Translation, please. What is Lambda-CDM and what is a concordance model? I know this is basic stuff, but I've got a lot to learn and understanding the terminology helps a lot.
Chris
- Status
Translation, please. What is Lambda-CDM and what is a concordance model? I know this is basic stuff, but I've got a lot to learn and understanding the terminology helps a lot.
Chris
csmyth3025":16woqgkm said:
Lambda is dark energy, CDM is cold dark matter, and the concordance model is what ties it all in with general relativity to produce a model that predicts the properties of the Cosmic Microwave Background Radiation, the formation and evolution of large scale structure, the expansion, and the acceleration of the expansion of the universe.
http://en.wikipedia.org/wiki/Lambda-CDM_model
And two very good papers on the subject:
Inflation and the Cosmic Microwave Background
Expanding Confusion: common misconceptions of cosmological horizons and the superluminal expansion of the Universe
harrycostas":1nh3oex8 said:
Abundances. It is the ratio of light to heavy elements that decreases as time goes on. I suppose I should have said that the further we look back in time, the more we seen an abundance of lighter elements.
harrycostas":1nh3oex8 said:
But what about the angular diameter and its relationship with luminosity, which mirrors its relationship with redshift? Is apparent luminosity not an indicator of light-travel distance either?
harrycostas":1nh3oex8 said:
And you need to research the other areas of cosmology that are actually relevant to the issue. The formation of structure evolves over time, as shown by the correlation between the overall density of galaxies across the universe (it has been shown that there were less galaxies in the past) and redshift or luminosity. Which all tie in with angular diameter to show an expanding universe.
Why on Earth do you keep citing "clustering effects in all images" as evidence against the expansion of the universe? Everything has been clustering since gravity could take effect on the slightly different densities of matter in the early universe. It is the distance between highly seperated clusters, where there is negligible gravitational influence between them, that increases due to the expansion of the universe. You wont see expansion in any picture, what are you looking for?
Thanks for the explanation and the links speedfreek. The Wikipedia article is concise, well written and understandable at my level. The paper is s bit technical for my level of understanding (a definite understatement).
Chris
Chris
You might get on better with the second "misconceptions" paper better than the first one. The space-time diagrams shown on page 3 and in detail on page 11 are a real aid to understanding the overall picture, at least, they were in my case.
Yes, the second paper is more "user friendly" than the first. The authors are careful to describe misconceptions and the reasons those misconceptions have developed in plain English. I still have a lot to learn about the various models of cosmic expansion, the terminology used, and the mathematical basis for the myriad calculations employed. It's very interesting stuff. Thanks.
Chris
G'day Speedfreek
You keep on saying that the distance between the galaxies is expanding.
OK
Nominate the galaxies.
Then show the evidence.
I need to see the evidence.
You keep on saying that the distance between the galaxies is expanding.
OK
Nominate the galaxies.
Then show the evidence.
I need to see the evidence.
Harry - you seem very well-read on the arXiv and ADS, but you really haven't read any papers showing that galaxies are universally moving away from us* at a velocity proportional to their distance from us? I recommend Hubble's 1929 paper showing just this fact:
http://adsabs.harvard.edu/cgi-bin/nph-b ... 22c9c30954
or Riess et al. 1998:
http://arxiv.org/abs/astro-ph/9805201
as classics in the field.
*with the exception of some Local Group members
http://adsabs.harvard.edu/cgi-bin/nph-b ... 22c9c30954
or Riess et al. 1998:
http://arxiv.org/abs/astro-ph/9805201
as classics in the field.
*with the exception of some Local Group members
G'day Ramparts
Thank you for those posts. I read them some time ago
The papers that you posted are out of date and give little consideration to the intrinsic properties of supernova. Since we use the supernova as a standard candle we should eliminate the errors and understand that redshift can be created by many processes, even when the object is moving towards us.
Also Hubble till the day he died questioned the velocity/redshift.
Look there is plenty of galaxies out there, if there is a general expansion we should be able to see it.
The pattern of motion within our local group of galaxies is gravity bound and is moving towards the great attractor which is a cluster of local groups of galaxies such as our own. Now this great attractor belongs to a super cluster that has clusters of clusters of local galxies.
Knowing this, please show me where the expansion occurs.
With due respect please read more, this does not mean that the links that I post are correct. It allows us to become awear of options and alternatives.
http://arxiv.org/abs/0806.4085
A review of redshift and its interpretation in cosmology and astrophysics
Authors: R. Gray, J. Dunning-Davies
(Submitted on 25 Jun 2008)
Thank you for those posts. I read them some time ago
The papers that you posted are out of date and give little consideration to the intrinsic properties of supernova. Since we use the supernova as a standard candle we should eliminate the errors and understand that redshift can be created by many processes, even when the object is moving towards us.
Also Hubble till the day he died questioned the velocity/redshift.
Look there is plenty of galaxies out there, if there is a general expansion we should be able to see it.
The pattern of motion within our local group of galaxies is gravity bound and is moving towards the great attractor which is a cluster of local groups of galaxies such as our own. Now this great attractor belongs to a super cluster that has clusters of clusters of local galxies.
Knowing this, please show me where the expansion occurs.
With due respect please read more, this does not mean that the links that I post are correct. It allows us to become awear of options and alternatives.
http://arxiv.org/abs/0806.4085
A review of redshift and its interpretation in cosmology and astrophysics
Authors: R. Gray, J. Dunning-Davies
(Submitted on 25 Jun 2008)
G'day Ramparts
The following paper gives a good description of the processes within galaxies and yet applies redshift data to it.
What I'm trying to say is that redshift data needs to be taken with a pinch of salt and not dictate the final story until we get a better understanding of the data. Bursting and quenching is one of the main processes in the evolution of form in galaxies. During bursting the vector forces coming out give a different redhift reading to the vector forces going into the galaxy.
Bursting and quenching in massive galaxies without major mergers or AGNs
Sep-07
http://adsabs.harvard.edu/abs/2007MNRAS.380..339B
http://adsabs.harvard.edu/cgi-bin/nph-d ... db_key=AST
The following paper gives a good description of the processes within galaxies and yet applies redshift data to it.
What I'm trying to say is that redshift data needs to be taken with a pinch of salt and not dictate the final story until we get a better understanding of the data. Bursting and quenching is one of the main processes in the evolution of form in galaxies. During bursting the vector forces coming out give a different redhift reading to the vector forces going into the galaxy.
Bursting and quenching in massive galaxies without major mergers or AGNs
Sep-07
http://adsabs.harvard.edu/abs/2007MNRAS.380..339B
http://adsabs.harvard.edu/cgi-bin/nph-d ... db_key=AST
G'day Ramparts
Sorry for the posted links. My opinion should not influence your thinking. May be reading these links may give you a better understanding. Imagine if we agreed with whats flowing down main stream without questioning and finding out years later that we were taken for a stream ride.
The following paper researches the intrinsic properties and applies science to the logic.
Evidence for an anticorrelation between the duration of the shallow decay phase of GRB X-ray afterglows and redshift
Feb-09
http://adsabs.harvard.edu/abs/2009A%26A...494L...9S
http://adsabs.harvard.edu/cgi-bin/nph-d ... db_key=AST
Sorry for the posted links. My opinion should not influence your thinking. May be reading these links may give you a better understanding. Imagine if we agreed with whats flowing down main stream without questioning and finding out years later that we were taken for a stream ride.
The following paper researches the intrinsic properties and applies science to the logic.
Evidence for an anticorrelation between the duration of the shallow decay phase of GRB X-ray afterglows and redshift
Feb-09
http://adsabs.harvard.edu/abs/2009A%26A...494L...9S
http://adsabs.harvard.edu/cgi-bin/nph-d ... db_key=AST
harrycostas":16kzd0y8 said:
Harry, the supernova data is just one type of standard candle used to calibrate the "distance ladder", I thought we covered this some pages back in this thread (at least I think it was this thread!), where I listed all the various measurements used on the distance ladder, all of which are in agreement with the expansion of the universe.
Hubble did not use supernova data, he used Cepheid variables. Most of the evidence for expansion has nothing at all to do with supernova data. The recent supernova data is just one of many ways that we confirmed not only the expansion, but the acceleration of the expansion. You hear about the SN data a lot, as it is the most recent confirmation.
Whether Hubble thought that the universe was expanding or not is irrelevant - the answer is in the data, not the opinions of the author. Einstein himself did not want to believe the universe was expanding either, until he was presented with the evidence.
All galaxies (not supernovae, but galaxies) outside of our local supercluster are redshifted and the amount of redshift increases as apparent luminosity decreases.
Then, over a certain distance (as measured by apparent luminosity), the apparent angular diameter of objects starts to increase, implying that those objects were close to us when they emitted the light (which is now very dim) that we see. That relationship, when combined with the previous one, is even harder to explain using an alternative model.
Then, the ratio of light to heavy elements increases as we look at increasing distances, so those most distant galaxies were mainly comprised of light elements, whereas modern galaxies contain a much larger concentration of heavy elements. That, when combined with the previous two relationships, is even harder still to explain using an alternative model.
Then we have the existence of the cosmic microwave background radiation, which is predicted in an expanding universe, due to nucleosynthesis when everything was much closer together than it is today. An alternative model needs to explain what all this very cold background radiation is doing here.
The list goes on and on... large scale structure formation (there were less galaxies around 13 billion years ago), the age of stars (the lowest mass stars have potential lifetimes of trillions of years, yet we see none older than 13 billion years old), the evolution of galaxies (the most distant of the galaxies in the Hubble Ultra Deep field look strange and irregular, nothing like modern galaxies), and then finally we get on to supernovae!
We have the time-dilation of supernova light-curves, which seem in general to correspond with all the previous relationships, as predicted in an expanding universe. The more distant the supernova of a given duration, the longer the apparent duration when we finally see it - cosmological time-dilation caused by the expansion of the universe.
Unless, that is, you think that galaxies actually used to be twice the size, all at the same time, in a universe that was static and had no beginning... or that supernovae used to burn for a lot longer than they do nowadays, in a universe that has always been here. Or that galaxies used to be comprised of lighter elements than today, for some unexplained reason. Or that the universe has always been here, but we have seen no stars over 13 billion years old. Or why there used to be less galaxies, and they looked strange and irregular.
Did our universe have a beginning? It certainly seems so.
Is our universe static? It certainly seems not.
Is the universe cyclic? Perhaps it is, but if so, that cycle includes the expansion of our universe from something where the gaps between things were very small, to a universe where the gaps between things are very large. In that case, everything in our current "cycle" is as described by the Big Bang.
It has been stated that there is a cosmic background radiation which is covering all of " SPACE ". This cosmic background radiation is believe to had arised from the BB and is still around today creating distubances as for example, when you listen to your radio station or T.V. What many had falied to realize is that we are confine to an area of " SPACE ", and in our confinement we can only reached as far as our confinement allows us to. Many of the discoveries which we encountered can only be applied to our part of our galaxy. If there was a BB it does not include all of what is in existence and least of all to Space or all of its content. The quest to find a theory of everything as a way to finalized the origin of life or of the universe is illogical and futile. The evolutionary proccess of life, matter, elements, energy is something which will be defined according to the nature of the Universe in question. You can shuffle the evolutionary order in any manner and still find that for our existence and for our galaxy it fit us as tailored made but once you travel outside of our galaxy and further to the most remote galaxy and beyond it where not even the hubble space telescope nor any other can reached, there the " Laws of Physics and of Quantum Mechanics " are none existence as we know them. Theories will continued to be theories and evidence pointing in support of such theories as the BBT will only apply to our immediate confinement of Space.
harrycostas":3w45uiss said:
In fact, we do! But if you ignore redshifts, then it's pretty hard to see expansion. So how do you propose to see expansion otherwise?
I'm very confused as to exactly what you want me to show you.
harrycostas":2lurxb81 said:
That's a fine paper, but I don't see how this paper on galaxy formation simulations is supporting your point. Harry, we keep asking you this - please give us an explanation when you post links, or don't post them at all. This says nothing new about redshifts, and only (like thousands of other papers in the last few decades) uses redshifts as synonyms for "age" or "distance" - exactly because of Hubble's relation! So once again, you've posted a paper that seems to disagree with you.
Also, what on Earth is a "vector force"? Is that different from a regular force (which can be described with a vector)? Which forces are you talking about here?
harrycostas":2wkikofq said:
But we have redshift measurements for literally thousands upon thousands of galaxies. As redshift increases, surface brightness decreases and so does angular diameter, up to redshifts of z~1.6. Above that redshift, the surface brightness continues to decrease, whilst the angular diameter increases again.
What might be the cause of that redshift, if it does not represent the apparent recession of galaxies due to the expansion of the universe? How would that cause correlate with the observations above?
G'day from the land of ozzzzzzz
I posted that link for your information , to get some form of understanding of the workings of the universe. I think the point went over your heads. In understanding redshift we first need to understand what causes redshift.
Regardless
These links may give you further understanding. The ABS speak for themselves.
http://arxiv.org/abs/0908.1539
The case for a non-expanding universe
Authors: Antonio Alfonso-Faus
(Submitted on 11 Aug 2009)
and
http://arxiv.org/abs/0806.4085
A review of redshift and its interpretation in cosmology and astrophysics
Authors: R. Gray, J. Dunning-Davies
(Submitted on 25 Jun 2008)
I posted that link for your information , to get some form of understanding of the workings of the universe. I think the point went over your heads. In understanding redshift we first need to understand what causes redshift.
Regardless
These links may give you further understanding. The ABS speak for themselves.
http://arxiv.org/abs/0908.1539
The case for a non-expanding universe
Authors: Antonio Alfonso-Faus
(Submitted on 11 Aug 2009)
and
http://arxiv.org/abs/0806.4085
A review of redshift and its interpretation in cosmology and astrophysics
Authors: R. Gray, J. Dunning-Davies
(Submitted on 25 Jun 2008)
The abstracts don't tell the whole story, it is a good idea to read the whole paper.
Here we have the proposal of a static universe that had a beginning, light reducing in speed, increasing mass in the universe with time, and...
"The stability of a non-expanding universe may be achieved by the equilibrium between expanding electrical forces and contracting gravitational ones."
Wow. That's really messing with the fine structure constant there, and consequently having to somehow introduce new mass into a static universe throughout time, and somehow create expanding electrical forces to balance gravity. And this static universe still had a beginning.
And all just to get rid of expansion...
And here we have a paper which starts off well and seems to cover the Big Bang model at length. The author is unfortunately unaware that we have now seen plenty of observational evidence for dark matter, from gravitational lensing in the Abell cluster, for instance, and evidence for dark energy from the Chandra X-Ray observatory's studies of hot gases in various galaxy clusters, so his statement about unobservable forms of energy and matter is now misleading (this paper is out of date, in other words!).
Dark matter and energy aren't just ad hoc ideas cooked up to account for anomalies in the mainstream theory, they have been confirmed in tests completely separate from those anomalies that caused us to assume their existence. We have the rotation curves of galaxies, that tells us there is unseen mass around the galaxy. Now we have seen distant galaxies gravitationally lensed by that unseen extra mass. We have the time-dilation of SNIa light-curves that tells us the expansion of the universe is accelerating. Now we have the studies of hot gas in galaxy clusters over a range of distances which shows us how the increase in mass within those clusters is affected by dark energy, the cause of that acceleration.
The author then glosses over the problems with the Quasi Steady State model with glib statements such as:
"However, “mainstream” cosmologists who have reviewed the QSS model have disregarded it due to “flaws and discrepancies” with observations left unexplained by the proponents"
i.e. the proponents of QSS cannot explain the flaws and discrepancies, and yet the author seems to think it is wrong for the mainstream to have disregarded the model. There is far more wrong with QSS than there is with BBT, so the mainstream will stick to studying BBT until such a time as proponents of QSS can show it to be a better model.
He does not even address all the known problems with tired light/intrinsic redshift, he presents them as valid alternatives even though it has been shown, for example, that the Compton effect would scatter light, making distant galaxies look blurred, and that tired light fails the Tolman Test.
harrycostas":2u34iodo said:
Here we have the proposal of a static universe that had a beginning, light reducing in speed, increasing mass in the universe with time, and...
"The stability of a non-expanding universe may be achieved by the equilibrium between expanding electrical forces and contracting gravitational ones."
Wow. That's really messing with the fine structure constant there, and consequently having to somehow introduce new mass into a static universe throughout time, and somehow create expanding electrical forces to balance gravity. And this static universe still had a beginning.
And all just to get rid of expansion...
harrycostas":2u34iodo said:
And here we have a paper which starts off well and seems to cover the Big Bang model at length. The author is unfortunately unaware that we have now seen plenty of observational evidence for dark matter, from gravitational lensing in the Abell cluster, for instance, and evidence for dark energy from the Chandra X-Ray observatory's studies of hot gases in various galaxy clusters, so his statement about unobservable forms of energy and matter is now misleading (this paper is out of date, in other words!).
Dark matter and energy aren't just ad hoc ideas cooked up to account for anomalies in the mainstream theory, they have been confirmed in tests completely separate from those anomalies that caused us to assume their existence. We have the rotation curves of galaxies, that tells us there is unseen mass around the galaxy. Now we have seen distant galaxies gravitationally lensed by that unseen extra mass. We have the time-dilation of SNIa light-curves that tells us the expansion of the universe is accelerating. Now we have the studies of hot gas in galaxy clusters over a range of distances which shows us how the increase in mass within those clusters is affected by dark energy, the cause of that acceleration.
The author then glosses over the problems with the Quasi Steady State model with glib statements such as:
"However, “mainstream” cosmologists who have reviewed the QSS model have disregarded it due to “flaws and discrepancies” with observations left unexplained by the proponents"
i.e. the proponents of QSS cannot explain the flaws and discrepancies, and yet the author seems to think it is wrong for the mainstream to have disregarded the model. There is far more wrong with QSS than there is with BBT, so the mainstream will stick to studying BBT until such a time as proponents of QSS can show it to be a better model.
He does not even address all the known problems with tired light/intrinsic redshift, he presents them as valid alternatives even though it has been shown, for example, that the Compton effect would scatter light, making distant galaxies look blurred, and that tired light fails the Tolman Test.
CommonMan":3bk6yxap said:
Seriously? Orion's Belt? (My name is the stars of orions belt) :lol:
Don't search atround for it. It's in my PMs.
On Topic: Bang! That's my opinion. I think there was a bang. I saw this articl in the Astronomy Magazing about some theroie son how the universe formed. On of them was about a loop where we are this plane. One of two, just milimeters into another dimension, and they hit eachoter, go away (expansion) then get closer (colapse) and then hit (Big Bang).
G'day speedfreek
You said
You need to research the workings of compact matter and the formation of jets. Also the transient processes of normal matter to various degenerate phases and the ejection of this matter via jets and the formation of normal matter. This is well documented. Your responses basically tells me that you do not know.
You said
You need to research the workings of compact matter and the formation of jets. Also the transient processes of normal matter to various degenerate phases and the ejection of this matter via jets and the formation of normal matter. This is well documented. Your responses basically tells me that you do not know.
Harry, it's impossible for me to tell from your responses what it is that you think you know that speedfreek (or anyone else, for that matter) doesn't know. It would be very helpful if you would state your position - in you own words - before posting a link purporting to support your position.
That said, it's interesting to note that the basis for all of the various theories regarding cosmology and our observations of distant events is the principal that the laws of physics as we understand them are invariant throughout time and space. This principal is necessary if we are going to attempt to understand events that are remote from us since such events are, by definition, separated from us in both time and space.
The fact that we must rely on this principal to make sense of our world doesn't make it an absolute fact, however. I say this not to dispute any of the physical laws we hold so dear, but only to point out that we should keep an open mind about how valid this assumption really is.
Chris
G'day Chris
Mate you got it wrong.
My position is not important.
It's to be awear of the information that is out there.
I think that I'm wasting my time.
People feel more comfortable feeling what they know is right.
So be it.
Mate you got it wrong.
My position is not important.
It's to be awear of the information that is out there.
I think that I'm wasting my time.
People feel more comfortable feeling what they know is right.
So be it.
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