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Topic: say I flip a coin 100 times...
Replies: 46   Last Post: Apr 18, 2005 9:42 PM

 Messages: [ Previous | Next ]
 George Greene Posts: 448 Registered: 12/12/04
Re: say I flip a coin 100 times...
Posted: Apr 16, 2005 2:58 PM

HERC777 wrote:
> OK lets move on to Q3...
> at time 0 there are 0 people flipping coins.
> At time 1/2 there is 1 person flipping
> coins at t=1/2, t=3/4, t=7/8...
> At time 3/4 there is another person flipping
> coins at t=3/4, t=7/8, t=15/16..
> At time 7/8 another person joins in flipping coins...
> and so on...

This means you will have an infinite number of people
flipping an infinite number of times each, if t ever
gets to 1.

>
> At time t = 1, Herc starts flipping
> coins at t=1, t=2, t=3, t=4, t=5...
>
> How long does Herc flip out for until it is
> recognised he is unique
> from all of the masses?

Forever, basically. At any given finite time,
you have only flipped a finite number of times.
But there are infinitely many people flipping before
you, and the expected number of them that match you,
for a prefix-length equal to
the-number-of-times-you-have-flipped-so-far,
is ALSO INFINITE. In order to get the number of expected
matches-so-far down to something finite,
you have to determine some finite subset of the flippers
that are worth thinking about, at any given time.

Date Subject Author
4/12/05 HERC777
4/12/05 Jan Burse
4/12/05 HERC777
4/12/05 George Greene
4/13/05 Barb Knox
4/13/05 HERC777
4/13/05 Yajun
4/13/05 HERC777
4/13/05 Jay
4/13/05 HERC777
4/13/05 Jay
4/14/05 Yajun
4/14/05 George Greene
4/14/05 George Greene
4/13/05 Will Twentyman
4/13/05 briggs@encompasserve.org
4/13/05 briggs@encompasserve.org
4/14/05 George Greene
4/14/05 tchow@lsa.umich.edu
4/14/05 briggs@encompasserve.org
4/12/05 Tony
4/13/05 HERC777
4/13/05 ken quirici
4/13/05 Ralph Hartley
4/13/05 Robert Low
4/13/05 Ralph Hartley
4/13/05 Robert Low
4/13/05 tchow@lsa.umich.edu
4/13/05 HERC777
4/13/05 tchow@lsa.umich.edu
4/14/05 HERC777
4/14/05 George Greene
4/14/05 HERC777
4/15/05 tchow@lsa.umich.edu
4/15/05 tchow@lsa.umich.edu
4/16/05 George Greene
4/16/05 HERC777
4/17/05 George Greene
4/17/05 Patricia Shanahan
4/17/05 HERC777
4/18/05 Patricia Shanahan
4/17/05 tchow@lsa.umich.edu
4/18/05 HERC777
4/18/05 George Greene
4/18/05 tchow@lsa.umich.edu
4/18/05 HERC777