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Forum » SpaceEngine » Science and Astronomy Discussions » Big Bang Theory questioned? (Aussie scientists have a new theory)
Big Bang Theory questioned?
DaninAusDate: Tuesday, 21.08.2012, 00:36 | Message # 1
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Hey guys, was wanting your thoughts on this. My missus found an article that pretty much says the Big Bang theory could be incorrect.

http://news.ninemsn.com.au/technol....-theory

What do you guys think?
 
TalismanDate: Tuesday, 21.08.2012, 01:34 | Message # 2
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Looks like some decent speculation. There wasn't a single reason for why the big bang theory could be wrong in that article. cool




 
NeonDate: Tuesday, 21.08.2012, 04:07 | Message # 3
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Going to be hard pressed to dislodge The Big Bang. The Steady State theory was the last contender for that role, but
it died a good death. It stated the universe remains the same, and as old matter dies, new matter is created. Sort of
a new age view on the universe.
 
midtskogenDate: Tuesday, 13.08.2013, 11:27 | Message # 4
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Another way Big Bang and the singularity could be incorrect:

http://arxiv.org/pdf/1303.6878v3.pdf

Its main problem seems to be that there is no way to verify their proposal?





NIL DIFFICILE VOLENTI


Edited by midtskogen - Tuesday, 13.08.2013, 11:27
 
WatsisnameDate: Wednesday, 14.08.2013, 11:20 | Message # 5
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He does not suggest there was no Big Bang, but that Big Bang may not have occurred as a singularity (infinite density). The universe clearly went through a hot, dense, rapidly expanding phase, as evident by existence of CMB, nucleosynthesis, etc, and his model is (apparently) capable of reproducing this. His model is also capable of producing a Big Bang as a singularity. It depends on choice of parameters. Sadly the media have by and large completely missed this nuance when reporting on it. :/

My issue with all this is that the core of his theory rests on what seems to be an unfalsifiable assumption: that there is some 'cosmon field' which increases particle masses. It is an interesting idea, but unless it can be tested it is pretty much useless. Would be like saying 'maybe other galaxies don't actually exist, but are instead lights painted on the inside of a giant sphere designed to fool us.' Practical falsifiability is one of the most important things in science.

That said, the theory does have testable implications to limited extent. Depending on the nature of the field, the universe's evolution may play out differently, such as whether it is expanding or contracting or static at various eras. These are testable by examining the scale factor of the universe through time, for which there are observable consequences which may not depend on interpretation of the origin of redshift. For example, under the standard model the average density of the universe should decrease with time, so the farther out you look the higher the mass density should be. Also, the angular sizes of galaxies should increase beyond a certain threshold of distance. So from these observations one could find limits to the cosmon field's parameters, but cannot refute its existence entirely.

His paper is also in desperate need of peer review by a professional cosmologist. So far I haven't seen any critical response.





 
midtskogenDate: Wednesday, 14.08.2013, 12:18 | Message # 6
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Quote (Watsisname)
His paper is also in desperate need of peer review by a professional cosmologist. So far I haven't seen any critical response.

A critical response only needs to point out that no method for testing the idea of increasing masses has been given. The author is no doubt aware of this already, so what the paper really needs is help in the form of such a method. But if it doesn't exist, the response will never come.

Peer review musn't stop scientists from thinking aloud from time to time, so publications like this should be welcome even if it's not really fit for the regular peer process. Alternative interpretations not meeting the requirements of scientific hypotheses or theories shouldn't be left to the amateurs alone.

Little would be better if someone becomes able to show that the Big Bang, like we understand it today as an expansion from a singularity, is an incorrect interpretation. I would love to see the new insight capable of demonstrating that. But something unfalsifiable does not have that power, of course.





NIL DIFFICILE VOLENTI
 
WatsisnameDate: Wednesday, 14.08.2013, 20:49 | Message # 7
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A critical response/review is needed to make sure his calculations are correct and that his model actually does reproduce all cosmological observations. And it is possible that someone could figure out a way to test it that he has not thought of.

Standard Big Bang cosmology does not actually state that there was a singularity by the way. It says the universe is expanding from a hot and dense initial state, but says nothing about the first instant, or what if anything came before. (Anytime someone says the universe came from nothing, I cringe.) The singularity is an extrapolation of universe's properties to zero size and is also a prediction of relativistic field equations, in similar fashion as with black hole singularities. However, quantum mechanical effects, or perhaps some new physics we don't even begin to understand, may very well become important and prevent a singularity. At this point the singularity is an unsolved question.

There are also many other theories for origin of Big Bang that don't require singularities. One of my favorites is Poplawski's Cosmology With Torsion model, where instead of singularities, black holes create new universes inside them, which leads to the conclusion that our universe was also created in a black hole from another universe, like Russian Doll kind of thing. It's only slightly better in the testability department, but if it is correct then it naturally solves a great deal of outstanding problems in cosmology and physics, and is such an insane idea I can't help but be intrigued by it. smile

The cosmon field model on the other hand doesn't really lead to explaining anything.





 
InariusDate: Friday, 16.08.2013, 00:56 | Message # 8
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Quote
but says nothing about the first instant


Well, only if you consider the big bang is "the first instant". It's possible that the big bang hasn't been the first moment and that this moment of expansion just followed a moment of contraction.
The fact that we can't (yet) know anything beyond the Planck's wall doesn't mean there is nothing beyond the Planck's wall .
 
VakarianDate: Thursday, 18.09.2014, 13:16 | Message # 9
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By the mid-1960s, the big bang theory had received wide acceptance from scientists. However, some problems with the theory still remained. When the big bang occurred, hot radiation (energy in the form of waves or particles) given off by the explosion expanded and cooled with the universe. This radiation, known as the cosmic microwave background, appears as a weak hiss of radio noise coming from all directions in space. It is, in a sense, the oldest light in the universe. When astronomers measured this cosmic microwave background, they found its temperature to be just under −450°F (−270°C). This was the correct temperature if the universe had expanded and cooled since the big bang.

But the radiation seemed smooth, with no temperature fluctuations. If the radiation had cooled at a steady rate, then the universe would have had to expand and cool at a steady rate. If this were true, planets and galaxies would not have been able to form because gravity, which would help them clump together, would have caused fluctuations in the temperature readings.

In 1980, American astronomer Alan Guth proposed a supplemental idea to the big bang theory. Called the inflationary theory, it suggests that at first the universe expanded at a much faster rate than it does now. This concept of accelerated expansion allows for the formation of the stars and planets we see in the universe today.
COBE and MAP

Guth's inflationary theory was supported in April 1992, when NASA (National Aeronautics and Space Administration) announced that its Cosmic Background Explorer (COBE) satellite had discovered those fluctuations. COBE looked about 13 billion light-years into space (hence, 13 billion years into the past) and detected tiny temperature fluctuations in the cosmic microwave background. Scientists regard these fluctuations as proof that gravitational disturbances existed in the early universe, which allowed matter to clump together to form large stellar bodies such as galaxies and planets.

In late 2000, scientists added further supporting evidence to the validity of the big bang theory when they announced that they had analyzed light from a quasar that was absorbed by a distant cloud of gas dust billions of years ago. At that time, the universe would have been about one-sixth of its present age. Based on their findings, the scientists estimated that the background temperature at that point was about −443°F (−264°C), a temperature mark that agrees with the prediction of the big bang theory.

Read more: http://www.scienceclarified.com/As-Bi....fXIIS1C
 
Forum » SpaceEngine » Science and Astronomy Discussions » Big Bang Theory questioned? (Aussie scientists have a new theory)
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