Schrödinger's cat sits in a closed box, and as long as no one opens the lid, it is both alive and dead at the same time. This is strange, but that's how the quantum world works. Physicists have long debated exactly when the cat becomes one or the other. A new study says: at the moment the measuring device finishes its job.
Imagine you're listening to a very quiet whisper. You can't make out the words until you amplify the sound. The amplifier makes the whisper loud, and then you hear either "yes" or "no". It's the same with the cat. The amplitude that describes its state is amplified, and with strong amplification two branches appear: a live cat and a dead cat.
When the amplification is complete and the connection to the measuring device is severed, the cat is already determined. It's as if a judge has pronounced a verdict and closed the case. Until that moment, the cat was in limbo. This view aligns with our intuition: large objects have properties in and of themselves, regardless of whether we look at them or not.
Schrödinger's cat was proposed as a mockery of the Copenhagen interpretation, yet today cat states are created in laboratories with hundreds of photons.
The idea that reality is determined by measurement is played with in the film Interstellar, where quantum data are transmitted through a wormhole.