Michel Janssen argues that often used patterns of reasoning that he
calls common origin inferences (or COIs) count as evidence for some
ideas over others. He sees that special relativity is preferable to
some mature version of Lorentz's theory (such as Lorentz's own
1906/1915 version in his "The Theory of Electrons" or Ives, or
Prokhovnik, etc.) because special relativity *explains* things that
are unexplained coincidences in Lorentz's theory. Janssen development
and elaboration of this thesis can be found in his recent papers:

"COI Stories: Explanation and Evidence from Copernicus to Hockney." [
http://www.tc.umn.edu/~janss011/pdf files/COI-POS.pdf ] Longer version
of a paper in Perspectives on Science, 10 (2002): 457-522.

"Reconsidering a Scientific Revolution: The Case of Einstein versus
Lorentz."
Physics in Perspective, 4 (2002): 421-446.

More related papers can be found on his website [
http://www.tc.umn.edu/~janss011/ ].

I'm interested in how LET supporters counter this criticism. Do these
COIs make the standard special relativity (Einstein-Minkowski)
interpretation a "better" or "real" theory while LET is not? Does the
standard interpretation have it's own as "bad" or "worse" explanatory
problems that LET does not?

"Mark Szlazak" wrote in message
om...
Michel Janssen argues that often used patterns of reasoning that he
calls common origin inferences (or COIs) count as evidence for some
ideas over others. He sees that special relativity is preferable to
some mature version of Lorentz's theory (such as Lorentz's own
1906/1915 version in his "The Theory of Electrons" or Ives, or
Prokhovnik, etc.) because special relativity *explains* things that
are unexplained coincidences in Lorentz's theory. Janssen development
and elaboration of this thesis can be found in his recent papers:

"COI Stories: Explanation and Evidence from Copernicus to Hockney." [
http://www.tc.umn.edu/~janss011/pdf files/COI-POS.pdf ] Longer version
of a paper in Perspectives on Science, 10 (2002): 457-522.

"Reconsidering a Scientific Revolution: The Case of Einstein versus
Lorentz."
Physics in Perspective, 4 (2002): 421-446.

More related papers can be found on his website [
http://www.tc.umn.edu/~janss011/ ].

I'm interested in how LET supporters counter this criticism. Do these
COIs make the standard special relativity (Einstein-Minkowski)
interpretation a "better" or "real" theory while LET is not? Does the
standard interpretation have it's own as "bad" or "worse" explanatory
problems that LET does not?

Great! And thanks for pointing out that very interesting and informative
paper of Janssen.

Before anything else:
To be clear about the subject matter, I suppose that with LET you mean SRT
according to Lorentz, and with SRT you mean SRT according to Einstein. And
please note that although I do think SRT is handy, I'm not exactly an
SRT-Lorentz / LET supporter as the alternative hypothesis of Poincare seems
more probable to me.

Starting with a little negative criticism on Janssen's paper:

Janssen claims that Lorentz proposed the Lorentz contraction as a pure
coincidence.
To the contrary, Lorentz proposed in 1904 that not only light but also
matter is of electromagnetic nature so that all forces transform similarly
(kind of ether waves or, in modern jargon, vacuum vibrations), thus
explaining the assumed contraction with his own COI - and Janssen gives away
that he knows about that when mentioning the "electromagnetic world
picture".
Lorentz' COI was supported by later experiments that established the wave
nature of all matter.
I agree that "electromagnetic" may be too restrictive, especially if it is
assumed that one may only use the Maxwell equations - but being more
agnostic about it does not increase explanatory power, it is only safer to
say less. If we strip Lorentz' theory from all explanation attempts, we end
up with basic textbook SRT for engineers.

When citing the graciousness of Lorentz with regards to Einstein, he
overlooks that Lorentz was there giving unjust credit about the Principle of
Relativity to Einstein that originated with Poincare - and therefore that it
had nothing to do with the subject matter at hand.
- I have no explanation for this blooper(?) of Lorentz; anyone who does?!

The magnetic induction example that he cites of Einstein mainly illustrates
Einstein's confusion, as the case where only relative movement of source and
receiver matters is not the same subject as SRT, in which the relative
movement of these to the reference system is supposed to matter - in
SRT-Einstein, "ether" is replaced by "reference system", and the world view
is *not* reduced to only coil and magnet.

In general, his arguments in favour of the COI approach look good to me, but
his arguments that the COI approach favours SRT-Einstein are not convincing
to me.

As a counter argument, Lorentz' theory provides the ether as a
straightforward single physical explanation for the clock paradox, which in
that light is hardly a paradox (but this important point was perhaps not
clear to Lorentz himself!).
Einstein on the other hand was not able to give one single explanation for
the clock paradox:
According to him two incompatible "explanations" are both right - relative
velocity on the one hand, and relative velocity combined with the stronger
effect of gravitational potential on the other hand, always causing the
other clock to be affected (Einstein 1918). Moreover, neither explanation
attempt can be considered to be a true physical explanation for the observed
physical effect.

By the way, since I received little response to my recent question about the
clock paradox (Message-ID: ), I wonder if
indeed the GRT explanation "explains" the time difference according to an
observation system with the clock that is subject to the forces, but fails
to correctly predict the arrival times of light pulses at that clock
according to that system.

Harald

"Mark Szlazak" wrote in message om...
Michel Janssen argues that often used patterns of reasoning that he
calls common origin inferences (or COIs) count as evidence for some
ideas over others.

COI can count as evidence that some ideas are preferred
by most people, but in the case of LET vs. SR it is self
evident that most people prefer SR.

To use philosophical arguments as 'evidence' that SR is
better than LET is, in my opinion not justified. It as
wring as those who claim that LET _must_ be the
correct interpretation of the experimental facts.


I'm interested in how LET supporters counter this criticism. Do these
COIs make the standard special relativity (Einstein-Minkowski)
interpretation a "better" or "real" theory while LET is not?

There is no 'real' theory.

Does the
standard interpretation have it's own as "bad" or "worse" explanatory
problems that LET does not?

The experimental evidence is weird, thus both interpretations
must have some element of weirdness. All you can do is
move it from place to place.

If you like, I can give the reasons I prefer SR to LET.

Martin Hogbin

"Martin Hogbin" wrote in message ...

There is no 'real' theory.


Could you elaborate?

The experimental evidence is weird, thus both interpretations
must have some element of weirdness. All you can do is
move it from place to place.

If you like, I can give the reasons I prefer SR to LET.

Martin Hogbin

Yes, please do.

"Mark Szlazak" wrote in message
om...
Michel Janssen argues that often used patterns of reasoning that he
calls common origin inferences (or COIs) count as evidence for some
ideas over others. He sees that special relativity is preferable to
some mature version of Lorentz's theory (such as Lorentz's own
1906/1915 version in his "The Theory of Electrons" or Ives, or
Prokhovnik, etc.) because special relativity *explains* things that
are unexplained coincidences in Lorentz's theory. Janssen development
and elaboration of this thesis can be found in his recent papers:

Not only that Mark but the POR on which SR is based explains other things
besides - like conservation of energy, momentum and angular momentum to name
just a few. Indeed that the POR is really a symmetry principle (it tells
what remains the same when other things change) which has powerful
implications by something called Noethers Theorem. This particular theorem
is not that well known outside physics and applied math but is actually
something quite marvelous that you should be acquainted with. See for
example http://math.ucr.edu/home/baez/noether.html.

Thanks
Bill

"Mark Szlazak" wrote in message om...
"Martin Hogbin" wrote in message ...

There is no 'real' theory.

Could you elaborate?

I have to admit that I am not quite sure what you
meant by a 'real' theory. My point was that there
is no justification for assuming that the universe
operates by a set of rules or even, if it does, that
we can discover those rules.

If you like, I can give the reasons I prefer SR to LET.

Yes, please do.

I see LET, together with the concept of an aether,
as something of a historical quirk. Throughout most
of the history of physics, inertial motion has been taken
to be relative. It was only when the wavelike nature of
light was discovered that the idea of an aether became
prominent. Using the concept of a fixed frame of
reference to explain why inertial motion is relative,
whilst acceleration appears not to be, seems like a bad
idea to me.

The primary advantage that latter day LET supporters
cite for their theory is that ultimately the universe is just
as we perceive it in everyday life. In particular, time is
the same everywhere.This is clearly desirable for any
theory since it makes it easier for our human brains to
understand and innovate.

But at what cost is this benefit achieved? At the cost
of having the 'real' world completely unmeasurable,
undetectable, and inaccessible to us. The 'real' world
becomes something of a fairyland, where everything is
how it should be, but no one can go there.

SR, on the other hand, is a what-you-measure-is-
what-you-get theory. The apparent nature of the
universe, complete with all its weirdness, is there
for all to see (measure).

Enough for now.

Martin Hogbin

Bill, symmetry objections against the Lorentzian-type interpretations
have been traditional objections, they are also known as the "no
conspiracy" objections: Nature would not conspire, via length
contraction and clock retardation, to conceal from us fundamental
asymmetries in nature. There is a rebuttal to this traditional
objection.

However, Janssen's formulation of this objection is not about
concealment of asymmetries. Rather it is that Lorentz invariance is a
property shared accidentally by all matter and fields in space and
time. He claims that this is a case of an unexplained coincidence
where the laws governing different sorts of matter all share the
property of Lorentz invariance.

Do you see anything wrong with it?

"Mark Szlazak" wrote in message om...
Bill, symmetry objections against the Lorentzian-type interpretations
have been traditional objections, they are also known as the "no
conspiracy" objections: Nature would not conspire, via length
contraction and clock retardation, to conceal from us fundamental
asymmetries in nature.

I would put this another way. Why would we want to use a theory
which contains such a 'conspiracy'?

There is a rebuttal to this traditional objection.

Do I sense an imminent ambush?

Martin Hogbin

"Mark Szlazak" wrote in message
om...
Bill, symmetry objections against the Lorentzian-type interpretations
have been traditional objections, they are also known as the "no
conspiracy" objections: Nature would not conspire, via length
contraction and clock retardation, to conceal from us fundamental
asymmetries in nature. There is a rebuttal to this traditional
objection.

What is that rebuttal?

However, Janssen's formulation of this objection is not about
concealment of asymmetries. Rather it is that Lorentz invariance is a
property shared accidentally by all matter and fields in space and
time. He claims that this is a case of an unexplained coincidence
where the laws governing different sorts of matter all share the
property of Lorentz invariance.

Do you see anything wrong with it?

I do, and I explained that and other things. Didn't you get my posting?`
Message-ID:

Harald

"Martin Hogbin" wrote in message ...
"Mark Szlazak" wrote in message om...
Bill, symmetry objections against the Lorentzian-type interpretations
have been traditional objections, they are also known as the "no
conspiracy" objections: Nature would not conspire, via length
contraction and clock retardation, to conceal from us fundamental
asymmetries in nature.

I would put this another way. Why would we want to use a theory
which contains such a 'conspiracy'?

There is a rebuttal to this traditional objection.

Do I sense an imminent ambush?

Martin Hogbin

The thought of an impending denouement maybe titilating to some, but I
may disappoint them. My intent is to set up a table of "pro vs con
talking points" on the spacetime and Lorentzian interpretations of
STR. So, the process is more exploratory to see what's out there and
will not result in one logically coherent argument. At least not here,
not yet. Others may benefit from such a table and can "run with it" as
they please.