scienceisbeauty:

The Perfect Nap: Sleeping Is a Mix of Art and Science via WSJ (high-res)

Personal note: I remember in my times of “working student”, when I went to my classes in the morning, had to teach (math, physics and chemistry) my students during the afternoon, and studied my subjects on late night (starting at 10 pm). The exam seasons were absolutely criminals, I often just had time for a short siesta of 10-minutes after lunch and I remember the feeling of clear-sightedness just after those naps. So, in my opinion… ¡Viva la siesta!