[net.physics] Correction to my Helmut Schmidt article

lew@ihuxr.UUCP (Lew Mammel, Jr.) (02/01/84)

A week or so ago, I posted a comment about the psychokinesis experiment
by Helmut Schmidt which was described on the NOVA ESP show. I noted
that a net displacement of 120 after 6000 random binary steps was not
statistically exceptional. Dean Radin has convinced me that the figure
of 120 is NOT the displacement but the number of steps-to-the-right
above average. This is 1/2 the displacement. A displacement of 240 steps
after 6000 total IS significant. About one trial in 10,000 would be expected
to achieve this.

It seems that the NOVA graph is taken from one in the book, MIND AT LARGE
which shows deviations of +160 and -144 out of 6400 "trials". This adds a new
confusion since (according to Dean) the cumulative deviations are shown
"after each section of 256 trials". Presumably a set of 256 trials means
one session of 256 binary events. Of course, the division into sets of
256 raises the old spectre of selected data.

I have obtained the source article of another graph shown on the NOVA
show. It is by R.G. Jahn (Dean of the Princeton School of Engineering)
and appears in Proceedings of IEEE, Vol 70, no.2, February 1982.
It is a long survey article which includes a description of a REG
(Random Event Generator) experiment conducted by a Princeton undergrad.
This was cited on NOVA as one of the corroborations of Schmidt's results.
I'll post some more comments about this article to net.misc.

	Lew Mammel, Jr. ihnp4!ihuxr!lew

Barker.PA@PARC-MAXC.ARPA (02/07/84)

Lew,


	I have followed this subject with keen interest, I have even obtained a
gieger counter to fool around with. There are a couple of confusiong
points about your last message. First you mention that someone has
stated that the data presented in the graph is movement to the right
above average. However, stasticly average is zero.  If however you mean
the average number of steps away from center in either direction that
number is given by the square root of the number of total steps and is
therefore about 77. Even so the data that I saw  on the nova program was
compared to a curve of random data centered around zero, as if the were
implying that the deviation was away from a random walk that resulted in
no net average displacement.

	I agree with your earlier computer simulation and have generated the
same datsa myself. I have also evaluated the probabilities for a random
walk according to the following formula


		P(X)  =  (1/2)**N*N! / (X!*((NX)/2)!)

where N is total number os steps and P(X) is the prob. of landing on the
Xth step.

which gives the following results,




		  #      P(X)	      total P(all steps below X)

   step= +/-      0     .010300216203     .010300216203
   step= +/-      1     .000000000000     .010300216203
   step= +/-      2     .020593567883     .030893784085
   step= +/-      3     .000000000000     .030893784085
   step= +/-      4     .020572988035     .051466772120
   step= +/-      5     .000000000000     .051466772120
   step= +/-      6     .020538733975     .072005506095
   step= +/-      7     .000000000000     .072005506095
   step= +/-      8     .020490874076     .092496380171
   step= +/-      9     .000000000000     .092496380171


   step= +/-     60     .015261862398     .569012209115
   step= +/-     61     .000000000000     .569012209115


   step= +/-    120     .006205475647     .881743699915
   step= +/-    121     .000000000000     .881743699915


   step= +/-    240     .000169454944     .998139688874



	Points to be made are that there is almost a 12% chance that the data
will come out with a displacement above 120. Not hard to reproduce in a
lab. The chance that it will be beyond 240 is .2 % not 1/10000. 1/10000
is closer to the probability that the displacement is on step # 240 ONLY