Dear Editor:
I work at Nanaimo Correctional Centre on Brannen Lake in Nanaimo, British Columbia. NCC is a provincial medium security facility which houses approximately 225 inmates serving prison sentences of 2 years less a day. I was facilitating a week long program I run monthly called CREST (Community Re-entry Education Skills Training). We had 18 clients in attendance and started each day viewing a couple of 'scenes' from WTB, followed by a discussion of the viewing. Today, I was asked by one of my clients "how is it that if we never touch anything (reference to the basketball and electrical charges) that I am able to have my fingerprints picked up by the police" AND "if I believe strong enough that my finger prints will not be detectable will I be able to pick up something without leaving any prints???". I am pleased they are watching this wonderful film and engaging themselves in the 'mystery'...your response to these questions would be helpful to them staying curious. Thanks in advance.
Ralph Motzek, BC, Canada
Ralph - Your clients questions were so excellent I decided to forward them to one of the scientists, Fred Alan Wolf, Ph.D.. His reply is below. As for the second question, I guess the best thing is to contemplate Fred’s answer to question #1!
Editor
Dear Ralph,
Yes fingerprints certainly indicate that you touched something! So what could we mean by the remark in the movie? Briefly the word "touch" or the
marks our fingers leave on surfaces are simply explained by saying a contact
was made between two objects.
In the case of fingerprints, actually three
objects are involved: the fingers, the ink, and the paper or at a crime
scene, the fingers, the oil or dirt from the skin, and the contacted
surface. Let's just look at two--the finger and the surface, for what I
explain about them holds for any two objects in "contact". When we examine
a point of contact very closely we see that there is actually a gap between
the two objects at that point. That's because everything is made of atoms
and even the atoms which make up an object are not even touching--there is a
space between the atoms that is larger than the atoms themselves. Between
two objects that space is even larger.
So what gives? We say that there
are forces or interactions between objects and these forces are what
actually led to the sensation of touch and the marks of fingerprints and all
contacts between objects. These forces are mostly governed by
electromagnetic light waves that turn into objects called photons. The
relation between atoms and photons is a very interesting, and at times
mysterious, field of physics called QED (quantum electrodynamics). Next > 1 2 3 4
