Quantum Mechanics
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Thinking of what science is about, it is to discover or to explain what has been in existence. From this point of view, "true randomness" is just something we have not discovered or explained. It may not be random at all.
TOMZ_KV
I just read this whole thread and I think the problem we're facing is that there's no good definition of "deterministic". Like, does it make a difference whether the universe is deterministic if there is no way to tell the difference? Maybe particles actually have fixed positions and velocities and interact via deterministic laws of physics like billiard balls (but we obviously cannot observe them because of Heisenberg's principle). Maybe particles are just blurs and they bump into each other going off in "random" directions. There is no way to distinguish the two scenarios. So what is determinism and how does it change anything? Think of it this way. Whatever happens, just happens. Whether it was pre-determined or not is an invalid question because it is ill-defined. The space-time development of the universe just exists and we encounter it moving along the time dimension. When you see the stuff on your desk, you don't ask whether the coffee cup's particular spatial coordinates are "determined" by the monitor's spatial coordinates. You'd ask, what does "determined" even mean in this case? What we do know is that the future state of the universe is not "predictable" because we cannot observe the current state.
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My verbage isn't that great, but I think I get my point accross ok... Every action has an equal and opposite reaction. This can be taken as true in any form from an atomic level to a macro level (solar systems and galaxies). As far as I know, you can safely say that each molecule affects the molecule next to it, to some degree, and in the same regard each atom reacts from interaction with other atoms around it. Like a game of marbles, each flick of a marble has an impact on all the other marbles near it; you project the marble with force, and based on so many variables such as gravity, speed, acceleration, mass, velocity, surface area, etc, etc, it hits another marble sending it moving along it's OWN course. Obviously losing energy through other resistances such as friction the second marble may hit a third marble, repeating these effects, but to a lower degree, until all that energy is disipated and the marbles no longer move. You could say that throwing that marble a billion times will NEVER render the exact same results; there will always be some kind of "randomness" associated with the event, and this is completely true. Throw it forever, and you will no doubt never see the same outcome. However, this does not mean that true randomness exists in our universe. Say we were using the big bang as a point of origin for an event. Similar to the marbles, the explosion sends debris, rocks, elements, gasses, energy, etc eminating, rather speeding away from the event horizon heading out into the universe (or as some presume, CREATING the universe itself by expanding at the speed of light). Now at a macro level these bits and pieces hitting each other cause enormous explosions and other major disruptions in space-time, which in turn ricochet off on their own courses, causing more explosions, et al. Imagine, however, what is happening at an atomic level. Atoms changing, breaking apart(?), forming molecules, etc, but importantly, the path of each individual atom is governed entirely by the forces and resistances surrounding it, and of course in large part by other atoms hitting it (or coming close and deterring them electromagnetically(?)). If you knew the position of every single atom in existence at any one point in time :wtf: , you could without error predict the movement of the entire universe, or the exact, and i mean EXACT path of a marble that has been hit by another marble, that was itself hit by a marble being flicked.... You could predict EXACTLY the movement of the leaves on a tree, an
So if you created a mechanism for knowing the exact movement of every nanoscopic element of the universe (or any other universes that might impinge on ours) that could calculate the exact result of all of the universe's behavior you'd have to factor in the Heisenberg uncertainty created by it's measurements and it would have to factor in its own existence and any calculations it might potentially make and, of necessity, have to recursively recalculate until it's stack was blown, which would ultimately blow the stack for the universe. So quotes Obi.
Windows is a pane.
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The universe is random fundamentally, but emergently ordered macroscopically because it is bounded by probability. What I mean by that is that at the quantum level there's nothing to stop a particle from ceasing to be here and spontaneously appear over there, it's just very unlikely. In fact quarks and anti-quarks spontaneously appear and anhillate each other all the time. We like to think of an electron as a point. A solid particle. It's not. It's a fuzzy potential field around an atom. Everything in this universe is probability nothing more.
Truer words were probably said, but this is pretty accurate :)
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
The short answer is -- both. QM actually implies that the various properties of sub-atomic particles <b><u>do not have a value until measured</u></b>. It is not that the value is random or unknown, but that it <b><u>does not exist</u></b>. When measured, that property will have a definite value that will fall within an expected range which can be predicted accurately by probabilistic equations. The collection of all possible values is referred to as part of the super-position of the particle. Measurement collapses the super-position. This question actually mirrors the debate between Einstein and Bohr. Einstein maintained that the properties of quantum particles always had definite values and that we simply were unable to determine those values until we measured them. i.e. He maintained that if we had perfect knowledge of all the particles and their current state and how they interacted with each other we could predict their behavior perfectly as far into the future as we wanted. Bohr maintained the values did not exist at all until the moment they were measured. That perfect knowledge of all the particles and their properties was not merely impractical, but fundamentally impossible. Perfect prediction was a pipe dream, and the best you could hope for was a probabilistic model that accurately bounded the range of possible states a particle could achieve. The experiments performed to decide this debate favor Bohr’s interpretation. The end result: At a fundamental level, the current state of the universe can be precisely explained, and the future state can be predicted accurately to a large degree, but the precise details are not determined until the precise moment they are directly observed and measured.
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Chris Maunder wrote:
Below a certain threshold the universe is fuzzy. The more you try and measure the position of a particle, the less you will be able to measure its momentum, and vice versa.
Ok, this is what I also believe, but isn't that only if WE attempt to measure or intercept a particle? The laws of physics that govern a particle or something so small are different to the laws for objects the size of, say, a human being, or Earth. So trying to measure or observe the characteristics of a particle in our real-time 'macro-verse'(?) could potentially report incorrect results, or missing or contradictory information. Are the properties of the 'fuzzy' parts of the universe not completely defined simply because we cannot measure them effectively? Don't a particles properties exist as a uniform constant regardless of the outcome that the observers best attempts had at defining them? Does a falling tree make a sound if there's no one there to hear it? :-\ Am I completely off track? I have to review every bloody sentence I write! :doh:
MichaelGallagher wrote:
Ok, this is what I also believe, but isn't that only if WE attempt to measure or intercept a particle?
No it does not. This is probably the worst misconception that comes out of attempts to popularize QM. While observations can affect the state of a system, uncertainty is an inherent component of physics and exists completely independently of what an observer does.
Today's lesson is brought to you by the word "niggardly". Remember kids, don't attribute to racism what can be explained by Scandinavian language roots. -- Robert Royall
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I just read this whole thread and I think the problem we're facing is that there's no good definition of "deterministic". Like, does it make a difference whether the universe is deterministic if there is no way to tell the difference? Maybe particles actually have fixed positions and velocities and interact via deterministic laws of physics like billiard balls (but we obviously cannot observe them because of Heisenberg's principle). Maybe particles are just blurs and they bump into each other going off in "random" directions. There is no way to distinguish the two scenarios. So what is determinism and how does it change anything? Think of it this way. Whatever happens, just happens. Whether it was pre-determined or not is an invalid question because it is ill-defined. The space-time development of the universe just exists and we encounter it moving along the time dimension. When you see the stuff on your desk, you don't ask whether the coffee cup's particular spatial coordinates are "determined" by the monitor's spatial coordinates. You'd ask, what does "determined" even mean in this case? What we do know is that the future state of the universe is not "predictable" because we cannot observe the current state.
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
I think you are incorrect in this case, but so is your friend, kind of. QM does not provide for "true randomness". Regular predeterminate formulas don't make sense either. When a formula "approaches infinity", what happens is the solutions get so compressed together the reach a point where the possibilities are too numerous for us or our computers to comprehend, so it is "infinite enough". At the level of quantum physics, the structures are so delicate even human thoughts, or invisible, unseen forces can affect them. "Sub-matter" has "possibility states" but the resulting cow, pig or donkey, of all those "random states" is not random, or it could end up a broom... This is not the same as randomness. Even quantum physics follows formulas, but add in "random factors" for what we do not comprehend. Following quantum physics to it's absolute root, the universe is constantly shifting around and essentially all matter is being recreated every microsecond. The resulting universe, or how those pieces "fall back together" every micrsecond certainly isn't random.
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
What if the universe is a finite state machine? That would mean what people say about God being "outside time" - knowing everything, of all of time, at once - be correct. What if randomness, as we currently know it, and with our knowledge limited by our participation in the universe that we are observing, is actually (on some grander scale) not random? Then our universe would, in fact, be a finite state machine. Further, even if the universe is a finite state machine, that doesn't change the fact that to our perceptions we have a distinct future and past. Perhaps our experience is like a finger moving along the edge of a ruler: the entire ruler exists all the while, but the finger has a past and a future experience of the scale it progresses along. If, then, the universe is a finite state machine, the interesting question is: "How come our experience of it occurs as a cursor moving unidirectionally through it?" ~Chris
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
Contrary to popular opinion quantum mechanics doesn't actually answer the question of whether or not the universe is deterministic. Bell's Theorem shows that it cannot be both local and deterministic. Most physicists today elect to give up the deterministic part and keep the locality. However, there are interpretations which do just the opposite. The Bohm Interpretation is currently the most popular among these. This theory is an example of a Hidden Variable Theory. While these theories have fallen out of favor with the physics community the very first documented explanation of quantum phenomenon was of this kind. The Matter Wave interpretation, proposed by Louis de Broglie in his 1924 PhD thesis, preceded the currently fashionable Copenhagen Interpretation by several years. Interestingly enough the Copenhagen Interpretation denies physical meaning to the central construct in quantum mechanics, the Wave Function, while the nonlocal theories tend to embrace it.
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My verbage isn't that great, but I think I get my point accross ok... Every action has an equal and opposite reaction. This can be taken as true in any form from an atomic level to a macro level (solar systems and galaxies). As far as I know, you can safely say that each molecule affects the molecule next to it, to some degree, and in the same regard each atom reacts from interaction with other atoms around it. Like a game of marbles, each flick of a marble has an impact on all the other marbles near it; you project the marble with force, and based on so many variables such as gravity, speed, acceleration, mass, velocity, surface area, etc, etc, it hits another marble sending it moving along it's OWN course. Obviously losing energy through other resistances such as friction the second marble may hit a third marble, repeating these effects, but to a lower degree, until all that energy is disipated and the marbles no longer move. You could say that throwing that marble a billion times will NEVER render the exact same results; there will always be some kind of "randomness" associated with the event, and this is completely true. Throw it forever, and you will no doubt never see the same outcome. However, this does not mean that true randomness exists in our universe. Say we were using the big bang as a point of origin for an event. Similar to the marbles, the explosion sends debris, rocks, elements, gasses, energy, etc eminating, rather speeding away from the event horizon heading out into the universe (or as some presume, CREATING the universe itself by expanding at the speed of light). Now at a macro level these bits and pieces hitting each other cause enormous explosions and other major disruptions in space-time, which in turn ricochet off on their own courses, causing more explosions, et al. Imagine, however, what is happening at an atomic level. Atoms changing, breaking apart(?), forming molecules, etc, but importantly, the path of each individual atom is governed entirely by the forces and resistances surrounding it, and of course in large part by other atoms hitting it (or coming close and deterring them electromagnetically(?)). If you knew the position of every single atom in existence at any one point in time :wtf: , you could without error predict the movement of the entire universe, or the exact, and i mean EXACT path of a marble that has been hit by another marble, that was itself hit by a marble being flicked.... You could predict EXACTLY the movement of the leaves on a tree, an
MichaelGallagher wrote:
Every action has an equal and opposite reaction. This can be taken as true in any form from an atomic level to ...
I take it you're not too familiar with probability distribution. Say hi to Heisenberg for me.
I wanna be a eunuchs developer! Pass me a bread knife!
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
The problem is, QM only proves true complexity, not true randomness. In other words, a limit to what human beings, working in four dimensions, can know. To prove true randomness, you'd have to account for *all* possible causes, including those that appear from our frame of reference to move backwards in time (like quantum entangled particle spin, or certain waves that appear to break the light speed barrier). True randomness requires uncaused events to happen. And that's about as easy to prove as the existence of God. Having said that, there is a third possibility pointed to by probability and quantum mechanics that is in between you and your friend; quantum universes. That way the future (and perhaps even the past, since there were many possible paths to get to the current state) is an infinite state machine; but every state gets "hit" someplace in the tangled wobbily bits of the multiverse. Ok, now that I'm talking like Doctor Who, I'd better stop. But it would be wise of both of you to consider the possibility that a lack of randomness does not necessarily imply predeterminism.
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4D? Only 4? I think you'll find you need a few more dimensions than that :(
Jane Williams wrote:
4D? Only 4? I think you'll find you need a few more dimensions than that :(
You may need more than 4d to describe full brane existence in string theory, but 4d is the minimum number to fry a mind by trying to visualize it. :laugh: Outside of string theory, 4D is the appropriate number. Even curvature of space-time is considered to be a property of space time, not really curvature of extra dimensions on top of the 4. So 4d is a minimum description of what we see, and is useful as a way of describing space time as a unified, unchanging (outside of the 4d) object.
Silver member by constant and unflinching longevity.
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Jane Williams wrote:
4D? Only 4? I think you'll find you need a few more dimensions than that :(
You may need more than 4d to describe full brane existence in string theory, but 4d is the minimum number to fry a mind by trying to visualize it. :laugh: Outside of string theory, 4D is the appropriate number. Even curvature of space-time is considered to be a property of space time, not really curvature of extra dimensions on top of the 4. So 4d is a minimum description of what we see, and is useful as a way of describing space time as a unified, unchanging (outside of the 4d) object.
Silver member by constant and unflinching longevity.
Worryingly, back in my college days, I know I used to visualise in 4D without too much trouble. I'd hate to try to now, though.
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
As I recall, an early biology class instructor mentioned that everything tends toward randomness. And if the physics of Quantum Mechanics goes towards randomness, how does one explain something as complicated as a human being. A human is not the perfect result of randomness (or evolution), but fairly well along the way. Even it if humans required well over a billion years to evolve, even given the best of conditions, if random behavior of the molecules were the norm, then how could we be here now. Could it be some very early design technique well before our time (and well beyond our comprehension) is in place that provided just the correct conditions for the current outcome? It is like playing a game pool with the design of how the board is to be laid out for every shot (until the last ball is sunk) before the balls are even racked. It is interesting to philosophize how everything up to now, including Man’s history played out. Did it just evolve through random happenstance or was there a design in place that is executing according to plan?
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But aren't they one in the same? If you played a game of snooker, and slowed it down to one atomic movement per frame, you could see the interaction between all of the molecules, on every level from what you see as the pool ball all the way down to the most finite part, an atom. Each of those interactions, frictions, movements and collisions would all cause a determined reaction on the next atom, and the angle at which that atom flies off would be determined by the angle of approach by the previous atom, just like the white ball hitting another ball, hitting another, and then hitting the black, etc. From a macro view, watching and playing the table, you have a certain amount of control, to put the ball in the hole using other collisions before hand. If you had control at an atomic level, you could direct each ball with 100% certainty in any direction, and DETERMINE exactly where it should go, and therefore know exactly where the hits after that would go also, assuming you had no other resistances such as the pool table itself, etc. Apart from all of that, string theory says that, since there may be something smaller than an atom, randomness may exist after all. If the string theory determines the properties of an atom, or of the nucleus, proton, electrons or something else, then if the absolute smallest element of matter should be studied to see how IT affects the overall nature of energy and mass itself. :confused:
But what combination of friction, movement, and interaction determines the player's choice of expletive when he flubbs the shot?
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
Watch the Dr. Who episode: Blink - 2 June 2007 It has an interesting slant on the 'is observed' property. :-D
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Maxxx_ wrote:
My understanding is that yes, that's exactly what it means - in the 'slit' experiment with a single photon going through the slit, its state does not exist until it is measured.
It's state must surely exist all the time. How else can it interact with everything else in a meaningful manner? Regardless of whether anyone is looking or not... This thing about canging models (wave or particle) and behavior depending on who (if any) is looking is just pure nonsence to me.
That is what Schroedinger was demonstrating - state is meaningless and non-existent until actualized by interaction: it is the very observation or other interaction tht creates state! Tough to get the head around, but experimentaly demonstrable!
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Kick him in the shin, they say "Hey! I'm sorry, you were right all along, it's all predetermined, I couldn't prevent it". Then see what he says ...
Randomness must be defined with respect to predictability. If you have a good random-number generator, you won't be able to predict the numbers, and it will be random. BUT, if you get the algorithm used by the random-number generator, you WILL be able to predict them, and THEY WILL NO LONGER BE RANDOM. If you knew the state of every particle in the universe, you could predict everything. In a sense everything is predetermined. But since in reality we don't have that predictability, everything's random for all practical purposes.
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
achimera wrote:
Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
Well, Einstein is on record as agreeing with your friend: "God does not play dice with the Universe." That said, quantum mechanics doesn't establish randomness as the rule - it simply establishes the limits to our ability to observe with certainty what is going on. Read this for some thoughts about what this means: Concept of 'hypercosmic God' wins Templeton Prize . Whatever the answer is, it cannot be established within the physical framework we know.