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 @ 4:39 PM
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.
A free daily summary of the latest news in scientific research. Each story is summarized concisely and linked directly to the original source for further reading.
An early peek at each new issue, with descriptions of feature articles, columns,
and more. Every other issue contains links to everything in the latest issue's table of contents.
News of book reviews published in
and around the web, as well as other noteworthy happenings in the world of science books.
To sign up for automatic emails of the
Update and Scientists' Nightstand issues, create an
online profile, then sign up in the
My AmSci area.