(Roughly) Daily

Your correspondent is headed away for a week or so, ranging more then ten times zones from home– the current limit to continuous timely posting of (R)D…  So, while regular service will resume on-or-around the 20th, a little something to keep one occupied:

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Readers will recall that, on the occasion of an earlier hiatus, your correspondent wheeled out “the Monty Hall Problem” (c.f., “Riddle Me This” and “Birdbrains“).  This time, with thanks to Prof. Stan Wagon at Macalester College:

Monty Hall Takes a Vacation

Alice and Bob face three doors marked 1, 2, 3. Behind the doors are placed, randomly, a car, a key, and a goat. The couple wins the car if Bob finds the car and Alice finds the key.

First Bob (with Alice removed from the scene) will open a door; if the car is not behind it he can open a second door. If he fails to find the car, they lose. If he does find the car, then all doors are closed and Alice gets to open a door in the hope of finding the key and, if not, trying again with a second door.

Alice and Bob do not communicate except to make a plan beforehand. What is their best strategy?

Source: A. S. Landsberg (Physics, Claremont Colleges, California), Letters, Spring 2009 issue of The Mathematical Intelligencer.

The answer is here— and more nifty puzzles, here.

As we craft our own strategies, we might solve a memorial problem for Gabrielle-Émilie Le Tonnelier de Breteuil, Marquise du Châtelet, the French mathematician and physicist who is probably better known as Voltaire’s mistress; she died on this date in 1749.  Fascinated by the work of Newton and Leibniz, she dressed as a man to frequent the cafes where the scientific discussions of the time were held. Her major work was a translation of Newton’s Principia, for which Voltaire wrote the preface. The work was published a decade after her death, and was for many years the only translation of the Principia into French.

Judge me for my own merits, or lack of them, but do not look upon me as a mere appendage to this great general or that great scholar, this star that shines at the court of France or that famed author. I am in my own right a whole person, responsible to myself alone for all that I am, all that I say, all that I do. it may be that there are metaphysicians and philosophers whose learning is greater than mine, although I have not met them. Yet, they are but frail humans, too, and have their faults; so, when I add the sum total of my graces, I confess I am inferior to no one.
– Mme du Châtelet to Frederick the Great of Prussia

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