Astronomical distances, light speed, and uncertainty

[MyshkinCommaPrince]

6. So we can be reasonably certain

We can make pretty good predictions, then, and be sure we've gotten it pretty much right. There shouldn't be any tremendously huge surprises, and most things should be more or less where the math would tell us. Umm. Right?

I end up with questions. Maybe I need to drink less coffee. Heh. How many stars we see are still there? One would assume many of them would have burned out by the time we see the light they sent our way. How sure can we be about the effects of objects colliding or interacting? Two galaxies crunching into one another, say, would be... complicated. We couldn't begin to project a lot of the specific outcomes. Or interactions between objects we can see with matter we can't see. Wouldn't that complicate things? I end up thinking our predictions would be less accurate as we deal with more distant objects. Overall, we should expect that the general state of one area should be more or less like the others, but some of the specifics would be hard to predict.

Umm. I need to listen to that podcast. I'm just repeating variations on my original puzzlement. Also, I think this post was meant as a reply up-thread, but I goofed and responded to the main thread. Oopsie.