Posts: 30974
Threads: 204
Joined: July 19, 2011
Reputation:
141
RE: Thoughts on the scale of the universe?
September 20, 2012 at 11:36 pm
There really needs to be a third option on the poll - "Finite, but unbounded".
Posts: 19789
Threads: 57
Joined: September 24, 2010
Reputation:
85
RE: Thoughts on the scale of the universe?
September 20, 2012 at 11:47 pm
Perhaps also forth options that offer the most brain twisting possibility:
Infinite but profoundly nonhomogenous
Posts: 29647
Threads: 116
Joined: February 22, 2011
Reputation:
159
RE: Thoughts on the scale of the universe?
September 21, 2012 at 8:21 am
(This post was last modified: September 21, 2012 at 8:42 am by Angrboda.)
I'm skipping ahead a bit, not having read the thread. What I've read is that the universe is finite but unbounded. Generally speaking, when you're dealing with either the universe as a whole, or the transfinite, you need to tread very carefully as everyday intuitions are often unhelpful in those realms. (For example, one scenario is that, if you skip ahead in time many, many years, the universe would look — to us — as if our little realm was all there is, and that there's nothingness extending in all directions. Evolution has resulted in brains that are good at, "throw rock, get food," more than, "if it's turtles all the way down, then what?" [As an aside, this probably has to do with an interaction between heuristics' instrumental utility being dependent on domain specificity, and thus when you get outside the domains under which the heuristics were selectively optimized, their instrumental utility degrades in ugly but predictable ways; just a thought.])
Failing actually reading the literature (ick), that's about all I have to say.
Oh, actually, I do have one thing more. I have had the question recently of wondering if there isn't, for lack of a better way of putting it, an analogous model of physics similar to the hypothetical universal grammar, such that we conceive of the behavior of macroscopic objects along specific types of models. The alternative is that our behaviors and heuristics for such may be physical model agnostic (e.g. the way the brain tracks and responds to a baseball in flight in order to successfully catch a fly ball does not really require a model at all, or at least not an obviously specific one.) The main impetus of this question for me is less about that model and its specifics but rather about the philosophical questions raised by Hume's analysis of causality and of the inference of causality. It seems to me, intuitively, that our notions of cause and effect might be a part of a naive physics, as in, when we imagine a billiard ball hitting another billiard ball, we in some sense intuitively imagine a physical interaction of one ball reaching out and touching the other ball and physically making something physical happen. My notion is that cause and effect is an abstracted notion of the naive laws of motion with respect to macroscopic objects extending into the realm of what is a cause and what is an effect, that the relation is one based on our physical model. (e.g. note that "proximity" seems especially relevant in determining likely involvement as cause and effect. Why? Why is it difficult to imagine physically separated objects as having causal interaction? [I think I've transited over into rambling, so I'll stop now.].)