r/cosmology

13K archived posts · Sep 2009 – Sep 2026

cosmology

r/cosmology

**/r/cosmology** - a community for questions, discussions, and articles about cosmology.

Created Aug 29, 2009

103KMembers (last snapshot)

13KArchived posts

Welcome to r/cosmology, the subreddit for questions, discussions, and articles about cosmology. Cosmology is the study of the early universe and the universe on the largest scales. Things galactic size and smaller generally belong elsewhere.

Reddiquette is enforced. Disrespectful and irrelevant comments will be removed.

If you claim an alternative model of the universe and ignore known data or have no equations or calculations, then your post will be removed. It isn't the responsibility of experts to review your "what if the universe was...?" idea. Homework questions will be removed. Repeated infractions will result in a ban.

Rude behavior is not tolerated.

If you do not see your submission in the new queue, please message the moderators as it may have been sent to the spam filter.

Find today's cosmology preprints on arXiv:astro-ph.CO.

Check out some other great subreddits:

Common questions:

The universe is not expanding faster than light. Expansion has units of inverse time.
The evidence for dark matter is overwhelming and reaches far beyond rotation curves.

Anything not related to cosmology will be removed.

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