### Usenet Newsgroups

# Rec.Puzzles Hall of Fame

The rec.puzzles Hall of Fame is a compilation of over 500 of the most popular puzzles that have been posted and discussed in the rec.puzzles newsgroup. In most cases a detailed solution has been provided. Many of these puzzles also appear in Braingle's own collection.

Categories

## pickover : pickover.02.p

Title: Cliff Puzzle 2: Grid of the Gods From: cliff@watson.ibm.com If you respond to this puzzle, if possible please include your name, address, affiliation, e-mail address. If you like, tell me a little bit about yourself. You might also directly mail me a copy of your response in addition to any responding you do in the newsgroup. I will assume it is OK to describe your answer in any article or publication I may write in the future, with attribution to you, unless you state otherwise. Thanks, Cliff Pickover * * * Consider a grid of infinitesimal dots spaced 1 inch apart in a cube with an edge equal in length to the diameter of the sun (4.5x10**9 feet). For conceptual purposes, you can think of the dots as having unit spacing, being precisely placed at 1.00000...., 2.00000...., 3.00000...., etc. Next choose one of the dots and draw a line through it which extends from that dot to the edge of the huge cube in both directions. Stop And Think 1. What is the probability that your line will intersect another dot in the fine grid of dots within the cube the size of the sun? Would your answer be different if the cube were the size of the solar system? 2. Could a computer program be written to simulate this process? 3. Answer the two questions above, but this time assume the line to have some finite thickness, T.

Solution

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