"Mark Szlazak" wrote in message om...
"Martin Hogbin" wrote in message news:c19ua5

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.

OK, I have given my reasons for preferring SR to LET
(or at least some of them). What reasons are there for
preferring LET?

Martin Hogbin

Mark Szlazak:
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.

Which happens to be what? I can think of quite a few of those
coincidental conspiracies to explain, none of which are fundamentally
tied to the obvious things you mentioned.

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?

Well, for one thing, one doesn't have to resort to an unexplained
coincidence that led to all matter accidentally having lorentz invariance
as a common denominator if you don't try to avoid relativity.

Mark Szlazak
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?

That was not my point - my point is that the POR explains not just the
Lorentz transformations but a lot more besides. The POR is in fact the
basis of classical mechanics - thus it makes sense to base other theories,
such as relativity, on principles we already know and accept - and - in its
domain of applicability, classical mechanics is a good theory, a very good
theory indeed.

Thanks
Bill

Martin Hogbin
OK, I have given my reasons for preferring SR to LET
(or at least some of them). What reasons are there for
preferring LET?

If you believe the Galilean transformations have some kind of absolute truth
like Kant thought Euclidian geometry had then you can still maintain nature
works that way at rock bottom while still maintaining agreement with
experiment. Of course I do not believe the Galilean transformation should
be given that type of primacy (or Euclidian geometry for that matter) but to
some it may be very important.

Thanks
Bill

"Bill Hobba" wrote in message ...
That was not my point - my point is that the POR explains not just the
Lorentz transformations but a lot more besides. The POR is in fact the
basis of classical mechanics - thus it makes sense to base other theories,
such as relativity, on principles we already know and accept - and - in its
domain of applicability, classical mechanics is a good theory, a very good
theory indeed.

Thanks
Bill

Bill, I guess I don't see your point. You mentioned Noether's theorems
and as far as I can tell they're about symmetries/invariance and
conservation principles:

The symmetries of laws of motion do entail conservation principles and
conversly.

Now, the laws of motion aren't "written on thin air" alone, but
require the support of various space-time structures. Are you worried
that a neo-Lorentzian theory has more structure to space-time than is
necessary to explain the symmetries required by relativistic laws of
motion? Are you making an Ockham's razor argument?

Mark Szlazak wrote:
Bill, I guess I don't see your point. You mentioned Noether's theorems
and as far as I can tell they're about symmetries/invariance and
conservation principles:

Yes they are

Mark Szlazak wrote:
The symmetries of laws of motion do entail conservation principles and
conversly.

Yes

Now, the laws of motion aren't "written on thin air" alone, but
require the support of various space-time structures. Are you worried
that a neo-Lorentzian theory has more structure to space-time than is
necessary to explain the symmetries required by relativistic laws of
motion? Are you making an Ockham's razor argument?

The argument I am making is simple. SR is based on the POR - aether
theories are not. But the POR is also the basis of classical mechanics and
in fact is the reason it has its conservation laws (via Noethers theorem).
Now when formulating a new theory, SR, what you rather base it on - a new
assumption (the existence of an aether we have no experimental support for)
or a principle we already know to be true from another area of physics? Why
introduce new principles? I guess it is an 'Ockham's razor argument'.

Thanks
Bill

"Bill Hobba" wrote in message ...

The argument I am making is simple. SR is based on the POR - aether
theories are not. But the POR is also the basis of classical mechanics and
in fact is the reason it has its conservation laws (via Noethers theorem).
Now when formulating a new theory, SR, what you rather base it on - a new
assumption (the existence of an aether we have no experimental support for)
or a principle we already know to be true from another area of physics? Why
introduce new principles? I guess it is an 'Ockham's razor argument'.

Thanks
Bill

OK, please correct me if I'm wrong but I take it that you have a
couple of related complaints with Lorentz-Poincare type views. 1)
Extra space-time structure that you claim there isn't any experimental
support for, and 2) because of this extra structure a status change
occurs, POR and conservation laws get a secondary status unlike the
primary status they enjoyed in Galilean and Einstein-Minkowski
space-time. [Well, that's what you get when you move to a better
neighborhood ... just kidding.]

Bill, did I get it right?

Bill Hobba wrote:

The argument I am making is simple. SR is based on the POR - aether
theories are not. But the POR is also the basis of classical mechanics and
in fact is the reason it has its conservation laws (via Noethers theorem).
Now when formulating a new theory, SR, what you rather base it on - a new
assumption (the existence of an aether we have no experimental support for)
or a principle we already know to be true from another area of physics? Why
introduce new principles? I guess it is an 'Ockham's razor argument'.

Agree fully.
I believe, you could tell Ilja Schmelzer exactly that.
He invented a nice and (probably) mathematically correct theory.
I wonder, what is it of use for ?

Ulrich

"Bill Hobba" wrote in message
...

The argument I am making is simple. SR is based on the POR - aether
theories are not. But the POR is also the basis of classical mechanics
and
in fact is the reason it has its conservation laws (via Noethers
theorem).
Now when formulating a new theory, SR, what you rather base it on - a
new
assumption (the existence of an aether we have no experimental support
for)
or a principle we already know to be true from another area of physics?
Why
introduce new principles? I guess it is an 'Ockham's razor argument'.

Thanks
Bill

Mark Szlazak wrote:
OK, please correct me if I'm wrong but I take it that you have a
couple of related complaints with Lorentz-Poincare type views. 1)
Extra space-time structure that you claim there isn't any experimental
support for, and 2) because of this extra structure a status change
occurs, POR and conservation laws get a secondary status unlike the
primary status they enjoyed in Galilean and Einstein-Minkowski
space-time. [Well, that's what you get when you move to a better
neighborhood ... just kidding.]

Bill, did I get it right?

No. Look here is an example. I plug in a shaver and switch it on - from
experience I formulate the explanation that it is the electric power that
makes it work.
I go somewhere else and plug it in - do I need to make another assumption
about why it works - that the outlet supplied electric power still explains
it; there is no reason to give a different explanation. The same with SR
and the POR. I know the POR and the PLA explain classical mechanics. I
then look at SR - do I assume a different explanation if the old one - the
POR - still works. Without additional evidence I doubt that most people
would.

Thanks
Bill

ueb wrote:
Agree fully.
I believe, you could tell Ilja Schmelzer exactly that.
He invented a nice and (probably) mathematically correct theory.
I wonder, what is it of use for ?

Well some people find the anther a better explanation eg it allows one to
maintain the a priori validity of the Galelain transformations. Also Ilja
likes Bohmean mechanics which for multiparticel states demands an anther.

Thanks
Bill