In this sixth article on Demystifying Science, we are going to explore the most mystifying subject of science - The Principle of Quantum Indeterminacy (PQI), Typically known as the Principle of Quantum Uncertainty. Unfortunately, a proper treatment of the subject would take volumes. I am here risking an overly simplistic account and encourage readers to explore the matter for themselves.
To properly introduce the PQI we first covered the historical background in the previous article leading up to Einstein’s miracle year of 1905 when he published four legendary papers: His paper on Brownian motion served to convince the scientific community of the existence of atoms, previously thought to be only mathematical entities. His papers on the photoelectric effect and on the equivalence of matter and energy would herald the quantum age, and his paper on Special Theory of Relativity would not yet be widely recognized for years to come for its significance, until it was accompanied by the General Theory of Relativity in 1916.
Getting a Few Things Straight
First, I want to sharpen the distinction in terminology: Quantum Mechanics is the body of mathematical formulae used by physicists to describe the subatomic realm. Quantum Physics encompasses these formulae and further includes theories and hypotheses about the subatomic realm. Quantum Theory is a more general extrapolation concerning how Quantum Physics may apply to other scientific disciplines. I suspect some readers will have difficulty with this distinction, but we will see why it is important. Ultimately, it is our desire to understand Quantum Theory above all else.
We also must consider a little more history. Around a decade after Einstein had published his papers Niels Bohr (1885-1962) began laying the foundations for Quantum Physics. Based on the atomic models of Earnest Rutherford (1871-1937), he introduced the idea that as a photon strikes an orbiting electron the electron instantly absorbs then releases the energy in the form of another photon. This occurs instantaneously causing the electron to change then return to its energy state. Strangely, however, the electron does not move in any conventional way - it teleportes in what is known as a “quantum leap”.
Vanished in a Puff of Logic
Werner Heisenberg (1901-1976) and Louis de Broglie (1892–1987) are actually at the center of this issue. Heisenberg was the one to establish the PQI in 1927. The PQI is important because it completely shatters the assumptions in classical physics and our common sense about cause and effect relationships. From as early as Pierre Simon Laplace (1749-1847) it had been supposed that the only thing preventing us from making perfect predictions of physical events in the universe was the absence of perfect information.
Only an omniscient being with a perfect inventory of information concerning the motions and positions of elementary particles at a given instant could make perfect predictions and this omniscience was seen merely as an obstacle of technology. Heisenberg found, however, that it was simply not possible to construct a research design to collect data about both the position and momentum of particles simultaneously. This is because experiments collect raw data in units and those units can come in particles or waves, but not both simultaneously.
He found that as you seek finer degrees of precision in position you lose precision in determining momentum at a given instant. Likewise, as you seek finer degrees of precision in momentum you lose precision in determining position at a given instant. He captured this inverse relationship in a simple equation where a change in position multiplied by a change in momentum was always equal to or greater than half of Plank’s Constant. Laplace’s omniscient being thus vanished in a puff of logic against the wings of a butterfly and for the past 90 years the physics community has left everyone else and their common sense behind.
At around the same time Louis de Broglie (1892-1987) was shattering yet another common sense notion. He had the temerity to suggest that if events can have particle-like properties then physical objects can have wave-like properties. Can a baseball have a wave function? It turns out that yes, it can. As Heisenberg’s equation and de Broglie’s relation clearly indicate, as we cast our gaze further and further into microscopic scales of size and distance at or below the diameter of an ordinary atom the distinction between waves and particles, objects and events vanishes.
Likewise, as Einstein demonstrated in his theories of relativity, as we cast our gaze further and further into macroscopic scales of size and distance the distinction between time and space vanishes and distances can only be properly understood in terms of light years.
God's Casino - Open 24/7
What truly lies at microscopic scales of size and distance seems at first blush to be both wave-like and particle-like phenomena simultaneously, but Bohr and assorted other contributors of Quantum Physics held the more radical notion that what truly lies at microscopic scales of size and distance is neither.
It is only our inability to know the world in any other way that prevents us from knowing the truth. We have only mathematical descriptions with no adequate conceptual models that can make any sense to us. When we describe an electron as a particle or a wave it depends on the context. This is known as the Copenhagen Interpretation. So radical was this notion that even Einstein had great difficulty accepting it, once telling Bohr, God doesn’t play dice with the universe.” To which Bohr replied, “Albert, stop telling God what to do.”
In conclusion, I have cut to the chase and treated this subject with extreme simplicity, but we have in fact reached an end to physics as a passive study of the universe to find that it is much more an active, co-creative process between the observer and the observation. Many contemporary physicists remain locked onto an age old mirage that we are on the precipice of some grand unified theory that explains everything, but this is as close as it gets. Go back and reread this series to get the larger picture. As always, comments and questions are welcome.
"Reality testing is built into the process of naming things, one of the most elementary transactions of existence, that back and forth between the stimulus of the environment and reflections of the mind makes up the kind of thought we will be trying to capture for analysis." ~Hoover, Kenneth, Elements of Social Scientific Thinking.
Sources:
- Hoover, Kenneth, Elements of Social Scientific Thinking, Wadsworth Publishing; 2010 edition (February 17, 1954, 2010)
- Hawking, Stephen, A Brief History of Time, Bantam; 10th anniversary edition (September 1, 1998)
- Hazen, Robert M & Trefil, James, Science Matters: Acheiving Scientific Literacy, Anchor; Reprint edition (June 2, 2009)
- Shermer, Michael, Why People Believe Weird Things, Pseudo-Science, Superstition and Bogus Notions of Our Time, MJF Books (August 1997)
- Postman, Niel, Amusing Ourselves to Death: Public Discourse in the Age of Show Business, Penguin (Non-Classics); 20 Anv edition (December 27, 2005)
- Bodanis, David, E = MC Squared: A Biography of the World's Most Famous Equation, Berkley Trade; 1st edition (October 9, 2001)
- Chaos & Fractals: The Butterfly Effect
Join the Conversation