Delta1212 Posted August 18, 2017 Posted August 18, 2017 3 minutes ago, Lord Antares said: And why do others assume that ''random'' is the default state of things? Because they can't find a pattern to QM's randomness, which is ironic, because the sole prerequisite of events being random is not knowing the pattern! It is my belief. I've had many thought experiments about this as well. Too long or drawn out to write here. My point is, the default shouldn't be assumed either way. It is not being assumed as the default. It is following the evidence. If new evidence comes to light showing that the rules of QM could somehow be explained by a deeper, deterministic level, then opinion would shift to match the new evidence. You are currently stating that you don't believe the current evidence for probabilistic QM and that you think eventually some new evidence will be discovered that contradicts current evidence because you don't like where the current evidence points.
studiot Posted August 18, 2017 Posted August 18, 2017 34 minutes ago, Strange said: 1. QM is not random. 2. The probabilistic nature is not an assumption. 1) Yes and 2) Yes There is a difference between random and probabilistic (and all of probability theory). 1 is a random number, as is 15, 328 and many more. But ithey are all quite definite, there is nothing probabilistic about them.
Lord Antares Posted August 18, 2017 Posted August 18, 2017 59 minutes ago, Strange said: 1. QM is not random. 2. The probabilistic nature is not an assumption. 1. By random, I mean unpredictable. QM is considered to be unpredictable. 2. I understand that, but take a step back a read the back and forth between me and Delta. You will see what I mean by ''probabilistic nature is an assumption''. 59 minutes ago, Delta1212 said: It is not being assumed as the default. It is following the evidence. If new evidence comes to light showing that the rules of QM could somehow be explained by a deeper, deterministic level, then opinion would shift to match the new evidence. You are currently stating that you don't believe the current evidence for probabilistic QM and that you think eventually some new evidence will be discovered that contradicts current evidence because you don't like where the current evidence points. Correct me if I'm wrong, but isn't the only evidence for that the fact that we couldn't find the pattern to the behaviour? If so, that point is paradoxical because anything we cannot find a way to predict is, by definition, random. Why can it simply not be that we haven't learned how QM behaves to a better degree?
Delta1212 Posted August 18, 2017 Posted August 18, 2017 The Heisenberg Uncertainty Principle seems to me to be a rather large obstacle to the idea that we just haven't figured out the underlying deterministic mechanism. It's a fundamental "baked in" mathematical uncertainty that is not merely a result of technical limitations but of fundamental limits on what is determined prior to an interaction.
studiot Posted August 18, 2017 Posted August 18, 2017 @Delta1212 and Lord Antares There is a difference between prediction and measurement. Not only can we not predict certain properties of an individual particle, we cannot measure them either. So we can never fully know this data. But for many properties that we cannot predict we can measure them and then know the data. QM is a red herring here.
Strange Posted August 18, 2017 Posted August 18, 2017 1 hour ago, Lord Antares said: 1. By random, I mean unpredictable. QM is considered to be unpredictable No it isn't unpredictable. It is completely deterministic (but only in terms of probabilities). 1 hour ago, Lord Antares said: Correct me if I'm wrong, but isn't the only evidence for that the fact that we couldn't find the pattern to the behaviour? No. Tests of Bell's inequality show that there isn't some "hidden" information that we are missing. 1 hour ago, Lord Antares said: If so, that point is paradoxical because anything we cannot find a way to predict is, by definition, random. Not the definition of random.
studiot Posted August 18, 2017 Posted August 18, 2017 17 minutes ago, Strange said: No it isn't unpredictable. It is completely deterministic (but only in terms of probabilities). No. Tests of Bell's inequality show that there isn't some "hidden" information that we are missing. Not the definition of random. Again, Yes, (but some things are unpredictable, yet can be measured afterwards.) Yes Yes.
Lord Antares Posted August 18, 2017 Posted August 18, 2017 2 hours ago, Delta1212 said: The Heisenberg Uncertainty Principle seems to me to be a rather large obstacle to the idea that we just haven't figured out the underlying deterministic mechanism. It's a fundamental "baked in" mathematical uncertainty that is not merely a result of technical limitations but of fundamental limits on what is determined prior to an interaction. I know of the Heisenberg uncertainty principle, but I'm not aware of anything which would point to this. I'm not familiar with the mathematics, so perhaps I'm missing some deeper knowledge to apply this to. 38 minutes ago, Strange said: No. Tests of Bell's inequality show that there isn't some "hidden" information that we are missing. Same goes for this. At this point in time, I have trouble understanding how we can tell that for certain, so knowing this in depth must be interesting, to say the least. I suppose these two would be very lengthy topics, though.
studiot Posted August 18, 2017 Posted August 18, 2017 (edited) 22 minutes ago, Lord Antares said: I know of the Heisenberg uncertainty principle, but I'm not aware of anything which would point to this. I'm not familiar with the mathematics, so perhaps I'm missing some deeper knowledge to apply this to. Same goes for this. At this point in time, I have trouble understanding how we can tell that for certain, so knowing this in depth must be interesting, to say the least. I suppose these two would be very lengthy topics, though. The Heisenberg principle is a direct result of the mathematics. The quantity of interest is the product of two quantities, but that product does not commute. That is AB is not equal to BA so the result depends which you take first. #That is Uncertainty 101. Incidentally there is a similar uncertainty in the same quantities in classical mechanics for the same reasons, they are just trivially small in the classical case. Edit But 'uncertainty' is not probabilistic ans Heisenberg is not the reason QM is probabilistic, which is why I said it to be a red herring here. QM descibes probability distributions for aggregates of energy states and their populations, as Boltzman in thermodynamics. There are several distributions available, including Boltzmans. That is what makes it probabilistic. /Edit Bells has no such 'proof' in mathematics. It is the result of observation and the results could have gone the other way without breaking the mathematics. This is similar to the Michelson Morely experiment in Relativity, determining the presence or absence of aether. Edited August 18, 2017 by studiot
cladking Posted August 19, 2017 Posted August 19, 2017 Quote So I totally agree that the present unfolds based on what happened in the past, but the likelihood of the universe being what it is is not uncalculably small...it is actually quite likely that the Sun will rise tomorrow in the East. We don't have to start from the big bang each time we calculate the next moment. We can start from this moment. Sure, once you have the sun and the earth orbiting it it's pretty safe to predict "sunrise". Try predicting that when the universe was new.
tar Posted August 19, 2017 Author Posted August 19, 2017 cladking, Right, I don't think the color of the colored pencil sticking out of the furthest coffee cup of the two next to my computer at about the 7 o'clock position in the cup, looking at it from above could be predicted from the first principles extant in the moments after big bang. That is, even if you had complete information of all the particles and positions and momentums, I don't think the color of the pencil I am looking at would be forced, at that point. There is random stuff that would have to happen on the way to even have an Earth, and life on Earth and pencil manufacturers and pigments and cones in human eyes and such. I don't think the plan was there, the universe had to play itself out, to this point to see what would develop, what would emerge from all the entities and patterns that the universe has put together, interacted and destroyed in the last 13.8 billion years. So yes, it is impossible to know what the universe is going to do next, just based on current information...but some things, like bridges, stick around for 100 years, and if you pass it on the way home, you can predict pretty well that it will be there on the way to work, tomorrow. Seems we have to keep an open mind, to things emerging when components are put together in ways they have not been put together before in, that result in the combination having characteristics not present in any of the components. Once this kind of thing is allowed, then knowing beforehand, what the characteristics are going to be is not only hard, but actually impossible. because the universe has not yet done the experiment, the first time, so you don't know the results of the experiment yet. You just have to do the experiment. Now afterward, you can make the same combination again, and expect similar results, but beforehand, you don't have enough information, because such information does not exist in any mind, in any pictures, in any memory or any recording, because the combination has not yet been tried. Regards, TAR
tar Posted August 20, 2017 Author Posted August 20, 2017 Thread, There is another way, that reality exists in the large grey area between random chance and sure thing. When one considers a system, or an entity, or an event, one defines a subset of reality, and usually only certain descriptive characteristics of the event. Like when you consider flipping a coin and only having two possible ways it will wind up settling, one does not record where the coin landed, or whether you caught it and flipped your hand over and placed the coin on the back of your other hand and whether or not you missed the coin and it fell to the ground and showed a head or tail "that did not count". That is, the particular arrangement we are attempting to find the odds of, is a very closely considered system, entity or event, where the rest of the world around the thing, in space and time, could be, and always is in a new arrangement, every nanosecond. That is, in the strictest definition of all of reality, it NEVER repeats itself. It can't because you can't wind everything back to the moment of the big bang and do it again, and see how it turns out the second time. For instance, let's say I am counting heads, while it is 9:41 on Sunday the 20th of August,2017. Once it is 9:42, fulfilling one of the conditions becomes impossible. Never again will the conditions be right, to flip a head at 9:41 on Sunday the 20th of August. So one of the ways you can define anything as impossible, is to require conditions that will never line up again in the same pattern because of the nature of space and time. Here the odds are not very small, they are actually non existent. You would have to posit alternate universes, or multiple universes which are, for all intents and purposes, not available for study and recording repeating conditions. And one of the ways you can define something as a sure thing, is to limit your time frame, and limit your special area, and loosen you allowance for small difference that of course had to happen between the first measurement, and the next. So I can consider the railway bridge being in the same place tomorrow, as a sure thing, even though the Earth has turned on its axis, the Earth has proceeded around the Sun and the Sun has proceeded around the center of the Milky Way and the Milky Way has proceeded toward the great attractor, to where, in actuality, it is NEVER possible that the bridge be exactly in the same position in the universe as it was when I was on my way home from work...ever again, and the universe, every component of it, will never be in that exact orientation, as it was on my way home from work when I went under the bridge, ever again. So the chance event has some many consistently repeatable aspects to it, and the sure thing is nothing of the sort, depending on how you define stuff, and the reason for your argument. Leaving of course, that large grey area between for us to live our lives in. Regards, TAR Thread, And yet another way to consider that reality exists in a large grey area between two things, is to consider that we each have an analog model of the entire universe, built in the large grey matter area between our ears. Regards, TAR 1
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