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Author | Topic: Misconceptions in Relativity | |||||||||||||||||||||||||||
slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
Any chance Cavediver that you read John Hartnett's book Starlight Time nad the New physics
I would have liked to have your opinion on this. I just finished reading it, unfortunately I understand half of the appendix, which is had of the book lol. (I'm going to maths and physics at university so hopefully I'll come to understand it) Do you have any opinion concerning Carmelian Cosmology also ?? thx!
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
Thanks for the comments CD.
As I've said, I could not really evaluate Hartnetts calculations in his book, since I'm not educated enough on this (as I've said, im starting maths and physics in september). I didn't buy Carmeli's books on cosmological general relativity either. But I like the introduction Hartnett put in his book, so I'll put it here so you can tell me what you think. He talks about the time in Greece where they thought that earth was at the centre of the universe, but that this view would not apply very well with the observations and measurements. But rather then change their theory (geocentricism) they simply added epicycles to make it match their observations. As we all know, the right solution was to change the theory from geocentricism to heliocentricism. A sort of similar thing happened in astronomy a bit 100 years ago. Newton's theory of universal gravitation was viewed as the supreme theory in cosmology, and was being applied to the objects in the solar system. Once again, as we all know, the observation didn't fit the theory. It could not fully explain the precession of the perihelion of the orbits of the planets, especially of planet Mercury. Once again, rather then changing the theory, they postulated the existence of another planet between mercury and the sun, a planet we could not see, but its existence was essential to correct the mismatch between the theory and the observations: Planet Vulcan. Here again, it was the wrong way to proceed, since it was the theory which was in error, and it took Einstein Relativity to fully reconcile Observation and theory. Hartnett feels that this is happening yet again. We are seeing that our observations do not fit with our theory. And once again, we are postulating undetected matter and energy to make the observatiosn match the current theory. Could it be that, once again, it is the theory who should be changed ? This is what Hartnett thought, and made him discover Carmeli's Cosmological Relativity. AStonishingly, applying this theory to the large-scale structure of the universe, he found out that dark matter and energy was not needed, because the new theory matched perfectly with the observations! As I've said, I could only understand his explanation of the results of his theory, and although he put all his calculations in his book, I am progressing at a page per day rate trying to digest it a little at a time lol. I'll be exploring carmeli's new physics also, because if it involves is true, then it may well crucial to our understanding of the universe. Basically, from what I read, the velocity of the expansion of the universe works as a 5th dimension in his calculations. Instead solved the planet vulcan problem by adding a 4th dimension, could it be that the dark matter problem could be solved by adding a 5th dimension ? One last thing I found very compelling about Carmeli's physics is that his theory predicts that the universe is in accelerated expansion. He predicted this in 1996, and it was discovered (through supernova 1A observations if i remember correctly) in 1998 that this was the case. Such a prediction is very interesting, it is almost equivalent to if Einstein had predicted the expansion of the universe back in his days. Waiting for your thoughts on this, thanks
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
Not really the way I wanted this discussion to go, I would have like to know you thoughts on dark matter-energy and the way it seems to act as a 'fudge factor' in the conventionnel big bang model.
So creationist Hartnett "discovers" creationist Carmeli's amazing new cosmology By the way, Carmeli is not a creationist at all. Although he looks like some sort of 'creationist rebel' because he challenges the established thinking, in his mind his new theory does not present anything more than a new type of big bang cosmology.
We have been adding dimensions for the past 100 years. I have worked in every dimension from 2 to 12, and 26. The only thing interesting about Carmeli's approach is just how little sense it makes. Has the velocity of an expanding universe being one of the dimensions you worked on ?
No, it "predicts" three possible states, of which one is accelerated expansion. A bit like FLRW, except about seventy years later Maybe I misexpressed myself there. He did not predict three possible states, he predicted that we MUST be in an accelerating-expading universe. (Carmeli M. Cosmological general relativity, Communications in Theoretical Physics 5:159, 1996) Edited by slevesque, : No reason given.
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
quote: Err, did you read what followed you quote ? (link: http://arxiv.org/abs/astro-ph/0008040)
We show in the following that the viewpoint of the Bible is actually compatible with the theory of cosmology — the days of our life now are not equal to the days at the time of the creation of the Universe. In this note we calculate the lengths of days of the early Universe, day by day, from the first day on up to our present time. We find that the first day actually lasted the Hubble time in the limit of zero gravity. If we denote the Hubble time in the zero-gravity limit by which equals 11.5 billion years and Tn denotes the length of the n-th day in units of times of the early Universe, It was probably just unintentional on your part, so I'll assume it was. But had I misquoted someone like that, there would have been some evolutionist out there who would have discarded me on the spot.
quote: No of course I know you didn't. But your comment (''We have been adding dimensions for the past 100 years. I have worked in every dimension from 2 to 12, and 26. The only thing interesting about Carmeli's approach is just how little sense it makes.'') gave the impression you were saying 'been there, done that', when this was not it obviously. You were reffering to (i believe) the extra dimensions in string theory, where this dimensions are unperceivable in reality. This is very different to what Carmeli is proposing: the extra dimension (5th) is the veolicity of the expanding universe, which would be a perceivable dimension in our universe, just as time is. So it is no longer spacetime, but spacetimevelocity, or simply spacevelocity.
quote: ... and see section 4 to see that he says:
Thus H0 depends on the distance it is being measured [12]. It is
...
well-known that the farther the distance, the lower the value for H0 is measured. This is possible only for m < 1, i.e. when the Universe is accelerating. In that case the pressure is positive. This then followed by going to the upper curves (7) and (8) with m < 1, where the Universe expands with acceleration according to Eq. (3.2). Curve no. 8 fits the present situation of the Universe. I'm not saying his calculations are right, nor that they are even sensical since I do not have the knowledge right now to judge this. I'm just saying that he did predict the universe was in an accelerated expansion in 1996, 2 years before the discovery that this was the case.
quote: I'm not in any position to call dark matter and energy 'fudge factors', but these guys are: Open Letter on Cosmology With the vast majority of them being secular scientists Finally, ''if gravitationnal lensing is correct in the bullet cluster, why don't we see it in the CMB ? After all, cosmic microwave radiation is supposed to come from the background of all the galaxies (supposedly containing putative dark matter) in the visible universe and therefore should be lensed by foreground galaxiesbut it isn’t.'' (Hartnett, Has 'dark matter' really been proven? - creation.com) Lieu, R, Mittaz, J.P.D., On the absence of gravitational lensing of the Cosmic Microwave Background, ApJ 628(2):583—593, 2005. In my limited knowledge, I don't think you can rightfully claim that the bullet cluster discovery is emperical proof of the existence of dark matter unless you can answer that question. Edited by slevesque, : No reason given.
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
Ok, just to make it clear about the difference between a creationist and a theistic evolutionist
Creationists believe that the 6 days of creation are actual,literal, 24hour days of earth time. The earth is 6000 years old, etc. Theistic evolutionists see the 6 days of creation as figurative,poetic and metaphoric. Thus, for a theistic evolutionist, the days mentioned in the genesis account of creation are actually millions, or in this case, billions of years. Evolution is simply the way God used to create life, etc. So Carmeli is, as I've said in my previous post, a theistic evolutionist. He probably believes that the Bible is the innerrant word of God, but seeing the difference with the creation account and science (such as anthropology), he advocates that God was actually speaking in metaphors, and that the days in genesis are actually billion of years. Only reading his abstract, it is very creationist-like. But reading the rest of the paper, it is clear that he is a advocating a theistic evolutionist approach of the 6 days of creation. Edited by slevesque, : No reason given.
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
Ok, I think it would be pointless to discuss the Carmeli cosmology unless you think you can explain in a way I can understand where he goes wrong. I have my CEGEP physics and maths, which is (I think) equivalent to the first year university knowledge in the US. (educationnal system is different here in quebec)
First, I do not have access to his 1996 publication, only his papers in 2004. He makes no claim that he had predicted acceleration back in 1996, and he does not even cite the 1996 book, despite having it listed in the references! Can you shed any light on this? It is in his book Cosmological Relativity, page 78, section 4.6.this is the preview() Unfortunately, you don't have page 79 in that preview of his book. I would suspect it would be similar to section 4here Harnett said this?? He doesn't have the first fucking clue How can someone write papers on cosmology and not know what the CMBR is? And this is the guy the creationist community is heralding as their new saviour... I followed your advice and went on wikipedia to see what they say about the CMB.
quote: This is what Hartnett said:
quote: Maybe its the language barrier (I speak french), but I don't see where the discrepancy is. What am I missing ?
quote: Hey, if I'm on these forums discussing this with other people, it is precisely because I do NOT want to solely listen to what Hartnett has to say ...
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
Hmmm, ever heard of Old Earth Creationist? Btw I didn't see him talking about biological life (only cosmology I think) so we can't say what he really thinks about evolution. The difference between old-earth creationism and theistic evolutionism is very small. There are so many names for the different positions (progressive creationism, old-earth creationism, young-earth creationism, theistic evolutionism, gap creationism, evolutionary creationism) I use the term theistic evolutionism because I view it as more general. He mentions anthropology as one of the sciences by which we can know that the earth is old, so I would think he does accept evolution. Anyhow, I think it is way less complicated like this: creationist: Young earth-creationismevolutionist: atheistic evolutionism theistic evolutionist: all the others Edited by slevesque, : No reason given.
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
He says it comes from the background of galaxies, not from galaxies. Maybe it is his phrasing, but I understood it as that the CMBR comes from behind the galaxies, and so the galaxies and its dark matter should create gravitationnal lensing on it.
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
I agree that last group envelops maybe too much people, anyhow its pretty much only semantics as long as we are talking the same thing
I try to use the reply button, but I forget sometimes
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
True, I did think of this earlier today, but even if this was his meaning it still suggests a very loose understanding of the CMBR. The CMBR does not emanate from "behind" the galaxies, whatever the hell that means. I agree it makes little sense for those who know exactly what the CMBR really is. But you gotta remember the article was intended for readers who, for the most part, do not have much knowledge in cosmology, and so you can't really go in the details. Its similar to layman's scientific journals calling a gas cloud a ''space blob''.
And your 2005 paper, "Lieu, R, Mittaz, J.P.D., On the absence of gravitational lensing of the Cosmic Microwave Background, ApJ 628(2):583—593, 2005", with its total of four cites, is rather negated by the plethora of papers such as "Antony Lewis, Anthony Challinor, Weak Gravitational Lensing of the CMB, Phys.Rept. 429 (2006) 1-65", with its 70 cites. Consider it answered... Thanks for taking this a bit more seriously, its appreciated. Now first of all, you'll have to excuse me for my lack of english knowledge, but what do you mean by 'cites' ? I didn't read the whole paper on weak gravitationnal lensing of the CMB, as you might guess it gets complicated for me to read technical papers in English. But skipping threw it I noticed this on page 77:
11 Status and applications of CMB lensing 11.1 Observational status At the time of writing there is no detection of lensing of the CMB or of lensing-induced cross-correlation with large scale structure (152). This is expected to change very shortly, either by direct detection of the non-Gaussian signature in the small-scale CMB, or by the improvement to model fitting by using the lensed as opposed to the unlensed CMB power spectra. Current data restrict the amplitude of the lensing effect to be within a factor of three of the expected result, but consistent with zero. However lensing is a robust prediction, so in the next subsections we discuss what new cosmological and/or astrophysical information we might be able to extract from future observations of CMB lensing. The reference (152) lead to this paper, http://arxiv.org/PS_cache/astro-ph/pdf/0406/0406004v2.pdf, which found no detection of lensing. That paper was written in 2004 (and the first one in 2006), and so I was asking myself if it had been observed since that time. Edited by slevesque, : No reason given.
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
Off-topic question here I have been asking myself for quite a while, and I would hope you could answer me CD:
Are the gravitationnal effects of a body instanteneous, or do they propagate at the speed of light ? (or at some other speed)
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slevesque Member (Idle past 4662 days) Posts: 1456 Joined: |
I knew what a citation was, but i didn't know of the concept CD described (comparing papers threw their numbers of citations)
Edited by slevesque, : No reason given.
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