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byronm
2008-Jul-01, 10:14 PM
Total newbie here but just pondering things. (and sorry if already debated to no end)

Its my understanding the most of the expansion theories are based upon the concept of an expanding universe per the witnessed redshift effect.

From what i understand we know now the impact of photons passing through molecular hydrogen have the displayed the same redshift as photons portraying a Doppler effect - couldn't the redshift more so quantify the mass of molecular hydrogen vs sustain the expansion theory? (or a little bit of both?)

Could it simply be that redshift quantifies the abundance of life giving molecular hydrogen and prove that you're seeing the photons as they were emitted 14 billion years ago from very hydrogen rich galaxies in a very young universe?

Just thinking out loud i guess. Occums Razor seems to come to mind when it try and fathom dark energy/dark matter/WIMPs and other theoretical energies when there could be something as simple as hydrogens abundance to explain it.

again, i'm a total computer nerd.. i only know astronomy from what i read and obviously there is bad astronomy out there so you can't beleive everything you read ;)

antoniseb
2008-Jul-01, 10:36 PM
... From what i understand we know now the impact of photons passing through molecular hydrogen have the displayed the same redshift as photons portraying a Doppler effect ...

Where did you read this? This is not true, but we sometimes see this from some of our ATM (not Mainstream) members. If you want to pursue this please visit the ATM section of our forum.

byronm
2008-Jul-02, 12:30 AM
I was researching star formation when i finally came across molecular hydrogen. Not knowing the differences i googled it and came across some papers published a while ago that described dense clouds of hydrogen had similar redshifts as the doppler interpretation.


A New Non-Doppler Redshift
Paul Marmet, Herzberg Institute of Astrophysics
National Research Council, Ottawa, Ontario, Canada, K1A 0R6

Updated from: Physics Essays, Vol. 1, No: 1, p. 24-32, 1988

Have no idea how trusted that resource is.

mods, if this is an ATM thread, please move. thanks!

Nereid
2008-Jul-02, 12:32 PM
There is a great deal of material on the internet, on astronomy and on physics (and on any other subject under the sun).

Unfortunately, there is no certain way to tell by looking at any particular material you might come across whether it is crackpot material, illucid, fringe science, pseudo-science, good science, or anything in between.

You can find several 'crackpot' detectors online - webpages that give a few, quick guidelines (lack of math, equations, numbers; lack of references to papers published in relevant peer-reviewed journals; invoking Galileo; and so on) - and they are often quite good at making a first cut.

The case of Marmet: the material is most certainly ATM (Against The Mainstream).

byronm
2008-Jul-02, 02:22 PM
Another question on expansion of the universe.

I can't wrap my head around this generalized statement. "If we were to detect deviations from flatness in the observable universe, then it would provide evidence against inflation. "

What does that mean? to me expansion/inflation would suggest a non flat observable universe. I can't wrap my mind around a concept that to me makes it sound like the expansion is linear vs the "loaf of bread" concept where space is increasing regardless.

spratleyj
2008-Jul-05, 04:11 AM
You must remember that inflation and expansion are two different things... there is believed to have been a sort of inflationary stage, where the universe grow exponentially in a relatively short amount of time, while most all astronomers/physicists believe that the universe is still expanding and has been doing so ever since the big bang...

m1omg
2008-Jul-05, 10:10 AM
You must remember that inflation and expansion are two different things... there is believed to have been a sort of inflationary stage, where the universe grow exponentially in a relatively short amount of time, while most all astronomers/physicists believe that the earth is still expanding and has been doing so ever since the big bang...

LOL.Sorry, but Earth expanding?

Space is expanding only on the galaxy supercluster scale where the gravity between things is lower than the expansion force.

Cougar
2008-Jul-06, 10:16 PM
I can't wrap my head around this generalized statement. "If we were to detect deviations from flatness in the observable universe, then it would provide evidence against inflation.".... What does that mean?

Actually, explaining the apparent flatness is one of the unintended but happy consequences of inflation. The analogy is, blow up a spherical balloon to have a diameter of 100 billion lightyears or so, and the region around any point on the surface is going to look pretty flat. One might expect small deviations, but not large ones if inflation is to hold.

William
2008-Jul-15, 02:48 AM
In reply to Cougar's comment:

Cougar said:
Actually, explaining the apparent flatness is one of the unintended but happy consequences of inflation. The analogy is, blow up a spherical balloon to have a diameter of 100 billion lightyears or so, and the region around any point on the surface is going to look pretty flat. One might expect small deviations, but not large ones if inflation is to hold.

"Inflation" is a theory place holder. The current known physical forces and energy sources could not cause "inflation" and could not stop "inflation". The laws of physics must be temporary changed and turned off during the "inflation" period. Inertia and kinetic energy must be turned off during the "inflation" period. Faster than light movement is permitted during the "inflation" period.

"Inflation" was proposed to explain the lack of variation in the CMB. Less than 1/100000.

Spaceman Spiff
2008-Jul-18, 02:50 PM
In reply to Cougar's comment:

"Inflation" is a theory place holder. The current known physical forces and energy sources could not cause "inflation" and could not stop "inflation". The laws of physics must be temporary changed and turned off during the "inflation" period. Inertia and kinetic energy must be turned off during the "inflation" period. Faster than light movement is permitted during the "inflation" period.]

Why make uninformed statements? This contains almost no valid information, and I'm being generous. Why not try reading what the models actually say, here (http://en.wikipedia.org/wiki/Cosmic_inflation) (and references therein) for starters.


"Inflation" was proposed to explain the lack of variation in the CMB. Less than 1/100000.

Actually, the CMB fluctuation spectrum was a prediction of the inflationary model.

spratleyj
2008-Jul-18, 09:46 PM
Yes, not to be rude, but William has made several "uniformed" statements in different threads... as Spaceman suggested you might want to read up on the topics before you post.

loglo
2008-Jul-27, 10:21 AM
"The current known physical forces and energy sources could not cause "inflation" and could not stop "inflation".


Since the "current known physical forces" don't exist during the inflationary period this is hardly an argument against inflation theory.

Jerry
2008-Jul-27, 08:54 PM
Since the "current known physical forces" don't exist during the inflationary period this is hardly an argument against inflation theory.
????
Newton's rules of reasoning are the preface to The Principia:


We are to admit no more causes of natural things, than such as are both true and sufficient to explain their appearances.

Therefore to the same natural effects we must, as far as possible, assign the same causes.

The qualities of bodies, which admit neither intension nor remission of degrees, and which are found to belong to all bodies within reach of our experiments, are to be esteemed the universal qualities of all bodies whatsoever.

This is a valid argument against any theory that relies upon hypothetical forces, of which there is no local analog. If you ignore Newton's rules of reasoning, you are on shaky ground. You have to be very careful with the 'as far as possible' qualifier. You can propose unknown physics for the inflationary period, but you better have a way to test this hypothesis - some observation in which to ground the speculation. You should also be aware that the CMB has severely constrained the list of possible mechanisms.

antoniseb
2008-Jul-27, 09:10 PM
Originally Posted by Newton
Newton was great. Why did he stop posting (what was it? 281 years ago)?

Anyway I agree with your point that loglo and others should be a little more careful to not speak of the details of the inflationary period as fact. It is, however reasonable to cite mainstream speculation about this period... and for goodness sake, when new discoveries are made that either confirm or refute mainstream notions of this period, PLEASE post the link.

Kaptain K
2008-Jul-27, 09:22 PM
Inflation is, like dark matter and dark energy, a "place holder". Not quite "here be dragons", but "something is here we haven't figured out yet, but we're working on it".

William
2008-Jul-27, 09:59 PM
In reply to Spaceman Spiff's comment:


Why make uninformed statements? This contains almost no valid information, and I'm being generous. Why not try reading what the models actually say, here (and references therein) for starters.

I read Alan Guth's book which is a promotion of his superseded theory.

If I understand the jest of the inflation theory something suddenly expands the entire universe, at many, many times greater than the speed of light, for a very, very short period of time. This is sort of like a super, super, afterburner. Suddenly something stops this rapid expansion. Is that physically what is hypothesized to have happened?

Are you saying "inflation" is not a place holder?

Are you saying that this problem is solved? I am saying this next comment from Wikipedia is not science. The problem with the "inflation" theory is if it did not happen, is it allows fantasy scientific theories to be promoted.

Is our universe one bubble? Why not a rectangle or a triangle?

When we discuss the MECO hypothesis Vs the Hairless Black Hole hypothesis that is science. There are observations, there are two theories with a connection to standard physics.

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


Linde's Key Idea

"Eternal chaotic inflation" the false vacuum is eternally inflating in exponential growth powered by repulsive constant random zero point dark energy of negative pressure. This false vacuum is like supersaturated steam in which liquid bubbles of more stable vacuum form with Higgs-Goldstone fields that describe the cohering of most of the pre-inflationary random dark energy into the smooth fabric of curved spacetime. Our universe is only a small causal part of a single bubble. There are an infinity of bubbles and in fact there are an infinity of universes like ours on a single bubble which is more like an expanding infinite sheet than a finite spherical surface (suppressing 1 space dimension for ease of visualization.

The problem with this, as pointed out by Lee Smolin in "The Trouble With Physics" for example, is that it is not Popper falsifiable if nonlocal signals outside of the local light cones are not possible. One way to get such nonlocal signals is if there are stable traversable wormholes connecting the different "Hubble horizon limited" "pocket universes" (Leonard Susskind) on the same bubble and on different bubbles floating in hyperspace (see also floating "branes"). Antony Valentini has, in addition, proposed a generalization of quantum theory that allows nonlocal signaling that is forbidden in orthodox quantum theory.

Kaptain K
2008-Jul-28, 01:51 AM
Calling inflation a superseded theory requires a citation. Last I heard it was still the bedrock of modern cosmology.

William
2008-Jul-28, 02:57 AM
In reply to Kaptain K.'s comment:


Calling inflation a superseded theory requires a citation. Last I heard it was still the bedrock of modern cosmology.

Your comment is correct, I believe it is a fact that, without "inflation" or some other explanation the big bang theory has a paradox and is a theory in crisis. What inflation is lacking is a physical mechanism. As string/bane theories have no limits and anything is possible, they are not yet theories this is a flexible area if approached from strings/banes.

There is old inflation (Alan Guth's mechanism) which was superseded by Linde et al.'s mechanism which is now called new inflation. I believe new inflation hypothesis a new type field which has the special properties required to make new inflation work.

The following is from Wikipedia:

Guth (Old Inflation)
Guth proposed that as the early universe cooled, it was trapped in a false vacuum with a high energy density, which is much like a cosmological constant. As the very early universe cooled it was trapped in a metastable state (it was supercooled) which it could only decay out of through the process of bubble nucleation via quantum tunneling. Bubbles of true vacuum spontaneously form in the sea of false vacuum and rapidly begin expanding at the speed of light. Guth recognized that this model was problematic because the model did not reheat properly: when the bubbles nucleated, they did not generate any radiation. Radiation could only be generated in collisions between bubble walls. But if inflation lasted long enough to solve the initial conditions problems, collisions between bubbles became exceedingly rare. In any one causal patch, it is likely that only one bubble will nucleate.


Linde, Albrecht and Steinhardt (New Inflation)

The bubble collision problem was solved by Andrei Linde[4] and independently by Andreas Albrecht and Paul Steinhardt[5] in a model named new inflation or slow-roll inflation (Guth's model then became known as old inflation). In this model, instead of tunneling out of a false vacuum state, inflation occurred by a scalar field rolling down a potential energy hill. When the field rolls very slowly compared to the expansion of the universe, inflation occurs. However, when the hill becomes steeper, inflation ends and reheating can occur.



Inflaton
The inflaton is the generic name of the unidentified scalar field (and its associated particle) that may be responsible for an episode of inflation in the very early universe. According to inflation theory, the inflaton field provided the mechanism to drive a period of rapid expansion from 10^−35 to 10^−34 seconds after the initial expansion that formed the universe.

The inflaton field's lowest energy state may or may not be a zero energy state. This depends on the chosen potential energy density of the field. Prior to the expansion period, the inflaton field was at a higher energy state. Random quantum fluctuations triggered a phase transition whereby the inflaton field released its potential energy as matter and radiation as it settled to its lowest energy state. This action generated a repulsive force that drove the portion of the universe that is observable to us today to expand from approximately 10−50 metres in radius at 10−35 seconds to almost 1 metre in radius at 10−34 seconds.

autumn1971
2008-Jul-29, 06:18 AM
In reply to Kaptain K.'s comment:



Your comment is correct, I believe it is a fact that, without "inflation" or some other explanation the big bang theory has a paradox and is a theory in crisis. What inflation is lacking is a physical mechanism. As string/bane theories have no limits and anything is possible, they are not yet theories this is a flexible area if approached from strings/banes.

There is old inflation (Alan Guth's mechanism) which was superseded by Linde et al.'s mechanism which is now called new inflation. I believe new inflation hypothesis a new type field which has the special properties required to make new inflation work.

The following is from Wikipedia:

Dude, if you are actually trying to use Wikipedia to disprove or advance various notions in advanced physics, please stop it.
The layman's understanding of things (and I admit that I am a layman, although I have taken a lot of undergraduate physics and math) is not a very good "jumping off point" for theories of fundamental significance.
I do not mean to be condescending here, or to imply that you are not an intelligent person, but if you can not present the math behind your assertion (and I gladly admit that I can only follow the bare bones of what goes on in advanced physics), you will not be taken seriously.
Please develop your ideas in the language of mathematics.
Also, remember that to be wrong is. . . Amazing!
To be wrong is to have a result!
That is much more than most people ever get to!
Be wrong!
Be wronger the next time!

But always be able to be wrong.
If you are on the right track, it will eventually become evident, no matter what the establishment has said.
Don't be discouraged by failure, but don't be encouraged by it if it persists.

There is a happy medium.

Kaptain K
2008-Jul-29, 05:50 PM
When in doubt, shoot the messenger!

Jerry
2008-Jul-30, 05:57 PM
The introduction to this paper provides a good one paragraph summary of the current status of inflation in the cosmic picture:

http://arxiv.org/PS_cache/arxiv/pdf/0807/0807.4528v1.pdf


Observations of the temperature and polarisation anisotropies in the cosmic microwave background (CMB) radiation strongly support the idea that the initial conditions for structure formation were set by an earlier period of cosmic inflation [1–4]. During this period, the rapid expansion of space caused quantum fluctuations of the inflaton field to be blown up to macroscopic scales. The initial state of these quantum fluctuations is typically assumed to be given by the Bunch-Davies vacuum of de Sitter space at a time when k ≫ aH, i.e., the physical wavenumber k/a is much larger than the Hubble expansion rate. Along with the usual assumptions of single-field, slowroll inflation, this leads to the almost scale-invariant spectrum of Gaussian adiabatic scalar perturbations that constitutes the “primordial” state of perturbations in today’s cosmological concordance model.
This is the bubbly-fissy concept found in Wikipedia

In Paragraph two of the introduction, Hamann continues:


However, in an expanding space-time the notion of a vacuum is not unique. This can
easily be understood by observing that the expanding space-time makes the Hamiltonian
depend explicitly on time, so there is no time-independent lowest energy state that can
serve as a vacuum at all times. We might then worry about how sensitive our predictions
are to the choice of initial state...

Backtracking, the simplest models of the BB are size limited, smaller than what is observed. The Guth model made specific predictions about the 'acoustic' reflections, the fine structure and polarity of the CMB, that are inconsistent with the observed background attributes. Now the 'frothy' model has emerge, but there is an 'initial state' problem: There is not an exact trail backward from frothy galactic formation: You cannot tell whether there was one hog in the wallow or many. Remember a theory is only an unsupported guess, unless there is also a way to test the theory using established physical laws.

It is hoped that the PLANCK mission, and in this paper, the Large Synoptic Survey Telescope (LSST); will provide useful parametric discriminators between a primal big bang and perhaps other viable models. This is why the BB model is saddled with qualifiers that were not necessary just a few years ago - predicted observations have not been observed, and the new inflation qualifiers have yet to be substantiated using known physical laws. Other possibilities exist, as Hamann continues:


...The choice of vacua other than the Bunch-Davies one leads in principle to unacceptable ultraviolet divergences in the observables, although this deficiency can be cured by introducing a high-energy cutoff to the theory. In practice, such a cutoff will be given by the Planck scale, or possibly even lower, by a scale of new physics Alpha (if the cutoff is too close to the Planck scale, an unorthodox vacuum choice may in fact lead to backreaction problems). An ultraviolet cutoff in the inflaton fluctuation modes violates energy conservation and has to be associated with a source term for the fluctuations, in order to account for the modes redshifting across the new physics hypersurface. Unless inflation started only just before the wavelengths corresponding to today’s observable scales left the horizon, these fluctuations can be mapped to wavenumbers larger than Alpha during inflation and have emerged from above the new physics hypersurface.

It is thus very well conceivable that the fluctuations bear an imprint of the unknown new physics.