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WalterP last won the day on October 20 2019

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About WalterP

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    Armchair astronomer under marmalade skies.

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  • Still have any Gods? If so, who or what?

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  1. Hello Disillusioned and Josh. I have some more news. Over the past week I've checked all of Hawking's published science papers from this listing, which I think is complete and exhaustive. http://www.hawking.org.uk/publications.html In none of them does he openly embrace or accept the universe's positive cosmological constant. But rather than this being a case of stubborns on his part, I think there's another reason for this. Back in the 60's and 70's Hawking and Penrose reasoned that all of physics breaks down at the initial singularity, leading to a breakdown in predictability. Hawking worked with Jim Hartle on the problem of restoring predictability and found a way of eliminating the initial singularity, which they called the No-Boundary Proposal. https://en.wikipedia.org/wiki/Hartle–Hawking_state This mathematical solution restored a degree of quantum predictability, allowing them to calculate certain probabilities about the origins of the universe. This was much better than the situation with the Hawking - Penrose singularity theory, where ALL predictability broke down completely at the initial singularity. So Hawking was satisfied with this and stayed with his No-Boundary Proposal until his dying day. Because Hawking believed that he had restored predictability to the science of cosmic origins he effectively discarded the 1970 singularity theory that he and Penrose had worked on. I know this to be so because I recall him saying so in his book, 'A Brief History of Time'. What I'll do over the next few days is to find that quote from that book and cite it in this thread. I'll also explain about how the paper I've linked to below is relevant to our discussion of William Lane Craig's (failed) cosmology. https://arxiv.org/pdf/hep-th/9803156.pdf Open Inflation, the Four Form and the Cosmological Constant. The quote from Hawking's book will be easy enough for you guys to follow but the above science paper will need some careful explanation. Thank you, Walter.
  2. No I thank you Walter P. Putting it at me this way made me think. All I had to do is see it this way. I now realize I have a lot of deprogramming to do. Rewiring of my brain. To really think about it. I would kiss you if you were in front of me. Without some fucking God I can truly be free. -------------------------------------------------------------------------------------------------------------------------------------------------------------------- That's ok, freedwoman. But please do note that as far as the science of cosmology is concerned, there is currently no definitive answer to the question, 'Is the universe eternal or did it have a beginning?' The catch is that many Christians deeply feel the need for 'something' science-based to confirm what they believe by faith. So, they do as William Lane Craig does and misuse/misunderstand science. Even though they genuinely believe with all their heart (as Craig does) that science 'proves' the Bible, the fact is that it doesn't. Going with facts and not faith sets you free from superstition. Thank you. Walter. (Kiss gratefully received, btw. )
  3. I think you missed the point of the RedneckProfessor's re-wording of your opening post, freedwoman. If the universe has always existed, then there is no need to invoke any kind of God, deity, intelligent designer or pink unicorn to explain its existence. Also, to say that one thing is exempt (i.e. God) from a rule (everything has to have a beginning) that applies to all other things is to commit the informal logical fallacy of Special Pleading. This is what Dave was referring to. https://en.wikipedia.org/wiki/Special_pleading Ok, you can believe otherwise, but you have no logical or scientific grounds for doing so. Thank you, Walter.
  4. To Freedwoman and Dave... 'Christians say that everything needs a creator.' Well, as far as I know the leading Christian apologist who advocates this philosophical position is one William Lane Craig. https://en.wikipedia.org/wiki/William_Lane_Craig He uses the Kalam Cosmological Argument, which is in turn based upon his interpretation of a science paper by Stephen Hawking and Roger Penrose that was published in 1970. In that paper these scientists present a mathematical proof that the universe had an absolute beginning. Craig uses this proof to assert that therefore science agrees with the Bible, specifically Genesis 1:1, where the universe didn't exist and then, by the will of God, it did. With all of time and space having a starting point (Hawking and Penrose call this the 'initial singularity') some 13.72 billion years ago. According to Craig this 'proves' that everything, including the universe, MUST have had a creator. However, Hawking and Penrose placed very strict limits on what their 1970 singularity theory can and can't do. If the universe possesses something called a positive cosmological constant, then their theory doesn't apply to the universe. Their theory only works if the cosmological constant has a zero or negative value. Fast forward to 1998 and three separate teams of astronomers measured the universe's cosmological constant to be a small, but positive value. https://arxiv.org/abs/astro-ph/9805201 Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant https://arxiv.org/abs/astro-ph/9805200 The High-Z Supernova Search: Measuring Cosmic Deceleration and Global Curvature of the Universe Using Type Ia Supernovae https://arxiv.org/abs/astro-ph/9812133 Measurements of Omega and Lambda from 42 High-Redshift Supernovae The Hawking - Penrose singularity theory therefore cannot be used to prove anything about our universe. It's been refuted by evidence. The irony is that this happened in 1998 and Craig didn't start publicly making his assertions about this theory in 2007. On his own website, Reasonablefaith.com. So he was wrong from get go. In fact, any Christian who claims that science 'proves' that the universe had a beginning is wrong. Firstly, because the currently accepted theory of cosmic origins, the Lambda Cold Dark Matter model, says nothing about the actual 'creation' of the universe. It takes over after that and begins with the universe in a hot, dense state, from which it 'inflates'. Please Google 'Cosmic Inflation' to learn more about this. Or I can provide you with some helpful links. Secondly, in the sciences only mathematics uses proofs. A mathematical proof is complete, absolute and unchanging. Whereas all the other sciences use theories, not proofs. Theories are tentative and not absolute. They can be overturned by new evidence, just as the Hawking - Penrose theory was overturned, over twenty years ago. The bottom line is that Christians can argue that the universe had a beginning and they can believe by faith that it did, but they cannot 'prove' that from science, nor can they even demonstrate from evidence that it did. Anyway, Disillusioned, JoshPantera and I have been discussing the shortcomings of William Lane Craig's cosmology in this thread since Oct 1 last year. https://www.ex-christian.net/topic/82597-the-failed-cosmology-of-william-lane-craig/ Thank you, Walter.
  5. Hello Ficino. I can understand your confusion, but there's no need to worry. Disillusioned, Josh and I are all well aware that the only scientific theories that are proved are mathematical ones. Please note that I was taking the part of William Lane Craig in my dialogue with Josh because Craig does assert that science proves that the universe had a definite beginning. If you go to the start of this thread I explain that Craig misuses a 1970 science paper by Stephen Hawking and Roger Penrose in which they present a mathematical proof for a definite beginning of the universe - the initial singularity. In this thread I've been at pains to explain that Hawking and Penrose set down very precise limits under which their proof would be viable. In 1998 one of those limits was found to be violated and so their proof does not apply to this universe. It can't be used as WLC has been using it - as the basis for the Kalam Cosmological Argument. The proof was refuted even before Craig started up his ReasonableFaith forum. Does that help to explain things? Thank you. Walter.
  6. Hello Josh. To answer your first question, here's some information that I posted in this thread on Oct 4. -------------------------------------------------------------------------------- So, the $64,000 question that’s now screaming to be answered is this. “Do we live in a universe with a cosmological constant of a negative value, of a zero value or of something else?” The answer to this question will tell us if Hawking and Penrose’s theory applies to our universe or not. I will let the following links supply the answer to the big question. https://arxiv.org/abs/1706.07482 http://physics.princeton.edu/~steinh/lambda16.pdf https://ned.ipac.caltech.edu/level5/Carroll2/Carroll2_2.html https://www.edge.org/response-detail/27194 https://en.wikipedia.org/wiki/Cosmological_constant https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5256042/ https://arxiv.org/ftp/arxiv/papers/1711/1711.06890.pdf https://cds.cern.ch/record/485959/files/0102033.pdf --------------------------------------------------------------------------------------------------- These links are, more or less, up to date. They confirm that our universe has a positive cosmological constant, invalidating the H - P singularity theory and destroying WLC's cosmology, which is based solely upon that theory. However, the original findings are these, dating from 1998 and 1999. https://arxiv.org/abs/astro-ph/9805201 Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant https://arxiv.org/abs/astro-ph/9805200 The High-Z Supernova Search: Measuring Cosmic Deceleration and Global Curvature of the Universe Using Type Ia Supernovae https://arxiv.org/abs/astro-ph/9812133 Measurements of Omega and Lambda from 42 High-Redshift Supernovae When the same result was found by different teams this was enough to convince the scientific community that the cosmological constant had a small positive value. Now to your second question. Yes, I know that Hawking could be stubborn, but I don't think that's what being displayed here. Please remember that the information I've posted in this thread about Roger Penrose dates from well after that 1998/9 watershed moment. Penrose's Conformal Cyclic Cosmology theory adopted the positive cosmological constant years after it was generally accepted by the majority of scientists. Also, prior to 1998 almost everyone expected it to be zero. So, Hawking was simply following the crowd in treating it as zero in all of his papers prior to 1998. If he had maintained that it was zero, in the face of the 1998 evidence, then that would have been sheer stubbornness on his part. The final point to take into account Josh is that so far I've listed Hawking's relevant science papers from 1966 to 1984. The accusation of stubbornness can't leveled at Hawking for his work in this period because the discovery of a positive cosmological constant didn't happen until 1998. As far as I can see this puts Hawking in the clear. Why wouldn't he hold to his 1970 position on the cosmological constant's value until contradictory evidence comes to hand? Does that explain things? Thank you. Walter.
  7. Hello guys. I have news. The paper, Open Inflation, the Four Form and the Cosmological Constant, which I mentioned in my previous post is more complex than at first glance and will need some careful explanation on my part if I'm to convey it's meaning to you with clarity. That will have to wait for a little while. For now I'd like to acquaint you with my current findings, which have to do with the evolution of Stephen Hawking's thinking about the cosmological constant. From the mid 1960's through to 1984. http://www.hawking.org.uk/publications.html This link gives all of his published science papers, lectures and books, but in reverse chronological order, with his last paper first and his first paper last. So, I'll present the salient information as a timeline, in the proper chronological order. I've highlighted the dates for the sake of clarity and my explanatory notes will be preceded by a 'W'. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.14.57 Gravitational Collapse and Space-Time Singularities Roger Penrose Phys. Rev. Lett. 14, 57 – Published 18 January 1965 W. This is Penrose's seminal paper where he shows that a very massive star undergoing gravitational collapse must form a gravitational singularity. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.17.445 Singularities in Closed Universes R. P. Geroch Phys. Rev. Lett. 17, 445 – Published 22 August 1966 https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1966.0221 The occurrence of singularities in cosmology Stephen William Hawking Published:18 October 1966 W. Here Hawking reverses the time direction equations of Penrose’s 1965 paper to show that in general relativity an expanding universe must be preceded by an initial singularity. https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1966.0255 The occurrence of singularities in cosmology. II Stephen William Hawking Published:20 December 1966 https://royalsocietypublishing.org/doi/10.1098/rspa.1967.0164 The occurrence of singularities in cosmology. ɪɪɪ. Causality and singularities Stephen William Hawking Published:30 August 1967 W. The three above papers by Hawking, the one by Geroch and Penrose's paper are all incorporated into the one below. This is the paper that WLC's cosmology is based upon. The essential point to remember is this. For the H – P singularity theory to apply in our universe, the cosmological constant MUST have a negative or zero value. Any positive value negates its applicability. Which means that Craig cannot use it to ‘prove’ that the universe had a definite beginning. The Singularities of gravitational collapse and cosmology. S.W. Hawking (Cambridge U.), R. Penrose (Birkbeck Coll.). Jan 1970. 20 pp. Published in Proc.Roy.Soc.Lond. A314 (1970) 529-548, DOI: https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1970.0021 Why Is The Apparent Cosmological Constant Zero? (talk). S.W. Hawking (Cambridge U.). 1981. Published in In *Muenchen 1981, Proceedings, Unified Theories Of Elementary Particles*, 167-175 Abstract The apparent cosmological constant is measured to be zero with an accuracy greater than that for any other quantity in Physics. On the other hand one would expect a large induced cosmological constant unless the various contributions from symmetry breaking, etc., were balanced against each other to better than 1 part in 1040 It is suggested that this puzzle can be resolved by assuming that quantum state of the universe is not chosen at random but contains only states with a very large Euclidean 4-volume. In this situation the actual value of the cosmological constant is unobservable. There are solutions of the Einstein equations with a large cosmological constant which appear nearly flat on large length scales but which are highly curved and topologically complicated on very small length scales. Estimates are made of the spectrum of these topological fluctuations and of their effects on the propagation of particles. W. A decade later, even though Hawking is still supporting the idea that while the apparent cosmological constant is zero on very large (i.e., cosmic) scales, he posits the idea that it may actually be very large at Planck length scales. He speculates that some other physical phenomenon would be needed to cancel out this large value and bring it down to the zero it appears to be on cosmic scales. The Cosmological Constant Is Probably Zero. S.W. Hawking (Cambridge U.).Print-84-0116 (CAMBRIDGE). Feb 1984. 5 pp. Published in Phys.Lett. B134 (1984) 403, DOI: 10.1016/0370-2693(84)91370-4 Abstract It is suggested that the apparent cosmological constant is not necessarily zero but that zero is by far the most probable value. One requires some mechanism like a three-index antisymmetric tensor field or topological fluctuations of the metric which can give rise to an effective cosmological constant of arbitrary magnitude. The action of solutions of the euclidean field equations is most negative, and the probability is therefore highest, when this effective cosmological constant is very small. W. Three years on, Hawking suggests that the apparent cosmological constant may not be zero after all. So, he has shifted his position. He still requires some mechanism to adjust its value to keep its apparent value very small, but he doesn’t commit himself as to whether it would be a very small negative or positive value. Providing that it is a small negative value, the 1970 H – P singularity theory would still be viable. Any positive value would mean that the H - P theory doesn't apply in our universe. Disillusioned and Josh, at this stage I'd just like to ask if you have any questions about what I've written here. Please let me know. Thank you. Walter.
  8. Thanks, older. As you say, an interesting article. Cheers, Walter.
  9. I honestly did know this off the top of my head... Because Venus orbits between the Earth and the Sun, we see phases, just like we see phases of the Moon. When Venus is on the same side of the Sun as the Earth, its day side is mostly facing away from us, so we only see a crescent Venus, or maybe a quarter-phase. When Venus is in the furthest part of its orbit from us, it's on the other side of the Sun, so we see its sunlit side, a "full Venus". Venus is very reflective because it is completely covered in clouds. So a distant "full" Venus is brighter than a nearby "crescent" Venus. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Ok folks, I can officially declare that the top of TABA's head has the correct answer. (Fanfare!) Here's a helpful illustration. TABA's 'full Venus' is # 1, when it's furthest away from us and his 'crescent Venus' is when it's closest. The maximum area of illuminated surface happens at 1, not at 15. When Venus is closest to us we see most of its un-illuminated dark side. Kudos to TABA! Thank you, Walter.
  10. TABA, I must reserve judgment on your reply until you post an image of the top of your head. What I would need to see is such an image with the answer to my question written in reverse, so that you could hold a mirror up and read the words the right way round. Then I will be satisfied that you did know the answer off the top of your head. Tongue firmly in cheek, Walter. 5a6a0f26127d7ca2c00689cb.webp
  11. Hello all. Over the past couple of days we've had fine weather, here in England. This means that the planet Venus has been shining very brightly in the early evening skies. Just look towards where the sun has set and you can't miss it. Next to the Sun and the Moon, Venus is the brightest object in the sky. Now for the test. Without cheating (looking online or in a book) can you explain why Venus appears brighter when its at its furthest away from us and dimmest when its at its closest? Have fun! Walter.
  12. Hello Disillusioned and Josh. I've just found something of interest and thought I'd let you guys know, asap. As you know I've been able to show that Roger Penrose has changed his mind about Singularity theory and has embraced the discovery of a positive cosmological constant. Today I was looking through a listing of Stephen Hawking's science papers... http://www.hawking.org.uk/publications.html ...and found this. https://arxiv.org/pdf/hep-th/9803156.pdf Open Inflation, the Four Form and the Cosmological Constant. I haven't had a chance to look through it carefully yet, but a quick once over tells me that it could be very interesting indeed. This paper was first published in April 1998, just before the discovery of a positive cosmological constant was announced, but is shown in its revised, 2008 form. Anyway, if things pan out I might be able to demonstrate that both Penrose and Hawking changed their thinking about the initial singularity. This would mean that they both discarded their 1970 paper, The Singularities of Gravitational Collapse and Cosmology. https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1970.0021 If this is so, then WLC hasn't a leg to stand on. He'd be relying on a theory that has been refuted by evidence and rejected by its authors. I'll get back to this thread when I've completed a proper read-through. Thank you. Walter.
  13. Have any of you debated anyone on the fine tuning argument? I was told recently that it is the strongest rational argument for a god, but I don't understand how it's any different than a god of the gaps. Doesn't it just insert God into an unknown variable as if God is the obvious answer because we just don't know better? P.S. I hope everyone is doing well during this pandemic. --------------------------------------------------------------------------------------------------------- Hello AcrobaticDetective. Yes thanks, we're coping for now with C19. Not many cases in our area, tho' that's sure to change. We'll adapt. Since arriving at Ex-C I haven't debated with anyone (no Christians, certainly) about this topic. But I do know that there's a fundamental flaw with the way Christian apologists use it. Instead of clearly indicating the identity of the finely-tuning agent as the Christian god of the Bible, it actually levels the playing field, enabling anyone of any religious belief to claim that their particular god is responsible. Muslims, Jews, Christians, Sikhs and many others all have equally good claims because they can all employ fine-tuning arguments. Therefore fine-tuning arguments may be the strongest rational arguments for a god... but which one? Thank you. Walter.
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