Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Neutrino Speed
Name: Richard
Status: other
Grade: other
Location: CA
Country: N/A
Date: 9/5/2005


Question:
I have been doing research on Neutrinos for a children's story.

Can neutrinos be captured? In my reading, one site said, 'they travel below c': "the neutrinos could be accelerated to .999999c and we might not notice that it was moving a bit less than c." So ... they travel through space at the speed of light?


Replies:
According to the latest information available to me neutrinos have a mass (but a very tiny mass). But things are not so simple because neutrinos hardly interact with "regular" matter at all, so it is very difficult to observe them directly, which means that their mass is inferred indirectly. It is reasonably well established that there are several types of neutrinos that can change into the other varieties. In fact this interconversion is the best evidence that they have mass. For reasons beyond the scope of this format, particles without mass cannot interconvert. Their small mass and the fact that they do not interact with other types of matter means that they travel "almost" at the speed of light, c. This also means that with the best available technology now available (2005), they cannot be rapped or captured. Their fleeting existence is detected with enormous detectors deep underground (to minimize "noise" from other types of particles and radiation). You may find the site interesting, or confusing: http://cupp.oulu.fi/neutrino/nd-mass.html but it shows just how difficult it is to measure "almost nothing" very accurately!!

Vince Calder



Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory