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

"LCDM Paradigm Is Consistent With All Observations"? - Not So!



 
 
Thread Tools Display Modes
  #1  
Old July 25th 14, 08:45 AM posted to sci.astro.research
Robert L. Oldershaw
external usenet poster
 
Posts: 617
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

Read this for example;

http://www.sciencedaily.com/releases...0721100418.htm

Can we expect a strained explanation
that saves the paradigm from those pesky
dwarf galaxies, which are not numerous enough,
don't have the right amount of dark matter,
and now dance to a tune that the LCDM cannot
play?
  #2  
Old July 25th 14, 08:53 PM posted to sci.astro.research
Phillip Helbig---undress to reply
external usenet poster
 
Posts: 629
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

In article , "Robert L.
Oldershaw" writes:

Read this for example;

http://www.sciencedaily.com/releases...0721100418.htm

Can we expect a strained explanation
that saves the paradigm from those pesky
dwarf galaxies, which are not numerous enough,
don't have the right amount of dark matter,
and now dance to a tune that the LCDM cannot
play?


Don't throw the baby out with the bathwater. There are many
observations which DO support LCDM. Even if one observation doesn't,
one cannot toss aside LCDM unless one has another theory that explains
this new observation AND ALL OTHER OBSERVATIONS WHICH SUPPORT LCDM.

It also depends on what "LCDM" means. If it means a positive
cosmological constant and most of the matter being non-baryonic, then
this observation does not contradict that. What it might contradict is
a specific model of galaxy formation.

A common mistake is to think that a correction to details rules out the
underlying theory, like when creationists claim that some minor
modification in the field of genetics (which didn't even exist in
Darwin's day), say, rules out the theory of evolution (and perhaps even
proves that Genesis is literally true).
  #3  
Old July 27th 14, 09:28 AM posted to sci.astro.research
Jos Bergervoet
external usenet poster
 
Posts: 126
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

On 7/25/2014 9:53 PM, Phillip Helbig---undress to reply wrote:
..
It also depends on what "LCDM" means. If it means a positive
cosmological constant and most of the matter being non-baryonic,


And cold! That is what the C stands for, isn't it?

.. then this observation does not contradict that. What it
might contradict is a specific model of galaxy formation.


But how can LCDM be seen as a specific model of galaxy
formation?

--
Jos
  #4  
Old July 27th 14, 09:35 AM posted to sci.astro.research
Robert L. Oldershaw
external usenet poster
 
Posts: 617
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

On Friday, July 25, 2014 3:53:05 PM UTC-4, Phillip Helbig---undress to reply wrote:

Don't throw the baby out with the bathwater. There are many

observations which DO support LCDM. Even if one observation doesn't,

one cannot toss aside LCDM unless one has another theory that explains

this new observation AND ALL OTHER OBSERVATIONS WHICH SUPPORT LCDM.

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

I find it a bit humorous that in other contexts you
espouse the attitude that if a theory fails ONE
definitive prediction it's "time to move on" to
other ideas.

Does the LCDM apologist speak with forked tongue?

[Mod. note: this would be a valid point if one could demonstrate that
a different result for this observation was indeed a 'definitive
prediction' of LCDM -- mjh]
  #5  
Old July 28th 14, 08:52 AM posted to sci.astro.research
Phillip Helbig---undress to reply
external usenet poster
 
Posts: 629
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

In article , Jos Bergervoet
writes:

On 7/25/2014 9:53 PM, Phillip Helbig---undress to reply wrote:
..
It also depends on what "LCDM" means. If it means a positive
cosmological constant and most of the matter being non-baryonic,


And cold! That is what the C stands for, isn't it?


Right. HDM would imply that structure forms top-down, while CDM implies
that it forms bottom-up. There is so much evidence for that latter that
HDM is rarely even considered anymore.

.. then this observation does not contradict that. What it
might contradict is a specific model of galaxy formation.


But how can LCDM be seen as a specific model of galaxy
formation?


Because people are not always exact with language. What is the big
bang? To me, it is the fact that the universe is expanding from a very
hot, very dense former state. Some include things like nucleosynthesis,
which follows rather clearly from this. Others include things like
inflation. When some people include a model of galaxy formation in
LCDM, they mean some current galaxy-formation idea which is based on
LCDM, i.e. the cosmological parameters and presence of dark matter. But
there is a lot more to galaxy formation than that.
  #6  
Old July 28th 14, 08:53 AM posted to sci.astro.research
Phillip Helbig---undress to reply
external usenet poster
 
Posts: 629
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

In article , "Robert L.
Oldershaw" writes:

one cannot toss aside LCDM unless one has another theory that explains
this new observation AND ALL OTHER OBSERVATIONS WHICH SUPPORT LCDM.

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

I find it a bit humorous that in other contexts you
espouse the attitude that if a theory fails ONE
definitive prediction it's "time to move on" to
other ideas.

Does the LCDM apologist speak with forked tongue?

[Mod. note: this would be a valid point if one could demonstrate that
a different result for this observation was indeed a 'definitive
prediction' of LCDM -- mjh]


Indeed. Also, before an observation is believable, it needs to be
reproduced independently. Sandage measured the Hubble constant to be
42, but that doesn't make it so. Obviously, if various observations
disagree, then at least some of them are wrong. This is obvious if they
are made at the same time. That doesn't imply, though, that if one
makes a particular observation which no-one else does, then one is
automatically correct.

In this case, my hunch is that the observation is correct and that the
model of galaxy formation is not completely correct.

Whatever the final status of this observation is, it doesn't rule out
LCDM in the narrow sense of the term, though it might very well rule out
a specific model of galaxy formation (which some carelessly subsume into
LCDM) if it does indeed contradict a definitive prediction of said
model.
  #7  
Old July 28th 14, 08:56 AM posted to sci.astro.research
Robert L. Oldershaw
external usenet poster
 
Posts: 617
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

On Sunday, July 27, 2014 4:35:04 AM UTC-4, a moderator wrote:
[Mod. note: this would be a valid point if one could demonstrate that
a different result for this observation was indeed a 'definitive
prediction' of LCDM -- mjh]


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

One could quibble ad nauseaum about exactly
how "definitive" the relevant LCDM prediction
was. However, it is quite clear that the LCDM
paradigm predicted that the distribution of
satellite galaxies would be roughly random.

This is not observed. What is observed is a
distribution that proponents of the LCDM in
no way anticipated.

Right.

[Mod. note: right, but given the complicated steps in between a LCDM
model and an actual realization of the distribution of galaxies in a
particular system, that is not sufficient to rule out LCDM. -- mjh]
  #8  
Old July 29th 14, 08:10 AM posted to sci.astro.research
Phillip Helbig---undress to reply
external usenet poster
 
Posts: 629
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

In article , "Robert L.
Oldershaw" writes:

One could quibble ad nauseaum about exactly
how "definitive" the relevant LCDM prediction
was.


One could first try to find a refereed-journal paper which claims that
this was a definitive prediction at all. If one is found, one could
determine whether this is consensus. If no-one has ever claimed that it
is a definitive prediction, then the question is moot.
  #9  
Old July 29th 14, 08:12 AM posted to sci.astro.research
Robert L. Oldershaw
external usenet poster
 
Posts: 617
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

On Monday, July 28, 2014 3:56:50 AM UTC-4, Robert L. Oldershaw wrote:
On Sunday, July 27, 2014 4:35:04 AM UTC-4, a moderator wrote:

[Mod. note: right, but given the complicated steps in between a LCDM

model and an actual realization of the distribution of galaxies in a

particular system, that is not sufficient to rule out LCDM. -- mjh]

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

Sigh.

I have neither stated nor implied that
the specified empirical evidence should
"rule out" the LCDM paradigm.

I leave such unscientific absolutism to others.

I just think the new satellite distribution
data, and several other key pieces of
observational evidence, should motivate
people to question the LCDM assumptions
and to consider other models.
  #10  
Old July 30th 14, 07:50 AM posted to sci.astro.research
Phillip Helbig---undress to reply
external usenet poster
 
Posts: 629
Default "LCDM Paradigm Is Consistent With All Observations"? - Not So!

In article , "Robert L.
Oldershaw" writes:

Sigh.

I have neither stated nor implied that
the specified empirical evidence should
"rule out" the LCDM paradigm.


You wrote:

Can we expect a strained explanation
that saves the paradigm from those pesky
dwarf galaxies, which are not numerous enough,
don't have the right amount of dark matter,
and now dance to a tune that the LCDM cannot
play?

which certainly sounds like you have ruled it out.

I just think the new satellite distribution
data, and several other key pieces of
observational evidence, should motivate
people to question the LCDM assumptions
and to consider other models.


Almost every conference has a few talks on non-mainstream models.
Several people have built their careers on them. Papers appear.
Science is an on-going process. There is no conspiracy.
 




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
just THREE YEARS AFTER my "CREWLESS Space Shuttle" article, theNSF """experts""" discover the idea of an unmanned Shuttle to fill the2010-2016 cargo-to-ISS (six+ years) GAP gaetanomarano Policy 3 September 15th 08 04:47 PM
and now, Ladies and Gentlemen, the NSF "slow motion experts" have(finally) "invented" MY "Multipurpose Orbital Rescue Vehicle"... just 20 gaetanomarano Policy 9 August 30th 08 12:05 AM
First Announcement of Opportunity (AO-1) for Observations with "Suzaku" and Publication of Test Observation Data Jacques van Oene News 0 December 5th 05 04:07 PM


All times are GMT +1. The time now is 11:59 PM.


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.