🧵 Astronomy Questions
Anonymous at Tue, 18 Feb 2025 14:26:17 UTC No. 16590207
Figured I'd ask here since most of the board consists of /stem/ majors. I'm doing the brainstorming for a fictional universe that is meant to be hard sci-fi in most respects. The setting is meant to be a galaxy resembling the Sombrero galaxy, and some things stumped me.
>1 universe age
Does it matter for galaxy formation how old the universe is past a certain #? Since this is a fictional universe, and the question of where this galaxy is relative to others will not be answered anytime soon, it shouldn't matter if the universe is 5bln years old or 10.
>galaxy star composition
This depends on the last question a bit. I want this fictional galaxy to be rife with younger stars that host life, but some stars also only come into being after long periods of time. Does the universe/galaxy need to be older/younger to ensure desirable stars are commonplace?
>galaxy size
I'm not worried about a large or small galaxy, since FTL is a needed trope to ensure the plot doesn't stagnate the moment people try and leave a star system. The issue is.....how big is a galaxy in width typically? Assuming light-years are used, not sure what the numbers end up being. I'm also not sure on the total number of stars in this galaxy, and if that also depends on galaxy age.
Anonymous at Tue, 18 Feb 2025 14:53:18 UTC No. 16590235
>>16590207
Didn't you get blown out earlier?
Anonymous at Tue, 18 Feb 2025 15:36:57 UTC No. 16590302
>>16590235
First time posting here in 11 years, last time was 2016.
Anonymous at Tue, 18 Feb 2025 15:37:58 UTC No. 16590305
>>16590302
*woops, 9
Anonymous at Tue, 18 Feb 2025 22:04:17 UTC No. 16590777
>>16590207
bump
Anonymous at Thu, 20 Feb 2025 19:36:18 UTC No. 16593600
>>16590207
Many stars we see today are recycled from the matter from old stars, so in a galaxy new stars will form for billions of years.
Seems the Milky way is fairly ordinary in size, so that is about 100,000 lightyears across. Ours also have at least two companion dwarf galaxies so you can give these different star age profiles if you wish while still remain plausible.
Anonymous at Thu, 20 Feb 2025 19:55:21 UTC No. 16593633
>>16590207
>the plot doesn't stagnate the moment people try and leave a star system
it does with people. it doesn't with not people but something else.
it still does, because nobody will allow anything sentient leave here, without FTL.