PHYSICS NEWS UPDATE
The American Institute of Physics Bulletin of Physics News
Number 465 (Story #3) January 7, 1999 by Phillip F. Scheve and Ben Stein
COSMIC RAYS OBSERVED BY GRAVITY-WAVE DETECTOR
at the Frascati Laboratory in Italy consists of a 2300-kg
aluminum cylinder cooled to a temperature of 0.1
K. The plan is that a passing gravitational wave (broadcast,
say, by the collision of two neutron stars)
would excite a noticeable vibration in the cylinder.
NAUTILUS has not
yet recorded any gravitational waves, but scientists
have now witnessed the cylinder vibrated by energetic
particle showers initiated when cosmic rays strike the
atmosphere.
The signal generated by the rays is believable because
conventional cosmic-ray detectors surrounding the
bar also lit up when they were struck by the particles.
In effect the detector is able to discern a mechanical
vibration as small as 10-18 meters,
corresponding to an energy deposit as small as 10-6
eV.
(Astone et al., Physical Review Letters , 3 January 2000;
Contact Giuseppina Modestino, modestino@lnf.infn.it,
011-39-694-032-756.)
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