Heisenberg cut

plural Heisenberg cuts · alternative Heisenberg's cut

1. quantum mechanicshuman sciencesA conceptualised division separating the quantum system being observed from the classical system that comprises the observer's information, knowledge and conscious awareness.

   The location of the Heisenberg cut is arbitrary, but it must be at a point where classical physics assuredly holds.

   2021, Carl S. Helrich, The Quantum Theory—Origins and Ideas, Springer, page 192

   2 more examples

   The original "Copenhagen" way of describing the collapse process was tied to a mysterious thing called the "Heisenberg cut". Everything lying "below" this cut was supposed to be described in the mathematical language of quantum mechanics, whereas everything lying "above" the cut was described either in the language of classical physics, or in psychological or mental terms.[…]A principal move made by von Neumann was to show that the Heisenberg cut could be moved all the way up, so that reality was unambiguously separated into a purely mental part, and a part described in the mathematical language of quantum mechanics.

   2014, Henry P. Stapp, “Quantum Physics and Philosophy of Mind”, in Antonella Corradini, Uwe Meixner, editors, Quantum Physics Meets the Philosophy of Mind, Walter de Gruyter, page 9

   Another idea is to question the impermeability of the Heisenberg cut: Is the separation between the macro and micro worlds really as sharp as Heisenberg and Bohr assumed?

   2018, Lars Jaeger, The Second Quantum Revolution, Springer, page 252