The current foundations of physics are relativity and quantum theory.
Relativity theory is very badly taught. There are two ways of
presenting it, in the first the assumptions for SR a

1. the speed of light is a constant for all observers
2. the laws of physics are the same for all observers (includes all
motion is relative).
3. the universe is homogenous and isotropic

In the second, modern approach, the assumptions a

1. The universe has a metric ds^2 = dx^2 + dy^2 + dz^2 - c^2dt^2
2. Any coordinate displacement (delta Y) in one coordinate system can
be expressed as a sum of terms of differentials of the coordinates in
another coordinate system.
3. Noether's theorem applies and ds^2 is invariant.

See http://pancake.uchicago.edu/~carroll/notes/

The first approach is not inconsistent with the second, it just has
sweeping assumptions that unnerve the novice (ie: the novice thinks
'why should the speed of light be constant, what is so special about
light?' and misses the whole point of relativity). The second
approach needs a lot of study but has simpler assumptions.

If contributors to sci.physics and sci.physics.relativity wish to
object to relativity they have several attack points:

1. The assumed metric ds^2 = dx^2 + dy^2 + dz^2 - c^2dt^2 is wrong ie:
inconsistent with observations or a special case.

2. A change in a first set of coordinates is not given in terms of the
second by:

deltaY = delta x (dY/dx) + delta y (dY/dy)+ etc..

This is a basic theorem of maths so might be hard to criticise.

3. Symmetries do not exist and/or there is not an invariant for every
symmetry.

Now, attacking relativity because you don't like the twin paradox or
time dilation or can't see why the speed of light is constant is where
lack of humility comes in. Nobel prize winning physicists are the
intellectual equivalent of olympic gold medallists but much more
selected. Even your university physics/maths professor is a regional
champ. If you believe that all of these people could have considered
time dilation and the twin paradox over a whole century and all got it
wrong then humility should suggest to you that the fault could be with
yourself.

So how can we be sceptical about a century old theory such as
relativity?

Any new, replacement theory must contain most of the results of the
old theory because Relativity predicts a host of phenomena from black
holes to quantum physics that have been discovered. Sorry, but if
your new replacement for relativity does not contain most of the
tensor maths of the current theory then you must be wrong. So
sceptics, off you go to uni for a 3 year course on advanced maths.

Alternatively you might replace the original assumptions in some way
so that relativity is a special case. I have been trying to do this
with the metric tensor but sci.physics.research will not post these
musings for a good reason: without strong predictions for experiment
and a clearly argued case the ideas are unduly speculative.

One method of criticising Relativity that is absurd is to go back to
Einstein's century old papers and nit pick every problematic phrase.
This is as crazy as maintaining that science is 'wrong' because Roger
Bacon was not always consistent. Relativity theory is the product of a
million or more papers over the past century, it is not contained in a
single publication a century ago.

Sci.physics is a good place for punting odd ideas around but if we are
sceptical of current theory we should also be sceptical of our own
theories, especially if no one but ourselves accepts them.

Best Wishes

Alex Green

Alex Green wrote:
The current foundations of physics are relativity and quantum theory.
Relativity theory is very badly taught. There are two ways of
presenting it, in the first the assumptions for SR a

1. the speed of light is a constant for all observers
2. the laws of physics are the same for all observers (includes all
motion is relative).
3. the universe is homogenous and isotropic

In the second, modern approach, the assumptions a

1. The universe has a metric ds^2 = dx^2 + dy^2 + dz^2 - c^2dt^2

So you are talking only about Special Relativity?


2. Any coordinate displacement (delta Y) in one coordinate system can
be expressed as a sum of terms of differentials of the coordinates in
another coordinate system.
3. Noether's theorem applies and ds^2 is invariant.

Doesn't one need also an assumption like "all physical laws have to
be expressed with tensors with respect to the transformation which leave
the metric invariant"?


See http://pancake.uchicago.edu/~carroll/notes/

The first approach is not inconsistent with the second, it just has
sweeping assumptions that unnerve the novice (ie: the novice thinks
'why should the speed of light be constant, what is so special about
light?' and misses the whole point of relativity). The second
approach needs a lot of study but has simpler assumptions.

I like the mathematical beauty of the second approch, but I nevertheless
think that the first approach is better for teaching. If you first have
to learn all this fancy math, you won't understand relativity as well as
if you had been taught it using the first approach. Don't understand me
wrong: I think that *both* approaches should be taught, but starting
with the first one.


[snip]


Now, attacking relativity because you don't like the twin paradox or
time dilation or can't see why the speed of light is constant is where
lack of humility comes in. Nobel prize winning physicists are the
intellectual equivalent of olympic gold medallists but much more
selected. Even your university physics/maths professor is a regional
champ. If you believe that all of these people could have considered
time dilation and the twin paradox over a whole century and all got it
wrong then humility should suggest to you that the fault could be with
yourself.

So how can we be sceptical about a century old theory such as
relativity?

The usual responses of cranks here are either that all this people see
the flaws, but don't dare to speak up, because they fear for their jobs,
or that they are so indoctrinated that they are too blind to see the errors.

You can't reason people out of a position they didn't use reason to get
into...



Any new, replacement theory must contain most of the results of the
old theory because Relativity predicts a host of phenomena from black
holes to quantum physics that have been discovered.

Pardon? Above you talked only about Special Relativity. SR does not
predict black holes! And neither SR nor GR do predict quantum physics!


Sorry, but if
your new replacement for relativity does not contain most of the
tensor maths of the current theory then you must be wrong. So
sceptics, off you go to uni for a 3 year course on advanced maths.

The label "sceptics" for those people is misapplied. *True* sceptics
*first* study a topic closely before they start attacking it.


[snip]

Bye,
Bjoern

Alex Green wrote:

The current foundations of physics are relativity and quantum theory.
Relativity theory is very badly taught. There are two ways of
presenting it, in the first the assumptions for SR a
[snip crap]

Idiot.

http://math.ucr.edu/home/baez/RelWWW/tests.html
Mathematics of gravitation

http://wugrav.wustl.edu/people/CMW/update98.pdf
http://www.astro.northwestern.edu/AspenW04/Papers/lorimer1.pdf
Equivalence Principle testing

http://rattler.cameron.edu/EMIS/journals/LRG/Articles/Volume4/2001-4will/index.html
http://arXiv.org/abs/gr-qc/0311039
http://www.weburbia.demon.co.uk/physics/experiments.html
Experimental constraints on General Relativity

http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
Nature 425 374 (2003)
http://rattler.cameron.edu/EMIS/journals/LRG/Articles/Volume6/2003-1ashby/index.html
http://www.eftaylor.com/pub/projecta.pdf
http://www.public.asu.edu/~rjjacob/Lecture16.pdf
Relativity in the GPS system

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/airtim.html
Hafele-Keating Experiment

Science 303(5661) 1143;1153 (2004)
http://arXiv.org/abs/astro-ph/0401086
http://arxiv.org/abs/astro-ph/0312071
Deeply relativistic neutron star binaries

Physics Today 57(7) 40 (2004)
No aether

http://www.npl.washington.edu/eotwash/pdf/prl83-3585.pdf
http://arXiv.org/abs/gr-qc/0301024
Nordtvedt Effect

http://arxiv.org/abs/gr-qc/0306076.pdf
http://www.metaresearch.org/solar%20system/gps/absolute-gps-1meter-3.ASP
http://www.navcen.uscg.gov/pubs/gps/gpsuser/gpsuser.pdf
http://www.navcen.uscg.gov/pubs/gps/sigspec/default.htm
http://www.navcen.uscg.gov/pubs/gps/icd200/default.htm
http://www.trimble.com/gps/index.html
http://sirius.chinalake.navy.mil/satpred/
http://www.phys.lsu.edu/mog/mog9/node9.html
http://egtphysics.net/GPS/RelGPS.htm
http://www.schriever.af.mil/gps/Current/current.oa1
http://edu-observatory.org/gps/gps_books.html
http://www-astronomy.mps.ohio-state.edu/~pogge/Ast162/Unit5/gps.html


--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf

"Alex Green" wrote in message
m...
| The current foundations of physics are relativity and quantum theory.
| Relativity theory is very badly taught.

That's because it is pure nonsense.

There are two ways of
| presenting it, in the first the assumptions for SR a
|
| 1. the speed of light is a constant for all observers

So why teach an assumption?
Teaching assumptions is VERY poor science. Nor is that assumption a
postulate of relativity. It is a result. Do you have the slightest idea what
is meant by "circularity"?

| 2. the laws of physics are the same for all observers (includes all
| motion is relative).

You just don't get it, do you?
"Examples of this sort, together with the unsuccessful attempts to discover
any motion of the earth relatively to the ``light medium,'' suggest that the
phenomena of electrodynamics as well as of mechanics possess no properties
corresponding to the idea of absolute rest. "
The examples referred to are examples of the PoR, and clearly NOT all motion
is relative. The stars do NOT revolve around the Earth. Foucaults pendulum
and the gyroscope act in a universal frame of reference. Do you wish to deny
they covered by the laws of physics?


| 3. the universe is homogenous and isotropic

homogeneous :
Etymology: Medieval Latin homogeneus, homogenus, from Greek homogenEs, from
hom- + genos kind -- more at KIN
1 : of the same or a similar kind or nature
2 : of uniform structure or composition throughout a culturally homogeneous
neighborhood
3 : having the property that if each variable is replaced by a constant
times that variable the constant can be factored out : having each term of
the same degree if all variables are considered a homogeneous equation

2 rules out quasars, cepheids and supernovae from main sequence stars
3 rules out time dilation

isotropic
Etymology: International Scientific Vocabulary
exhibiting properties (as velocity of light transmission) with the same
values when measured along axes in all directions an isotropic crystal

Are you suggesting the universe has the properties of aether?
MMX says you are wrong.

|
| In the second, modern approach, the assumptions a
|
| 1. The universe has a metric ds^2 = dx^2 + dy^2 + dz^2 - c^2dt^2

So why teach an assumption?
Teaching assumptions is VERY poor science. Nor is that assumption a
postulate of relativity. It is a result. Do you have the slightest idea what
is meant by "circularity"?


| 2. Any coordinate displacement (delta Y) in one coordinate system can
| be expressed as a sum of terms of differentials of the coordinates in
| another coordinate system.
| 3. Noether's theorem applies and ds^2 is invariant.
|
| See http://pancake.uchicago.edu/~carroll/notes/
|
| The first approach is not inconsistent with the second, it just has
| sweeping assumptions that unnerve the novice (ie: the novice thinks
| 'why should the speed of light be constant, what is so special about
| light?' and misses the whole point of relativity).

Oh? and what IS the whole point of relativity?
Why should the speed of light be constant, what is so special about
light?'


| The second
| approach needs a lot of study but has simpler assumptions.

So why teach an assumption?
Teaching assumptions is VERY poor science. Do you have the slightest idea
what is meant by "circularity"?

|
| If contributors to sci.physics and sci.physics.relativity wish to
| object to relativity they have several attack points:
|
| 1. The assumed metric ds^2 = dx^2 + dy^2 + dz^2 - c^2dt^2 is wrong ie:
| inconsistent with observations or a special case.

Yes. It is wrong. It is abject nonsense. It nothing more than assumption as
you admit, and you have the burden of proving its validity.

|
| 2. A change in a first set of coordinates is not given in terms of the
| second by:
|
| deltaY = delta x (dY/dx) + delta y (dY/dy)+ etc..
|
| This is a basic theorem of maths so might be hard to criticise.

Then I won't bother. I only have to attack your assumptions, and I do.


|
| 3. Symmetries do not exist and/or there is not an invariant for every
| symmetry.

Then dtau/dt = 1 exactly, by symmetry.


|
| Now, attacking relativity because you don't like the twin paradox or
| time dilation or can't see why the speed of light is constant is where
| lack of humility comes in.

What the **** do human emotions have to do with anything?

Claiming the speed of light is independent of the source is where
the height of pomposity comes in.


| Nobel prize winning physicists are the
| intellectual equivalent of olympic gold medallists but much more
| selected. Even your university physics/maths professor is a regional
| champ. If you believe that all of these people could have considered
| time dilation and the twin paradox over a whole century and all got it
| wrong then humility should suggest to you that the fault could be with
| yourself.

Considered, carefully thought over and rejected, based on logic.

|
| So how can we be sceptical about a century old theory such as
| relativity?
Because it is illogical nonsense, of course.
Nobody got a Nobel Prize for relativity, so your argument is groundless
anyway.
Here's why relativity is a **** up. Doubtless you'll continue with your
anecdotal arguments and claim that mathematics is not to be criticized while
ignoring the criticism, still trying to to teach assumptions, but in your
face with them anyway.

The Seven Deadly Sins of Special Relativity.

For quotations following, reference:
http://www.fourmilab.ch/etexts/einstein/specrel/www/
("On the Electrodynamics of Moving Bodies" by Albert Einstein)

1) "light is always propagated in empty space with a definite velocity c
which is independent of the state of motion of the emitting body",
a totally unproven assumption without any evidence to support it.

2) "In agreement with experience we further assume the quantity
2AB/(t'A-tA) = c to be a universal constant- the velocity of light in empty
space.",
an admitted assumption that is quite worthless when there is any
relative motion between A and B, yet essential to the derivation of the
remainder of Einstein's nonsense.

3) The equation
½[tau(0,0,0,t)+tau(0,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v)) ,
the ½ of which is derived from 2) above and is tantamount to saying
(1/3 + 2/3)/2 = 1/3.

4) The missing 0' from that equation, since x' = x-vt, hence 0' = 0-vt,
and the equation should be
½[tau(-vt,0,0,t)+tau(-vt,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v))
at the very least.

5) The further assumption "IF we place x' = x-vt ... " without considering
IF we place x' = x+vt, from which we derive (using Einstein's method)
tau = (t+xv/c^2)/sqrt(1-v^2/c^2)
xi = (x + vt)/sqrt(1-v^2/c^2)" -Paul B. Andersen

6) The statements
"But the ray moves relatively to the initial point of k,
when measured in the stationary system, with the velocity c-v..."
and
"It follows, further, that the velocity of light c cannot be altered by
composition with a velocity less than that of light. For this case we obtain
V = (c+w)/(1+w/c) = c."
which are contradictory, the first being Galilean, the second being
contrary to the vector addition of velocities, an axiom of a vector space.

7) The lack of a check to verify the theory is self-consistent by feeding
the new PoR given in 6) into the equation given in 3) and finding a total
failure.
Check:
(t1-t)/(t2-t)*[tau(-vt,0,0,t)+tau(-vt,0,0,t+x'/V+x'/V)] = tau(x',0,0,t+x'/V)

Androcles.
|
| Any new, replacement theory must contain most of the results of the
| old theory because Relativity predicts a host of phenomena from black
| holes to quantum physics that have been discovered.

Here's a prediction from SR:
"Thence we conclude that a balance-clock at the equator must go more slowly,
by a very small amount, than a precisely similar clock situated at one of
the poles under otherwise identical conditions. "
Since it is false, SR is a FAILURE. Its predictions are USELESS and WRONG.

Sorry, but if
| your new replacement for relativity does not contain most of the
| tensor maths of the current theory then you must be wrong.
Nonsense. Relativity is wrong, period. Its predictions are worthless idiocy
and count for nothing.

| So
| sceptics, off you go to uni for a 3 year course on advanced maths.

Already done, I have my degrees, thanks. Have you? It is you that could use
a course in pure math, there is more than just linear algebra to math.
Don't you realize mathematicians are the most sceptical of all?
We know the difference between an axiom and an assumption
right from the get-go, and assumptions are definitely called
hypotheses to be tested.
Hypothesis: the speed of light is a constant for all observers.
True or false?
I move toward one light source and away from another.
c+v = c-v = c.
Calculation. trivial, by inspection v = 0.
This denies I am moving. By the contradition found, the hypothesis is false.
Your assumption is dead. Done. Finished.
|
| Alternatively you might replace the original assumptions in some way
| so that relativity is a special case. I have been trying to do this
| with the metric tensor but sci.physics.research will not post these
| musings for a good reason: without strong predictions for experiment
| and a clearly argued case the ideas are unduly speculative.

You don't have a clearly argued case. You have an assumption that is clearly
false.
|
| One method of criticising Relativity that is absurd is to go back to
| Einstein's century old papers and nit pick every problematic phrase.

Done.

| This is as crazy as maintaining that science is 'wrong' because Roger
| Bacon was not always consistent.

Oh, crap. You are blustering, trying to generalize. By your argument I'd
have maintain the whole of science was wrong because Einstein didnlt have a
consisten bone in his body. One man is not science.

| Relativity theory is the product of a
| million or more papers over the past century, it is not contained in a
| single publication a century ago.

Eat **** because 100,000,000 flies can't be wrong.
Honestly, who cares about repetition?

|
| Sci.physics is a good place for punting odd ideas around but if we are
| sceptical of current theory we should also be sceptical of our own
| theories, especially if no one but ourselves accepts them.

That's the most sensible thing you've said. Scepticism is healthy. Ignoring
empirical data is unhealthy.
http://www.androc1es.pwp.blueyonder....ctual_data.htm
Read and understand.
Androcles.


| Best Wishes
|
| Alex Green

"Androcles" wrote in message news

"Alex Green" wrote in message
m...
| The current foundations of physics are relativity and quantum theory.
| Relativity theory is very badly taught.

That's because it is pure nonsense.

That's because your skull is filled with crap:
http://users.pandora.be/vdmoortel/di.../LoadCrap.html
http://users.pandora.be/vdmoortel/di...s/CrapHuh.html

Best Wishes - as Alex will surely say ;-)

Dirk Vdm

To Bjoern Feuerbacher:

I generally agree with you, but had to note something to following:

| So how can we be sceptical about a century old theory such as
| relativity?
|
| The usual responses of cranks here are either that all this people see
| the flaws, but don't dare to speak up, because they fear for their jobs,
| or that they are so indoctrinated that they are too blind to see the errors.

You surely refer to SR/GR, and it may be that cranks use to tell that
in this context. Unfortunately, there are indeed serious flaws, and
paid physicists and mathematicians are too arrogant (or too cowardly)
to admit them. The worst is, that they suppress results of tests, which
could reveal such flaw.
Before you switch to pig-headed, you should read
http://home.t-online.de/home/Ulrich.Bruchholz/

Ulrich

In article , Uncle Al writes:
Alex Green wrote:

The current foundations of physics are relativity and quantum theory.
Relativity theory is very badly taught. There are two ways of
presenting it, in the first the assumptions for SR a
[snip crap]

Idiot.

Unc, you appear to have a problem with reading lately.

Mati Meron | "When you argue with a fool,
| chances are he is doing just the same"

"Alex Green" wrote in message
m...
The current foundations of physics are relativity and quantum theory.
Relativity theory is very badly taught.

Depends on the source. I think the pesentation by Rindler in Introducution
to Special Relativity is quite good.

There are two ways of
presenting it, in the first the assumptions for SR a

1. the speed of light is a constant for all observers
2. the laws of physics are the same for all observers (includes all
motion is relative).
3. the universe is homogenous and isotropic

In the second, modern approach, the assumptions a

1. The universe has a metric ds^2 = dx^2 + dy^2 + dz^2 - c^2dt^2
2. Any coordinate displacement (delta Y) in one coordinate system can
be expressed as a sum of terms of differentials of the coordinates in
another coordinate system.
3. Noether's theorem applies and ds^2 is invariant.

The second approach is better but requires greater knowledge of physics and
math meaning you can not understand it until say at least 3rd year uni.
Also it is reasonable to present an argument why 1 holds and to emphasize it
is really based on the symmetry properties of an inertial frame and to
de-emphasize the importance of c being the speed of light. For that purpose
I rather like the following (admittedly ancient) post by Tom Roberts


http://groups.google.com/groups?q=Ma...ent.com&rnum=5


See http://pancake.uchicago.edu/~carroll/notes/

The first approach is not inconsistent with the second, it just has
sweeping assumptions that unnerve the novice (ie: the novice thinks
'why should the speed of light be constant, what is so special about
light?' and misses the whole point of relativity). The second
approach needs a lot of study but has simpler assumptions.

True.


If contributors to sci.physics and sci.physics.relativity wish to
object to relativity they have several attack points:

1. The assumed metric ds^2 = dx^2 + dy^2 + dz^2 - c^2dt^2 is wrong ie:
inconsistent with observations or a special case.

2. A change in a first set of coordinates is not given in terms of the
second by:

deltaY = delta x (dY/dx) + delta y (dY/dy)+ etc..

This is a basic theorem of maths so might be hard to criticise.

3. Symmetries do not exist and/or there is not an invariant for every
symmetry.

Now, attacking relativity because you don't like the twin paradox or
time dilation or can't see why the speed of light is constant is where
lack of humility comes in. Nobel prize winning physicists are the
intellectual equivalent of olympic gold medallists but much more
selected. Even your university physics/maths professor is a regional
champ. If you believe that all of these people could have considered
time dilation and the twin paradox over a whole century and all got it
wrong then humility should suggest to you that the fault could be with
yourself.

So how can we be sceptical about a century old theory such as
relativity?

Any new, replacement theory must contain most of the results of the
old theory because Relativity predicts a host of phenomena from black
holes to quantum physics that have been discovered. Sorry, but if
your new replacement for relativity does not contain most of the
tensor maths of the current theory then you must be wrong. So
sceptics, off you go to uni for a 3 year course on advanced maths.

Alternatively you might replace the original assumptions in some way
so that relativity is a special case. I have been trying to do this
with the metric tensor but sci.physics.research will not post these
musings for a good reason: without strong predictions for experiment
and a clearly argued case the ideas are unduly speculative.

One method of criticising Relativity that is absurd is to go back to
Einstein's century old papers and nit pick every problematic phrase.
This is as crazy as maintaining that science is 'wrong' because Roger
Bacon was not always consistent. Relativity theory is the product of a
million or more papers over the past century, it is not contained in a
single publication a century ago.

Sci.physics is a good place for punting odd ideas around but if we are
sceptical of current theory we should also be sceptical of our own
theories, especially if no one but ourselves accepts them.

Best Wishes

Good post.

My preferred approach is that outlined by Tom followed by what you recommend
once the students math and physics is up to scratch. BTW Rindler uses an
approach similar to the following link http://arxiv.org/abs/physics/0110076.
It is not quite as simple as it can be but is not bad either.

Thanks
Bill


Alex Green

"Bjoern Feuerbacher" wrote in message
...
Alex Green wrote:
The current foundations of physics are relativity and quantum theory.
Relativity theory is very badly taught. There are two ways of
presenting it, in the first the assumptions for SR a

1. the speed of light is a constant for all observers
2. the laws of physics are the same for all observers (includes all
motion is relative).
3. the universe is homogenous and isotropic

In the second, modern approach, the assumptions a

1. The universe has a metric ds^2 = dx^2 + dy^2 + dz^2 - c^2dt^2

So you are talking only about Special Relativity?


2. Any coordinate displacement (delta Y) in one coordinate system can
be expressed as a sum of terms of differentials of the coordinates in
another coordinate system.
3. Noether's theorem applies and ds^2 is invariant.

Doesn't one need also an assumption like "all physical laws have to
be expressed with tensors with respect to the transformation which leave
the metric invariant"?


See http://pancake.uchicago.edu/~carroll/notes/

The first approach is not inconsistent with the second, it just has
sweeping assumptions that unnerve the novice (ie: the novice thinks
'why should the speed of light be constant, what is so special about
light?' and misses the whole point of relativity). The second
approach needs a lot of study but has simpler assumptions.

I like the mathematical beauty of the second approch, but I nevertheless
think that the first approach is better for teaching.

Problem with the first approach is it emphasizes the importance of light too
much and some beginners get the impression it really has something to do
with light when it really is a theory of space-time symmetry. I prefer, for
the beginning student, the approaches that emphasize the symmetry of the POR
and it is really a theory about space time - approaches similar to

http://groups.google.com/groups?q=Ma...ent.com&rnum=5
and
http://arxiv.org/abs/physics/0110076
(which is similar to Rindler - Introduction to Special Relativity)

If you first have
to learn all this fancy math, you won't understand relativity as well as
if you had been taught it using the first approach. Don't understand me
wrong: I think that *both* approaches should be taught, but starting
with the first one.

Hmmmmm. Even my recommended first approached requires math at least at
second year university level. However I have been assured Wheeler and
Taylor Space-time Physics requires even less math and is an excellent text.
Maybe students need to be taught it at different levels which each level
increasing their understanding as their mathematical and physical
sophistication increases?

Thanks
Bill



[snip]


Now, attacking relativity because you don't like the twin paradox or
time dilation or can't see why the speed of light is constant is where
lack of humility comes in. Nobel prize winning physicists are the
intellectual equivalent of olympic gold medallists but much more
selected. Even your university physics/maths professor is a regional
champ. If you believe that all of these people could have considered
time dilation and the twin paradox over a whole century and all got it
wrong then humility should suggest to you that the fault could be with
yourself.

So how can we be sceptical about a century old theory such as
relativity?

The usual responses of cranks here are either that all this people see
the flaws, but don't dare to speak up, because they fear for their jobs,
or that they are so indoctrinated that they are too blind to see the
errors.

You can't reason people out of a position they didn't use reason to get
into...



Any new, replacement theory must contain most of the results of the
old theory because Relativity predicts a host of phenomena from black
holes to quantum physics that have been discovered.

Pardon? Above you talked only about Special Relativity. SR does not
predict black holes! And neither SR nor GR do predict quantum physics!


Sorry, but if
your new replacement for relativity does not contain most of the
tensor maths of the current theory then you must be wrong. So
sceptics, off you go to uni for a 3 year course on advanced maths.

The label "sceptics" for those people is misapplied. *True* sceptics
*first* study a topic closely before they start attacking it.


[snip]

Bye,
Bjoern

Alex Green:

If contributors to sci.physics and sci.physics.relativity wish to
object to relativity they have several attack points:

1. The assumed metric ds^2 = dx^2 + dy^2 + dz^2 - c^2dt^2 is wrong ie:
inconsistent with observations or a special case.


That isn't a reasonable ``attack point'' as the metric is a measure
of distance. To make that explicit, drop the `c' and it's obvious that
the metric is nothing more than measure of distance on a four-dimensional
manifold with a lorentzian signature. By comparison, the pythagorean
theorem, ds^2 = dx^2 + dy^2 + dz^2 is the metric on a three dimensional
manifold with a euclidean signature. ``Attacking'' the metric is the
equivalent of disproving the pythagorean theorem. That's a realistic
possibility in the quantum regime, but most people attacking relativity
on the newsgroups don't even understand what they are attacking and
quite a number even object because they think relativity means some-
thing contrary to rekativity.

2. A change in a first set of coordinates is not given in terms of the
second by:

deltaY = delta x (dY/dx) + delta y (dY/dy)+ etc..

This is a basic theorem of maths so might be hard to criticise.

As per the above, I've found it difficult to even explain to
some people what that means. For example, several posters criticize
the validity of the lorentz boosts based upon what the seriously
consider a ``mathematical'' argument, but can't understand why the
sane argument would invalidate the concept of a rotation. Really.
I'm not making this up.

3. Symmetries do not exist and/or there is not an invariant for every
symmetry.

Noether's theorem guarantees a conserved current for every symmetry
of L where L satisfies the euler-lagrange equations. Since the interval,
ds^2 satisfies that criteria, the symmetry exists (mathematically).
Whether or not the symmetry exists in realty is an experimental issue,
but in general, if you expect experiments performed in inertial frames
to be (1) repeatable, (2) independent of location or orientation in
space, then you are assuming the symmetry exists. Most people assume
this, but criticize special relativity anyway because they don't under-
stand why special relativity is equivalent to those assumptions.

(Alternatively, you can assume the symmetry and see if experiments
agree. But, since experiments _do_ agree, that route is unavailable.)


Alternatively you might replace the original assumptions in some way
so that relativity is a special case. I have been trying to do this
with the metric tensor but sci.physics.research will not post these
musings for a good reason: without strong predictions for experiment
and a clearly argued case the ideas are unduly speculative.

Changing the metric tensor means one of three things. (1) You're
really doing general relativity, in which case special relativity
really is a limiting case, (2) You're basing the invariance on some-
thing other than pure spacetime displacements, (e.g., doubly special
relativity), (3) You are really building in a new force of some kind
in which either the force will go away leaving you with general
relativity or it will be wrong, since inertial frames are force free.

In (2) the only real opportunities are in the quantum regime.

One method of criticising Relativity that is absurd is to go back to
Einstein's century old papers and nit pick every problematic phrase.

The main reason it's absurd is because no one really cares how einstein
phrased anything or what his personal motivations were at the time.
Special relativity is what it is as it's understood today in 2004. One
could imagine being able to ask einstein if he agreed with the theory
as it's understood today and it wouldn't matter if one imagines he
disagreed unless one can also imagine the good enough reason he gave
which is supported by data.