Newsgroups: sci.math
From: boll@CS.ColoState.EDU (dave boll)
Subject: 3 sided coin - experimental data
Date: Tue, 24 Nov 1992 21:07:55 GMT

  Re: the 3 sided coin problem

  Screw the theory, we've got some experimental data here.

  I went down to the local hardware store and bought (or attempted to
  buy) a metal cylinder with height=radius. What I got was a metal
  cylinder with height = 5.5 units, and radius=4.5 units (as measured
  with a micrometer). So, it's a bit off.

  I gave it a total of 40 coin-type flips (I was going to do more, but
  the results are so lopsided it's not worth it), and got 33 'sides' and
  only 7 heads/tails. Heads and tails were more common if the flipped
  object lands in a small area; initially I was flipping it into an
  old cardboard pizza box and getting maybe 70% sides. The 33/40 data
  came about when I discarded the box and flipped over my kitchen
  floor (lineoleum (sp???)).

  Even tho my object was a bit tall for its radius, I now think the 
  height must be a fair amount less than the radius in order to get
  the % of 'sides' down to 33% Maybe H=2/3R or H=1/2R or some such.

  Any comments (other than "Dave, get a life!") are welcome.
-- 
     ------------------------------------------------------------
     Dave Boll  boll@handel.cs.colostate.edu
                "The speed of time is 1 second per second"
     ------------------------------------------------------------
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From: dwboll@gr.hp.com (David Boll)
Newsgroups: sci.math
Subject: 3-sided coins, some experimental results
Date: 17 Jul 1998 15:10:56 GMT

Hi all:

I've been playing with real 3-sided coins lately (cylinders thick 
enough that they land on heads, tails, and sides with equal probability).

Check out http://www.frii.com/~dboll/coin3.htm
for some interesting results.

It turns out that Thickness=Radius isn't far from the truth, although there
are a host of unanswered questions and concerns, some of which are
discussed on the URL above.

Enjoy!

ps: If you want to generate some data, I'll send you my disks if you
promise to send me results of at least 2000 trials

--
Dave Boll
http://www.frii.com

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From: dwboll@gr.hp.com (David Boll)
Newsgroups: sci.math,sci.physics
Subject: 3-sided coin, update
Date: 31 Jul 1998 17:12:37 GMT

Hi all:

Re: the 3-sided coin problem (A coin thick enough that it lands on heads,
tails, and sides with equal probability), check out

http://www.frii.com/~dboll/coin3.htm

for a update on trying to find the critical thickness empirically.
We now have the results of over 10,000 trials, thanks mostly to some
dedicated flipping by Justin Smith.

It looks like thickness=radius is close to the answer. I have machined
some disks to experiment with, and I'll send them to you if you send them
back along with the results of at least 2000 trials.

---
Dave Boll
==============================================================================
[For some theoretical considerations see also
	99/3sided