Astronomy/Cosmology

Please click on the item in the list below to go to the article in question:

1. Shifts in Cosmology
A summary of modern cosmology

2. The center of our Galaxy
An investigation of this central region

3. The Redshift
Controversy over this galactic distance measurement

4. Cosmology
On cosmological theory

5. Comments

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Shifts in Cosmology

If you find the ideas of cosmology – the study of the large scale structure of the universe – as interesting as I do, then you’ll probably have discovered that assumptions have to be made in order to arrive at scientific theories of its evolution.
Homogeneity and isotropy (HI) of energy at large scales is the leading assumption and is called the Cosmological Principal which states simply that “The universe appears the same in all directions and at all locations”. It is obvious that this does not apply at smaller scales such as those of galaxies where violent interactions are taking place, known as heterogeneous spaces. Recent findings may have found evidence that the Cosmological Principle does not apply at larger scales either, see Ref 1.
There is a principal in science called Occam’s Razor which popularly states that “when you have two competing theories that make exactly the same predictions, the simpler one is the better.”
When viewing the distant universe through a large telescope one sees a seemingly endless number and variety of galaxies, some similar in form to ours and others completely different, all containing a variety of stars and other objects. There are galaxies which are interacting and some may be giving birth to new galaxies. There are so called quasars, which appear as very concentrated but highly luminous objects and may be these newly born galaxies, though there are still serious doubts concerning their origin and composition.
So, at first glance one could come to the conclusion that the universe contains a variety of energy structures that are moving relative to one another under the influence of their mutual gravitational attraction. Through known physical processes galaxies, stars and other objects are constantly being created and destroyed. This would seem sufficient to form a theory of the universe.
But then along comes Edwin Hubble who early in the twentieth century observed that there was a relation between the distance of a galaxy and an increase in the wavelengths of its emitted radiation, called the redshift. This was true of distant galaxies in all directions of space. The only way science could account for such a redshift at the time was through the Doppler Effect which had been observed in laboratory experiments. This shows that if an object moves away from or towards the observer the wavelength of its emitted radiation increases or decreases by an amount proportional to its speed.
Hubble’s discovery literally meant that the earth appeared to be situated at the centre of the universe, or at least the detectable portion of it, with surrounding galaxies flying away from us at velocities proportional to their distance. This notion horrified the majority of influential scientists as it put us in a privileged position, an idea that their scientific determinism could not accept. Something had to be done to rectify the situation. They asked themselves how the observed redshift could be made to apply to observers anywhere in the universe, thus obviating the need for a preferred centre and in accordance with the Cosmological Principal.
The answer they found was to allow space itself to expand with time, so that all objects carried by it would be moving away from one another. The simple way to visualize this is to think of galaxies sprinkled within a sphere which is expanding. The view from any one galaxy would show all others moving away from it with their emitted radiation redshifted. Though this was recognized as an assumption, it took hold as being the only “acceptable” explanation. In due course a formulation of Einstein’s General Relativity equations was found to support such a scenario.
This theory is still being defended as the only acceptable one which can account for all observational data and is called the Big Bang Theory (BBT).
So, according to the BBT we now have a universe about fourteen billion years old, according to the presently accepted rate of expansion. Another consequence of the theory is that at some earlier period everything in the universe must have been much closer together. If one carries the argument to the limit then one must assume that at some moment space must have been filled with pure energy which somehow with time condensed to form the celestial objects we see today.
The theory therefore implies a large scale evolution with time. As we look further out into space (in effect further back in time) we should observe changes in the large scale structure.
Of course, the further we look into the universe the more distorted are the objects due to intervening ones and this can effectively disguise evolutionary trends. Nevertheless, one would assume with improving telescopic resolutions and techniques that before long we shall know whether or not the BBT is the correct one.
Hopefully it is, as largely thanks to prejudice and bigotry we don’t have another one waiting in the wings.

References:

1. Kashlinsky, A., et al. (2008) “A measurement of large-scale peculiar velocities of clusters of galaxies: results and cosmological implications.” Astrophysical Journal Letters (Science Daily

, Space.com

2. Big Bang Theory – A good site for digging deeper into the theory can be found at http://www.talkorigins.org/faqs/astronomy/bigbang.html

3. A critique of the Big Bang theory can be found at
http://www.metaresearch.org/cosmology/BB-top-30.asp
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Centre of our galaxy

Credit: ESO – European Organisation for Astronomical Research in the Southern Hemisphere.
The lower photo is older but shows the scale and position of the supposed black hole with to close arrows.

Interestingly German Astronomers have recently completed a study of our Galactic Centre¹ and say they have proof “beyond any reasonable doubt” that a black hole exists there. It is known as “Sagittarius A*” (pronounced “Sagittarius A star”).

The concept of a Black Hole: a gravitational object that draws energy into itself without emitting any and thus effectively a “black body”, is purely a theoretical one evolving from the equations of Einstein’s Theory of Relativity. It is worth noting that the actual description can be complicated by considerations of quantum mechanics but I won’t go into that here, there are enough sources on the internet for interested parties.

The astronomers add that there are still mysteries however. The blue stars orbiting close to this center are relatively young and couldn’t have formed in the black hole’s vicinity due to gravitational tidal stresses, although it must be said that the actual process of star formation is not understood. They could also not have traveled from far away due to their youthful age.

The question that then arises is how did they come to be where they are. There are about 100 situated in an elongated rotating disc around the black hole at about half a light year’s distance and 25 massive stars in randomly oriented orbits even closer to it. One of them, designated S2, has orbited the center once during the sixteen years of observations. That star orbits the black hole in just 15 years, a bit longer than it takes Jupiter to make its way around the Sun.

An animation of the star movements can be found here²

The study suggests that the black hole’s mass is four million solar masses and its distance 27000 light-years.

It would seem obvious that any explanation would have to involve a diminished gravitational field and/or alternative distance measurements. If the local distances were, for example, doubled then the gravitational force of the black hole would decrease by a factor of four in accordance with the inverse square law. However, one model³ has shown that, at least in theory, a matter distribution is possible that could be sustained long enough to give birth to stars this close to a black hole. Of course the black hole model may not be the right description of this entity. One can imagine something that reaches some exotic state of equilibrium as yet unknown to science. A closer look at such an entity is needed before a definite statement can be made.
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Red-shift

There is a long standing dispute over galactic distance measurements in the universe. The accepted method involves the Doppler Effect whereby objects moving away from the observer emit radiation whose wavelength is increased and visa versa. Hubble’s original observations of external galaxies found that the further away these astronomical objects were, the more their radiating energy wavelengths increase or were shifted towards the red end if the electromagnetic spectrum. This shifting of wavelengths is aptly termed – The Red-shift.

Recent studies have also suggested other more exotic explanations for the red-shifts observed involving matter transformations in radiating bodies⁴. These were found by some to be necessary to explain certain anomalies such as Quasars (enormous star-like concentrations of energy but huge in comparison) being associated with Galaxies having very differing red-shifts. Haltom Arp, especially, has done much research on this topic as can be read in this article⁵.

Note:
Of course if the present method of determining distances in the outer reaches of the observable universe were proved to be wrong then this would have a devastating effect on present scientific theory.

References:

1. http://www.mpe.mpg.de/news.html
2. http://www.mpe.mpg.de/ir/GC/res_dance.php?lang=en
3. http://www.sciam.com/article.cfm?id=how-stars-formed-near-black-hole
4. http://www.astr.ua.edu/keel/galaxies/arp.html
5. http://creationontheweb.com/images/pdfs/tj/j19_2/j19_2_5-6.pdf.

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Cosmology

Ok, let’s look at the state of Cosmology. One principle I rather like is the Anthropic one which states that the universe is the way it is because if it wasn’t we wouldn’t be here to ponder about it. This is particularly evident in the Earth being where it is and how it is. This would seem to indicate that some intelligence has gone to a lot of trouble to arrange for us to be here, and to be able to survive long enough to send greeting cards. Discussions on this can reduce to circular and unenlightening arguments of course.
Then one can look at our surroundings and see what they can tell us about any such intelligence. Well, there are animate and inanimate objects constructed of smaller parts. There are populations of living things whose intelligence can rise above that of its individuals. Both can be born and can die though for the latter it is built-in. The former would seem to be more important as their lifespan is only dependent on their ability to adapt to changing circumstances employing the latter to this end. There is an enormous diversity and a striving for adaptability to survive. Everything animate and inanimate is interlaced and forms part of a larger whole – there is inseparability.
When we look out into the universe with the above in mind we see similar arrangements.
Stars and presumably planets are being born in gas clouds associated with galaxies and when they eventually die, their atoms are recycled to form more stars and planets. These are seen to form groups that interact as in our solar system and in star clusters containing a few or hundreds of thousands of members.
Galaxies themselves are seen to form groups. Some are merging or have merged and in doing so induce new star formation and perhaps new lifeforms. There is evidence that they can produce new infant galaxies called quasars.
All these objects come in a variety of shapes and sizes often indicative of age.
Of these processes science can tell us little or nothing.
There seems to be no necessity in the universe to rush into things, changes can occur rapidly but also extremely slowly.
Man has tried to quantify the knowledge he has of the universe based on discoveries made here on Earth. The principles and laws of science derived locally are taken to apply elsewhere unless proven otherwise. Accepted physical constants are taken to be universally valid.
Cosmological models are formulated that attempt to describe what the observations reveal.
There is the Big Bang model (BBM) favoring expansion of space and there are others favoring a static universe or something in between.
Although I admit it is a personal standpoint I would call into play Occam’s Razor, as many do, and say that the simplest solution should be applied that fits the facts.
For me this is a Steady State Model (SSM) which avoids the increasing complications of the expansion models with their intrinsic global evolutionary tendencies that up to now refuse to reveal themselves. This forces their adherents to constantly invent new theoretical constructs to explain the observations, only making things more and more complicated.
So let’s examine the SSM.

1. Space isn’t expanding
So there’s no need to explain why the solar system maintains its form while space itself expands, which would suggest that objects within it would move further away from one another with time. The answer that “solves” this problem for the BBM is to say that gravitationally bound systems are immune from the expansion. Considering that the basis for our understanding of the relation between space and matter (energy) is the general theory of relativity (GR) that relates the gravitational field to the curvature of space on which it is thus dependent rather destroys the argument. That the gravitational force between two bodies is relayed almost if not instantaneously implies that this is independent of the theory. Latest measurements put its speed of action at 2×1010 c,
where c is the speed of light (ref.1).
2. The Redshift
This relationship of emitted radiation’s frequency falloff with distance is either caused by intrinsic differences in the emitters and/or energy loss caused by its transition through space. The former would seem to be implied by the observation that many quasars are clearly associated with galaxies having vastly different redshifts. This suggests an evolutionary factor in particle physics.
3. The microwave background radiation (MCR)
For our purposes this is just old radiation that’s been pumped out into space from all directions reaching a cooling limit. This was calculated by Eddington in 1926 as being the lowest temperature to which a body would cool to, given that it is immersed in the radiation of distant starlight. He found 3K which agrees with the observed measurement. BBM cannot predict this value.

4. Observation supporting the SSM:
a.    The large scale structure of observable galaxy groupings is not smooth.
b.    Evolution of galaxies with distance (and thus with time) has not been seen.
c.    Galaxies at large distances are too evolved.
d.    The oldest star clusters are older then the age of the universe predicted by the BBM
e.    Metals are much to abundant in the early universe of the BBM

More comparisons of the SSM with the BBM can be found here (ref. 2).

Summary
Although I’m delving into speculation I would say that an intelligence concerned with the matters as outlined above would have no use for an expansion that would effectively go against the interactive nature of its creative process. The shear enormity of the universe and its unlimited variation illuminate the importance of this aspect and the observational evidence would also seem to support it. Of course, this is just an assumption, but as other theories are also based on assumptions this does not make it any less probable. No doubt the near future will decide one way or the other.

References:
1. http://www.metaresearch.org/cosmology/speed_of_gravity.asp
2. http://www.metaresearch.org/cosmology/BB-top-30.asp

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