Which says that if there are more holes than pigeons, some pigeons must share:
In the study, three photons took the place of the pigeons. Rather than crowding the photons into holes, the researchers studied the polarization of the particles, or the orientation of the photons’ wiggling electromagnetic waves, which can be either horizontal or vertical. Since there were three photons and two polarizations, standard math would suggest that at least two must have had the same polarization. When the scientists compared the particles’ polarizations, the team found that no two particles matched, verifying that the quantum pigeonhole effect is real.Emily Conover, “Photons reveal a weird effect called the quantum pigeonhole paradox” at Science News
Paper. (paywall) Significance:
We have demonstrated the quantum pigeonhole paradox with three single photons. The effect of variable-strength quantum measurement is experimentally analyzed order by order and a transition of violation of the pigeonhole principle is observed. We find that the different kinds of measurement-induced entanglement are responsible for the photons’ abnormal collective behavior in the paradox. The experimental violation of pigeonhole principle presents a challenge to the fundamental counting principle of nature. – Ming-Cheng Chen, Chang Liu, Yi-Han Luo, He-Liang Huang, Bi-Ying Wang, Xi-Lin Wang, Li Li, Nai-Le Liu, Chao-Yang Lu, and Jian-Wei Pan PNAS January 29, 2019 116 (5) 1549-1552; published ahead of print January 29, 2019 https://doi.org/10.1073/pnas.1815462116
See also: Whether or not man has free will, quantum mechanics means that nature does
and
If quantum mechanics were a researcher, she’d be fired
Note: The recent uproar around a review of Adam Becker’s book at Inference Review, denounced by Becker at Undark, turned on issues in quantum mechanics. “So Inference Review allows dissenting opinion and Peter (PayPal) Thiel made money in the new economy. Which proves what, exactly? Becker goes on at length, editorializing against Inference Review, which he is compelled neither to read nor support through his tax funds. – News ”