Originally Posted by aaronson
But if you listen a little further in the diavlog, one of the main things I was trying to do was to express skepticism about cosmological speculations that are inherently beyond the possibility of observation (for example, because they refer to parts of the universe that are receding away from us faster than the speed of light). What makes things tricky is that some of those speculations might not be beyond the possibility of observation: they might yield predictions (for example, about the anisotropies in the cosmic background radiation) that we can actually check. But even just sorting out what does or doesn't count as a "prediction" is hard here, and that's part of what Anthony and I were talking about. (But maybe just caring enough about potentially-unfalsifiable speculations to want to respond to them already puts us beyond the pale? ;-) )
I'm still catching up with diavlogs. I watched this one and found it fascinating although beyond my ability to understand all the detail due to my lack of knowledge. But in terms of the generalities, and following the spirit of discussion that other commenters pursued, I find Scott's statement above truly central to the discussion. I think that much of the debate about the limits of science and the compatibility between science and religion has to do with the manner in which we want to handle speculation. Let's define speculation as:
b. A conclusion, opinion, or theory reached by conjecture.
c. Reasoning based on inconclusive evidence; conjecture or supposition.
In this case, we should either qualify speculation according to the relative scientific strength of the conjecture, or we are at risk of lumping informed speculation and crazy fantasy together.
Ignoring completely what is beyond our capacity to observe or falsify would jeopardize advancement and discovery, as Jeff points out in his comment
On the other hand, going overboard with unfounded speculation will put us in a world of fantasy and chaos, since any arbitrary explanation, pseudo-scientific, religious, or magical would be equally possible.
We keep seeing the arguments between people holding each extreme of this continuum of speculation. Again, qualifying speculation according to how closely if follows scientific knowledge, would be at least a start to begin to sort out possibilities.
Beyond that, one's ability to tolerate uncertainty and stick to skepticism seems to be the most promising way of making progress in those science fields that continue to open up puzzling possibilities. It is also helpful to remind ourselves that much of the perplexity we encounter in these topics has to do with our own cognitive make up and limitations. We seem to be so tightly bound to the idea of linear temporal causality, the idea of a maker, that it's difficult to detach and entertain concepts that lie outside those constructs.
Thank you to both participants for the discussion and to my fellow commenters for their enriching posts.