Quantum Measurement

My question relates to the observation element of the two slit experiment and whether anybody has taken it further in the following way or similar? Suppose the "camera" is set up to record which slit the electron passes through, and the data is recorded but retrievable only after the experiment. Before the experiment, the scientists toss a coin, heads means the data will definitely be retrieved and analysed afterwards, and tails means the data will definitely be destroyed without viewing it. Could or would this affect the outcome at all - i.e. has it been established that recording the data (even if it will never ever be observed by a conscious being!) is what 'collapses' the wave behaviour, or does it have to be observed in the sense of "consciousness" for this to happen. I'm sure something along these lines would have been tested but I cannot find the answer anywhere and am curious so any insight would be much appreciated. Thanks, Rob
- Rob (age 36)
London, UK

There are many experiments on quantum decoherence, quantum erasers, and so forth. They are all consistent with the idea that two paths quit showing interference if which-way information exists somewhere.  It's not necessary for anybody to actually look at it. It's also not necessary for the information even to be readable by any imaginable creature, just that something is different depending on which path was taken. So "destroying the data" in the usual sense of the word wouldn't restore the interference. Truly destroying any trace of the evidence (quantum erasure) does restore interference, but thee's no way to do that once any sort of ordinary record exists.

Mike W.

(published on 08/30/2016)