pcalau12i

@pcalau12i@lemmygrad.ml

• ⁨Comment⁩ on ⁨Don't look now⁩ ⁨⁨3⁩ ⁨weeks⁩ ago⁩:

  We know how it works, we just don’t yet understand what is going on under the hood.

  Why should we assume “there is something going on under the hood”? This is my problem with most “interpretations” of quantum mechanics. They are complex stories to try and “explain” quantum mechanics, like a whole branching multiverse, of which we have no evidence for.

  It’s kind of like if someone wanted to come up with deep explanation to “explain” Einstein’s field equations and what is “going on under the hood”. Why should anything be “underneath” those equations? If we begin to speculate, we’re doing just tha,t speculation, and if we take any of that speculation seriously as in actually genuinely believe it, then we’ve left the realm of being a scientifically-minded rational thinker.

  It is much simpler to just accept the equations at face-value, to accept quantum mechanics at face-value. “Measurement” is not in the theory anywhere, there is no rigorous formulation of what qualifies as a measurement. The state vector is reduced whenever a physical interaction occurs from the reference point of the systems participating in the interaction, but not for the systems not participating in it, in which the systems are then described as entangled with one another.

  This is not an “interpretation” but me just explaining literally how the terminology and mathematics works. If we just accept this at face value there is no “measurement problem.” The only reason there is a “measurement problem” is because this contradicts with people’s basic intuitions: if we accept quantum mechanics at face value then we have to admit that whether or not properties of systems have well-defined values actually depends upon your reference point and is contingent on a physical interaction taking place.

  Our basic intuition tells us that particles are autonomous entities floating around in space on their lonesome like little stones or billiard balls up until they collide with something, and so even if they are not interacting with anything at all they meaningfully can be said to “exist” with well-defined properties which should be the same properties for all reference points (i.e. the properties are absolute rather than relational). Quantum mechanics contradicts with this basic intuition so people think there must be something “wrong” with it, there must be something “under the hood” we don’t yet understand and only if we make the story more complicated or make a new discovery one day we’d “solve” the “problem.”

  Einstein once said, God does not place dice, and Bohr rebutted with, stop telling God what to do. This is my response to people who believe in the “measurement problem.” Stop with your preconceptions on how reality should work. Quantum theory is our best theory of nature and there is currently no evidence it is going away any time soon, and it’s withstood the test of time for decades. We should stop waiting for the day it gets overturned and disappears and just accept this is genuinely how reality works, accept it at face-value and drop our preconceptions. We do not need any additional “stories” to explain it.

• ⁨Comment⁩ on ⁨Gottem. :)⁩ ⁨⁨4⁩ ⁨weeks⁩ ago⁩:

  So usually this is explained with two scientists, Alice and Bob, on far away planets. They’re each in the possession of a particle that is entangled with the other, and in a superposition of state 1 and state 2.

  This “usual” way of explaining it is just overly complicating it and making it seem more mystical than it actually is. We should not say the particles are “in a superposition” as if this describes the current state of the particle. The superposition notation should be interpreted as merely a list of probability amplitudes predicting the different likelihoods of observing different states of the system in the future.

  It is sort of like if you flip a coin, while it’s in the air, you can say there is a 50% chance it will land heads and a 50% chance it will land tails. This is not a description of the coin in the present as if the coin is in some smeared out state of 50% landed heads and 50% landed tails. It has not landed at all yet!

  Unlike classical physics, quantum physics is fundamentally random, so you can only predict events probabilistically, but one should not conflate the prediction of a future event to the description of the present state of the system. The superposition notation is only writing down probability amplitudes of the likelihoods of what you will observe (state 1 or state 2) of the particles in the future event that you go to the interact with it and is not a description of the state of the particles in the present.

  When Alice measures the state of her particle, it collapses into one of the states, say state 1. When Bob measures the state of his particle immediately after, before any particle travelling at light speed could get there, it will also be in state 1 (assuming they were entangled in such a way that the state will be the same).

  This mistreatment of the mathematical notation as a description of the present state of the system also leads to confusing language like “it collapses into one of the states” as if the change in a probability distribution represents a physical change to the system. The mental picture people say this often have is that the particle literally physically becomes the probability distribution prior to measuring it—the particle “spreads out” like a wave according to the probability amplitudes of the state vector—and when you measure the particle, this allows you to update the probabilities, and so they must interpret this as the wave physically contracting into an eigenvalue—it “collapses” like a house of cards.

  But this is, again, overcomplicating things. The particle never spreads out like a wave and it never “collapses” back into a particle. The mathematical notation is just a way of capturing the likelihoods of the particle showing up in one state or the other, and when you measure what state it actually shows up in, then you can update your probabilities accordingly. For example, if you the coin is 50%/50% heads/tails and you observe it land on tails, you can update the probabilities to 0%/100% heads/tails because you know it landed on tails and not heads. Nothing “collapsed”: you’re just observing the actual outcome of the event you were predicting and updating your statistics accordingly.

• ⁨Comment⁩ on ⁨Observer⁩ ⁨⁨4⁩ ⁨weeks⁩ ago⁩:

  I don’t think solving the Schrodinger equation really gives you a good idea of why quantum mechanics is even interesting. You also shouldstudy very specific applications of it where it yields counterintuitive outcomes to see why it is interesting, such as in the GHZ experiment.

• ⁨Comment⁩ on ⁨You'll never see it coming⁩ ⁨⁨2⁩ ⁨months⁩ ago⁩:

  By applying both that and the many worlds hypothesis, the idea of quantum immortality comes up, and thats a real mind bender. Its also a way to verifiably prove many worlds accurate(afaik the only way)

  MWI only somewhat makes sense (it still doesn’t make much sense) if you assume the “branches” cannot communicate with each other after decoherence occurs. “Quantum immortality” mysticism assumes somehow your cognitive functions can hop between decoherent branches where you are still alive if they cease in a particular branch. It is self-contradictory. There is nothing in the mathematical model that would predict this and there is no mechanism to explain how it could occur.

  It also has a problem similar to reincarnation mysticism. If MWI is correct (it’s not), then there would be an infinite number of other decoherent branches containing other “yous.” Which “you” would your consciousness hop into when you die, assuming this even does occur (it doesn’t)? It makes zero sense.

• ⁨Comment⁩ on ⁨I'm literally a thinking lump of fat⁩ ⁨⁨3⁩ ⁨months⁩ ago⁩:

  Depends upon what you mean by “consciousness.” A lot of the literature seems to use “consciousness” just to refer to physical reality as it exists from a particular perspective, for some reason. For example, one popular definition is “what it is like to be in a particular perspective.” The term “to be” refers to, well, being, which refers to, well, reality. So we are just talking about reality as it actually exists from a particular perspective, as opposed to mere description of reality from that perspective.

  I find it bizarre to call this “consciousness,” but words are words. You can define them however you wish. If we define “consciousness” in this sense, as many philosophers do, then it does not make logical sense to speak of your “consciousness” doing anything at all after you die, as your “consciousness” would just be defined as reality as it actually exists from your perspective. Perspectives always implicitly entail a physical object that is at the basis of that perspective, akin to the zero-point of a coordinate system, which in this case that object is you.

  If you cease to exist, then your perspective ceases to even be defined. The concept of “your perspective” would no longer even be meaningful. It would be kind of like if a navigator kept telling you to go “more north” until eventually you reach the north pole, and then they tell you to go “more north” yet again. You’d be confused, because “more north” does not even make sense anymore at the north pole. The term ceases to be meaningfully applicable. If consciousness is defined as being from a particular perspective (as many philosophers in the literature define it), then by logical necessity the term ceases to be meaningful after the object that is the basis of that perspective ceases to exist.

  But, like I said, I’m not a fan of defining “consciousness” in this way, albeit it is popular to do so in the literature. My criticism of the “what it is like to be” definition is mainly that most people tend to associate “consciousness” with mammalian brains, yet the definition is so broad that there is no logical reason as to why it should not be applicable to even a single fundamental particle.

• ⁨Comment⁩ on ⁨I'm literally a thinking lump of fat⁩ ⁨⁨3⁩ ⁨months⁩ ago⁩:

  This problem presupposes metaphysical realism, so you have to be a metaphysical realist to take the problem seriously. Metaphysical realism is a particular kind of indirect realism whereby you posit that everything we observe is in some sense not real, sometimes likened to a kind of “illusion” created by the mammalian brain, called “consciousness” or sometimes “subjective experience” with the adjective “subjective” used to make it clear it is being interpreted as something unique to conscious subjects and not ontologically real.

  If everything we observe is in some sense not reality, then “true” reality must by definition be independent of what we observe. If this is the case, then it opens up a whole bunch of confusing philosophical problems, as it would logically mean the entire universe is invisible/unobservable/nonexperiential, except in the precise configuration of matter in the human brain which somehow “gives rise to” this property of visibility/observability/experience. It seems difficult to explain this without just presupposing this property arbitrarily attaches itself to brains in a particular configuration, i.e. to treat it as strongly emergent, which is effectively just dualism, indeed the founder of the “hard problem of consciousness” is a self-described dualist.

  This philosophical problem does not exist in direct realist schools of philosophy, however, such as Jocelyn Benoist’s contextual realism, Carlo Rovelli’s weak realism, or in Alexander Bogdanov’s empiriomonism. It is solely a philosophical problem for metaphysical realists, because they begin by positing that there exists some fundamental gap between what we observe and “true” reality, then later have to figure out how to mend the gap. Direct realist philosophies never posit this gap in the first place and treat reality as precisely equivalent to what we observe it to be, so it simply does not posit the existence of “consciousness” and it would seem odd in a direct realist standpoint to even call experience “subjective.”