DAVID: Cosmology: milky way size is enormous (Introduction)

by David Turell , Thursday, June 27, 2019, 18:31 (1977 days ago) @ dhw

DAVID: The entire universe is viewed as fine tuned for life everywhere.
[...]

DAVID: If the universal laws were different, that might be no matter at all. Our galaxy formed within the special parameters that made the universe, and seems to be a very special galaxy.

dhw: Yes indeed. Some people say it is fine tuned for life, unlike other galaxies. That is why it is absurd to claim that the whole universe is fine-tuned for life.

DAVID: There are many types of galaxies all appearing under the same rules. But all galaxies are under the same rules and diverse as they are individually. You are correct in that some special additional fine tuning applies to our galaxy and our Earth, all allowed under the general fine tuned rules of formation of our universe.

dhw: In other words, all galaxies are galaxies, but they are all different. And we cannot say all galaxies (i.e. the whole universe) are fine tuned for life. We can only say that of our own galaxy.

DAVID: Our galaxy seems very special, but the current scientific opinion among cosmologists is that our universe is at its basis fine-tuned for life to appear somewhere.

dhw: If all galaxies among an infinity of galaxies are different, a cosmologist could argue that eventually one of them is sure to come up with the right tuning for life. Perhaps that is why so many scientists do not see any need for a designer.

You have circled our discussion back to the anthropic principle.