In article <[EMAIL PROTECTED]>, Graham Jones <[EMAIL PROTECTED]> wrote:
>Subject: Re: [edstat] tossing a coin is not a random process >From: Graham Jones <[EMAIL PROTECTED]> >Date: Fri, 27 Feb 2004 19:35:59 +0000 >Newsgroups: sci.stat.edu > >In article <[EMAIL PROTECTED]>, Shareef Siddeek ><[EMAIL PROTECTED]> writes >>In a local radio presentation, one mathematician has shown that tossing >>a coin is not always random. If one positions the head up when tossing, >>he/she will more likely end up with the head more than 50% (to be exact >>51%) of the time. What do the stat gurus say about this? Cheers. Siddeek >> > >While lecturing on probability at Warwick University one day in October >1972, Jeffrey Hamilton, demonstrating the effect of chance, took a coin >from his pocket and casually tossed it in the air. The probability that >the coin would land face up (heads) was exactly the same as the >probability that it would land face down (tails); it was, Hamilton >explained, a 50-50 proposition. >Hamilton and the assembled students then watched as it hit the floor, >bounced, rolled, spun around - and came to rest on its edge. After a >stunned silence, the entire room broke into wild applause. > >This is from >http://www.anecdotage.com/index.php?aid=2741 > >I hope it is true. I have heard the claim several times that some skilled magicians are capable of controlling the number of rotations that a flipped coin will make before it is caught. As such they can reliably toss heads. Tossed coins are just very sensitive to their inital conditions and the skill is in controlling the initial conditions. So random would just mean very unskilled at controlling the toss. I have heard this ability attributed to Persi Diaconis who is both a good statistican and a skilled magician. He is well reputed for his ability to debunk various "supernatural" claims as a result of both skills. >-- >Graham Jones >http://www.visiv.co.uk >Emails to [EMAIL PROTECTED] may be deleted as spam >Please add a j just before the @ to ensure delivery > . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
