Based on a paper delivered at the Second International Conference of the
Society for Psychical Research at Cambridge, March 1977. Reprinted by permis-
sion from the fournal of the
Society for Psychical Research, March
7979.
— 8 5cm
-
The detection of dynamic strain signals in paranormal metal-
bending 'action'
(1) has enabled experimentation to be carried
out on the distribution of the action around the metal-bender.
A
resistive
strain gauge
is mounted
on
or
in
a
small
metal
specimen, which hangs from
its screened electrical connections;
electrical bridge,
amplifier and chart recorder enable dynamic
stram data
to be collected,
it
is found
that the
'action' occurs
in fiF
ts of extension or contraction, rather randomly distributed
in time, often at a rate of about fifty per hour.
An
early
resuit of experiments
with
several
independent
embedded resistive strain gauges was the finding (2) that dynamic
strain pulses were frequently registered simultaneously on two en-
tirely
separate metal specimens. The data were
interpreted
in
terms
of a crude
physical
model
of
a
'surface
of
action',
at
points on which
strain
pulses occur. The configuration and
movement
of
this
surface
with
respect
to
the metal-bending
subject can then be studied.
A further series of studies (3) were conducted with several
independent strain gauges on a single piece of metal. The linear
array of gauges along a thin strip of metal respond simultaneously
to the 'action', but the signals are strongest in the centre of a
'region of action', which extends about ten inches, and can move
slightly from event to event. A series of experiments was also con-
ducted with strain gauges on apposite sides of the metal strip. Fora
'pure bend' the signals should be in opposite directions, but these
conditions were only ootained in the limit of ioiiniteiy fcnin metal
strip; for strips of thickness in the region of 1 cm, one strain gauge
receives a much
smaller
signal than the other,
as though the
penetration was incomplete.
Since there
is no very strong reason for expecting the signals
to be of magnitude or sense uniformly distributed
across
the
thickness of the
metai,
it appears important
to
investigate the
profile of strains in thick metal specimens. We therefore mounted
six sensors throughout the thickness of a metal speciman, and
cqa-
-»cted them
to
six
separate battery-operated
bridges and
,iers,
using two synchronized
three-pen
chart recorders.
Two different methods of fabricating the sensor were used: in one
interleaved with spacers stuck together with epoxy resin; both
methods are detailed
in Figure
1.
XKJcl
*4
EXPERIMENT WITH STEPHEN N.
Three
experimental
sessions
were
held
with
thirteen-
year-old Stephen
N., and simultaneous strain
signals were
re-
corded at six strain gauges. The thick metal strip was suspended
horizontally radially in front of the subject.
The subject w-as seated and was able to reach forward his
hand within a few inches of the end closest to him, but part of the
time he did not hold out either hand, and many signals were ob-
served during„these periods. One author would superintend the
working of the equipment, leaving the other free to witness the
action without touch produced by the subject. Members of the
subject's family were often present. The normal time for an ex-
perimental session was sixty to ninety minutes.
When a metal strip is bent, either elastically or plastically, the
convex face experiences extension
(positive
strain), whilst tne
concave face experiences contraction (negative
strain). At the
curved neutral surface, in the centre of the strip, there is no change
of strain. If a positive strain were represented by an arrow or length
proportional to its value pointing to the right and a negative strain
by an arrow pointing to the left, then the normal bending situation
could be represented by
a
series of arrows,
as shown
ai the
left-hand side of Figure 2.
if an array of synchronous paranormal bending signals
re-
presents a pure bend with the top face convex, then they could be
shown graphically as a
set of data points extending diagonally
from bottom
left
to top
right. A puie extension would be
re-
RDR&64)0f78SROQ2(»Q01 SO01^5"ia
1 y onc ahove tiic
other.
The arrays of signals recorded in experimental sessions are