Being on the HN's homepage isn't as simple as "most upvoted articles in last X hours". They take into account upvote velocity: 40 upvotes in 40 minutes isn't the same as 40 upvotes in 4 yours.
no, it wasnt 40 upvotes in 40 minutes, it was at 8 upvotes after 34 minutes posted
no, it wasnt 40 upvotes in 40 minutes, it was at 8 upvotes after 34 minutes posted