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r/AskPhysics

1.6M members. The best post we have captured here reached 260 upvotes, which works out to 0 per 1,000 members.

0peak upvotes per 1,000 members
1.6Mmembers
260best post
255most comments
300posts we track

Open r/AskPhysics on Reddit β†—

What actually lands here

The mix of post types among everything we have captured. Posting a link where almost nothing but images lands is wasted effort, and this is the fastest way to see it.

61% 31% 8%
Question 61% Text 31% Link 8%

What the ceiling looks like

The biggest posts we have captured here. Links go to the original on Reddit.

Why is water incompressible?

↑ 260 πŸ’¬ 168 question 2026

How can supermassive black holes on the scale of TON 618 even exist?

↑ 251 πŸ’¬ 78 question 2026

Why doesn’t the sun have an iron core like the planets?

↑ 245 πŸ’¬ 255 question 2026

If molecular motion is related to temperature, is there a maximum temperature because nothing with mass can move at the speed of light

↑ 163 πŸ’¬ 67 text 2026

Why is water so amazing?

↑ 138 πŸ’¬ 74 question 2026

Would an antimatter radio be able to communicate with a regular matter radio?

↑ 99 πŸ’¬ 44 question 2026

Why must there be a particle for gravity? Do we observe gravity to behave as if there are gravity particles?

↑ 98 πŸ’¬ 127 question 2026

What state is our sun in?

↑ 98 πŸ’¬ 104 question 2026

Can someone please explain the string theory to me in simplified layman's terms?

↑ 86 πŸ’¬ 40 question 2026

Any physics majors/physicists that read philosophy in their spare time

↑ 86 πŸ’¬ 86 text 2026

Communities its size

Within four times the member count either way, so the comparison is fair. Sorted by upside.

r/AskPhysics, in numbers

Answered from the posts ViralHunt holds from this community, not from Reddit's own about page.

How many members does r/AskPhysics have?
r/AskPhysics has about 1.6M members. ViralHunt has tracked 300 of its posts; the biggest reached 260 upvotes, which is 0 per 1,000 members.
What is the most viral post on r/AskPhysics?
"Why is water incompressible?" reached 260 upvotes and 168 comments in 2026, the highest score among the posts we hold from r/AskPhysics.
What subreddits are similar to r/AskPhysics?
Communities of a comparable size we track: r/StarWarsBattlefront, r/alberta, r/goodnews, r/AnarchyChess, r/Amazing, r/minnesota.
What kind of posts do best on r/AskPhysics?
Of the posts we hold, 61% are question posts and 31% are text posts.
When is the best time to post on r/AskPhysics?
Across 300 timestamped posts we hold, the slots whose posts averaged the highest score are Monday at 18:00 UTC (87 avg upvotes), Friday at 00:00 UTC (79 avg upvotes), Saturday at 18:00 UTC (36 avg upvotes). The busiest day is Wednesday. For Reddit as a whole, see the best time to post on Reddit page.
How many upvotes does a post need to reach the top of r/AskPhysics?
The 20th-best post we hold from r/AskPhysics has 49 upvotes, so that is roughly the bar for the top twenty. We captured 300 posts from it in the last 30 days.

See what is climbing here before you write

ViralHunt tracks Reddit and eight other networks, records how every post grows, and puts what is taking off in front of your team in one list.

Start free β†’

Every figure here is what ViralHunt has captured from r/AskPhysics, not everything the community has ever posted. We deliberately do not publish an average score: our sample is weighted toward a community's best posts, so an average would be flattering and wrong. Peak per 1,000 members is computed the same way for every community listed. See how we measure.