An alchemist’s puzzle: Can you solve it?


BOYNTON BEACH, Fla. ­ – You don’t usually expect to find logic puzzles and Judaism in the same sentence, but, really, what could be more appropriate? Jewish law is a history of applying logical analysis to our sacred texts to extract their meanings. The answer to the puzzle, which appears, below, appears on page 27.

( creates puzzles in Boynton Beach.

A little known legend found in a secret chapter of the Zohar tells the story of Nachman, one of the Jewish who wandered in the desert for 40 years. Nachman was an alchemist who knew many magic formulas. While everyone else was gathering manna in the desert in the hot son, he decided to see if he could grow his own.

One day at exactly noon, he took a small piece of manna about the size of an olive and placed it in a large clay vessel containing a special nutrient solution that he had devised. The vessel was a very large cylinder with a height of two cubits and a radius of one cubit.

He watched as the manna grew and then split in two to form two olive-size pieces. The two pieces coalesced to form one double-size piece. A minute later, the piece had grown to form a piece with four times the volume of the original piece.

A minute later, the piece had grown and coalesced so that every minute the manna doubled in volume.

Nachman smiled at this wonderful sight. Now, he would have an endless supply of manna. He would no longer need to gather manna in the hot desert sun. Perhaps he could even sell some.

When it was precisely 2 p.m., Nachman found that the vessel was exactly full of manna. What time was the vessel half-full of manna?

(After you think you’ve figured out the answer, check out the solution on page 27 .)