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prase comments on Philosophical apologetics book suggests replacing Bayes theorem with "Inference to the Best Explanation" (IBE) - Less Wrong
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That seems non-obvious to me. It's highly problematic, sure -- but not "key". "Key" is "adequate range of data". That cannot be an objective measure. It occurs to me that Bayes' theorem has no such problem; it simply takes additional input and revises its conclusions as they come -- it makes no presumption of its conclusions necessarily being representative of absolute truth.
I also, personally, take objection to:
I find it is highly unlikely that "a world-creator" exists. For two reasons. 1) Our universe necessarily possesses an infinite history (Big Bang + Special Relativity says this.) 2) Any ruleset which allows for spontaneous manifestation of an agentless system is by definition less unlikely than the rulesets which allow for the spontaneous manifestation of an agent that can itself manifest rulesets. (The latter being a subset of the former, and possessed of greater 'complexity' -- an ugly term but there just isn't a better one I am familiar with; in this case I use it to mean "more pieces that could go wrong if not assembled 'precisely so'.)
I can't say, as a person who is still neutral on this whole "Bayesian theory" thing (i.e.; I feel no special attachment to the idea and can't say I entirely agree with the notion that our universe in no ways truly behaves probabilistically) -- I can't say that this topic as related is at all convincing.
Can you clarify? Big Bang is usually put a little more than 13 billion years ago; that's a lot of time, but not infinity.
Here's a thought experiment for you: Imagine that you've decided to take a short walk to the black hole at the corner 7-11 / Circle-K / 'Kwik-E-Mart'. How long will it take you to reach the event horizon? (The answer, of course, is that you never will.)
As you approach the event horizon of a quantum singularity, time is distorted until it reaches an infinitessimal rate of progression. The Bing Bang states that the entire universe inflated from a single point; a singularity. The same rules, thusly govern -- in reverse; the first instants of the universe took an infinitely long period of time to progress.
It helps if you think of this as a two-dimensional graph, with the history of the universe as a line. As we approach the origin mark, the graph of history curves; the "absolute zero instant" of the Universe is, thusly, shown to be an asymptotic limit; a point that can only ever be approached but never, ever reached.
If you decide to really walk inside, you could be well behind the horizon before you remember to check your watch and hit the singularity not long afterwards.
There are different times in general relativistic problems. There is the coordinate time, which is what one usually plots on the vertical axis of a graph. This is (with usual choice of coordinates) infinite when any object reaches the horizon, but it also lacks immediate physical meaning, since GR is invariant with respect to (almost) arbitrary coordinate changes. Then there may be times measured by individual observers. A static observer looking at an object falling into a black hole will never see the object cross the horizon, apparently it takes infinite time to reach it. But the proper time of a falling observer (the time measured by the falling observer's clocks) is finite and nothing special happens at the horizon.
Correct, but since the entire universe was at that singularity, the distortion of time is relevant.
How exactly? It is the physical proper time since the Big Bang which is 13,7 billion years, isn't it?
Yes and no. Since the first second took an infinitely long period of time to occur.
What does that mean? Do you say that proper time measured along geodesics was infinite between the Big Bang and the moment denoted as "first second" by the coordinate time, or that the coordinate time difference between those events is infinite while the proper time is one second?
The latter statement conforms to my understanding of the topic.
I agree. But now, how does that justify talking about infinite history? Coordinate time has no physical meaning, it's an arbitrary artifact of our description and it's possible to choose the coordinates in such a way to have the time difference finite.
It is currently unknown how to apply special relativity SR and general relativity GR to quantum systems and it appears likely that they break down at this level. Thus applying us SR or GR on black holes or the very beginning of the universe is unlikely to result in perfectly accurate description of how the universe works.