Real numbers don’t cut it in the real world, this physicist argues | Science News

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Real numbers don’t cut it in the real world, this physicist argues

They may fall short in describing nature, potentially opening the door in physics to free will

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10:00am, May 8, 2018
illustration of numbers

REALLY REAL  The mathematical ideal of real numbers might not appropriately represent the reality of the real world, says physicist Nicolas Gisin.

You would be forgiven for thinking that real numbers are, in fact, real — the word is right there in the name. But physicist Nicolas Gisin doesn’t think so.

He’s not questioning the mathematical concept of a real number. The term refers to a number that isn’t imaginary: It has no factor of i, the square root of negative one. Instead, Gisin, of the University of Geneva, debates the physical reality of real numbers: Do they appropriately represent nature? Physicists regularly use real numbers to describe the world: velocities, positions, temperatures, energies. But is that description really correct?

Gisin — known for his work on the foundations and applications of quantum mechanics — takes issue with real numbers that consist of a never-ending string of digits with no discernable pattern and that can’t be calculated by a computer. Such numbers (for example, 1.9801545341073… and so on) contain an infinite amount of

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