Open_Minded
Nothing is Separate
NPR Article
It's an interesting Reality that we live in.
Of the many mysteries of modern physics, few compare to "nonlocality" in quantum physics. Nonlocality means that far away objects can influence one another instantaneously (or, at least, much faster than the speed of light). It is as if space and time didn't exist!
"Influence" may not be the right word here; in fact, we don't have a good word for it given that words are devices we create to express experiences anchored in our sensorial perception of reality.
When a ball hits the goal or a raindrop falls, we know there is a local cause: the kick, the heavy raincloud. In the quantum world, the world of electrons and photons, effects can occur without a local cause, something I explored here a .
Experiments have verified nonlocality beyond any reasonable doubt.
On the other hand, very serious scientists, such as Nobel laureate Eugene Wigner and his Princeton colleague John Wheeler, have considered the role of consciousness in physics and to what point it determines the reality in which we live.
We use a detector when we measure something small. We don't have direct contact with an electron or an atom. Its existence is registered when it interacts with (the electrons and atoms of) a detector and we hear a click or see a pointer move. In the orthodox interpretation of quantum physics, it is this interaction that determines the existence of the particle: before the measurement we can't say that the particle exists. Something only exists after it is detected.
Wigner and Wheeler suggested that without an observer to set things up and interpret the results, without a consciousness with intent, this measurement doesn't make sense. In this case, the particle's existence is contingent on its interaction with the human consciousness. More dramatically, consciousness has an active role in determining what exists.
Wheeler imagined an experiment where a particle goes through a double-slit obstacle and then meets a screen. This screen is movable and can be taken away. Behind it, there are two detectors aligned with each of the two slits of the obstacle. This way, without the screen in the middle, the detectors can tell through which slit the particle passed. There are thus two options: with the screen, the particle (as a wave) "passes through both slits" and we see an interference pattern on the screen made of dark and light stripes; without the screen one of the two detectors will click when the particle hits it and the particle "goes through one slit." Two very different paths, depending on the screen being there or not.
Wheeler added an amazing twist to this set up: take the screen away after the particle passed through the double-slit. This way, the observer controls whether the particle should create an interference pattern (as a wave) or just hit one of the two detectors (as a particle); the particle doesn't "know" which of the two it will be, or which path it must take. In other words, the observer determines the physical reality of the particle (wave or particle) backwards in time!
Remarkably, Wheeler's "delayed choice" experiment has been performed and and again with even more stringent controls.
Somehow, observer and observed form an indissoluble whole that functions outside the boundaries of time.
Note, however, that the observer need not be a human, but a mechanical control that moved the screen in an out. Still, the intent is human. As Wheeler put it:We have a strange inversion of the normal order of time. We, now, by moving the [screen] in or out have an unavoidable effect on what we have a right to say about the already past history of that photon.