More than one Big Bang Theory

[jmbgouveia]

Hi good people,

 

I need help on this mater:

 

Well, I belive in the Big Bang theory with the exception of "singularity"(as Jeff says), so, at the begining "this" wasnt a piece of matter highly dense!....is just not possible!!!....I do believe in more than one Big Bang occured!!!....I believe each Galaxy had its own Big Bang!!! So, please, somebody with more knowledge than me about this mater, explain to me if it is possible and if not, why?......Thank you very much advanced....

 

best regards

 

Joao Gouveia

 

International Analyst Programmer

[Airbrush]

I also have always had a problem with an original singularity for the entire universe. It just seems too implausible that the entire universe could be contained, even for the tiniest fraction of a second, within an area smaller than a proton. But I am not an expert, and the experts believe this.

 

Interesting idea that each galaxy had its' own little big bang. That resembles a supenova with remnant in the center a neutron star or black hole. The supermassisve black holes at the center of each galaxy could be "mini-big-bang remnants"?

 

I hope an expert tells us how this is not plausible. Maybe the bang would be too great to allow matter to linger near the center to become stars?

Edited October 4, 2012 by Airbrush

[Spyman]

The singularity is not part of the Big Bang theory and is in general considered to show a limit for applications of the theory of Relativity.

 

There is little evidence regarding the absolute earliest instant of the expansion. Thus, the Big Bang theory cannot and does not provide any explanation for such an initial condition; rather, it describes and explains the general evolution of the universe going forward from that point on.

http://en.wikipedia.org/wiki/Big_Bang

 

Extrapolation of the expansion of the Universe backwards in time using general relativity yields an infinite density and temperature at a finite time in the past. This singularity signals the breakdown of general relativity.

http://en.wikipedia.org/wiki/Big_Bang#Timeline_of_the_Big_Bang

 

However, certain physical phenomena, such as singularities, are "very small" spatially yet are "very large" from a mass or energy perspective; such objects cannot be understood with current theories of quantum mechanics or general relativity, thus motivating the search for a quantum theory of gravity.

http://en.wikipedia.org/wiki/Quantum_gravity

 

 

If each galaxy started out with its own little bang then they should be rapidly expanding, but that is not what we observe. We see galaxies of different ages and structures that are all growing by accumulating matter from their surroundings and by mergers with other galaxies. Galaxies and clusters of galaxies are observed to be bound by gravity and not expanding like the Universe on a large scale.

 

A galaxy is a massive, gravitationally bound system consisting of stars, stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component called dark matter.

http://en.wikipedia.org/wiki/Galaxy

 

Galaxy groups and clusters are the largest known gravitationally bound objects to have arisen thus far in the process of cosmic structure formation.

http://en.wikipedia.org/wiki/Galaxy_groups_and_clusters

 

In addition to slowing the overall expansion, gravity causes local clumping of matter into stars and galaxies. Once objects are formed and bound by gravity, they "drop out" of the expansion and do not subsequently expand under the influence of the cosmological metric, there being no force compelling them to do so. There is no difference between the inertial expansion of the universe and the inertial separation of nearby objects in a vacuum; the former is simply a large-scale extrapolation of the latter. Once objects are bound by gravity, they no longer recede from each other. Thus, the Andromeda galaxy, which is bound to the Milky Way galaxy, is actually falling towards us and is not expanding away. Within our Local Group of galaxies, the gravitational interactions have changed the inertial patterns of objects such that there is no cosmological expansion taking place. Once one goes beyond the local group, the inertial expansion is measurable, though systematic gravitational effects imply that larger and larger parts of space will eventually fall out of the "Hubble Flow" and end up as bound, non-expanding objects up to the scales of superclusters of galaxies.

http://en.wikipedia.org/wiki/Metric_expansion_of_space

 

Formation

Current cosmological models of the early Universe are based on the Big Bang theory. About 300,000 years after this event, atoms of hydrogen and helium began to form, in an event called recombination. Nearly all the hydrogen was neutral (non-ionized) and readily absorbed light, and no stars had yet formed. As a result this period has been called the "Dark Ages". It was from density fluctuations (or anisotropic irregularities) in this primordial matter that larger structures began to appear. As a result, masses of baryonic matter started to condense within cold dark matter halos. These primordial structures would eventually become the galaxies we see today.

 

Evidence for the early appearance of galaxies was found in 2006, when it was discovered that the galaxy IOK-1 has an unusually high redshift of 6.96, corresponding to just 750 million years after the Big Bang and making it the most distant and primordial galaxy yet seen.[80] While some scientists have claimed other objects (such as Abell 1835 IR1916) have higher redshifts (and therefore are seen in an earlier stage of the Universe's evolution), IOK-1's age and composition have been more reliably established. The existence of such early protogalaxies suggests that they must have grown in the so-called "Dark Ages".

 

The detailed process by which such early galaxy formation occurred is a major open question in astronomy. Theories could be divided into two categories: top-down and bottom-up. In top-down theories (such as the Eggen–Lynden-Bell–Sandage [ELS] model), protogalaxies form in a large-scale simultaneous collapse lasting about one hundred million years. In bottom-up theories (such as the Searle-Zinn [sZ] model), small structures such as globular clusters form first, and then a number of such bodies accrete to form a larger galaxy.

 

Once protogalaxies began to form and contract, the first halo stars (called Population III stars) appeared within them. These were composed almost entirely of hydrogen and helium, and may have been massive. If so, these huge stars would have quickly consumed their supply of fuel and became supernovae, releasing heavy elements into the interstellar medium. This first generation of stars re-ionized the surrounding neutral hydrogen, creating expanding bubbles of space through which light could readily travel.

 

Evolution

Within a billion years of a galaxy's formation, key structures begin to appear. Globular clusters, the central supermassive black hole, and a galactic bulge of metal-poor Population II stars form. The creation of a supermassive black hole appears to play a key role in actively regulating the growth of galaxies by limiting the total amount of additional matter added. During this early epoch, galaxies undergo a major burst of star formation.

 

During the following two billion years, the accumulated matter settles into a galactic disc. A galaxy will continue to absorb infalling material from high-velocity clouds and dwarf galaxies throughout its life. This matter is mostly hydrogen and helium. The cycle of stellar birth and death slowly increases the abundance of heavy elements, eventually allowing the formation of planets.

 

The evolution of galaxies can be significantly affected by interactions and collisions. Mergers of galaxies were common during the early epoch, and the majority of galaxies were peculiar in morphology.

http://en.wikipedia.org/wiki/Galaxy#Formation_and_evolution

[Airbrush]

Nice answer Spyman, thanks for the info!

[granpa]

a redshift of 7 corresponds to a time when teh universe was 1/7 the size it is today.

 

if it was 1/7 the age of the current universe then it would have been 2 billion years old

 

not 750 million years

Edited October 6, 2012 by granpa

[JohnStu]

The experts do not really believe in the Big Bang Theory but it's the best answer so far to explain all the obeserved phonomenons. That is one of the reason why some of the scientists that worked on Big Bang Theory also worked on String Theory

[Spyman]

a redshift of 7 corresponds to a time when teh universe was 1/7 the size it is today.

 

if it was 1/7 the age of the current universe then it would have been 2 billion years old

 

not 750 million years

Ned Wright's Cosmology Calculator agrees with the value from Wikipedia, a redshift of 7 corresponds to an age of ~780 million years.

Link: http://www.astro.ucla.edu/~wright/CosmoCalc.html

 

The experts do not really believe in the Big Bang Theory but it's the best answer so far to explain all the obeserved phonomenons. That is one of the reason why some of the scientists that worked on Big Bang Theory also worked on String Theory

JohnStu, you don't seem to even have a clue.

[IM Egdall]

The experts do not really believe in the Big Bang Theory but it's the best answer so far to explain all the obeserved phonomenons. That is one of the reason why some of the scientists that worked on Big Bang Theory also worked on String Theory

 

Science is a work in progress. The big bang theory is our best current theory of the creation and evolution of the universe because of all the evidence confirming its predictions.

 

Hopefully some day string theory or some other theory of quantum gravity will tell us what happened at time zero of the big bang -- an unknown in the current big bang theory. And maybe a new theory will tell us what happened, if anything, before the big bang.

 

To make the generalization that "the experts do not believe in the big bang" is ridiculous. As Swansont put it, when someone says "the experts" but gives no names, this should raise suspicion. Name your experts, please.

Edited October 7, 2012 by IM Egdall