Last Friday at the Mathematical Sciences Research Institute (MSRI) I met Gary Antonick, who writes a numbers blog for the New York Times, a fun blog that you must check out. I gave him a puzzle and he loved it so much he thought it was going to be one of the best he has posted on his blog.
We had gathered together at the Berkeley site of MSRI for an annual celebration to honor Martin Gardner, the famous gamer, puzzler and magician who wrote the column Mathematical Games for The Scientific American for 25 years. Many of us grew up loving his column and spent endless hours solving his posers and reveling in his tricks.
Elwyn Berlekamp, the well known author of several books on Nim-like games was there, playing Dots and Boxes with kids and other visitors. He runs a nifty outfit called Gathering for Gardner, whose website is here. Their logo reproduced below is really cool as it reads exactly the same when you turn it upside down – this is the sort of thing Martin Gardner loved.
In the spirit of Martin Gardner many math puzzles were presented to the attendees.
I discussed the following 13-link chain puzzle with Gary – a puzzle that I have known since my grandfather posed it to me many, many years ago and one I had immensely enjoyed. Gary loved the puzzle and has posted it on the New York Times blog today. So check it out, see if you can solve it and send me the solution, or your comments or questions. I’m reproducing the puzzle below as well:
The 13-Link Chain Puzzle
You have a balance scale and a single chain with thirteen links. Each link of the chain weighs one ounce. How many links of the chain do you need to break in order to be able to weigh items from 1 to 13 ounces in 1-ounce increments?
As with all puzzles that have Martin Gardner’s elegance and spirit, this puzzle is very pleasing at many levels and encompasses some more general math patterns that are endlessly extended by people who then pose ever-more evolutionary puzzles based on this.
For those of you who want more of these fun puzzles try out the ten off-the-shelf classical (and simple) Martin Gardner puzzles here. (From Elwyn’s Gathering for Gardner site)