## HO. Crazies on the Plane

We all know this feeling: someone’s in your seat, and now you’re the nutcase who’s going to take someone else’s seat. After all that what’s the probability the last person on the plane will be able to sit in the correct seat?

The three number trick is just a simple version of this one (but here it is quicker and simpler).

## GY. Chaitin on the Ubiquity of Undecidability

Greg Chaitin, author most recently of MetaMath!,  discusses the ubiquity of undecidability: incredibly all kinds of mathematical and physical systems exhibit utterly unpredictable, baffling behavior– and it’s possible to prove we can never fully understand why!

## G4G9: Report From the Festivities!

Quick interviews with folks here at the Gathering For Gardner, including Stephen Wolfram, Will Shortz,  Dale Seymour, John Conway and many others.

## GP, GQ, GR, GS: The Math Factor Catches Up (For Now)

A bit lazy, but we’re pretty far behind. Herewith, are

GP: Switcheroo!
GQ: Durned Ants
GR: VIth Anniversary Special
GS: I Met a Man

## GC. Another Buncha Prisoners

Man, what is it with puzzlers and prisoners? Jeff Yoak lines ’em up and the stakes are high in this week’s puzzle.

Also, we are now twittering at MathFactor; each of the authors has an account of his own; mine is CGoodmanStrauss. You can tag solutions and comments with #mathfactor. See you there!

## GB. Hat Strategy

How can three people, each required to guess the color of hat on their head, strategize and maximize the chances they’ll all be right?

## ET. Your Holiday Shopping Guide

Our favorite new and not-so-new products of 2008!

Hope this helps and have fun!! Let us know how it works out!

Happy Holidays from the Math Factor!

## Follow Up: The Harmonic Series

That the worm falls off the end of the rope depends on the fact that the incredible
harmonic series

1 + 1/2 + 1/3 + 1/4 + . . .
diverges to infinity, growing as large as you please!

## EG. The Colossal Book of Short Puzzles and Problems

Dana Richards, editor of The Colossal Book of Short Puzzles and Problems discusses the amazing Martin Gardner and his legacy!

## EC. Skyrocketing Functions!

Faster than an exponential! More powerful than double factorials!! The Busy Beaver Function tops anything that could ever be computed– and we mean ever