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I personally find the idea of finiteness much harder to accept. Infinity makes sense to me. It just means there’s no limit to stuff. Why should reality have a

I personally find the idea of finiteness much harder to accept. Infinity makes sense to me. It just means there’s no limit to stuff. Why should reality have a limit? A finite reality is just plain weird because it implies there’s a single actual number describing how much stuff there is. The universe contains X godzillion kilograms, or is Y billion light years across. Where did those numbers come from? What determined them? Why isn’t there more stuff, or less?

klodolph 9y ago
This reminds me of the kind of magical thinking that people like Aristotle used. Why should the universe be easy or hard for you to accept? Why is it important that these numbers "come from somewhere" or be determined by something? Why doesn't the same thing apply to e.g. energy density? Fine structure constant? Gravitational constant? Why isn't the gravitational constant higher or lower?
- mikeash 9y ago
  Where did I say the universe should be easy for me to accept? You seem to have inferred a “therefore that’s the way things really are” ending to my comment that I did not write nor intend to imply.
Tyr42 9y ago
I mean, it makes some sense if there was a big bang X years ago, that everything ends up withing X lightyears of each other. I find it easy enough to think of there being a beginning, since we know that stars age, and use up energy, so they can't have been running forever. Since we think the big bang was 13.7 billion years ago, we can put Y at about 2*13.7 billion light years across as a first guess. Though there's something funkey with the spacetime stretching or whatever. So maybe more.
- resource0x 9y ago
  Stars cannot run forever, they explode eventually, and other stars can form from the debris: https://www.quora.com/What-is-a-third-generation-star?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa https://www.quora.com/What-is-a-third-generation-star?utm_me... For the Universe having certain age - I don't understand it, b/c whatever is 13 billion years for one, might be 1 sec for another, due to relativistic time dilation. I think of this number as a kind of metaphor :)
  - neolefty 9y ago
    But eventually a region runs out of fusable (fuseable?) matter (Hydrogen / free protons). https://en.wikipedia.org/wiki/Elliptical_galaxy https://en.wikipedia.org/wiki/Elliptical_galaxy
- michaelcampbell 9y ago
  Lots more. https://en.wikipedia.org/wiki/Observable_universe#Size https://en.wikipedia.org/wiki/Observable_universe#Size Of particular note to your post: https://en.wikipedia.org/wiki/Observable_universe#Misconceptions_on_its_size https://en.wikipedia.org/wiki/Observable_universe#Misconcept... (#1)
  - Tyr42 9y ago
    Yeah, but in my defense, 46 billion is the same order of magnitude as 13 billion. And a lot easier to understand why it'd be around that magnitude without the stretching of spacetime.

klodolph 9y ago

This reminds me of the kind of magical thinking that people like Aristotle used. Why should the universe be easy or hard for you to accept? Why is it important that these numbers "come from somewhere" or be determined by something? Why doesn't the same thing apply to e.g. energy density? Fine structure constant? Gravitational constant? Why isn't the gravitational constant higher or lower?

mikeash 9y ago
Where did I say the universe should be easy for me to accept? You seem to have inferred a “therefore that’s the way things really are” ending to my comment that I did not write nor intend to imply.

Tyr42 9y ago

I mean, it makes some sense if there was a big bang X years ago, that everything ends up withing X lightyears of each other. I find it easy enough to think of there being a beginning, since we know that stars age, and use up energy, so they can't have been running forever. Since we think the big bang was 13.7 billion years ago, we can put Y at about 2*13.7 billion light years across as a first guess. Though there's something funkey with the spacetime stretching or whatever. So maybe more.

resource0x 9y ago
Stars cannot run forever, they explode eventually, and other stars can form from the debris: https://www.quora.com/What-is-a-third-generation-star?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa https://www.quora.com/What-is-a-third-generation-star?utm_me... For the Universe having certain age - I don't understand it, b/c whatever is 13 billion years for one, might be 1 sec for another, due to relativistic time dilation. I think of this number as a kind of metaphor :)
- neolefty 9y ago
  But eventually a region runs out of fusable (fuseable?) matter (Hydrogen / free protons). https://en.wikipedia.org/wiki/Elliptical_galaxy https://en.wikipedia.org/wiki/Elliptical_galaxy
michaelcampbell 9y ago
Lots more. https://en.wikipedia.org/wiki/Observable_universe#Size https://en.wikipedia.org/wiki/Observable_universe#Size Of particular note to your post: https://en.wikipedia.org/wiki/Observable_universe#Misconceptions_on_its_size https://en.wikipedia.org/wiki/Observable_universe#Misconcept... (#1)
- Tyr42 9y ago
  Yeah, but in my defense, 46 billion is the same order of magnitude as 13 billion. And a lot easier to understand why it'd be around that magnitude without the stretching of spacetime.