There is, of course, a fairly simple alternative solution, dealing with “real” particles; the photons coming out of the filters are not the photons that went in. Photons don’t travel through the sheet; the energy is absorbed, and the properties of individual components of energy determine what happens next. The properties of some chunks of energy cause similarly-propertied energy to be re-emitted on the other side. It’s not that the photons have mysteriously lost the information about their “spin” in the middle sheet—it’s that we’re dealing with new photons with new property sets, which are being re-emitted with the emission properties of the second sheet, rather than the first.
With this interpretation, the phenomenon makes perfect sense, and the old textbooks are right—after a fashion—that the second measurement destroyed the information that the first measurement generated.
There is, of course, a fairly simple alternative solution, dealing with “real” particles; the photons coming out of the filters are not the photons that went in. Photons don’t travel through the sheet; the energy is absorbed, and the properties of individual components of energy determine what happens next. The properties of some chunks of energy cause similarly-propertied energy to be re-emitted on the other side. It’s not that the photons have mysteriously lost the information about their “spin” in the middle sheet—it’s that we’re dealing with new photons with new property sets, which are being re-emitted with the emission properties of the second sheet, rather than the first.
With this interpretation, the phenomenon makes perfect sense, and the old textbooks are right—after a fashion—that the second measurement destroyed the information that the first measurement generated.