
> barriers,

They are NOT "artificial". The "barriers" represent boundaries between regimes 
in which the assumptions of one or the other theory hold.

SR is the local limit of GR. SR is NOT valid throughout the universe, but only 
in limited regions. This is unavoidable. Live with it (you have no choice).


> and saying that in such-and-such situation where you can get away
> with using SR, SR is obviously correct, and in these other situations where
> GR has to apply, we obviously //mustn't// use SR but GR ... but SR is still
> considered to be correct 

NONSENSE! SR is NOT "considered to be correct" in the sense you mean. SR is 
considered to be VALID (not "correct"), and its domain of validity is LIMITED. 
Validity of a theory does NOT mean "it is how nature actually behaves", but 
rather "it APPROXIMATES how nature behaves is this regime ...". There are limits 
to the accuracy of such APPROXIMATIONS, and that determines the domain of 
applicability for the theory.

	To one part per 1000, SR is valid throughout the solar system (yes,
	ALL the effects of gravity are smaller than that). But to parts
	per million is it valid only in much smaller regions. In the
	experimental halls of the LHC, for the measurements of elementary
	particles, SR is valid to parts per billion, which is MUCH smaller
	than their measurement resolutions -- so they can and do use SR in
	their analyses.

> [... repetitions]

You need to learn what science ACTUALLY is. Your GUESSES are wrong.

Tom Roberts

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#427473

On 7/24/17 7/24/17   5:24 PM, Eric Baird wrote:
> On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
>> WHAT is "wave theory"???? It seems to be a figment of your imagination, so I
>> cannot comment on it.
> 
> Try googling:
>   https://www.collinsdictionary.com/dictionary/english/wave-theory ::
> :: Wave theory definition: the theory proposed by Huygens that light is transmitted by waves

OK. Then we KNOW it is wrong -- light is NOT "transmitted by waves". Such waves 
cannot account for many observed properties of light, but the photons of QED do 
account for them.

There's no point in continuing to discuss "wave theory".

Tom Roberts

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#426000

On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
> On 5/19/17 5/19/17 - 6:56 PM, Eric Baird wrote:
> > Just a short post to let you know that I've uploaded something to
> > ResearchGate. [...]
...
...
...

> But I remark that the laws of physics must be independent of coordinates. This
> does NOT mean there is "a single agreed set of velocity-shift relationships", it
> just means the theories approximating those laws are independent of coordinates.

Well, wave theory (and therefore presumably also a geometrical theory of gravity) does pretty much require the existence of a single universal law for motion shifts, for simple motion. If you break that rule, you no longer have a light-metric, and the theory produces the same sort of incoherent optical mess as we got with C19th ballistic emission theory. But let's move on the the coordinate system arguments ...


==DIVERGENT PHYSICAL LAWS BASED ON DIVERGENT MATHEMATICAL DEFINITIONS==

It is an assumed requirement of classical physical law that the reality underlying our experiences is the same for all observers. We all live in the same universe. 
If we try to describe physics geometrically, this translates into a statement that there should be a single assumed underlying geometry whose shape and rules are the same for all observers. It might be that those observers cannot define the precise shape of their region //exactly// due to measurement limitations, but there should a single hypothetical underlying shape for the region that can explain the experiences of all observers in that region.

So far, so good. 

Where "SR-based physics" and "acoustic metric-based physics" diverge is at the precise geometrical definition of the word "all" when it appears in the phrase "all observers".

* In universe [#1], "all observers" means "all possible observers".
* In universe [#2], "all observers" means "all real observers".

That innocent-looking distinction leads to two different sets of geometrical rules, and two different, divergent universes with their own sets of associated physical law. Geometrical proofs constructed in one universe aren't necessarily geometrical proofs in the other.

===UNIVERSE [#1] SR-BASED PHYSICS====

In universe #1, the rule that the laws of physics apply to "all observers" is interpreted to mean that they apply to "all possible observers". This means that the resulting logic does not distinguish between "real", "physical" observers and "hypothetical", "mathematical" observers.

Real observers are built of particulate matter, whose presence and relative motion distort the light-metric. Purely-"mathematical" observers without physical counterparts do not have these associated distortions.

For the same derived laws of physics to apply to //all// observers (both physical //and// non-physical), we need the additional distortional effects associated with "real" observers to be irrelevant, because one of our two classes of observer doesn't have them. We have to select a set of laws of physics that work in the absence of these distortions, and assume that the laws of physics for real bodies must be identical to those that we derive for purely "mathematical" observers.

In other words, we are obliged to derive the laws of relativistic physics in such a way that they work in perfectly empty spacetime, as a flat-spacetime "pure vacuum" solution, and we can then declare that these laws must also be the correct laws for physical observers. We "know" that the real laws of physics must correspond to our empty flat-spacetime derivations, and that the real-world properties of matter do not change the equations. According to our initial specification that the same laws must hold for //all possible// observers, these distortions //cannot// change the physics or the derived relationships //on principle//.

In universe #1, we are obliged to derive special relativity and Minkowski spacetime, and when we go on to derive more complex gravitational models, they HAVE to reduce exactly to Minkowski spacetime geoemtry and SR physics over small regions. 

In [#1], Special relativity is provably //unavoidably correct//, as a matter of fundamental geometry.

===UNIVERSE [#2] ACOUSTIC-METRIC-BASED PHYSICS====

In universe #2, the rule that the same laws of physics apply to "all observers" is interpreted to mean that they apply to "all REAL observers". The principle of relativity then only has to apply to actual matter and material observers, and its "universality" only applies to observers that actually exist in our universe.

With this different interpretation of the phrase "all observers", we now return to the problem of light-grid distortions caused by the presence and relative motion of real-world matter. In [#1] we were forced to dismiss the importance of these effects, but in [#2], these effects define the difference between a "real" observer and one that is merely "mathematical". Focusing only on the "real" observers makes the relativistic properties of these distortions a critical piece of the physics. If a region's shape //must// include these distortions in order to be completely accurate, the region's shape does not define the set of all //conceivable// physical outcomes that could arise in the region - it defines only the set of physical outcomes that //will// arise in the region – the spacetime geometry includes distortional tracks that describe the positions and speeds of every piece of matter in the region, and therefore includes (in theory) all the information necessary to make a deterministic calculation of the region's future states.

Within [#2], the geometry does (in a sense) describe all possible outcomes in the region's future, because outcomes other than the deterministically calculated set are not "possible" – "What didn't happen, couldn't happen".

As a purely mathematical exercise we can still track a line through spacetime that might be said to represent the path of an additional observer, and note the signals intercepted by that track ... but since the track will be missing the distortions associated with a real physical observer moving along that path, the calculations will not correspond to what a "real" observer on that path would see. The signal-propagation calculations will be almost perfect, but the energetics for incoming and outgoing signals will be wrong. 

In [#1], Special relativity is provably //wrong//, as a matter of fundamental geometry.

====CONCLUSIONS====

The condition that "the laws of physics must be independent of coordinates" can be used to prove either that SR is fundamentally correct, or that SR is fundamentally wrong ... depending on how we define the "target audience" for those physical laws.

If the laws of physics have to apply equally to "real" and to purely hypothetical, "unreal" observers [#1], then relativistic logic creates frame-based arguments, Minkowski spacetime, and SR (and SR-based GR) as the only possible physical solution.
If the laws of physics only have to apply to //physical// observers [#2], then geometrical disproofs of SR become more compelling, relativity theory has to be implemented using gravitomagnetic arguments instead, and we get a different type of physics, based on a relativistic acoustic metric.

So it turns out that our geometrical proofs of SR don't stem from any deep, fundamental property of nature or geometry. They are the result of a purely human design decision as to how we should best regard the philosophical status of "hypothetical" observers who aren't real. Can only real observers observe?
If "physics is for everybody", and we don't discriminate against the unreal, then we get SR. If only the "physical" get a say in how physics operates, then we get a different, non-SR system.

It all depends on how "physical" one likes one's physics to be.

Eric Baird 
https://www.researchgate.net/publication/316981511_When_a_black_hole_moves_The_incompatibility_between_gravitational_theory_and_special_relativity  

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#427474

On 7/24/17 7/24/17   5:26 PM, Eric Baird wrote:
> Well, wave theory (and therefore presumably also a geometrical theory of
> gravity) ...

Hmmm. GR is a geometrical theory of gravity, but it has no light waves.

> ... does pretty much require the existence of a single universal law for
> motion shifts, for simple motion. 

And GR has exactly one that applies to all physical situations -- that's as 
"universal" as it gets. I gave it earlier in this thread.

Tom Roberts

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#426003

On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
> On 5/19/17 5/19/17 - 6:56 PM, Eric Baird wrote:
> > Just a short post to let you know that I've uploaded something to
> > ResearchGate. [...]
... ... ...
... ...

> > And if the same equations of motion apply to distant and nearby objects, then
> > a nearby hydrogen atom must obey those same non-SR equations, too.
>
> Hmmmm. Measurement and experiment show that emissions from hydrogen atoms are
> extremely well modeled by QED.

I expect this to be true.

> How they are observed from far away depends on
> how those emissions are affected by their propagation, and this is very well
> modeled by GR.

Flight times, probably.
Energetics, not so much.

If wave theory says that stars and atoms MUST frequency-shift by precisely the same amount as a function of relative velocity, and GR says that gravitomagnetic shift effects appear for the moving star, but don't appear for the moving atom, then you have a fundamental logical conflict.

The two measured shifts are either the same or they're not.

If they're //not// the same, then the theory is incompatible with wave theory and presumably also incompatible with the concept of there being a light-metric. In which case all bets are off for GR1960 being credible as a geometrical theory of gravity.

If they //are// the same, then since the star's motion-shift relationship can't be that of SR, the atom's motion-shift relationship can't be that of SR either. Since the moving star's disagreement with SR can be explained geometrically as a gravitomagnetic distortion effect, the spacetime geometry around the moving atom must show an analogous geometrical distortion. The moving star drags light in its vicinity, so the moving atom must show a light-dragging effect too for its geometry to match. This means that we're no longer using Minkowski spacetime to describe small-scale physics.

We can create a QM argument that particulate matter must drag light, and that that light-dragging effect must operate right down to the scale of an individual atom, we can make the particle-dragging effect "analogous" to the neutron star effect, and we can then contrive to give both shift effects exactly the same magnitude, so that the QM effect and the gravitomagnetic effect are interchangeable. It then doesn't matter which body is said to be moving and which is said to be stationary.

If we do this, we've (in one sense) successfully reconciled general relativity with quantum theory.

However, in the process, we've also rejected the idea that //any particle in the universe// obeys the SR motion-shift predictions, so SR is no longer fundamental physics. We have a single set of non-SR relationships for the motion of "gravitational" bodies and "particulate" bodies, and SR no longer has a role to play (except perhaps in engineering). 

Since SR is then not fundamental (in the sense that it doesn't correctly describe moving-body problems), residual traces of it need to be eliminated from GR, because GR1916 assumed that SR physics was a valid physical limiting case, and that assumption changed some of GR's predictions.

So the general theory that we're reconciling with QM is no longer //Einstein's// general theory. It's not the 1916 theory or the 1960 patched version, it's a rewritten and redesigned version, with some different principles, some different characteristics and some different physical predictions.  In other words, a different theory.

Eric Baird 
https://www.researchgate.net/publication/316981511_When_a_black_hole_moves_The_incompatibility_between_gravitational_theory_and_special_relativity  

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#426005

On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
> On 5/19/17 5/19/17 - 6:56 PM, Eric Baird wrote:
> > Just a short post to let you know that I've uploaded something to
> > ResearchGate. [...]
... ... ...
... ... ...

> > If we exist in a universe that allows gravitational masses to exist and to
> > move, then special relativity's equations may //almost// be the real
> > equations of motion, but they can't be quite correct.
>
> And that is essentially what GR says.

No, the 1916 theory assumes that SR is a ==perfect== limiting-case description of inertial physics. This is what puts GR1916/1960 irreconcilably at odds with quantum mechanics regarding black holes and Hawking radiation.

Consider a Newtonian "Dark Star", a star sufficiently dense that light emitted at its surface cannot completely escape by following a ballistic trajectory. It has a horizon surface at r=2M, just like a modern black hole. However, the dark star emits a form of Hawking radiation, entirely classically. Light emitted from just below r=2m can briefly visit the outside world before being recaptured, and while outside, it can strike objects and be reflected outwards along an accelerated path. The same goes for matter - an ultrarelativistic particle emitted outwards at or just below r=2m in a dark star model can escape along a nonballistic trajectory if it's struck sufficiently hard at the right angle by an outside body (or by another particle doing the same thing). So although a "single test-particle" model of a dark star might seem to say that it has zero emissions, the statistical interaction between particles gives a dark star a a nonzero temperature.

All the really freaky things that happen with Hawking radiation according to QM, like nearby objects being illuminated by virtual radiation that's converted to real radiation by acceleration as they bounce off the object ... happen "mundanely" in a dark star model as the result of classical physics.

The reason why we haven't already embraced the dark star approach to Hawking radiation (and why the black hole information paradox is still listed as unsolved after half a century) is because classical HR requires a non-SR shift relationship, and GR1916 is committed to the idea that the SR relationships are fundamental. 

If you are an initially-stationary particle created at r=2M in a dark star model and you want to escape, you only see the outside world to be ageing twice as fast. If you try to accelerate outwards then that blueshift increases, but it's a reasonable starting point.
OTOH, if we're using GR1916/1960, the gravitational blueshift on infalling light reaching you at the horizon is given by the SR shift equation, which says that freq'/freq equals infinity for a body approaching at lightspeed. So a particle created at the horizon under SR-based GR is not just intantaneously fried by an infinite inward energy flux, and an infinite inward radiation pressure, if it does somehow attempt to escape, that escape can't happen until an infinite amount of exterior time has already passed. Ignoring changes in background cosmological parameters over the hole's lifetime, the thing is utterly inescapable in anything less than an infinite amount of exterior time. 

And that's why we can't make minor modifications to GR1916/1960 to make it compatible with QM. It's because the modification needed to solve the black hole informaiton paradox by turning a black hole into a dark star would amount to ditching special relativity's shift equations in favour of the older Newtonian set. And this is (politically) an utterly unacceptable suggestion, otherwise we'd have already done it! :)


For reference, if we assume that the principle of relativity is correct but don't commit to a particular spacetime geometry, then, since we're already familiar with the SR predictions, we can we can express those as [SRshift], and write a generalised prediction for a family of potential models, of
[modelshiftprediction] = [SRshift] × [1- v^2/c^2]^(gde/2), where gde is the gravitomagnetic effect expressed as the strength of the surface gravitational dragging effect (values 0 to 1, for 0%-100% surface dragging)

If you graph the dependency between the value of gde and the inward blueshift at a gravitational horizon, you find that there is no value of gde that gives a finite inward blueshift at the horizon until you get all the way up to gde=1. Beyond 1, things go crazy.

So there appears to be no "small" classical relativistic fix to the black hole information paradox, the only known relativistic solution requires us to change the shift equations by a full additional Lorentz redshift, which reverts them back to the C19th Newtonian predictions.   


> > SR requires the region to be //perfectly// flat
>
> Again, why argue against a straw man?

That's the basis of the derivation of Minkowski spacetime. SR is the special, unique relativistic solution for a perfect vacuum, free from particulate matter, and SR's shift equations are only exact if spacetime's flatness isn't changed by the existence of the particles being watched, or those doing the observing. Add particulate-matter behviour to your observers and observed objects, and the predictions change.

If we use real matter for our objects and observers, the variation in energy-density associated with their localised mass makes the particles show up as dents in the metric. When those dents move, we have additional velocity-dependent distortions, in other words, gravitomagnetic effects.
If we decide that these gravitomagnetic distortions have to obey the principle of relativity just like the rest of physics, then we need a curved spacetime theory of relativity to deal with them.

That theory does not seem to be in the classical relativity texbooks. It's not SR, because SR implements the PoR by assuming that matter in the signal stream has zero effect on lightbeam geometry (it implements the principle of lightspeed constancy as the principle that lightspeed is globally constant ... which means that the lightbeam geometry is flat throughout the region). And it's also not Einstein's 1916 theory because GR1916 hands things back to SR for small-scale physics. 



It turns out that we can parameterise the problem. The general shift relationship can be written as the SR shift relationship, multiplied by an additional Lorentzlike factor whose exponent is zero when spacetime is perfectly flat, but increases with the supposed strength of gravitomagnetic dragging effects.

So we have, once again
[shift] = [SRshift] × [1- v^2/c^2]^(gde/2)
, where the value of the gravitomagnetic dragging effect varies between zero (giving SR) and 1, =100%, for full dragging at the horizon of a moving black hole.

We only get special relativity when gde=0, which is the case when particles have zero associated distortion. Any variation away from particles being considered as distortionless is associated with a positive value for gde, and a Lorentzlike deviation to the red, away from the SR math.

Eric Baird 
https://www.researchgate.net/publication/316981511_When_a_black_hole_moves_The_incompatibility_between_gravitational_theory_and_special_relativity

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#427475

On 7/24/17 7/24/17   5:34 PM, Eric Baird wrote:
> On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
>> On 5/19/17 5/19/17 - 6:56 PM, Eric Baird wrote:
>>> If we exist in a universe that allows gravitational masses to exist and
>>> to move, then special relativity's equations may //almost// be the real 
>>> equations of motion, but they can't be quite correct.
>> 
>> And that is essentially what GR says.
> 
> No, the 1916 theory assumes that SR is a ==perfect== limiting-case
> description of inertial physics. 

This is just plain not true -- there's nothing "perfect" about it. Applying SR 
in a local region of spacetime is an APPROXIMATION.

> This is what puts GR1916/1960 irreconcilably
> at odds with quantum mechanics regarding black holes and Hawking radiation.

No. This has nothing whatsoever to do with the problems relating QM with GR, 
BECAUSE IT IS WRONG. The difficulties in merging QM with GR are much more subtle 
and fundamental.

Tom Roberts

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#426010

On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
> On 5/19/17 5/19/17 - 6:56 PM, Eric Baird wrote:
> > Just a short post to let you know that I've uploaded something to
> > ResearchGate. [...]
... ... ... ...
... ... ...

> No physical theory is ever "perfect", and SR is IRRELEVANT.

Mathematically and geometrically, SR ==IS== perfect. It makes perfectly exact predictions about an idealised universe. It's deterministic, totally geometrically defined, has no free parameters, and can't be fudged or modified. In some ways, it's the perfect example of a falsifiable scientific theory. 

Its problem is not a lack of perfection. Its problem is that in order to //achieve// that perfection in 1905, Einstein had to make some simplifying assumptions, and the consequences of those simplifications change the theory's predictions so that special relativity becomes a perfect description of a universe ... that no longer corresponds to ours.

In the early days, Einstein's general theory was also considered to be a perfect theory. Karl Popper held it up as the archetype of a falsifiable scientic system – GR (said Popper) was perfect, in that it had no free parameters, no ad-hoc assumptions, no fudge factors or free variables. If anything about GR1916 didn't work, then the theory was simply wrong, and we'd move on to the next theory.

In practice, GR1916 turned out to fail in multiple ways, and instead of doing the honest thing and declaring it invalidated, we just kept on patching it up, and changing the definitions of what made a good theory every time GR turned out to fail another test.

The thing that currently goes by the name "GR" now corresponds to what Popper characterised as "pseudoscience" – a supposedly scientific theory that in practice only avoids falsification with a series of retrospective /ad hoc/ special rules and exceptions. 


It's the old story of physics vs mathematics. The physicist wants the correct answers even if they can't prove them rigorously, while the mathematician wants something that they can prove, even if it's wrong. Hence Hawking's comment, "I'd rather be right than rigorous", and Einstein's wry comment suggesting that perhaps if you can prove a result mathematically, the result is likely to be untrue.



>The real issue is:
> are the conditions of this theory satisfied well enough so the approximation in
> applying the theory is smaller than the resolution of the measurements. For many
> experiments applying SR, the answer is a resounding yes.

Well, some engineers will always tell you that the "real" physics is always done by people doing hardware experiments, and the only measure of a theory's worth is whether it's good enough to agree with experimental reality within the limitations of the available hardware.

The irony of using that argument to defend SR and SR-based GR is that if we'd applied this argument at the time, then neither of these theories would have been needed. Parameterised aether theory was probably perfectly capable of explaining all existing known relevant experimental data, and could be extended with additional parameters to cover any future data that didn't fit, and most of GR's better predictions can be approximated by retrofitting Einstein's general "gravitational time dilation" argument onto C19th Newtonian theory. The result wouldn't be pretty, but neither is current GR.
The reason for SR's initial ascendancy was not its accuracy in fitting data, but its efficiency and its minimalism. Even the most hardcore aether theorists were starting to get sick of the endless stream of additional optional parameters introduced by new aether models, and SR would have seemed like a breath of fresh air by comparison. Experimental evidence was of secondary importance.

A further irony is that the main organisation historically associated with the "experimentation is everything" view, that only practical physics was "real" physics and that the "real" measure of scientific theory was how well it agreed with experiment ... was the Deutsche Physik movement in 1930s Germany.

According to Deutche Physik, special and general relativity were distasteful, decadent, intellectual constructs that should have been strangled at birth (Lenard also reputedly wanted Einstein publicly hanged from a tree).

So you're championing two old theories that are now traditional and mainstream, but your value system seems to have a lot in common with that of the traditionalist reactionaries who created most opposition to the theories when they were first introduced.   

Eric Baird 
https://www.researchgate.net/publication/316981511_When_a_black_hole_moves_The_incompatibility_between_gravitational_theory_and_special_relativity   

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#426011

On Monday, 22 May 2017 22:53:08 UTC+1, tjrob137  wrote:
> On 5/19/17 5/19/17 - 6:56 PM, Eric Baird wrote:
> > Just a short post to let you know that I've uploaded something to
> > ResearchGate. [...]
... ... ... ...
... ... ... ...

> > In a fully gravitomagnetic theory of relativity, //all// physics is
> > curvature-based
>
> Hmmmm. "gravitomagnetic" is the wrong word. But in any case, EVERY ONE of our
> current fundamental theories of physics can be expressed via a Lagrangian that
> is an integral of the scalar curvature of the relevant manifold. For GR the
> relevant manifold is spacetime; for the standard model the manifold is a fiber
> bundle over spacetime (and the fields are quantum).

But gravitational theory is still a problem, because although general relativity nominally obeys certain wonderful principles (like the principle that the PoR applies to acceleration and rotation), in practice, our need to preserve special relativity's place within GR1916 means that those principles aren't actually treated as inviolable laws in practice. So if we're defending GR's status as a wonderful theory, we can say that GR1960 //obviously// applies the PoR generally, by definition ... until the PoR applied to acceleration or rotation turns out to generate a general disproof of the validity of SR, at which point we say that of course the GPoR was always really just a heuristically useful guideline, and not actually a law, and that applying the GPoR literally is "naive".

The real behaviour of current GR is moot, because it has no single logically-consistent set of agreeable behaviours. Its internal inconsistencies mean that different operators, working the theory from different starting points, can make different claims about what they believe the theory must say in a given situation to stop it crashing. This is why so many single-topic GR research papers start out by declaring that most of the rest of the community has somehow fundamentally misunderstood what the theory really says in a given situation, or how it should really be applied.

The reason why so many of our key researchers seem to believe that their colleagues are "doing it wrong" is that they believe that there IS a correct way to apply current GR. The truth is that there isn't.

The thing, in its current state, doesn't work properly.



> > If the real equations were “redder and shorter” than those of special
> > relativity by a Lorentzlike factor anywhere up to one complete additional
> > gamma factor, then most SR testing would come out exactly the same.
>
> This is just not true. SOME tests of SR are not sensitive to "extra factors of
> gamma", but not all.

Hence the use of the word "most". There are testable differences, just not that many.


> Particle accelerators would not work if there were "an
> extra factor of gamma".

Any cited analysis to support that? Nope. It's like a Christian fundamentalist saying that we know that God is real because otherwise the Sun wouldn't shine. Do they have an explanation of why the Sun shines? Yes. Does this mean that other competing interpretations and explanations are not possible? No. Can we imagine the Sun shining even if there isn't a god? Yes, we can.

Remember that SR redefines distances and times, and velocities by a gamma factor compared to the assigned values under Newtonian theory. If you're doing cross-theory analysis, you have to take into account that for an agreed energy or momentum, a particle's velocity will normally be assigned different nominal values under SR and NM, so when those two different nominal velocities are then used as the basis of different nominal shift equations (which diverge by the same Lorentz factor that appeared in the diverging nominal velocity values) ... sometimes the numerical differences simply cancel out.   


> Kinematics in particle collisions would not work if
> there were "an extra factor of gamma". These are among the best tests of SR we have.

Nah. Not when you remember that SR also redefines its distances and times and velocities with a gamma factor. 

Here's an entry from Cliff Will's listing of some compelling reasons why we know that Special Relativity is true "... Beyond a shadow of a doubt" (the section's subtitle)
Will ::
:: ...
:: //Evolution of the species//. One possible source of the genetic
:: mutations that permit evolution of living species is cosmic rays.
:: At sea level, the main component of the cosmic rays is the
:: unstable particle known as the mu meson or muon. But the 
:: muon is so unstable that it would decay long before reaching 
:: sea level from the upper atmosphere where it is created in the  
:: collision of an extraterrestrial cosmic-ray proton with an atom,
:: if it weren't for the time dilation of special relativity, which
:: increases its lifetime as a consequence of its high velocity.

The argument is certainly convincing ("SR predicts X, X is known to be true, if SR wasn't true we wouldn't have X, therefore SR must be true").

Unfortunately it's also trivially wrong.


It's a fun exercise to try. We take a muon with an agreed rest-frame decay time "T", and give it an agreed momentum "E". Under Newtonian theory, this lets us calculate its velocity "vNM", and the distance that it travels before decaying is then "dNM = vNM × T"
Under SR, things change. Because of the SR remappings of distances and times, under SR we assign a lower nominal velocity "vSR" to the muon, where "vSR" is less than "nNM" by the Lorentz factor "gamma", where gamma is the reduction SQRT[1 - v^2/c^2] , calculated using "v=vSR".
Under SR, we then say that the tracklength is extended by more than we'd otherwise expect if SR was wrong, because of the SR time dilation/length contraction effect, which either extends the particle's lifetime by gamma from the perspective of an Earth observer, or from the perspective of the muon, allows it to penetrate deeper than expected because of the Lorentz contraction of the Earth's atmosphere.

so under NM we have
dNM = vNM × T

, while under SR we have
dSR = vSR × T / gamma

, but the nominal SR velocity is smaller
vSR = vNM × gamma
, so
dSR = (vNM × gamma) × T / gamma
dSR = vNM × T
dSR = dNM


Will's argument certainly //seemed// reasonable and unarguable ... until you check the math, and find that it's actually horse poo. He said that the muon wouldn't reach the ground if SR was wrong, but if you do the NM calculations using properties that are agreed across both theories, you find that the //physical// NM and SR predictions are 100% identical for the same agreed inputs. The muon decays at //precisely// the same location regardless of whether we use SR or NM.

And a lot of claims made for SR are like that. People are taught things, and also see them in textbooks, and also hear their friends saying them, and they repeat them as fact assuming that someone, somewhere //must// have checked whether the thing was true for it to be in all these sources.

And with SR, it often turns out that nobody's actually bothered doing the calculations. 

Eric Baird 
https://www.researchgate.net/publication/316981511_When_a_black_hole_moves_The_incompatibility_between_gravitational_theory_and_special_relativity 

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#426660

On Monday, July 24, 2017 at 4:11:22 PM UTC-7, Eric Baird wrote:
> 
>  under SR we assign a lower nominal velocity "vSR" to the muon, where "vSR" is less than "nNM" by the Lorentz factor "gamma",

That's false, utter imbecile. You are unable to solve a simple exercise, yet you puff up yourself. A pathetic cretin masquerading as "scientist" posting on the pathetic "Research" Gate. 

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#427452

On Sunday, July 30, 2017 at 7:31:43 PM UTC-7, Dono, wrote:
> On Monday, July 24, 2017 at 4:11:22 PM UTC-7, Eric Baird wrote:
> > 
> >  under SR we assign a lower nominal velocity "vSR" to the muon, where "vSR" is less than "nNM" by the Lorentz factor "gamma",
> 
> That's false, utter imbecile. You are unable to solve a simple exercise, yet you puff up yourself. A pathetic cretin masquerading as "scientist" posting on the pathetic "Research" Gate.

See, that's specifically what Dono can reject, it's simple.

Then he uses the chance to spit to efface excusing himself.

Or "sarcasm", which could be interpreted as humble reserve.

Baird this is interesting and for you 
to explain it as "General Relativity".

I'd look at that and go on.

(After making enough understanding that 
"all science works together" or what.)


I am discussing this kind of thing itself 
with "SR as the local effect" for mass relations.

This is also here "GR letting SR" instead of 
"SR letting GR", i.e. with SR as the local effect, 
GR or General Relativity established constructively 
as the geodesy that is then the around with SR as 
conserving time of the travel of light.

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#427481

On Monday, 31 July 2017 03:31:43 UTC+1, Dono,  wrote:
> On Monday, July 24, 2017 at 4:11:22 PM UTC-7, Eric Baird wrote:
> > 
> >  under SR we assign a lower nominal velocity "vSR" to the muon, where "vSR" is less than "nNM" by the Lorentz factor "gamma",
> 
> That's false, utter imbecile. You are unable to solve a simple exercise, yet you puff up yourself. A pathetic cretin masquerading as "scientist" posting on the pathetic "Research" Gate.

Under C19th Newtonian theory, p=mv, so if we know the rest mass and momentum, the velocity of a particle can be defined as v=p/m .

Under special relativity, the relationship between "relativistic" momentum, rest mass and  and velocity is p=mv / [1-v^2/c^2]^0.5
http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/relmom.html
, so for a known (measurable) momentum and rest mass, we get the smaller v=gamma p/m   

The nominal velocity assigned to the particle by SR is lower than the one we use in the NM calculation by a gamma factor, where gamma is based on the SR velocity. In older textbooks, this increased momentum for a given velocity would typically be explained with the idea of "relativistic mass", a concept that is now less in favour.  

With the lower nominal velocity and an agreed rest-frame decay time, we might naively expect the muon decay path to be shorter under SR than NM, by the Lorentz factor ... except that SR //also// time-dilates the muon by the same gamma factor, extending the decay time and the decay path as seen by Earth observers (or, the muon reckons the approaching Earth atmosphere to be length-contracted, so it manages to travel through more of it before it decays, by a Lorentz factor) ...
...the two opposing Lorentz factors then cancel exactly (lower velocity value shortens the calculated distance, time dilation lengthens the calculated distance), so for an agreed rest mass, momentum and rest-frame decay time, the physical end result of the NM and SR calculations is _precisely_the_same_. 

Eric Baird 
https://www.researchgate.net/publication/316981511_When_a_black_hole_moves_The_incompatibility_between_gravitational_theory_and_special_relativity     

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#427506

On 8/6/17 8/6/17   5:27 PM, Eric Baird wrote:
> With the lower nominal velocity and an agreed rest-frame decay time, we might
> naively expect the muon decay path to be shorter under SR than NM, by the
> Lorentz factor ... except that SR //also// time-dilates the muon by the same
> gamma factor, extending the decay time and the decay path as seen by Earth
> observers (or, the muon reckons the approaching Earth atmosphere to be
> length-contracted, so it manages to travel through more of it before it
> decays, by a Lorentz factor) ... ...the two opposing Lorentz factors then
> cancel exactly (lower velocity value shortens the calculated distance, time
> dilation lengthens the calculated distance), so for an agreed rest mass,
> momentum and rest-frame decay time, the physical end result of the NM and SR
> calculations is _precisely_the_same_.

This is just plain wrong. You used "length contraction" where it does not apply. 
SR predicts a relativistic unstable particle can travel MUCH further than NM 
predicts.

A muon has a (proper) lifetime of 2.19 microseconds. When traveling at a speed ~ 
0.9999 c it could, on average, travel 685 meters. In practice high-energy muons 
can AND DO travel MUCH further than that (e.g. from the upper atmosphere to the 
surface, ~ 12 km.

For pions the measurements are more striking: c*lifetime = 7.8 meters, but both 
CERN and Fermilab have pion beams over a kilometer long, in which > 90% of the 
pions survive. These pions have kinetic energies > 100 GeV, so v = 0.999999 c, 
and gamma > 714.

Tom Roberts

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#428758

On Monday, 7 August 2017 02:34:07 UTC+1, tjrob137  wrote:
> On 8/6/17 8/6/17   5:27 PM, Eric Baird wrote:
> > With the lower nominal velocity and an agreed rest-frame decay time, we might
> > naively expect the muon decay path to be shorter under SR than NM, by the
> > Lorentz factor ... except that SR //also// time-dilates the muon by the same
> > gamma factor, extending the decay time and the decay path as seen by Earth
> > observers (or, the muon reckons the approaching Earth atmosphere to be
> > length-contracted, so it manages to travel through more of it before it
> > decays, by a Lorentz factor) ... ...the two opposing Lorentz factors then
> > cancel exactly (lower velocity value shortens the calculated distance, time
> > dilation lengthens the calculated distance), so for an agreed rest mass,
> > momentum and rest-frame decay time, the physical end result of the NM and SR
> > calculations is _precisely_the_same_.
> 
> This is just plain wrong. 

No, it's correct. You just have to remember that the nominal velocity that SR applies to the muon for an agreed energy and momentum, and the nominal velocity that SR applies to the same situation for the same energy and momentum, are different.

The Newtonian relationship is p=mv
https://en.wikipedia.org/wiki/Momentum

, while the corresponding SR relationship is p=mv gamma
http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/relmom.html

So if momentum p and the particle's rest mass m are known, then the calculated SR and NM velocities will be different, vNM=p/m, vSR=p/(m gamma), where gamma is an increase calculated using vSR as its velocity value.

If the particle survives for t seconds in its own frame, then the distance d that it travels before decaying will traditionally be d=vt. 
In the Newtonian calculation we then have the distance
: dNM = t vNM = t p/m 

In the SR calculation we have the distance
: dSR = t gamma vSR  
, where gamma is an increase in distance travelled at a given nominal velocity, due to time dilation. We now replace vSR (using the previous relativistic momentum equation) and get
: dSR = t gamma p/(m gamma)
Since the two identical gamma factors cancel, we have 
: dSR = t p/m
, just like we did in the NM calculation. So, for theory-neutral agreed parameters such as rest mass, rest frame decay time and impact momentum, 
: dSR=dNM
, and both calculations give precisely the same final physical prediction.



> You used "length contraction" where it does not apply. 

No, I provided a second SR explanation for how the muon penetrates the distance it does under SR, reasoned from the muon's point of view. This is a standard argument that appears in a stack of SR textbooks (I just checked, using Google Books).

For instance, Wikipedia, it say::
:: The atmosphere has its proper length in the Earth frame, 
:: while the increased muon range is explained by their 
:: longer lifetimes due to time dilation (see Time dilation 
:: of moving particles). However, in the muon frame their 
:: lifetime is unchanged but the atmosphere is contracted 
:: so that even their small range is sufficient to reach 
:: the surface of earth.
https://en.wikipedia.org/wiki/Length_contraction


So congratulations, by saying that //that's// wrong you just failed introductory special relativity.   

Eric Baird

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