tytalus wrote:RichieDickins wrote:Oh I'm all about credible evidence. I was laughing because, for many people on this forum, their definition of the term extends no further than physical considerations (empiricism and naturalism being very common around here). As I see it though, evidence for some claim
h is something like this: any proposition
d which, if true, makes the probability
P of h higher than it would otherwise be . That is,
d is "credible evidence" IFF
P(h/d) > P(h).
I don't see any reason to outright dismiss such a construction, but I could understand not placing much value on it, or placing greater value on something more substantial than probability and statistics. Do you find such probability calculations satisfying? Making up a percentage for the sake of argument, does a 51% chance of the xian god existing satisfy your desire for evidence before worshipping the supposed entity? Can you understand why someone used to finding evidential support in reality for things existing might not be satisfied by a probability calculation alone?
Yeah I like probability calculations, Bayes Theorem is exciting. And yeah, I side with the proposition that seems most probably true. But no, I don't have any idea what "in reality" means, or why one wouldn't consider such an inductive argument to be credible evidence
RichieDickins wrote:Hmm you might be right about the helpfulness of philosophy
. Look at it this way though, either the universe began to exist or it didn't. If it did, then there has to be some time t0 such that there was no prior time tn when the universe existed. Now, I think you would agree that physical laws are only descriptions of how things in the universe behave, not abstract entities which exist independently. If so, that means no laws until the universe began to exist. If you think the universe has always existed, then all that's beside the point (but I would be curious to hear what model you find most persuasive, if you don't mind).
I don't hold a position on whether or not our universe has always existed; I don't see much reason to pick one over the other right now. That said, it doesn't seem as if the 'laws of the universe' are as easy to pin down as your description makes it seem. Again, the
wiki article proves useful in pointing out some alternate possibilities.
I think the Borde Guth Vilenkin theorem gives good reason to think that the universe didn't always exist.
wikipedia wrote:Top-down cosmology
Stephen Hawking, along with Thomas Hertog of CERN, proposed that the universe's initial conditions consisted of a superposition of many possible initial conditions, only a small fraction of which contributed to the conditions we see today.[22] According to their theory, it is inevitable that we find our universe's "fine-tuned" physical constants, as the current universe "selects" only those past histories that led to the present conditions. In this way, top-down cosmology provides an anthropic explanation for why we find ourselves in a universe that allows matter and life, without invoking the current existence of a multiverse.
I've read that the laws 'break down' at the Planck epoch, though that may be too much of a layman's term, I don't know. But it may also be too simplistic to claim that they suddenly popped in out of nowhere.
I don't think I'm familiar with that theory of Hawking. I'll have to look into it, as I have no idea what it means to say that the universe selects conditions.
RichieDickins wrote:True, I suppose in the case of most questions, possibility doesn't get you very far. It's significant here however, because if different values for the initial conditions were
not possible, then it is not at all surprising that the universe has the constants and quantities it does (for it couldn't have been otherwise). But if it
is possible, then just the opposite is the case.
Again, we don't know if they can vary, or if they can, by how much. The proposed infinite variation is, again, merely what is logically possible.
Any result would be 'surprising.' Just like the particular series of cards dealt by a properly shuffled deck.
True, any given hand is equally improbable. So, should we not be suspicious when someone keeps getting royal flush?
RichieDickins wrote:You want a demonstration of reality? I'd have to know what you mean by reality - are you a materialist?
After
checking up on it a bit, I'm inclined to think so, yes. I could be wrong, but I wonder how it could be demonstrated. Are you planning a 'demonstration of reality' that cannot be detected by scientific investigation? Of what use would that be?
At this point, it seems clear that a series of semantic games is about to ensue. It's sad to consider how the mighty have fallen, here. It used to be so easy for the believer to point to something in reality and say 'look, there's god, that was god's doing'. Fire, lightning, earthquakes, plagues...look, there he is! And we still have these belief systems predicated on the idea. But the idea has gone extinct with the advance of science and real understanding; instead, we get dictionary wars and arguments over whose worldview e-peen is the biggest. Accusations of closed-mindedness seem nigh inevitable.
I thought when you were asking me to give a demonstration of reality that you meant a demonstration that was real/credible/reliable, as opposed to what you see as "endless philosophizing;" but in order to do that, ironically, I first had to know what sort of ontology you adhere to - you say materialism, ok thats helpful. I think there are some good arguments against materialism, but I that's another topic I suppose.
I don't find that scientific progress has at all undermined the belief in God.
Tytalus wrote:Oh, I was definitely playing a game there, just to demonstrate the absurdity of yours.
I just don't see the utility of a
baseless claim that life-supporting possibilities are extremely narrow. Some evidential support would be great.
See: Barrow and Tipler "The Anthropic Cosmological Principle"
Paul Davies, "The Goldilocks enigma: why is the universe just right for life?"
John Leslie "The Prerequisites of Life in Our Universe"
Martin Reese "Just Six Numbers"
Ernan McMullin "Anthropic Explanatino in Cosmology"
Roger Penrose, "The Road to Reality"
As for the 25% figure, that's one of the citations
here. Since it is apparently difficult to make good predictions on the possibility of a universe supporting life in great detail, scientists like Victor Stenger and Fred Adams have done math based on the possibility of star formation, which seems a useful prerequisite. Here is where the 25% figure pops up.
wikipedia wrote:Computer simulations suggest that not all of the purportedly "fine-tuned" parameters may be as fine-tuned as has been claimed. Victor Stenger has simulated different universes in which four fundamental parameters are varied (electromagnetic interaction, strong nuclear interaction, electron mass, and proton mass; tuning of other parameters such as the cosmological constant was not considered). He found that long-lived stars could exist over a wide parameter range, and concluded that "... a wide variation of constants of physics leads to universes that are long-lived enough for life to evolve, although human life need not exist in such universes".[7] Fred Adams has done a similar study, investigating the structure of stars in universes with different values of the gravitational constant G, the fine-structure constant α, and a nuclear reaction rate parameter C. His study suggests that roughly 25% of this parameter space allows stars to exist, but not necessarily to form. His analysis also does not take into account variations of other fundamental constants or considerations of habitability.[8]
Stenger's calculations on stellar lifetimes using different constants indicated over half the universes could support star lasting at least a billion years. What I found interesting about his article (a pdf from cite note 7) was that he didn't dispute that life as we know it wouldn't exist; it could be something radically different. Perhaps humanocentrism is part of the fine-tuning mindset that isn't spoken of.
Oh I see. Yes that's interesting, chances aren't too bad given just those constants I suppose. But, I don't see how there could be anything near half the universes supporting star formation given all the relevant variables - all of those that don't even contain the requisite materials, for instance, certainly couldn't.
RichieDickins wrote:If we found another universe with different values, how would that show it to be physically possible that our own universe could have had different values than it does? Possible based on what, if nomological possibility is a factor of antecedent states of the universe and its physical laws? And why wouldn't you just say, as you have with regard to the actual universe, that it may be physically necessary that this second universe's constants and quantities are what they are, too?
Not necessarily variance in our universe in particular; in general. An example of another, different universe would show that these constants can vary at all.
Unless there are broader physical laws which govern each of the two universes (or however many there may be), then I think we would have to call variance metaphysically possible, but not necessarily physically
by 
Apart from anything else, it leaves the term Christianity undefined.
