A tale of touching tubes | Science News



Science News is a nonprofit.

Help us keep you informed.

News in Brief

A tale of touching tubes

Mathematicians find way to put seven cylinders in contact without using their ends

4:13pm, April 2, 2014

NO IFS, ASHES OR BUTTS  Seven cylinders can each touch each other using only their sides, not their ends, mathematicians have discovered.

ATLANTA — Over 50 years ago, the popular mathematics writer Martin Gardner and readers of Scientific American pondered a challenge: Can you place seven cigarettes so that each cigarette touches every one of the others?

Gardner had a solution, but it was unsatisfying because some of the cigarettes’ ends touched others’ sides. If that end of a cigarette were lit, it would no longer touch its neighbor. Mathematicians wondered whether an arrangement could be found with only side-to-side contacts using infinitely long cylinders.

On March 20 at Gathering 4 Gardner, a conference to celebrate Gardner, mathematician Sándor Bozóki of the Hungarian Academy of Sciences in Budapest presented a solution of this more challenging problem, which was also posted online last summer at arXiv.org. Bozóki and colleagues used three months of computer time to solve 20

This article is only available to Science News subscribers. Already a subscriber? Log in now. Or subscribe today for full access.

Get Science News headlines by e-mail.

More from the Science News Archives

From the Nature Index Paid Content