r/AskPhysics (about 1.6M members, directory rank #669) is for physics questions, with rules against cheating and AI fluff. Physics community discussion and broader science Q&A live elsewhere.
See also physics vs askphysics on SubMouse.
How to choose
Stay on AskPhysics for physics questions and problem help. Use Physics for physics community discussion, askscience for moderated science answers across fields, and science for science news and papers.
Starting point: r/AskPhysics
r/AskPhysics
— Ask Physics
- Members: 1.6M
- Directory rank: #669
- 7-day growth: +966
Curated alternatives
Physics
- Members: 3.3M
- Directory rank: #320
When to choose it: Physics community discussion rather than a question helpdesk.
Why it is here: Paired on physics vs askphysics; listed as related (about 3.3M members, rank #320).
How it differs from r/AskPhysics: Community/discussion hub versus AskPhysics Q&A format.
AskScience: Got Questions? Get Answers.
- Members: 26.4M
- Directory rank: #20
When to choose it: Moderated science answers across disciplines, not only physics.
Why it is here: Listed among Ask* related neighbourhood rooms (about 26.4M members, rank #20).
How it differs from r/AskPhysics: Multi-field science Q&A versus physics-only AskPhysics.
Reddit Science
- Members: 34.6M
- Directory rank: #11
When to choose it: Science news and research discussion.
Why it is here: Broader science hub (about 34.6M members, rank #11).
How it differs from r/AskPhysics: News/research focus versus physics question threads.
Related comparisons
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Members and public descriptions come from SubMouse's safe-for-work directory (as of 2026-11-02 UTC); 7-day growth measured from 2026-10-26. Posts/day and culture claims appear only when we have them — missing fields stay n/a. Directory rank is listing order. Communities outside the published Top 100 open in the info tool instead of a full community page. Guide updated 2026-11-07.