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CraigS
14-08-2010, 04:55 PM
Thought I'd start a new thread following on from the paper Carl quoted in the 'Quasars' thread...

http://arxiv.org/abs/1006.5394

Galaxy Formation Theory

Authors: Andrew J. Benson (1) ((1) California Institute of Technology)
(Submitted on 28 Jun 2010 (v1), last revised 12 Jul 2010 (this version, v2)

I found the words in the Intro of great value, given our current deliberations/dilemma. Please excuse the length of the quote ... but hey ... its better than reading a Saturday newspaper:

"1. Introduction
While the concept of galaxies as “island universes” can be traced back to Wright (1750) and Kant (1755) the study of the formation of galaxies did not begin until after their extra-Galactic status was confirmed by Hubble (1929). In fact, much of the early work on galaxy evolution and formation was driven by the necessity of understanding galaxies in order to answer questions of cosmology (such as whether or not the Universe began with a Big Bang). While an understanding of galaxies remains necessary for such reasons even today, the field has since become an important one in its own right.
Modern galaxy formation theory therefore grew out of early studies of cosmology and structure formation and is set within the cold dark matter cosmological model and so proceeds via a fundamentally hierarchical paradigm.

Observational evidence and theoretical expectations indicate that galaxy formation is an ongoing process which has been occurring over the vast majority of the Universe’s history. The goal of galaxy formation theory then is to describe how simple physics gives rise to the complicated set of phenomena which galaxies encompass.

Galaxy formation is very much an observationally driven field in the sense that we are still decidedly in the stage of making new experimental discoveries rather than performing precision tests of well-specified theoretical models.

While this situation shows signs of a gradual shift to the “precision tests” phase it seems unlikely that the transition will be completed any time soon. In addition, astronomy is perhaps uniquely hindered by experimental biases, since we are not able to design the experiment, merely to observe what the Universe has decided to put on show. The complicated nature of the resulting selection effects result in a secondary, but very important, role for theoretical models, namely in quantifying these biases and interpreting the data. While this secondary role is well established it needs to become more so, in particular it should become an integral part of any observational campaign and will require direct and simple access to modeling capabilities for all."

Profound words which I feel are general enough to be used as reasonable ground rules for just about anyone attempting to explain the origins of anything in Astronomical Science - mainstream or not.

Cheers

renormalised
14-08-2010, 05:19 PM
There's still a lot to do with working out and understanding the processes which drive the formation of galaxies. Not all of it is well understood, but enough is known to know what works and what doesn't. But as the quote says, theoretical modeling and observational evidence must go hand in hand, otherwise it'll be nigh on impossible to understand what's going on.

A lot of people don't understand that you can't always design terrestrial analogues of processes and such that occur in astronomy simply because of the scales and the energies/processes involved. You just have to go with what you've got and that's what comes down the to the detector via the mirror/lens/dish. Simple as that.

Jarvamundo
14-08-2010, 06:21 PM
Interesting words Craig, it is what sparked my interest in plasma cosmology as terrestrial experimentation is available, and very very scalable.

Terrestrial experimentation being the method used to formulate the current theory of auroras.
http://upload.wikimedia.org/wikipedia/commons/thumb/a/a0/Birkeland-terrella.jpg/800px-Birkeland-terrella.jpg

Can we add to mirror/lens/dish the Langmuir probe?

KenGee
15-08-2010, 12:36 AM
yeap everyone can understand the idea of big fridges and really really big fridges.:P

Craig you seem to be hell bent on following Alice do the rabbit hole, Why? :shrug:Mainstream science is just as interesting and your much more likely to learn some worth knowing.:thumbsup:

CraigS
15-08-2010, 07:47 AM
Huh ? Did you read this paper ?
Meknows some are attempting to use me as their pawn !
Ken .. I'm as mainstream as it gets.

PS: Where I go, (figuratively), and what I believe, is irrelevant to Science or physical reality. Isn't that tremendous ?

Jarvamundo
15-08-2010, 09:46 AM
It's just a photo of a terrestrial analogue of a stellar event KG, don't see why this would make science uncomfortable?

renormalised
15-08-2010, 12:46 PM
You mean Alex, Ken. It's he who is going down the rabbit hole, not Craig. Craig is following mainstream science, not Alex. Alex is taking aspects of mainstream science and trying to equate them to processes and observations for which they have no basis of being involved with. In most cases it's a misuse of that science because it invariably becomes twisted up with all sort of EU (electric universe) nonsense. Best to leave magic to the magicians, and science to the scientists.

KenGee
15-08-2010, 06:11 PM
Yes I mean Alex, sorry about that Craig.:(

CraigS
15-08-2010, 06:46 PM
No worries Ken !!
:)
It's been a very confusing week with all this too-ing and fro-ing. I've also gone a bit loopy this week. Lets get back to some hardcore Science talk, to straighten us out, eh ?

:)

Cheers