On Oct 24, 2008, at 10:13 PM, Gary Nunn wrote:
Gheeze, who knew (well apparently the Russians 50 years ago). I'm
guessing
that environmental groups will start petitioning the court to outlaw
the use
of scotch tape in a vacuum in case it creates a black hole that will
instantly swallow the earth....
X-Rays Detected From Scotch Tape
Scotch tape. It turns out that if you peel the popular adhesive tape
off its
roll in a vacuum chamber, it emits X-rays. The researchers even made
an
X-ray image of one of their fingers.
http://abcnews.go.com/Technology/wireStory?id=6088719
Wouldn't have expected triboluminescence to emit anything that
energetic .. I've seen bluish light from a roll of tape in a darkened
room, but never suspected it went up to such short wavelengths. (I
wonder if wintergreen candy emits anything that hard..)
I'm guessing this is the publication (or a similar one) in Nature:
http://www.nature.com/nature/journal/v455/n7216/abs/nature07378.html?lang=en
Letter
Nature 455, 1089-1092 (23 October 2008) | doi:10.1038/nature07378;
Received 30 December 2007; Accepted 27 August 2008
Correlation between nanosecond X-ray flashes and stick–slip friction
in peeling tape
Carlos G. Camara1,2, Juan V. Escobar1,2, Jonathan R. Hird1 & Seth J.
Putterman1
• Department of Physics and Astronomy, University of California,
Los Angeles, Los Angeles, California 90095, USA
• These authors contributed equally to this work.
Correspondence to: Carlos G. Camara1,2Juan V. Escobar1,2
Correspondence and requests for materials should be addressed to
C.C. (Email: [EMAIL PROTECTED]) or J.E. (Email: [EMAIL PROTECTED]
).
Topof page
Relative motion between two contacting surfaces can produce visible
light, called triboluminescence1. This concentration of diffuse
mechanical energy into electromagnetic radiation has previously been
observed to extend even to X-ray energies2. Here we report that
peeling common adhesive tape in a moderate vacuum produces radio and
visible emission3, 4, along with nanosecond, 100-mW X-ray pulses
that are correlated with stick–slip peeling events. For the observed
15-keV peak in X-ray energy, various models5, 6 give a competing
picture of the discharge process, with the length of the gap between
the separating faces of the tape being 30 or 300
m at the moment of emission. The intensity of X-ray
triboluminescence allowed us to use it as a source for X-ray
imaging. The limits on energies and flash widths that can be
achieved are beyond current theories of tribology.
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