Definition: scientific principle stating that it is impossible to determine with perfect accuracy both the position and momentum of a particle at any given point in time.
Heisenberg Uncertainty Principle
By Anne Marie Helmenstine, Ph.D., About.com
Suggested Reading
Chemistry Glossary IndexChemistry 101Encyclopedia of Chemistry
Explore Chemistry
Must Reads
More from About.com
Work Hard, Travel Easy
The best tips for business travelers.Dog Care
Get tips on training and caring for dogs of all ages.48 Hours in Vegas
Plan a hot weekend in Sin City.Hotel Advice
The must-stay hotels worldwide.
©2008 About.com, a part of The New York Times Company.
All rights reserved.