I'm writing this just to set a line in the sand for both alternate-theory
posters and to those who respond to those posters. All too often,
pyrotechnic rhetoric gets in the way of a very simple evaluation.

1. A good theory has to refer to well-defined terms and concepts. It does no
good to exploit the softness of common language to fuzz the boundaries of
words. If you say "waves" and you don't mean everything that is included in
the definition of a wave as physicists define it, then provide a careful and
complete definition of your own, being sure to explicitly exclude the
conventional connotations that don't apply. It's not necessary to adopt the
same language and concepts from historically accepted physics terminology.
If it were so, we would have not come to understand "rest mass", "invariant
interval", "branes", "black holes", or "quarks". But it IS important to
define carefully what you mean.

But this isn't enough.

2. A good theory has to be self-consistent. That is, it can't predict
something that is counter to another prediction, or can't predict something
that is counter to one of its assumptions. It is not necessary that it be
consistent with assumptions and predictions of other theories. If it were
so, we would not have accepted the relativity of simultaneity. But it IS
important to check that the theory is coherent.

But this isn't enough. All too often, theorists come up with a model that is
pleasing to the eye and self-consistent and think that those virtues alone
make it appealing.

3. A good theory has to *qualitatively* account for all existing
observations and experimental results that pertain to its domain. A theory
that is patently inconsistent with a known result MUST be summarily
discarded, no matter how well 1 and 2 are satisfied. It is not necessary
that the underlying explanation agree with pre-existing theoretical
explanations. If it were so, we would would have dismissed special
relativity. But special relativity did not violate any hitherto observed
behavior at low velocity, and there were therefore no good reasons to
dismiss it on those grounds.

But this isn't enough. A plausible explanation does not substitute for a
real calculation. And this, unfortunately, is where most of our amateur
theorists with alternate theories come to a grinding halt.

4. A good theory has to *quantitatively* account for all existing
observations and experimental results that pertain to its domain. This is
where mathematical underpinnings start to become required. You can't make a
quantitative calculation of a behavior that can be measured without the
mathematical representation of the theory. It is not important that the
model agree with the form of the equations and formulas of other theories.
If it were so, then the Copernican model of the solar system would not have
supplanted the earth-centric epicycle model. But if the Copernican model had
not been able to CALCULATE the position of the planets in the sky as well
as, or better than, the epicycle model, then it would not have mattered how
well 1 and 2 and 3 were satisfied.

But this isn't enough. There may be dozens of completely equivalent models
that adequately describe the same known phenomena, both qualitatively and
quantitatively. If this is all a theory does -- match evenly against an
existing model -- then it is no good. Here again is where many "alternative
interpretations" fall flat.

5. A good theory has to *quantitatively predict* an observable behavior that
has not yet been measured, and preferably a behavior that is at odds with
the predicted behavior of other proposed theories. If it fails to predict
anything new, then it must be dismissed as a theory, no matter how well 1,
2, 3, and 4 are satisfied. If Einstein had written general relativity, but
he had failed to make the verifiable prediction that the apparent location
of a star would shift so many arc-seconds during an eclipse, then it would
have been a worthless theory. In this sense, most of the string models and
spin-network models of the universe are NOT good theories yet, because they
fail to make a verifiable prediction. In this sense, even the Standard Model
with the Higgs boson is not a very good theory yet, because one of its
primary verifiable predictions (the Higgs boson) has not been confirmed yet.

Alternative-theory-proposers: the onus is on you to make sure your model
satisfies ALL FIVE of the above requirements. If it does not, then the world
has a complete right to summarily dismiss your conjecture.

Alternative-theory flamers: the onus is on you to point accurately to the
failing of the theory. Inconsistency with existing, verified *theories* is
not a valid critique. For example, it is improper to discount a theory
because it disagrees with Dirac's equation or because it violates a
postulate of GR. It IS proper to point to an experimental observation which
an existing theory gets correct and the proposed model does not (steps 3, 4
and 5 above). It is improper to discount a theory because the proposer has
not calculated your favorite observable. It IS proper to point out that the
proposed theory either doesn't have the mathematical equipment to calculate
your favorite observable, or that it does but the calculation results in
something contrary to what's actually seen.

PD

Paul Draper wrote:


Alternative-theory flamers: the onus is on you to point accurately to the
failing of the theory.

The burden of proof of a theory lies squarely on the one proposing it.

Bob Kolker

"Paul Draper" wrote in message
om...
I'm writing this just to set a line in the sand for both
alternate-theory
posters and to those who respond to those posters. All too often,
pyrotechnic rhetoric gets in the way of a very simple evaluation.

1. A good theory has to refer to well-defined terms and concepts. It
does no

How about this

#6. A good theory has to be falsifiable under some set of experimental
facts.

John Lowry
Flight Physics

robert j. kolker wrote:


Paul Draper wrote:


Alternative-theory flamers: the onus is on you to point accurately to the
failing of the theory.


The burden of proof of a theory lies squarely on the one proposing it.

Bob Kolker

I think not. Theories cannot be proved. They can be tested, but never
proved. You don't actually expect every new theory to be tested
exhaustively by its authors, do you? That's an impossible task. The
onus is necessarily on the opposition to provide an empirical
contradiction to the theory.

Richard Perry

RP wrote:


I think not. Theories cannot be proved. They can be tested, but never
proved. You don't actually expect every new theory to be tested
exhaustively by its authors, do you? That's an impossible task. The
onus is necessarily on the opposition to provide an empirical
contradiction to the theory.

I am well aware that proof in the mathematical sense is not possible.
The burden of showing some evidence in favor of a theory lies with the
one proposing it. If the proposer cannot establish the possibility that
his theory might be sound on empirical grounds he is just blowing wind.

Bob Kolker

robert j. kolker wrote:



RP wrote:


I think not. Theories cannot be proved. They can be tested, but never
proved. You don't actually expect every new theory to be tested
exhaustively by its authors, do you? That's an impossible task. The
onus is necessarily on the opposition to provide an empirical
contradiction to the theory.


I am well aware that proof in the mathematical sense is not possible.
The burden of showing some evidence in favor of a theory lies with the
one proposing it. If the proposer cannot establish the possibility that
his theory might be sound on empirical grounds he is just blowing wind.

Bob Kolker

IOW, he should provide a test of the theory, one that distinguishes it
from existing theory.
Suppose, however, that the differences in predictions are much smaller
than the available experimental precision?
The onus is once again on the opposition.

Richard Perry

"robert j. kolker" wrote:

RP wrote:


I think not. Theories cannot be proved. They can be tested, but never
proved. You don't actually expect every new theory to be tested
exhaustively by its authors, do you? That's an impossible task. The
onus is necessarily on the opposition to provide an empirical
contradiction to the theory.

I am well aware that proof in the mathematical sense is not possible.
The burden of showing some evidence in favor of a theory lies with the
one proposing it. If the proposer cannot establish the possibility that
his theory might be sound on empirical grounds he is just blowing wind.

Rigorous mathematical proof is not the last word either. Euclid is
rigorously self-consistent and contains no flaws. Euclid doesn't work
for land surveying or navigation. Euclid is incomplete vs. hyperbolic
and elliptic geometries. The three taken together are *still*
incomplete vs. Thurston's eight simply-connected geometric 3-manifolds
with compact quotients.

If the parity Eotvos experiment empirically falsifies the Equivalence
Principle, then General Relativity that postulates it is only a
heuristic, demoted in the same way Euclid fell to his Fifth (Parallel)
postulate being counterdemonstrated by Riemann OTOH and Bolyai and
Lobechevsky OTOH. If the parity Eotvos experiment fails, Einstein is
validated but not proven. Until gravitation and quantum mechanics are
functionally united, we can be utterly certain that at least one of
them is wrong.

Religion and politics are based upon absolutes and faith. They will
always fail - bloodily dragging their adherents down with them.
Science adapts and improves. Science and its adherents are smart
enough to learn. That is what humanity is all about.

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

To Uncle Al: You said that Euclid geometry was shown to be wrong by
Riemann geometry, insofar as defining parallel lines is concerned. But
Euclid's geometry is limited by definition to 2 dimensions. Riemann
geometry addresses an entirely different domain. I would think that the
Euclidean definition of parallel lines still stands and has not been
refuted by Reimann geometry.

How is your experiment coming?

RP wrote:


IOW, he should provide a test of the theory, one that distinguishes it
from existing theory.
Suppose, however, that the differences in predictions are much smaller
than the available experimental precision?
The onus is once again on the opposition.

Not at all. If the theory cannot be tested, it should be put away in a
drawer until it can. Of course if someone falsifies the theory in the
mean time, the matter is settled.

In general, theories that cannot be tested are worthless. By that I mean
if a theory does not produce a testable quantitative asertion it is
vapor. It has no standing.

Bob Kolker

In sci.physics Uncle Al wrote:
snip
Religion and politics are based upon absolutes and faith. They will
always fail - bloodily dragging their adherents down with them.

Religious theries are not inherently less testable than physical ones,
as long as there is some divergance of religeous theory and the
predictions made by science.
If you hold that in 2020, there will be an anomolous ratio of
hydrogen/duterium/tritium evaporating from comet X as it hits periapsis,
and I hold that in 2020, the world will be painted a subtle shade of purple
by God, both are equally testable.

Something that's been missed is that the person doing the testing
has to be able to report back.

Belief in the afterlife is hard to prove - unless it turns out that
ghosts have just been awaiting the development of suitably sensitive
etevos balances to communicate through.