I’m not sure it’s really scientific, but I recommend reading this meditation on why you should drink coffee when you’re most alert (source: Rands). The morals I take from the story involve drinking my afternoon coffee slightly later, and getting a couch once I finally get an office.
On the other hand, taking an afternoon nap directly contradicts the piece of advice that you should treat your academic job like a 9-5. Which in turn contradicts Richard Hamming’s open door policy:
I noticed the following facts about people who work with the door open or the door closed. I notice that if you have the door to your office closed, you get more work done today and tomorrow, and you are more productive than most. But 10 years later somehow you don’t know quite know what problems are worth working on; all the hard work you do is sort of tangential in importance. He who works with the door open gets all kinds of interruptions, but he also occasionally gets clues as to what the world is and what might be important.
And all of this contradicts my policy that my sleep is sacrosanct. Seems that productivity is complicated stuff.