Communities related to r/Physics, with what each one is for and how it differs. Member figures come from SubMouse's safe-for-work directory.
r/Physics (about 3.3M members, directory rank #320) is for physicists and physics students. Straightforward homework-style questions, multi-field science news and mathematics each have clearer homes when the framing is not physics study or research.
Stay on Physics for physics discussion among students and researchers. Use AskPhysics for question-driven physics help, science for broader research news, and math for mathematics rather than physics.
r/Physics — Physics
For physicists and physics students. See the rules before posting, and the subreddit wiki for common questions. Basic homework questions are not allowed.
Ask Physics
When to choose it: Physics questions looking for answers.
Why it is here: Listed as related to Physics (about 1.6M members, rank #669).
How it differs from r/Physics: Question-driven help versus Physics’ discussion remit.
Reddit Science
When to choose it: Scientific research across disciplines.
Why it is here: Public description: This community is a place to share and discuss new scientific research. Read about the latest advances in astronomy, biology, medicine, physics, social science, and more. Find and (about 34.6M members, rank #11). Listed with Physics in science neighbourhoods.
How it differs from r/Physics: Multi-field news versus physics-specific community.
math
When to choose it: Mathematics discussion rather than physics.
Why it is here: Public description: This subreddit is for discussion of mathematics. All posts and comments should be directly related to mathematics, including topics related to the practice, profession and communit (about 4M members, rank #239).
How it differs from r/Physics: Math field versus physics field.
Use the related subreddits finder for r/Physics: Find related to r/Physics.
Members and public descriptions come from SubMouse's safe-for-work directory (as of 2026-11-09 UTC); 7-day growth measured from 2026-11-02. Directory rank is listing order. Guide updated 2026-11-07.