Chapter 9
The localisation of metal-bending action
We now address ourselves to the problem; how local is the paranormal
action on metal? Obviously this is related to the problems of
strain profile distribution (chapter 6) and also to the problem
of distance effects (chapter 8).
The localization along a metal strip is partly defined by the
width of the Gaussian curves of the last chapter, but this is
of course an incomplete definition; the resolution of the experiment
is limited by the distance between adjacent strain gauges, normally
several centimetres. It might be that the action varies in strength,
from millimetre to millimetre, or is even more locaised. As will
be discussed below, l have recently had the opportunity to conduct
experiments with the miniaturized strain gauges now available;
but at first I could rely only on less direct evidence.
In chapter 5 I suggested the model of a 'surface of action', a
surface or perhaps a laminar region in which all paranormal metal-bending
action takes place. If one imagined such a surface to be flat
or gently curved, one might suppose that the forces were not at
all local, but extended over a reasonably large area. Indeed,
at an early stage in the investigations, I was introduced not
only to the smoothly curving artwork of Andrew G., but to accurately
formed parabolas as much as 30 cm long; these first appeared among
the bends produced by David Nemeth; Julie Knowles and Andrew G.
were also able to produce large arcs of parabolas, hyperbolas
and even exact circles. But Nicholas Williams found it difficult
to produce gentle and regular curvature. Many of Willie G.'s smooth
parabolas were 'abnormal plane bends' in aluminium strip of cross-section
0.75 X 6.5 mm; they are in the plane of the long dimension, not
(as would be expected) in the plane of the short dimension. To
produce such smooth bends in this plane is quite a difficult operation
when achieved by normal means, for example by means of a conical
roller on a flat plate.
A normal parabolic bend is produced not by force applied at a
single point between two supporting points (three-point load)
but by a force uniform along the bent portion; this action would
be produced over the central part of the specimen by a four-point
load. It was the uniformity of the parabola bends which interested
me in the first instance. I believed that my early observations
favoured smooth and initially planar surfaces of action without
strong localization. Possibly the long parabolic bends might have
been produced by a uniform distribution of individual strain pulses.
But just how local is it possible for the action to get? I undertook
a number of experiments to throw light on this question. I offered
Andrew G. metal strips scaled to different sizes, in order to
see whether he could produce without touch similar objects of
different dimensions; what would be the upper, and more particularly
the lower limit to Andrew's paranormal craftsmanship? l found
that the smallest scale objects, involving curvatures of about
1 mm diameter, were not of the same high standard as the others.
Thus 1 mm diameter curved surfaces of action were not easily controlled
by Andrew. This is consistent with his failure to make tight twists
with the thinnest metal strips (chapter 7).
In another experiment I attached a number of resistive strain
gauges close together on a circular piece of metal, in order to
see whether paranormal signals were registered on neighbouring
gauges. I have in one such session with Mark Henry obtained more
than fifty signals without a single synchronism between any two
strain gauges. The strain gauges were arranged on a circular disc
radially with their inner edges on a circle of radius 8 mm. The
experiment was designed for the investigation of directional effects,
and other similar sessions are discussed in chapter 10. But since
no synchronous signals were obtained, the only conclusion possible
was that in this particular session (observed by Professor Barzilai
of the University of Rome) Mark's action was all locaised on
individual strain gauges. The metal disc did not bend visibly.
There is some evidence that in certain signals the paranormal
action is locaised on the strain gauge rather than on the metal.
On several occasions towards the end of sessions a strain gauge
has suddenly become open-circuit, although there had of course
been no touching. I always examined the open-circuit strain gauge
under magnification, and found unexplained damage which I eventually
attributed to strong locaised paranormal action. A magnified
photograph of a damaged strain gauge sensor appears in Plate 9.1b,
contrasted with an undamaged strain gauge in Plate 9.1a. It is
also possible that resistive strain gauge signals showing 'tails'
(e.g. in Figure 4.4b) are indicative of locaised action on the
strain gauge. The gauges are affixed to a prepared metal surface
with one of a number of recommended adhesives. The polymer film
on which the resistive film is deposited does not necessarily
expand and contract at the same time or rate as the metal to which
it is affixed. If the paranormal action is on the metal alone,
or simultaneously on the strain gauge and on the metal, the expansion
and contraction will be simultaneous. There is no tail on such
a signal. But if the action is locaised on the resistive strain
gauge, then a mechanical relaxation, of long time-constant, in
the adhesive film could influence the motion of the gauge. The
time-constants for these 'tails' are of the order of 1 to 5 seconds;
a thermal time constant interpretation is ruled out because compensation
of the strain gauges ensures that it would require a temperature
change of at least 10°. When employing temperature sensors
(chapter 14) we have never found such temperature changes on a
paranormally bent metal specimen. Nevertheless the physical origin
of tails on signals is not unambiguously decided, and further
experimentation is necessary. Tails cannot be avoided by embedding
the sensor in epoxy-resin within the metal.
Plate 9.1 Comparison between (a) an unused and (b) a paranormally
damaged strain gauge sensor. Overall length of the plastic mounting,
9 mm. The damage to the strain gauge is not to the solder tags,
which are soldered in blobs, but to two of the filaments, which
appear to be cut diagonally; some others show signs of incipient
damage.
Figure 9.1 Localization of dynamic strain signals on miniaturised
strain gauges, whose dimensions can be seen from the scale drawing
at the top. A family of Gaussians is drawn and their localization
parameters L are calculated. The localization parameters
from the strain gauge session are sorted into groups according
to magnitudes corresponding to the Gaussian L values. An
(inverted) histogram of the strain gauge L values is shown.
Mattuck and Scott Hill,(25) like ourselves, have drawn attention
to the possibility that locaised paranormal action might loosen
the strain gauge from the surface of the metal. In an experiment
with Girard, they observed an anomalous stretching signal on a
gauge attached to the concave side of a deformed bar. The 'strain
gauge slip' was confirmed by a subsequent normal deformation experiment
on the identical specimen, which demonstrated the failure of the
strain gauge to follow the normal deformation.
I have now been able to study localization with Stephen North
using five closely spaced miniature strain gauges whose working
length is each about one millimetre. Wide distributions of magnitudes
of signals, and even changes of sense between one strain gauge
and the next, were found.
These have been found by fitting to a trigonometric series
I=A +Bx + C1 sin x + C2 sin 2x + C3 sin 3x + . . .
The ratio L = |C3|/|C2| can be considered as a possible
quantitative measure of localization of each signal quintet, and
the value of L is compared to values calculated for Gaussian curves;
Figure 9.1 shows that the action can be said to be locaised to
distances of the order of 4 mm.
Back to books list.
Back to main index.
Back to Uri Geller's home page.