For new readers and those who request to be “好友 good friends” please read my 公告栏 first

To readers of my blogs more than 48 hours old

In looking over my older blog articles, I know there are plenty of readers (or new readers) of these articles constantly. But because of the policy of ScienceNet not allowing any change to or comment on any article older than 48 hours after posting, I miss these potential new feedbacks. Thus, I am inviting readers to write to me directly (ho@seas.harvard.edu) and promise I will respond. And if there are enough of these new comments on an article, I’ll post them separately in a new article (subject to approval by editors of Science Net as usual of course.) This way communication can be improved and the editorial department can maintain control easily.