: Puzzling Quantum Scenario Appears Not to Conserve Energy
by Kristina Armitage
The quantum paradox is akin to red light turning green.
The quantum physicists Sandu Popescu, Yakir Aharonov and Daniel Rohrlich have been troubled by the same scenario for three decades.
It started when they wrote about a surprising wave phenomenon called
superoscillation in 1990. “We were never able to really tell what
exactly was bothering us,” said Popescu, a professor at the University
of Bristol. “Since then, every year we come back and we see it from a
Finally, in December 2020, the trio published a paper
in the Proceedings of the National Academy of Sciences
explaining what the problem is: In quantum systems, superoscillation
appears to violate the law of conservation of energy. This law, which
states that the energy of an isolated system never changes, is more than
a bedrock physical principle. It’s now understood to be an expression
of the fundamental symmetries of the universe — a “very important part
of the edifice of physics,” said Chiara Marletto
, a physicist at the University of Oxford.
Physicists are divided as to whether the new paradox exposes a genuine
violation of the conservation of energy. Their attitudes toward the
problem depend in part on whether individual experimental outcomes in
quantum mechanics should be considered seriously, no matter how
improbable they may be. The hope is that by putting in the effort to
resolve the puzzle, researchers will be able to clarify some of the most
subtle and strange aspects of quantum theory...