Heisenberg's Uncertainty Principle
Einstein's broader theory of relativity told us more about how the universe works and helped to lay the foundation for quantum physics, but it also introduced more confusion into theoretical science. In 1927, this sense that the universe's laws were, in some contexts, flexible, led to a groundbreaking discovery by the German scientist Werner Heisenberg.
In postulating his Uncertainty Principle, Heisenberg realized that it was impossible to simultaneously know, with a high level of precision, two properties of a particle. In other words, you can know the position of an electron with a high degree of certainty, but not its momentum and vice versa.
Niels Bohr later made a discovery that helps to explain Heisenberg's principle. Bohr found that an electron has the qualities of both a particle and a wave, a concept known as wave-particle duality, which has become a cornerstone of quantum physics. So when we measure an electron's position, we are treating it as a particle at a specific point in space, with an uncertain wavelength. When we measure its momentum, we are treating it as a wave, meaning we can know the amplitude of its wavelength but not its location.
Keep reading for more science stuff you might like.
Last editorial update on Sep 12, 2018 02:11:02 pm.
- Ask an Astronomer. "The Theory of Relativity." Cornell University Astronomy Dept. March 21, 2008. (Jan. 5, 2011) http://curious.astro.cornell.edu/relativity.php
- Bragg, Melvyn. "The Second Law of Thermodynamics." BBC. Dec. 16, 2004. (Jan. 5, 2011) http://www.bbc.co.uk/programmes/p004y2bm
- Glenn Research Center. "First Law of Thermodynamics." NASA. July 11, 2008. (Jan. 5, 2011) http://www.grc.nasa.gov/WWW/K-12/airplane/thermo1.html
- Lambert, Frank L. "Shakespeare and Thermodynamics: Dam the Second Law!" Occidental College. 2008. (Jan. 5, 2011) http://shakespeare2ndlaw.oxy.edu/
- LaRocco, Chris and Blair Rothstein. "The Big Bang." University of Michigan. (Jan. 5, 2011) http://www.umich.edu/~gs265/bigbang.htm
- Lightman, Alan. "Relativity and the Cosmos." PBS Nova. June 2005. (Jan. 5, 2011) http://www.pbs.org/wgbh/nova/einstein/relativity/
- Matson, Ronald H. "Scientific Laws and Theories." Kennesaw State University. (Jan. 5, 2011) http://science.kennesaw.edu/~rmatson/3380theory.html
- Nave, C.R. "Hubble law and the expanding universe." Georgia State University. (Jan. 5, 2011) http://hyperphysics.phy-astr.gsu.edu/hbase/astro/hubble.html
- Nave, C.R. "Kepler's Laws." Georgia State University. (Jan. 5, 2011) http://hyperphysics.phy-astr.gsu.edu/hbase/kepler.html
- Nave, C.R. "The Uncertainty Principle." Georgia State University. (Jan. 5, 2011) http://hyperphysics.phy-astr.gsu.edu/hbase/uncer.html
- PBS. "Big bang theory is introduced." 1998. (Jan. 5, 2011) http://www.pbs.org/wgbh/aso/databank/entries/dp27bi.html
- PBS. "Heisenberg states the uncertainty principle." 1998. (Jan. 5, 2011) http://www.pbs.org/wgbh/aso/databank/entries/dp27un.html
- PBS. "Penzias and Wilson discover cosmic microwave radiation." 1998. (Jan. 5, 2011) http://www.pbs.org/wgbh/aso/databank/entries/dp65co.html
- Pidwirny, Michael. "Laws of Thermodynamics." Physical Geography. April 6, 2010. (Jan. 5, 2011) http://www.physicalgeography.net/fundamentals/6e.html
- Quake, Stephen. "Practically pure." The New York Times. Nov. 8, 2009. (Jan. 5, 2011) http://www.nytimes.com/2009/02/18/opinion/18iht-edquake.1.20274600.html
- Stern, David P. "Kepler's Three Laws of Planetary Motion." Phy6.org. March 21, 2005. (Jan. 5, 2011) http://www.phy6.org/stargaze/Kep3laws.htm
- Stern, David P. "Newton's theory of 'Universal Gravitation'." NASA. March 24, 2006. (Jan. 5, 2011) http://www-istp.gsfc.nasa.gov/stargaze/Sgravity.htm
- University of California Museum of Paleontology (UCMP). "Understanding Evolution: An introduction to evolution." (Jan. 5, 2011) http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_02
- University of California Museum of Paleontology (UCMP). "Understanding Evolution: Natural selection." (Jan. 5, 2011) http://evolution.berkeley.edu/evolibrary/article/evo_25
- University of Tennessee, Knoxville, Dept. of Physics & Astronomy. "Newton's Three Laws of Motion." (Jan. 5, 2011) http://csep10.phys.utk.edu/astr161/lect/history/newton3laws.html
- University of Tennessee, Knoxville, Dept. of Physics & Astronomy. "Sir Isaac Newton: The Universal Law of Gravitation." (Jan. 5, 2011) http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html
- Weisstein, Eric W. "Gravitational Constant." Wolfram Research. (Jan. 5, 2011) http://scienceworld.wolfram.com/physics/GravitationalConstant.html
- Weisstein, Eric W. "Kepler's Laws." Wolfram Research. (Jan. 5, 2011)http://scienceworld.wolfram.com/physics/KeplersLaws.html
- White, Martin. "The Hubble Expansion." University of California, Berkeley. (Jan. 5, 2011) http://astro.berkeley.edu/~mwhite/darkmatter/hubble.html
A drone with some petri dishes attached is making research easier on whales and scientists. HowStuffWorks takes a look.