There is a couple of (probable) improvements I would like to suggest for this fantastic site.
- Moving closed questions with a high number of up votes (for example $>10$) to a dedicated StackExchange site, where they would receive a single tag indicating the site where they come from (in this case, the tag would be Physics). There, the question would be alive and could receive new answers, points, etc, together with (highly voted) closed questions from the other StackExchange sites. That would be a solution for certain questions that very clearly interest us (this nobody can deny, and that's what upvotes are saying) like this one (incidentally, I have read one of the recommended papers in the first answer, and it has nearly changed my life for good, both as researcher and as physics student -which you never stop being- as well).
- Downvoters should be forced to leave an anonymous comment, otherwise the vote should only have a value of 0.2 points or similar. Only downvotes with an anonymous comment should have full consideration. That would improve the quality of bad answers, sure.
When a question/answer is really crap, it receives anyway a rainfall of downvotes (well, not always) whereas sometimes somebody drops a -1 with no explanations like a passing bird leaving an excrement, and the OP has no clue of what he/she could improve.
I received for example a downvote here. I don't give a damn as long as my reputation stays above a dozen of points so that I am able to post images, and also I am using an anonymous profile. But what I find annoying is not having the less clue of what could be wrong with the question...