Nice googling, Allan. Interesting how much I forgot of this problem (Mosteller's wording): ----- Two strangers who have a private recognition signal agree to meet on a certain Thursday at 12 noon in New York City, a town familiar to neither, to discuss an important business deal, but later they discover that they have not chosen a meeting place, and neither can reach the other because both have embarked on trips. If they try nevertheless to meet, where should they go? ----- And you make an interesting point, Allan, about unspoken rules to what the problem really is. Yet even though I might have trouble stating the rules, I suspect many people can solve it in the way the poser intended. So even without stating the rules, I think this is the kind of problem that AI will be able to eventually tackle after being given a lot of other typical word problems and their solutions as a training sample. —Dan
On May 19, 2017, at 12:58 PM, Allan Wechsler <acwacw@gmail.com> wrote:
A little Googling reveals that Mosteller's book is called "Fifty Challenging Problems in Probability with Solutions", and it was first published in 1965. Dover reprinted it at some point. The problem in question is #12, and is called "Quo Vadis?"
I am somewhat annoyed by the problem statement. This is not Dan's problem; he remembered the relevant circumstances well enough. But the poser clearly expects us to generate our own "rules of the game", and it's not clear what's on the table and what's not. How many "locations" are there in New York City? How long does it take to check one to see if it contains your friend? Does the "structure" of New York City (other than it being a set of possible locations) matter? If the New York City of the problem has a "geometry", how fast can one move through it?
On Fri, May 19, 2017 at 2:29 PM, Dan Asimov <asimov@msri.org> wrote:
This reminds me of the very first rendezvous problem I heard, in a little book on probability by Frederick Mosteller (et al.?) from the 1960s:
----- You have agreed to a rare meeting in New York City with an old friend at a date and time both of you will have no trouble remembering. When the arrangement was made, however, the location of the was to be determined, and now that the date and time are upon you, you realize that a) no place was ever set for the meeting and b) you have no way of communicating with your friend now that you are both somewhere in New York City unbeknownst to the other.
Problem: What do you do to maximize the chance of meeting the other person at the appointed time? -----
—Dan ———— Note: Wording of problem is my own, as I don't know which book I saw it in.
On May 17, 2017, at 10:58 PM, Dave Dyer <ddyer@real-me.net> wrote:
My ultimate rendezvous problem:
You and your partner are located at separate locations somewhere in the milky way galaxy. You have a ship capable of acceleration to light speed in negligible subjective time, and a beacon that can be detected over any distance its light reaches.
Rendezvous for a victory drink before either of you dies of old age.