A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Research
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

WIMPs AWOL Again?



 
 
Thread Tools Display Modes
  #1  
Old August 16th 11, 11:47 AM posted to sci.astro.research
Robert L. Oldershaw
external usenet poster
 
Posts: 617
Default WIMPs AWOL Again?

Analyses of Fermi gamma-ray observations of eight Milky Way Galaxy
dwarf galaxies may "exculde generic WIMP candidates with mass less
than 27 GeV..." .

Reference: http://arxiv.org/abs/1108.2914

Time to re-evaluate the conventional WIMP hypothesis?

Time to think about those hundreds of billions of unbound planetary-
mass objects indicated by the microlensing observations of Sumi et al?
See: http://arxiv.org/abs/1105.3544 .

Time to give a fair hearing to M.R.S. Hawkins' excellent discussion
"The case for primordial black holes as dark matter"? See:
http://arxiv.org/abs/1106.3875 .

Time to think about what might be generating the huge ARCADE-2 excess
in the radio background?

RLO
http://www3.amherst.edu/~rloldershaw
  #2  
Old August 16th 11, 12:42 PM posted to sci.astro.research
eric gisse
external usenet poster
 
Posts: 303
Default WIMPs AWOL Again?

"Robert L. Oldershaw" wrote in news:mt2.0-
:

Analyses of Fermi gamma-ray observations of eight Milky Way Galaxy
dwarf galaxies may "exculde generic WIMP candidates with mass less
than 27 GeV..." .

Reference:
http://arxiv.org/abs/1108.2914

Time to re-evaluate the conventional WIMP hypothesis?


One theory among several - one down, infinity minus one to go.


Time to think about those hundreds of billions of unbound planetary-
mass objects indicated by the microlensing observations of Sumi et al?
See: http://arxiv.org/abs/1105.3544 .


Sure, for a moment.

Let's take the number of objects at face value and disregard the author-
admitted (one that you have opined about as well) possibility this may
have just been a region with more than usual. Integrate the entire pile
across the volume of the galaxy, and you get something just south of 5%
of what constitutes the dark matter mass budget for this galaxy.

Just a little bit short.


Time to give a fair hearing to M.R.S. Hawkins' excellent discussion
"The case for primordial black holes as dark matter"? See:
http://arxiv.org/abs/1106.3875 .


Ah, M.R.S. Hawkins. Well, I guess its' nice that at least you aren't
citing his repeatedly-debunked claims regarding quasar variability.

Let us consider this key phrase:

"The most serious objection to dark matter in the form of compact
bodies has come from observations of microlensing of stars in the
Magellanic Clouds."

Let's look back at the SuperMACHO survey, one that was a survey of the
LMC specifically meant to look for such objects. No such populations.

Now replace SuperMACHO with "OGLE I", "OGLE II", and "OGLE III". The
only thing that changes is that there *are* enough observed events to be
largely consistent with the findings of Sumi, et. al.

However, the oft-claimed huge populations of dark matter tied up in
massive compacts are yet to be found. Without as much as a sniff from
you, I might add.


Time to think about what might be generating the huge ARCADE-2 excess
in the radio background?


Stranger than expected interplanetary medium?

I can never get too worked up about the galaxy, on the whole, glowing a
little more than expected in the radio because 'expected' is fully a
function of our current best guess model of stellar populations, the
interplanetary medium, presence of other structures like nebulae, etc.

How, if at all, this ties into dark matter is speculative at best.


RLO
http://www3.amherst.edu/~rloldershaw

  #3  
Old August 16th 11, 03:50 PM posted to sci.astro.research
Robert L. Oldershaw
external usenet poster
 
Posts: 617
Default WIMPs AWOL Again?

On Aug 16, 7:42*am, eric gisse wrote:
"Robert L. Oldershaw" wrote in news:mt2.0-
:


One theory among several - one down, infinity minus one to go.

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

This my main worry. Currently fashionable theoretical speculations
like string/brane notions, supersymmetry, quintessence, WIMPs, and so
on, are so "adjustable" that they are effectively untestable in any
definitive manner.

If WIMPs are complete no-shows in the canonical mass range, then one
can merely posit that the WIMPs are more exotic than expected and have
a much larger mass. This dodge has been used in so many theoretical
physics contexts in recent decades that its radical departure from
proper scientific norms is hardly noticed anymore. But the fact is
that it makes these "scenarios" effectively incapable of being
falsified.

If one can arbitrarily change the predictions of a "scenario", and/or
tack on ad hoc adjustable parameters, then is this good science? Is it
science at all?

RLO
http://www3.amherst.edu/~rloldershaw
  #4  
Old August 17th 11, 08:45 AM posted to sci.astro.research
Phillip Helbig---undress to reply
external usenet poster
 
Posts: 629
Default WIMPs AWOL Again?

In article , "Robert L.
Oldershaw" writes:

Analyses of Fermi gamma-ray observations of eight Milky Way Galaxy
dwarf galaxies may "exculde generic WIMP candidates with mass less
than 27 GeV..." .


They are weakly interacting MASSIVE particles---maybe more than 27 GeV.

For decades, neutrino masses kept being excluded from more and more mass
ranges, but today we know they have a mass.

Time to re-evaluate the conventional WIMP hypothesis?


Why?

We don't know what dark matter is. That's why we look for it. When we
find it, we'll know. There might be more than one kind. That is real
science, i.e. when one doesn't know the result beforehand.

Time to think about those hundreds of billions of unbound planetary-
mass objects indicated by the microlensing observations of Sumi et al?
See: http://arxiv.org/abs/1105.3544 .


Not in the context of dark matter, no. Yes, they might be dark matter,
but not an appreciable fraction of the dark matter.

Time to give a fair hearing to M.R.S. Hawkins' excellent discussion
"The case for primordial black holes as dark matter"? See:
http://arxiv.org/abs/1106.3875 .


Hawkins's claim has been proved wrong in the refereed literature, and
no-one has contested this in the refereed literature. That's enough for
most people.
  #5  
Old August 17th 11, 06:44 PM posted to sci.astro.research
Robert L. Oldershaw
external usenet poster
 
Posts: 617
Default WIMPs AWOL Again?

On Aug 17, 3:45*am, Phillip Helbig---undress to reply
wrote:
In article , "Robert L.


They are weakly interacting MASSIVE particles---maybe more than 27 GeV.

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

Or not?

Could you please tell us what that mass might be, or offer any sort of
predicted mass range by which the WIMP hypothesis might be
unambiguously falsified?

RLO
http://www3.amherst.edu/~rloldershaw
  #6  
Old August 18th 11, 08:33 AM posted to sci.astro.research
eric gisse
external usenet poster
 
Posts: 303
Default WIMPs AWOL Again?

"Robert L. Oldershaw" wrote in
:

On Aug 17, 3:45*am, Phillip Helbig---undress to reply
wrote:
In article , "Robert L.


They are weakly interacting MASSIVE particles---maybe more than 27
GeV.

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

Or not?

Could you please tell us what that mass might be, or offer any sort of
predicted mass range by which the WIMP hypothesis might be
unambiguously falsified?

RLO
http://www3.amherst.edu/~rloldershaw


It depends on the theory, Robert.

You'll note that "weakly interacting massive particle" applies to a lot of
different things, including neutrinos. There's no particular theory here,
which is something people, including myself, have been trying to tell you.
  #7  
Old August 18th 11, 02:15 PM posted to sci.astro.research
Robert L. Oldershaw
external usenet poster
 
Posts: 617
Default WIMPs AWOL Again?

On Aug 18, 3:33*am, eric gisse wrote:
"Robert L. Oldershaw" wrote :

Could you please tell us what that mass might be, or offer any sort of
predicted mass range by which the WIMP hypothesis might be
unambiguously falsified?


It depends on the theory, Robert.

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

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

You have a huge number of poorly constrained "theories" that offer you
a huge number of pseudo-predictions, any one of which can adopted or
explained away (if need be).

RLO
Discrete Scale Relativity
  #8  
Old August 18th 11, 10:21 PM posted to sci.astro.research
eric gisse
external usenet poster
 
Posts: 303
Default WIMPs AWOL Again?

"Robert L. Oldershaw" wrote in
:

On Aug 18, 3:33*am, eric gisse wrote:
"Robert L. Oldershaw" wrote
:

Could you please tell us what that mass might be, or offer any sort
of predicted mass range by which the WIMP hypothesis might be
unambiguously falsified?


It depends on the theory, Robert.

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

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

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


Plenty of _definitive_ predictions can be made in terms of interaction,
halo size, effects on lensing profiles, stellar orbits, etc. Why isn't
that good enough?


You have a huge number of poorly constrained "theories" that offer you
a huge number of pseudo-predictions, any one of which can adopted or
explained away (if need be).


Well, that's how science works. Scientists make some theories, and as
more evidence comes in the bad ones are excluded.

I note you have a different level of increduility for your theory
(factor of 15 wide prediction of neutron star masses) versus other
theories.


RLO
Discrete Scale Relativity

  #9  
Old August 19th 11, 07:48 AM posted to sci.astro.research
Robert L. Oldershaw
external usenet poster
 
Posts: 617
Default WIMPs AWOL Again?

On Aug 18, 5:21*pm, eric gisse wrote:
"Robert L. Oldershaw" wrote :

Well, that's how science works. Scientists make some theories, and as
more evidence comes in the bad ones are excluded.

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

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"?
Hardly! There are even super-optimists who hold out hope for magnetic
monopoles and proton decay after many, many falsifications. String
theory: 43 years and still not one definitive prediction!

The best science is science based on principles that can lead to
definitive predictions. See the development and evolution of
relativity theory for an archetypal example of this best science.

Even heuristic, model-building science is legitimate so long as it can
use its empirically-derived order, constraints and patterns to
generate definitive predictions.

But if a theory cannot make a definitive prediction then it is pure
speculation (to put it politely), and should be explicitly treated as
such by scientists and the media.

RLO
Fractal Cosmology
  #10  
Old August 21st 11, 09:14 AM posted to sci.astro.research
Phillip Helbig---undress to reply
external usenet poster
 
Posts: 629
Default WIMPs AWOL Again?

In article , "Robert L.
Oldershaw" writes:

They are weakly interacting MASSIVE particles---maybe more than 27 GeV.

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

Or not?

Could you please tell us what that mass might be, or offer any sort of
predicted mass range by which the WIMP hypothesis might be
unambiguously falsified?


No, because my science is based on observation. What is the mass of the
Earth? No way to find out except to measure it. Same idea. Yes, it
might be conceivably possible for a theory to predict everything, but
one shouldn't criticise observations in the absence of such a theory.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Xenon100: No "WIMPs" Robert L. Oldershaw Research 0 April 14th 11 09:39 AM
Chris Lord (Brayebrook) gone AWOL? Chris.B UK Astronomy 0 November 18th 05 08:07 PM
Did Galileo/Cassini anti-nuke crowd go AWOL? dinges Policy 17 October 1st 03 03:38 PM


All times are GMT +1. The time now is 11:30 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.