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De Sitter & Accelerating Expansion?
De Sitter and accelerated expansion
DeSitters model: a spherical three dimensional universe with time everywhere perpendicular to the three locally perpendicular, large, circular 'space` axes so that events viewed at a distance are subject to an 'angular` red shift due to distance from the observer without any 'real` expansion. ( Time 'stops` at 1/4 circumference, reverses at the antipode.) Has any observational evidence firmly ruled out this model? If such a universe were expanding, would not an observer perceive an acceleration in expansion measured by red shift velocities such as has lately been observed? Just an idle thought, besides, its such a pretty model. Pragmatist |
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De Sitter & Accelerating Expansion?
pragmatist wrote in message
om... De Sitter and accelerated expansion DeSitters model: a spherical three dimensional universe with time everywhere perpendicular to the three locally perpendicular, large, circular 'space` axes so that events viewed at a distance are subject to an 'angular` red shift due to distance from the observer without any 'real` expansion. ( Time 'stops` at 1/4 circumference, reverses at the antipode.) Has any observational evidence firmly ruled out this model? If such a universe were expanding, would not an observer perceive an acceleration in expansion measured by red shift velocities such as has lately been observed? Just an idle thought, besides, its such a pretty model. Pragmatist Within the last three months, Old Man has read most of the sections (a few without comprehension) in PJE Peebles' book, "Principles of Physical Cosmology", and although some the work of de Sitter is covered therein, Old Man does not recall any mention of this particular model. It sounds preposterous to Old Man, and since he doesn't put any emphasis on it, maybe Peebles feels the same way. [Old Man] |
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De Sitter & Accelerating Expansion?
"Old Man" wrote in message news:3f42b680_1@newsfeed...
Within the last three months, Old Man has read most of the sections (a few without comprehension) in PJE Peebles' book, "Principles of Physical Cosmology", and although some the work of de Sitter is covered therein, Old Man does not recall any mention of this particular model. It sounds preposterous to Old Man, and since he doesn't put any emphasis on it, maybe Peebles feels the same way. [Old Man] I haven't read Peebles, if that was a recommendation, I will look him up. The descripton I offered is my interpretation of a description I read in 'Space, Time, and Gravitation` - Sir Arthur Eddington - 1920, (Harper Ed. 1959) de Sitter is not completely ignored today, as a matter of fact he is refered to in a recent lecture by Hawking, (of which I understood little but enjoyed for what crumbs I could gather, and of course, for the language. You've got to hand it to them, the Brits can still write.) Pragmatist |
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De Sitter & Accelerating Expansion?
pragmatist wrote in message
om... "Old Man" wrote in message news:3f42b680_1@newsfeed... Within the last three months, Old Man has read most of the sections (a few without comprehension) in PJE Peebles' book, "Principles of Physical Cosmology", and although some the work of de Sitter is covered therein, Old Man does not recall any mention of this particular model. It sounds preposterous to Old Man, and since he doesn't put any emphasis on it, maybe Peebles feels the same way. [Old Man] I haven't read Peebles, if that was a recommendation, I will look him up. The descripton I offered is my interpretation of a description I read in 'Space, Time, and Gravitation` - Sir Arthur Eddington - 1920, (Harper Ed. 1959) de Sitter is not completely ignored today, as a matter of fact he is refered to in a recent lecture by Hawking, (of which I understood little but enjoyed for what crumbs I could gather, and of course, for the language. You've got to hand it to them, the Brits can still write.) Pragmatist Peebles' book is comprehensive, but the organization leaves something to be desired. Old Man had to put it down for awhile and do some background reading at the introductory level before starting over again from the beginning. It made a lot more sense the second time through. It was still a tough grind, and being retired and more or less carefree, that's not necessarily what Old Man is after. [Old Man] |
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De Sitter & Accelerating Expansion?
"Old Man" wrote in message news:3f440970_2@newsfeed...
Peebles' book is comprehensive, but the organization leaves something to be desired. Old Man had to put it down for awhile and do some background reading at the introductory level before starting over again from the beginning. It made a lot more sense the second time through. It was still a tough grind, and being retired and more or less carefree, that's not necessarily what Old Man is after. [Old Man] Pragmatist is also retired, didn't plan it this way, but it happened anyhow. A good grind is valuable sometimes in that it keeps the dust and cobwebs from collecting. (That third person stuff is catching.) Cheers - Pragmatist |
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De Sitter & Accelerating Expansion?
pragmatist wrote in message om... "Old Man" wrote in message news:3f440970_2@newsfeed... Peebles' book is comprehensive, but the organization leaves something to be desired. Old Man had to put it down for awhile and do some background reading at the introductory level before starting over again from the beginning. It made a lot more sense the second time through. It was still a tough grind, and being retired and more or less carefree, that's not necessarily what Old Man is after. [Old Man] Pragmatist is also retired, didn't plan it this way, but it happened anyhow. A good grind is valuable sometimes in that it keeps the dust and cobwebs from collecting. (That third person stuff is catching.) Cheers - Pragmatist A hard grind can be fun for that with illumination at the end of the tunnel, but there is little reward when, in the end, comprehension fails. Nothing ventured, nothing gained, but greed and vanity are poor masters. Frivolous time wasters that they are, they can make one old before his time. [Old Man] [Old Man] |
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De Sitter & Accelerating Expansion?
"Old Man" wrote in message news:3f456c5f_1@newsfeed...
A hard grind can be fun for that with illumination at the end of the tunnel, but there is little reward when, in the end, comprehension fails. Nothing ventured, nothing gained, but greed and vanity are poor masters. Frivolous time wasters that they are, they can make one old before his time. [Old Man] [Old Man] So look for easier pickings. There must be a lot of things of which you thought 'someday I've got to look into that`. Today is someday, and the learning curve for a new subject is so much easier. At entry/intermediate level in a new area, there are interesting things to learn just for the reading. Age broadens one, so while we sit here broadening our asses we might as well broaden our interests. Hang in there - Pragmatist |
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