Schrödinger found superposition so odd he tried to illustrate its absurdity by a thought experiment. He imagined his cat in a box with a radioactive source that could randomly emit a photon to trigger a deadly poison gas. In quantum theory, a photon plus detector is a quantum system that both detects and doesn’t detect the photon until observed. If the box is also a quantum system it also superposes and the poison is both released and not, so the cat is in an alive-dead superposition until Schrödinger opens the box. But how can a cat be alive and dead? Or if cats can’t be alive and dead, how can photons exist and not exist? Or if photons can do this but cats can’t, when does the superposition stop?
In quantum realism, a photon spreads on the network until an overload restarts it in what we call an “observation”. So observing the world formally causes what we see but this isn’t a sufficient cause as every observation is an interaction between two parties. Quantum realism isn’t that we alone are dreaming the physical world but that our interaction with the quantum world generates a physical view.
If quantum collapse is the result of a quantum network overload, then any overload will cause it, not just those that involve us. So the quantum superposition collapses immediately the detector records a photon. It then releases the poison regardless of whether Schrödinger sees it or not. Likewise, the cat interacts with the poison whether Schrödinger sees it or not. Before opening the box, Schrödinger doesn’t know whether the gas was released but the cat does (or did). Quantum superposition stops the moment any observation occurs. It is not delayed until we interact with the system. In quantum realism, quantum collapse occurs with any observation, not just those that involve human eyes.
This approach requires that we are not the only observers of physical reality. In quantum realism, every physical event is an observation, so when we observe a photon, it is also “observing” us. The universe isn’t a virtual reality just for us, as a dream would be, so quantum events were generating physical events long before our species came along. Quantum realism implies that everything is “observing” everything else in a fundamental sense.