thinking about this for about 15 minutes, I came up with this idea: using a magic marker, draw a vertical line on one narrow end of the mattress, and a horizontal line on the other. After six months, the vertical line (say) will tell you it's time to flip it vertically end-to-end on the narrow axis. This will reveal the horizontal line, which tells you to rotate the bed 180 degrees lying on the same surface on which it currently lies. This will in turn expose the vertical line, which when followed for the second time will complete the four possible surfaces on which you can sleep.
posted by Eduardo Santos
January 6, 2010
About once a month at Sigma Xi headquarters, we liven up the lunch hour with an American Scientist Pizza Lunch talk. In these informal lectures, scientists describe new research to nonscientists. The series is light on jargon but heavy on solid science. Each Pizza Lunch offers an in-depth look at its subject, whether it's bedbugs or the smart grid. Click below to read about and download these talks -- and to subscribe!
JSTOR, the online academic archive, now contains complete back issues of American Scientist from its inception in 1913 (as Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.