The Future Is Here
We may earn a commission from links on this page

Forget Schrödinger's Cat: The Latest Quantum Puzzle Is About Three Pigeons in Two Holes

We may earn a commission from links on this page.

For decades, Schrödinger’s famous thought experiment involving a cat has been the turn-to illustration of quantum mechanics. But now there’s a new quantum puzzle, which asks: Can three pigeons be placed into two pigeonholes with no two pigeons being in the same hole?

Prepare for your brain to hurt a little as you read what the researchers describe in the abstract of their newly published paper:

“If you put three pigeons in two pigeonholes, at least two of the pigeons end up in the same hole,” is an obvious yet fundamental principle of nature as it captures the very essence of counting. Here however we show that in quantum mechanics this is not true! We find instances when three quantum particles are put in two boxes, yet no two particles are in the same box.


The research, published in the Proceedings of the National Academy of Sciences, shows—through a series of complex quantum calculations that seem fairly impenetrable—that it’s possible to put an arbitrarily large number of particles into two boxes without any two particles ever ending up in the same one box.

Right. Yes, that is pretty bewildering—but then, it seems to be for the researchers too. Speaking to PhysOrg, Jeff Tollasken, one of the researchers, explained:

It is still very early to say what the full implications of this research are... But we feel one should expect them to be major because we are dealing with such fundamental concepts.


We can probably expect this new discovery to shape modern thinking about some of the weirder parts of quantum behavior, like spooky action at a distance. Quite how, though? We’ll just have to wait and see.

[Proceedings of the National Academy of Sciences via PhysOrg]

Image by Frank Serritelli