Why the Watched Pot May Actually Never Boil, According to Quantum Physics

June 29, 2014 Updated: June 29, 2014

Could your thoughts prevent a particle from decaying? Could your thoughts speed up the particle’s decay?

Experiments in quantum physics have shown that the researcher can physically impact what he or she is observing simply by observing it.

Researchers have found that the act of measuring some particles can either stop or speed up the particles’ decay. Measuring more frequently inhibits the decay. It’s like the proverbial watched pot that never boils.

By adjusting the measuring time in other ways (described in more detail below), the researchers were also able to speed up decay. These effects of observation violate the classical universal law of exponential decay.

Slowing the decay is known as the quantum Zeno effect. It was first presented in the 1977 paper “The Zeno’s Paradox in Quantum Theory,” published in the Journal of Mathematical Physics and written by Baidyanaith Misra and George Sudarshan. It is named for the ancient Greek philosopher Zeno of Elea.

Long-time physics writer Andrew Zimmerman Jones explains Zeno’s paradox in an About.com article: “In order to reach any distant point, you have to cross half of the distance to that point. But to reach that, you have to cross half that distance. But first, half of that distance. And so forth … so that it turns out you actually have an infinite number of half-distances to cross and, therefore, you can’t actually ever make it!”

It’s a mind-bender, but so is almost anything to do with quantum physics.

The act of speeding up the decay is known as the anti-Zeno effect.

Physicists at The University of Texas–Austin tested the Zeno and anti-Zeno effects on unstable particles and published their findings in the journal Physical Review Letters in 2001. Their research focused on sodium atoms. 

The Zeno effect worked. In comparison to unperturbed samples, the decay was suppressed in the particles that were frequently measured. The anti-Zeno effect was also successfully produced.


Anti-Zeno Effect

When the particles were left to decay uninterrupted by measurements, they showed a pattern in which an initial period of slow decay was followed by a steep drop, which was then balanced out to a more steady rate of decay.

The physicists hypothesized that, if they interrupted the decay right after the steep drop, they could keep the particles in that state—the state of very rapid decay. When they put this hypothesis into action, they found it worked.

This won’t help us achieve immortality, slowing our bodily decay to a virtual stand-still—or at least not without huge leaps in understanding from what scientists now know. But, it could help us develop quantum computers.


Quantum Computers

The super-computing power of the hypothetical quantum computer could help solve complex problems in a variety of fields, from chemistry to artificial intelligence.

In an article titled “Microsoft Makes Bet Quantum Computing Is Next Breakthrough,” New York Times reporter John Markoff explained: “Conventional computing is based on a bit that can be either a 1 or a 0, representing a single value in a computation. But quantum computing is based on qubits, which simultaneously represent both zero and one values.”

“In an ‘entangled’ state—physically separated but acting as though they are connected—with many other qubits, they can represent a vast number of values simultaneously,” he continued. “And the existing limitations of computing power are thrown out the window.”

Researchers at Humboldt University in Berlin found that the quantum Zeno effect may take place in diamonds, making diamonds a candidate material for building quantum computers. The researchers published their findings in the journal Physical Review A in 2013 titled “Study of the Quantum Zeno Phenomenon on a Single Solid State Spin.”

The team focused on an electron found in a kind of imperfection in a diamond. The team used microwaves to change the magnetic spin state of the electron. They found that the electron would stop oscillating between the two possible states if it was measured frequently.

Ronald Walsworth, an atomic physicist at Harvard University, had suggested in 2010 that the Zeno effect may operate in diamonds. After the Humbolt University researchers published their findings, Walsworth told Nature that evidence is growing, but before we start planning to build quantum computers with diamond, further research must verify that the disruption is due to the quantum process and not to other factors.

*Images of a boy looking down, a pot full of water, and a conceptual illustration related to quantum physics via Shutterstock