Imagine we have two free, entangled [by their spins, which are in this case non-separable, while $x$ (or $p$) electrons are clearly separable]. In an experimental setup, we can measure (and observe) the spin of one electron and the spin of the other electron becomes instantaneously the opposite of the other electron's spin.

Now imagine the same entangled pair existing in Nature, long before humans appeared who could do measurements and observations. Can this pair become disentangled by a process which resembles the process of the modern time experiment in Nature, say by a then in Nature existing uniform magnetic field, through which one electron of the pair travels making its spin have a well-defined value (up or down, relative to a certain axis) and thereby imparting instantaneously an opposite spin on the other electron along the same axis? Or do we need the human act of observation to let the electrons become disentangled?

I can't imagine that a pair of entangled electrons "knows" if we are making the measurement and observation, or Nature itself (of course the act of observation isn't present in the case of a Natural measurement) if some magnetic field in which one electron finds itself, causes the spin of this electron to become up or down into a preferred direction and thereby sending the spin of the other electron in a state of opposite spin.

Or does the act of observation (of which I already said that the spin of one electron has no "knowledge" about), and nothing else cause the spin of the electron to have a well-defined direction, and so the second electron. That is, we don't look at the measurements result, and only if we observe the measurements they become real measurements, after which the electrons take their final spins, in accordance with the measurements. Something I find even harder to imagine.

You may think there are resemblances with Schrodinger's cat, and rightly so.

And by the way, if observation by a conscious creature is necessary for letting the measurements become real, how could conscious creatures ever develop if you need the creatures themselves to make measurements real, a necessity for conscious creatures to develop?

  • $\begingroup$ Sure - one could scatter off of something. $\endgroup$ – Jon Custer Jun 19 '17 at 19:11
  • $\begingroup$ How this affects the spin of the other electron? Has the scattered electron a well-defined spin after the scattering? Which in turn makes the other electron have instantaneously an opposite spin. If so then this proves that the observation doesn't play a role in determining the outcome of an experiment (like in Schrodinger's cat). $\endgroup$ – descheleschilder Jun 20 '17 at 5:30

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