Little Lost wrote:I felt the YouTube clip about the 2 slit experiment seems to suggest that the action of simply visually “looking” at an electron, is what made it change its behavior, and in addition to this you ask “How does MATTER know it was being observed”
So the starting point is we know that observing the electron changed something.
View 1
It is the observation itself that makes the wave function collapse. Either the electron is self-aware, or perhaps the consciousness mind can have an direct effect on the physical world, later in the post you put forward an whole array of many fantastic examples of such a possibility (DNA manipulation, consciously focusing on influencing random number generators). So this view has been well represented. However as you will be aware there is a camp 2 and possibly a camp 3, so for the sake of balance let’s air them.
View 2:
In the experiment the observer is not a conscious agent, i.e, not a physicist actually directly visualising it. The observer is acyually a mechanical detector that is part of the experimental apparatus. In order to make an observation, this inorganic detector must interact with the electron, so this opens the possibility that it is the detector device and not a conscious person which collapses the wave function and destroys the interference pattern.
Steven Hawkins addresses this in his book “The Grand Design”. He says it is the “REQUIRING TO SEE” that changes the course. To see things requires the detector to use photons (packages of light) to hit and reflect off the object in this case the electron. Despite photons having no mass or electrical charge they can still move other particles around. Therefore the bouncing of the photons off the electron changes its energy, momentum and position. The electrons state is irrevocably changed thereby altering the outcome of the experiment.
Hawking likens it to rolling of a football along the ground (the electron). Now throw balls at it from the side (the light photons). You are then going to change the way the football behaves by physical interaction. ( additionally if this takes place in the dark it would not be possible to know where or at what velocity the football was moving before the hit).
View 3:
So in this camp are non quantum mechanical explanations. For example some doubt that the electron fired is the same electron that is being detected, due to the inability to establish the trajectory path.
I think they have recently used other methods to try to determine which slit the particle (a photon this time) went through, without interfering with its wave-like properties. This seems to generate even more arguments and counterarguments. It is termed one of the most curious and perplexing puzzles in physics.
It is interesting that one day in the 1920's when Albert Einstein was out walking in the woods with one of his close friends, he suddenly turned around and asked 'does the moon continue to exist when we stop looking at it.
I do understand and was taught about the observer effect. That every measurement changes the object that we want to measure, and this give rise to the whole question of whether we can ever know the true nature of things. How much it influences an experiment I think depends on 2 factors, firstly how large an influence it is , and secondly how predictable are the changes they evoke Hidden variables is one of the main reasons that experiments have to be reproducible Not everything can be compensated for, but variables can be reduced.
Without doubt the “observer effect” is hugely frustrating for certain sciences such as quantum physics, where investigatory methods influence the situation and velocity of small particles. Also running out into a field of lions blinding them with camera flashes will influence the lions' behaviour, but how far should the “observer effect” be considered. For example should we stop taking patients temperatures because the very act of placing the cool probe in the armpit (or ear) will interfere with the result by lowering the actual true temperature, so the reading won’t be true? No because the end result is the same, the patient has a high temperature. The observer effect has not been influential enough to render this equipment useless.
Radin et al attempted to differentiate in a series of double-slit experiments that appear to favor the consciousness-related interpretation of QM.
http://www.deanradin.com/papers/Physics ... 0final.pdf
Cheers,
Bill