- #1
Gerinski
- 323
- 15
Hi. I came to think that people use the term "observer effect", or "measurement problem", to talk about what I perceive as two distinct things, and I would like to hear opinions around here.
One sense people may use the term is the infamous "wavefunction collapse", why if quantum theory describes a world of waves we experience a world of particles. The dichotomy emerged in the early days of quantum experiments where "collapse" was related to the act of observation of experimental results, theory would predict some probabilities for certain outcomes and observations of the experimental results matched the predictions, and this was much before potential mechanisms for the "transition from waves to particles" like decoherence or the gravitational collapse proposed by Penrose would appear.
So some people deduced that it must be the actual measurement by the experimenter which caused the collapse.
Personally I like to think that the universe evolved in a definite state before any Life emerged, so I reject the "consciousness causes collapse" view. I believe in spontaneous collapse, I don't have enough knowledge to say whether it happens by decoherence, by gravity or any other mechanism. But I want to believe that the universe takes a definite state regardless whether there are any conscious observers or not.
The other sense people may use the term is what I would call, perhaps for lack of better words, "consciousness-induced collapse". It seems clear that given some identical experimental setup, we can decide what to do with it and our decision will change the outcome. We can decide whether to block one slit or whether to leave both open, and that decision will change what the future will be like.
Unless you believe in Superdeterminism, it seems that our conscious decisions can change what the evolution of a system will be like. This second sense is what to me represents "the real observer effect", not the first one regarding "spontaneous wavefunction collapse".
Whether all Life has the ability to cause such a collapse or not is a big question, surely many animals other than humans can take decisions which will alter the future, in a more or less conscious way. I guess this is a too difficult subject so I do not want to enter into it here, the purpose of the question is not this. It is only whether I am right in discerning two different subjects for what some people usually commonly describe as "observer effect" or "measurement problem", in my view two distinct subjects "spontaneous collapse" and "consciousness-induced collapse".
P.S. Of course I know that interpretations such as the Many Worlds Interpretation simply deny the existence of collapse. So replies along those lines, while welcome, will not offer much to the discussion subject. My main objection to MWI is that it still requires explanations as to in which realms does it manifest. We can observe superposition in "our universe", multitude of experiments show superposition. But we, ourselves, can not experience superposition. MWI suggests that the wavefunction extends to system plus observer, up to whatever scale. That each possible reality co-exists. But if so, we should not experience superposition in our universe, it should be a different universe for each state version. And yet, on small enough scales we do observe superposition. Why do realities in that tiny scale superpose in our universe but not superpositions on larger scales? In my humble opinion MWI runs into the same problems as those which decoherence wants to address. The MWI is not linear across the scale range, since it must explain why in anyone version of the universe we can still observe superposition in the small scales.
In summary, I would like to hear opinions about my distinction of the "observer effect" or "measurement problem" as two distinct subjects, "spontaneous collapse" and "consciousness-induced collapse", whether people agree with the distinction or nor, and in that case why so.
Thanks!
One sense people may use the term is the infamous "wavefunction collapse", why if quantum theory describes a world of waves we experience a world of particles. The dichotomy emerged in the early days of quantum experiments where "collapse" was related to the act of observation of experimental results, theory would predict some probabilities for certain outcomes and observations of the experimental results matched the predictions, and this was much before potential mechanisms for the "transition from waves to particles" like decoherence or the gravitational collapse proposed by Penrose would appear.
So some people deduced that it must be the actual measurement by the experimenter which caused the collapse.
Personally I like to think that the universe evolved in a definite state before any Life emerged, so I reject the "consciousness causes collapse" view. I believe in spontaneous collapse, I don't have enough knowledge to say whether it happens by decoherence, by gravity or any other mechanism. But I want to believe that the universe takes a definite state regardless whether there are any conscious observers or not.
The other sense people may use the term is what I would call, perhaps for lack of better words, "consciousness-induced collapse". It seems clear that given some identical experimental setup, we can decide what to do with it and our decision will change the outcome. We can decide whether to block one slit or whether to leave both open, and that decision will change what the future will be like.
Unless you believe in Superdeterminism, it seems that our conscious decisions can change what the evolution of a system will be like. This second sense is what to me represents "the real observer effect", not the first one regarding "spontaneous wavefunction collapse".
Whether all Life has the ability to cause such a collapse or not is a big question, surely many animals other than humans can take decisions which will alter the future, in a more or less conscious way. I guess this is a too difficult subject so I do not want to enter into it here, the purpose of the question is not this. It is only whether I am right in discerning two different subjects for what some people usually commonly describe as "observer effect" or "measurement problem", in my view two distinct subjects "spontaneous collapse" and "consciousness-induced collapse".
P.S. Of course I know that interpretations such as the Many Worlds Interpretation simply deny the existence of collapse. So replies along those lines, while welcome, will not offer much to the discussion subject. My main objection to MWI is that it still requires explanations as to in which realms does it manifest. We can observe superposition in "our universe", multitude of experiments show superposition. But we, ourselves, can not experience superposition. MWI suggests that the wavefunction extends to system plus observer, up to whatever scale. That each possible reality co-exists. But if so, we should not experience superposition in our universe, it should be a different universe for each state version. And yet, on small enough scales we do observe superposition. Why do realities in that tiny scale superpose in our universe but not superpositions on larger scales? In my humble opinion MWI runs into the same problems as those which decoherence wants to address. The MWI is not linear across the scale range, since it must explain why in anyone version of the universe we can still observe superposition in the small scales.
In summary, I would like to hear opinions about my distinction of the "observer effect" or "measurement problem" as two distinct subjects, "spontaneous collapse" and "consciousness-induced collapse", whether people agree with the distinction or nor, and in that case why so.
Thanks!