I did not know this was possible. It's certainly intuitively incomprehensible.
You can stack bricks (or anything with a rectangular cross-section) so that they form a staircase that never falls over, no matter how far it reaches.
When I saw this discussed in my forum, I just didn't believe it could be so. I had to see it with my own eyes.
Here's my staircase of 21 CDs, with an overhang of 1.75. (The right edge of the top CD overhangs the base by 1.75 times the diameter of a CD).
What is more astonishing is that there is no limit to how far this bridge can reach. In theory, you could build it all the way to China. Of course, the caveat is that its height grows much, MUCH faster than its span. To make a bridge that spans five feet (L=10), your stack would contain a half million CDs - i.e. taller than the CN Tower.
Further reading:
http://www.maztravel.com/maz/explain/series.htmlhttp://oak.ucc.nau.edu/jws8/classes/137.2006.1/index.htmlhttp://www.cs.tau.ac.il/~zwick/papers/overhang-SODA.pdf