Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page Visit Our Archives Ask A Question How To Ask A Question Question of the Week NEWTON Teachers Our Expert Scientists Volunteer at NEWTON! Referencing NEWTON Frequently Asked Questions About Ask A Scientist About NEWTON Education At Argonne Quantum Tunneling and Fusion

Name: Ruben
Status: student
Grade: 9-12
Country: Belgium
Date: Winter 2012-2013


Question:
Recently I heard about quantum tunneling. I heard it is the reason why the sun can turn hydrogen into helium, even if the required temperature for this fusion is not reached. But how exactly does this work? How can particles "borrow" energy to fuse, and then release this energy again? I understand the "mountain-metaphor" in which the particle has to 'climb' up the mountain, and then 'roll' down again, but how does this work on the scale of particles? Does it have to do something with the particle-wave duality?

Replies:
Ruben,

Single particles at the level of quantum physics do not behave according to what some call ?common sense?. What we see from day to day is only an average effect of millions of particles together. One uncertainty principle involves energy and time. Overall, energy is conserved. For extremely short lengths of time, energy can go out of balance. Energy shift multiplied by the time over which the shift exists has to be on the order of 10^-34 Joule-seconds or less. In day to day life, this is too small to have any noticeable effect. Within a single atom, this is enough to allow tunneling.

Dr. Ken Mellendorf Physics Instructor Illinois Central College


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 223
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: November 2011
Weclome To Newton

Argonne National Laboratory