I think he’s attacking a now-disproved hypothesis that the arms spiral galaxies started out as straight radial disturbances that then were “wound up” by the galaxy’s rotation. This hypothesis was rejected for exactly the reason given here: in billions of years the arms would wind up so much that they smeared out and disappeared.
The exact cause of spiral arm structure in galaxies is not well understood, but they are now thought to be density waves that propogate outward from the center of the galaxy.
This is a perfect example of YECs attacking and quite succesfully demolishing theories and hypotheses that were disproved by mainstream science decades ago. Either they’re too dumb to keep up, or they are dishonest enough to deliberately misrepresent modern science. (gasp Say it ain’t so!)
The galactic rotation period is more like a few hundred million years, by the way.
I apologize for the three posts in a row. I should have just read the whole thread carefully and composed one post.
Making up silly names for your opponents is a time-honored tactic among those who don’t have any intellectual capital to back up their argument.
But “Big Bangers” would be a great name for a softball team, wouldn’t it?
Probably he was talking about dark matter, and dark energy, not antimatter. This is something of a problem in modern astrophysics, in that we do not know exactly what dark matter or dark energy actually are. However, both of have multiple, independent lines of observational and theoretical evidence in support of them. Among scientists you can’t get away with just making stuff up. If you propose an idea that might explain an observation, then that idea is going to be tested. Either it will be disproved, or there will be other observations in its favor. The latter is the case for the dark stuff so far. Ultimately what you want is some kind of an explanation as to what it is, why it’s there, and why it behaves like it does, but we aren’t there yet.
And actually, I wouldn’t bet the farm that in 10 or 20 years, dark matter and dark energy won’t be replaced by some more elegant and fundamental theory that explains what we are observing.
This is one of the reasons why it’s just so cussedly hard to argue against Creationists. Neither the Big Bang no evolutionary can–or claim to!–explain everything. Obviously when your explanation for eveything is “Goddidit” then you don’t have to do any actual work trying to explain the Universe around you! You don’t have to make guesses and you don’t get proved wrong. You can just hang out at the sidelines and take potshots at the people who are doing the real work.
Nope, SlowMindThinking is correct that Newton did at least consider such infinite cosmological models, though it’s open to argument how seriously he took them. They were the subject of a famous exchange of letters between him and Richard Bentley in 1692. The latter was preparing his Boyle Lectures, which were to be on arguments against atheism, and he was interested in using Newton’s recently published ideas in natural philosophy as a source of new refutations.
Only one of Bentley’s letters survives, but Newton’s half of the correspondence was published after their deaths - the 1st, 2nd, and [url=“http://vms.cc.wmich.edu/~mcgrew/Bent4.htm”]4th of the letters from him. Bentley was the one wondering whether either finite or infinite even distributions of mass could explain the observed universe, while Newton was arguing that they couldn’t, at least without the intervention of a Creator. From the first letter:
Inferring Newton’s own views about the likely make-up of the universe from the letters and Bentley’s final published text of the lectures isn’t entirely straightforward and different interpretations have been advanced over the years. He does say explicitly at the start of the third letter that:
Note that Newton certainly believed that space was infinite and that there were a very large number of sun-like stars out there. And that whatever the arrangement and its history, God was necessarily intervening in creating and upholding it.
Not in England in the 1690s. Nobody could yet prove that the stars were very far away, but that was already the consensus view amongst intellectuals at the time.
[Incidentally, I’ll stand by my earlier remark that the model considered by Bentley and Newton, with or without God doing the legerdemain to keep everything apart, isn’t usefully regarded as a steady-state model. It was a static one.]
Thanks for the cite. I don’t remember reading about Newton’s speculations in any of the history cosmology books I’ve read - shame on you Tim Ferris.
It seems that Newton hadn’t noticed the black space paradox. This is, for those unfamiliar with it, the problem of why space in an infinite universe is mostly black. If the universe were infinite, every place you’d look would be in the direct line of sight of an infinite number of stars (though far away) causing the sky to glow at night. It is not a problem for a finite universe with a beginning.
What with Newton being the greatest genius humanity has ever known, and all, I probably should have figured. But then he turns around and makes an ID argument out of it. Sheesh.
And I guess I was a bit too literal in my reading of “fixed” (or “fixt!”) stars. Good to know.
Thank you bonzer. You, and Voyager, sound like the kind who would really enjoy reading Subramanyan Chandrasekhar’s translation of Newton’s Principia. I don’t know that history of science types were all that thrilled with it, but if you want to see Newton’s proofs as explained by one of the more brilliant men of the 20th century, you can’t do better. I loved a comment by Chandrasekhar when the book came out “I did my proof and compared it to Newton’s. In every case, his was better.” This from the man who derived Chandrasekhar’s Limit on a cruise across the Atlantic!
I just need to clarify one thing. I wouldn’t call what Newton did a version of the steady state model, I’m just not sure when the steady state model came into being. Clearly something similar was assumed by Einstein, who was pretty good at ignoring the prevailing paradigm. “Big Bangers” didn’t exist until Hoyle’s disparaging “Big Bang” remark. I will state that most (male?) physicists would proudly where the title of “Big Banger”.
And Voyager, I’m pretty sure I’ve read that Newton did know of Obler’s Paradox. Perhaps bonzer has some actual cites.
Maybe. William Stukeley does report a conversation in his anecdotal Memoirs of Sir Isaac Newton’s Life (1752) about how if an infinite universe were filled with stars it would shine like the Milky Way. If one is prepared to trust Stukeley’s memories, then Newton was indeed aware of the essentials of the issue - and, from Stukeley’s account, used this to conclude that there was only a finite number of stars. In his history of Olbers’s Paradox, Darkness at Night (Harvard, 1987), Ed Harrison dismisses Stukeley as unreliable and suggests he’s confusing his recollections of Newton c.1720 with what had become fashionable by 1752. I’m usually inclined to cut Stukeley more slack than Harrison does here, but it’s a plausible objection.
Harrison also reprints two short papers by Halley from 1721 that consider the issue of light in a universe with an infinite number of stars. These were read before the Royal Society while Newton was President and regularly attending meetings, so he probably heard or read the papers. But Halley screwed up his maths and so reached a meaningless conclusion; he ought to have stumbled upon Olbers’s Paradox here, but missed it. Harrison doesn’t make the point, but, since the mistake is in the printed versions that appeared in the Philosophical Transactions, it might be possible to convincingly claim that Newton heard the argument when the first papers were read and didn’t realise the mistake. I suppose this turns on whether Newton was in the chair for those two meetings, but that ought to be establishable from the minutes in the Society’s Journal Book.
So Newton was probably - and possibly certainly - exposed to Halley’s screwy discussion of what was to become Olber’s Paradox. And he may - or may not - have had a clearer discussion of the matter with Stukeley.
This entirely depends on how you care to define what counts as a “steady-state model” and there are at least two plausibly adoptable criteria. In their 1948 paper, Bondi and Gold introduced what Gold had dubbed the Perfect Cosmological Principle: the universe is both homogeneous and unchanging. Naturally, their model satisfied this. One could decide to define a “steady-state model” as any cosmological model satisfying this principle. If one does and is also prepared to apply it retrospectively to earlier models, then proposals like Einstein’s static universe would also be a steady-state one.
On the other hand, you can argue that this doesn’t capture what was novel about what Hoyle, Bondi and Gold were suggesting in 1948. Hoyle was later to put it this way:
The new 1948 models were not static, but they were unchanging in this sense. Aside from the relatively obscure examples I mentioned back up the thread, this was new. And Einstein’s model wasn’t a steady-state one in this sense.
The other aspect of the 1948 proposals that was striking was that they included continuous creation. But this was seen as a consequence of adopting a notion of “unchanging”, coupled with the Hubble expansion. Again, this was a feature of the obscure partial-anticipations of the 1948 models, but not static universes like Einstein’s.
Anyway, regardless of how one might classify past models, in practice “steady-state” is most usefully used just to refer to the Hoyle, Bondi and Gold models from 1948 and the tradition that derived from them. I’ve recommended it on the Dope before, but I’ll happily do it again: Helge Kragh’s Cosmology and Controversy (Princeton, 1996) is an excellent history of how the Steady State Theory fitted into 20th century cosmology.
I’ve actually been vaguely meaning to read the Chandrasekhar edition for some time, but haven’t got round to it. It’s bound to be intrinsically fascinating just to see what he came up with.
But then he turns around and makes an ID argument out of it. Sheesh.