WIMPs AWOL Again?

In article , "Robert L.
Oldershaw" writes:

It depends on the theory, Robert.

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So, the bottom line is that you cannot make a definitive prediction
regarding the galactic dark matter.

The whole idea of science is that different theories make different
predictions which can be used to distinguish them. You seem to think
that having more than one theory is a bad idea (and thus don't see the
need for observations).

Robert L. Oldershaw wrote:

That's how things have been going for decades, except that nothing
actually gets excluded, just "adjusted". Strings, branes, WIMPs,
SUSY, extra dimensions, and so on, have been around for decades and
are "adjusted" in an ad hoc manner when observations or theoretical
constraints do not support them. Has anything been "exluded"?

I have to say I'm no expert on these theories, but it seems to me that
adapting theories in light of new evidence is science, as long as there
is still room to do so within previously existing constraints. In that
case, there is not enough data to exclude the theory.

If future research were to reveal that the existance of WIMPS 27 GeV
would necessarily cause some observable effect, and that effect is never
observed, then it would be possible to exclude the theory.

It is only holding on to unmodified theories by ignoring
inconvenient data that would be a problem.

On Aug 21, 4:26*am, Phillip Helbig---undress to reply
wrote:
In article , "Robert L.

Oldershaw" writes:
It depends on the theory, Robert.

---------------------------------------------------------------------------*-----------------

So, the bottom line is that you cannot make a definitive prediction
regarding the galactic dark matter.

The whole idea of science is that different theories make different
predictions which can be used to distinguish them. *You seem to think
that having more than one theory is a bad idea (and thus don't see the
need for observations).
------------------------------------------------------------------------

Your two posts are somewhat contradictory.

If any theory that claims to be about "fundamental" understanding in
cosmology and/or physics and it cannot predict the fairly specific
nature of what the overwhelming majority of the Universe is composed
of, then I say that theory is mere arm-waving. If it provides no
definitive predictions, it is not science. It is still in a pseudo-
science stage of development.

RLO
Discrete Scale Relativity

[Mod. note: the weasel word here being 'definitive' -- mjh]

"Robert L. Oldershaw" wrote in
:
Your two posts are somewhat contradictory.

If any theory that claims to be about "fundamental" understanding in
cosmology and/or physics and it cannot predict the fairly specific
nature of what the overwhelming majority of the Universe is composed
of, then I say that theory is mere arm-waving. If it provides no
definitive predictions, it is not science. It is still in a pseudo-
science stage of development.

What, in your mind, constitutes a 'definitive' prediction?

The bulk properties of dark matter are pretty nailed down.

* Minimal or zero non-gravitational self interaction.
* Zero electromagnetic interaction.
* Most likely particulate in nature, due to massive observational exclusion
of MACHO theories.
* Nonrelativistic at decoupling, even more nonrelativistc now.
* The equation of state for dark matter is that of dust, which is highly
distinguishable between that of relativistic matter, photons, scalar and
higher spin fields, etc.

What further details are required of dark matter to explain cosmology
better? The problem for the last few years is that particle physics has no
answer.

Did you know that the tools used to describe modern cosmology (GR and its'
various solutions discovered over the years) all predate the standard
model? Knowledge of composition is not required here, which is something
you don't seem to grasp.

By the way, do you stand by your claim that a neutron star size that spans
a factor of 15 while extending into singularity territory is in any way
definitive? Or do you think the double standards are ok?


RLO
Discrete Scale Relativity

[Mod. note: the weasel word here being 'definitive' -- mjh]

On Aug 21, 3:54*pm, Christian Froeschlin wrote:

I have to say I'm no expert on these theories, but it seems to me that
adapting theories in light of new evidence is science, as long as there
is still room to do so within previously existing constraints. In that
case, there is not enough data to exclude the theory.

If future research were to reveal that the existance of WIMPS 27 GeV
would necessarily cause some observable effect, and that effect is never
observed, then it would be possible to exclude the theory.

It is only holding on to unmodified theories by ignoring
inconvenient data that would be a problem.
----------------------------------------------------------------------------

Let me put things in the most simple form.

Ideally we want theories that make definitive predictions that tell us
whether the theory is fundamentally right, or fundamentally wrong.

In the latter case, one does not "modify" the fundamentally wrong
theory. One seeks a new model based on a new theoretical principle.

We do not need epicycles. We need new and good ideas that lead to
definitive predictions.

RLO
Discrete Scale Relativity

On Aug 21, 5:23*pm, eric gisse wrote:

By the way, do you stand by your claim that a neutron star size that spans
a factor of 15 while extending into singularity territory is in any way
definitive? Or do you think the double standards are ok?

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To answer your question, the radius range for neutron stars is exactly
the same as the radius range for subatomic nuclei, except that you
must multiply the nuclear radii by a factor of 5.2 x 10^-17. This is
a definitive prediction, regardless of how you want to misconstrue
that.

Robert L. Oldershaw
http://www3.amherst.edu/~rloldershaw

"Robert L. Oldershaw" wrote in
:
Ideally we want theories that make definitive predictions that tell us
whether the theory is fundamentally right, or fundamentally wrong.

In the latter case, one does not "modify" the fundamentally wrong
theory. One seeks a new model based on a new theoretical principle.

Like for example, if one theory predicts dark matter is made of solar
mass MACHOs but years of surveys only find some planets that make up a
few percentage points, I suppose you would consider that an example of a
theory that is fundamentally wrong.

[Mod. note: quoted text trimmed. Please try to trim quoted text so
that only directly relevant material is quoted -- mjh]

In article , "Robert L.
Oldershaw" writes:

Ideally we want theories that make definitive predictions that tell us
whether the theory is fundamentally right, or fundamentally wrong.

Agreed.

In the latter case, one does not "modify" the fundamentally wrong
theory. One seeks a new model based on a new theoretical principle.

This is a straw-man argument. Most theories are not theories of
everything which unanimously predict everything of interest. Most
theories have some parameters which (as far as we know now) must be
determined by observation. This does not mean that the theory is
fundamentally wrong. For example, many new species of animals and
plants are still being discovered. Our theories of biology are not
fundamentally wrong on the grounds that they were not all predicted. In
some cases, further progress on the theoretical side can allow one to
predict things which were not possible in an older, coarser version of
the theory. (While not as clear-cut, even postdictions are OK as long
as they are unique and not adjustable. It is often an accident whether
theory or observation is more advanced and accidents of human history
have no bearing on the underlying physical reality.)

I recommend John D. Barrow's book THEORIES OF EVERYTHING. It is about
what we won't know even if we had a theory of everything (as the term is
commonly used). Check it out.

We do not need epicycles.

Epicycles are, of course, an example of adjusting a theory to meet
better observations, and rightly criticised for this. However, it is
important to keep two things in mind. First, epicycles make a testable
prediction, namely how the distance to a planet varies with time. The
angular motion can be fit exactly with a sufficient number of epicycles
(this is essentially Fourier synthesis (or analysis, depending one one's
point of view), but measuring the distance can distinguish epicycles
from other models. (To be sure, Copernicus's original heliocentric
model was LESS accurate regarding positions of the planets, but, even
disregarding the question of distance for the moment, in some sense more
accurate because it is closer to the truth. This is the (perhaps
undefinable) beauty of a theory which is often an indicator of what is
right.) Also, the main reason Ptolemy's epicycles stayed around for so
long is because the Church burned people who thought otherwise: not what
we today understand as scientific discourse.

Think of the so-called old quantum theory. It solved many problems in
classical physics, but was not definitive. What happened? Was it
replaced by a new paradigm? No, it was refined. Was there input from
observation? Sure---how else would one know that it was not correct.
Did this involve adjusting free parameters until they fit? No. It's
still not a complete theory in some sense, but it is better than the old
quantum theory. This is the way most science progresses. Kuhn's ideas
about overthrowing the paradigm, with the Copernican revolution (a pun
which many don't get) being an example, are mostly wrong since based on
examples like this when it was not debate within science but rather the
reduction of torture which allowed a new paradigm to arrive. (Also,
Kuhn's ideas contain the seeds of their own distruction. Either they
are scientific or not. If not, then we can ignore them. If they are,
then by his own reasoning they will soon be replaced with a new
paradigm.)

We need new and good ideas that lead to
definitive predictions.

Right. And when these definitive predictions are falsified by other
observations, one has to move on. The steady-state theory was, in
almost all respects, a very good theory. It made testable predictions.
They were falsified. Some people, like Bondi and Morison, moved on.
Others, like Hoyle (who had done very good work in other areas), started
to ignore reality.

"Robert L. Oldershaw" wrote in
:

On Aug 21, 5:23*pm, eric gisse wrote:

By the way, do you stand by your claim that a neutron star size that
spans a factor of 15 while extending into singularity territory is in
any way definitive? Or do you think the double standards are ok?

----------------------------------------------------------------------
-
-----------------------

To answer your question, the radius range for neutron stars is exactly
the same as the radius range for subatomic nuclei, except that you
must multiply the nuclear radii by a factor of 5.2 x 10^-17. This is
a definitive prediction, regardless of how you want to misconstrue
that.

Robert L. Oldershaw
http://www3.amherst.edu/~rloldershaw


How do you know that neutron stars fit inside such a range? You've been
arguing for the past few days that science has ABSOLUTELY NO IDEA!!! how
big a neutron star is.

A proton (Hydrogen) is about 0.8 fm, and Uranium is [1] roughly 175,000
fm. So taking 10km as the middle of the neutron star range gives a rough
upper limit of...two million kilometers? Using *your* "predicted" (when
are you going to show how you obtained that prediction?) 6km gives an
upper bound of about 1.8 million km. That's not even taking into account
that random factor that you pulled out of the air.

As for your claim that the range is the same, you aren't even within the
correct order of magnitude. Factor of 15 vs factor of ~200,000. When
your definitive prediction is incorrect by four orders of magnitude, are
you going to add epicycles or just admit your theory is wrong?

I consider this more of a test of how well you will stick to your claims
regarding definitive predictions and the validity of a theory more than
anything else, because you aren't even close to being correct here.

By the way, I would like to know if you even LOOKED at the published
litearture regarding neutron star radii. Did you?


[1] - http://www.chemicool.com/elements/uranium.html#radius

On Aug 22, 6:00*pm, eric gisse wrote:

Like for example, if one theory predicts dark matter is made of solar
mass MACHOs but years of surveys only find some planets that make up a
few percentage points, I suppose you would consider that an example of a
theory that is fundamentally wrong.
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Have you read Mike Hawkins' preprint: "The case for primordial black
holes as dark matter"?

I think that he would vigorously disagree with your statement above.

And bear in mind that he is a university professor who actually does
scientific research and publishes scientific papers, rather than an
amateur.

You might consider 0.2 trillion unbound planetary-mass objects
trivial, but I think if you had predicted them then you would be
singing quite a different tune.

RLO
Fractal Cosmology