Slashdot Mirror
Einstein and Schrodinger's Quest for a Unified Theory led to a Titanic Clash
StartsWithABang writes When it comes to the very nature of quantum mechanics — about the inherent uncertainty and indeterminism to reality — it's one of the most difficult things to accept. Perhaps, you imagine, there's some underlying cause, some hidden reality beneath what's visible that actually is deterministic. After all, a cat can't simultaneously be dead and alive until someone looks can it? That's one of the problems that both Einstein and Schrödinger wrestled with during their lives. An investigation of that story, their work on that front, and their friendship that ensued as both pursued that same end is thoroughly investigated here by physicist Paul Halpern.
...because this headline seems to have been cut sh
----------------------------------- My Other Sig Is Hilarious -----------------------------------
A light cruiser that hit an iceberg in 1912?
Depending on the model you chose this may differ but I am sure if you chose proper units (libraries of congress/Manhattans etc) you can arrive at 42.
Iceberg Incom
Eh? Around 3,4 now and changing over time. It's just the expansion of the universe, isn't it?
"After all, a cat can't simultaneously be dead and alive until someone looks can it?"
Why not? After all, falling trees make no noise when nobody's watching and bears also do not shit in the woods.
I check, it's not... sorry!
"You are still innocent until proven guilty. What's changed is what they do to innocent people." by notnAP (846325)
No, of course the cat can't be simultaneously alive and dead - that's Schrödinger's point.
I wish people would stop crapping on about that fucking cat when they have no idea what it means.
More hipster site spam from a serial hipster spam poster. Don't even need to read the summary, since it's all clickbait shoddily cooked up from other people's work anyway.
If you accept this universe is simply mathematical function, weirdnes goes away. Function, that is itself probably intersection of multiple functions, some of them being evaluated backwards of what we percieve as "time", therefore creating weird effects in our perceived direction of time. Actually, laws of physics in not all that interesting to me (beyond some level), because physics is going after "particles" and "forces" that happen to be in this function, describing this universe. There is infinite number of other configuration. Function y = sin(x) exists just like our universe, so does set of integer numbers or PI.
If "universe" is locally predictable in one direction (which becomes "axis of time"), then self-replicating features (life) can emerge. In the case of our universe, there is atomic/molecular level complex and yet locally perfectly predictable, that enabled (under "perfect circumstances"?) life forms. atomic/molecular level isolates low level quantum weirdness. After all, life doesn't care if this function is predictable at ALL levels, molecular level is enough, and it happens to be good for many other reasons. There is so many random things needed for universe to sustain life, that probably insignificantly small portion of functions has any self-replicating (living) features, let alone intelligent.
Why should I be surprised by weirdness of quantum world then? It never needed to be predictable in our direction of time.
839*929
Is the cat "somebody" or not? Because if it is somebody, it can look itself. It may also be a "semi-somebody", that has the action of "looking" fail some times and succeed sometimes. All it this quantum-babble really boils down to is the question whether the cat is sentient or not. Now, most young children will count the family cat as a person, albeit a somewhat different one, but most certainly a sentient. The problem here is that young children may not have full sentience themselves and hence that evaluation may be flawed. On the other hand, it may be right on the mark and adults may just have given in to external factors and may have suspended their own judgment on many things, causing questionable sentience levels in them.
And then there is the question of whether all adults are the same. If you put a politician in the box, will he or she be forever caught in a dual-state, of will they manage to make an observation and either die or free themselves? Form the statements politicians usually make, they are clearly not capable of making accurate observations, but live in a wired fantasy-world where reality is different. Hence the box idea may actually be a good way to test politicians for fitness to lead: Sure, you lose half of the good ones, but all of them that cannot accurately observe reality will stay in there forever. That would dramatically reduce the number of politicians free to act (in itself a decidedly good thing), and make sure all those that do act actually have some appreciation of reality.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Then have you heard of tau, which is 2pi? http://tauday.com/
How many cats live to be 80 in cat years, never mind human years.
Now that is quantum uncertainty...
5. And thus it is detected ALL THE TIME BY EVERYTHING AROUND IT, long before you put it through a diffraction grating, or whatever test you dream up.
Stop using the pop-sci version of things where it is about being "detected" or not, and it comes down to whether it interacts with things in specific ways. Turns out the fact it has a magnetic field, or even that the wavefunction has infinite extent, doesn't cause it to be "detected" and there are plenty of ways interactions that can happen without "detection," whether with things like the slits in a double slit experiment, or more explicitly involving magnetic fields like the Aharonov–Bohm effect.
It's not, I know its not, but without my glasses, I can no longer see the individual birds, only a cluster big enough to fire the nerve in my retina.
That description would be apt, except for the fact that some interactions will then cause all of the birds at other locations to instantly disappear, or to change into other states. If readers are curious, they can look for much longer rebuttals of this in response to many of your other posts, but it makes it look like you've only read about quantum mechanics from news outlets, and not an actual text book or class notes.
They can only be created and observed that way, so they must only exist that way.
Oh, maybe your the same AC that has been saying photons can only be created or seen by discrete processes of changing electron levels in atoms. That is flat out wrong, as there are several processes the photons can be created or detected by, some of which are continuous (e.g. scattering and bremsstrahlung).
I think the sun and planets go around the earth, I make an equation to explain the weird loop-the-loops that planets do.
Of course you can make an equation with "loop-the-loops" or epicycles, but the only way to get it to match observations would be an infinite series that ends up matching the actual paths they make around the sun. Just like any function can be broken down into components by Fourier transform or many other transforms, whether or not it makes sense to a given situation, but you still make the same predictions in the end with the full series.
But go ahead, keep reposting your BS, over the last couple years you've managed to get +5 before someone notices sometimes, or even get a few by without any replies if you post them to a story late enough.
Yes, you remember the half of the story that most people forget, but that is useless without the whole story.
The point of the Schrodiner's cat experiment was to be a reductio ad absurdum argument, except it turned out that quantum mechanics is quite absurd by comparison to most physics interacted with on a day-to-day basis. That doesn't mean the cat is not both dead and alive. It turns out that quantum mechanics does allow for macroscopic superposition of states that are suitably isolated
So yes, the cat can be both dead and alive, as long as quantum mechanics is still believed to an accurate prediction of how things work.
IANAP, but I'll give this one a bash.
Interactions with other stuff *IS* detection.
Detection/interaction is not the same as measurement (determination) of a quantum property, such as location, momentum, or spin. You can measure an electron's location with varying degrees of accuracy, if you so wish, and it's provably not a limit due to your measuring equipment. You can detect the presence of an electron without collapsing its spin to a definite state.
6. Thus your Quantum uncertainty theory can never work, the particle/photon/whatever's state MUST be determined BEFORE *you* detect it by its interactions with other matter.
Wrong. Not all interactions collapse the wave function, and that's one of the great mysteries still being explored.
This is false reasoning.
Your reasoning seems to amount to "bricks exist, and photons exist. You can have half a brick, therefore you can half a photon." That's just idiotic.
But I *can* make an equation that will predict the planets looping, and you observe them looping, ergo the planets and sun orbit around the earth?
Yes, you can. But it won't be long before someone comes up with a simpler one that better fits the observations, and that will oust your theory. (hint: it already happened)
Then there's the 'it matches my equations so it must be true'. I simply contrived a complex solution rather than give up on a bad idea.
Perhaps you should learn how science works. Science is never happy with a complex solution. In fact, in some ways science is the constant striving for a simpler solution.
if it fits you say "my theory works, I have proof", if it doesn't fit, you invent some extra tweak to your equation, this is a logical falsehood.
No it's not, because it's a continuous process. If it doesn't fit, sure, you tweak things. But you tweak them because they are necessary, not because you're being lazy.
systemd is Roko's Basilisk.
Your photon has a magnetic field, and that influences the matter around it, depending on its wave function....And thus it is detected ALL THE TIME BY EVERYTHING AROUND IT
Sorry but that is just wrong. Photons do indeed contain an EM field but the photon is small in size. In addition the interactions are quantum in nature i.e. they either happen or they do not. You cannot use your simple, classical view of physics to assume that there is an EM field and so therefore there must be an interaction: the universe does not work like that.
Many of the high energy photons we produce in the ATLAS experiment at the LHC will travel through multiple layers of silicon before they interact in the calorimeter - not all of them though there is a chance for them to interact. If you passed them through a vacuum though the chance of them interacting with the remaining molecules would be tiny. Indeed if you assertion were right the LHC would not work because the protons in the beam would also be interacting with the beam gas all the time and the beam would rapidly dissipate.
People forget that. But that doesn't mean the model can't be useful as a conceptual framework or have predictive power if t conforms closely enough to actual data.
putting the 'B' in LGBTQ+
I never knew that Schrödinger joined at some point in Einstein quixotic quest for a classical unified field theory. Cool story, bro.
But I'm annoyed about the portrait of Schrödinger as Sancho Panza to Einstein's Don Quixote. Schrödinger was a major genius! He invented quantum mechanics, for fuck's sake! I'm particularly riled up by the statement
Embarrassed by the incident, Schrödinger would give up his quest for unity altogether and turn to other topics. Similarly, he would never collaborate again with a prominent physicist.
This seems to imply that Schrödinger never accomplished anything after he stopped collaborating with Einstein. Well, he helped discover DNA.
entropy happens
Customer Intelligence? Continual Improvement? Counterintelligence? Channel Islands?
What? The classical halting problem is based on a deterministic machine. For any given state, you can calculate the future state, at any specific time, by just running the machine it is built on. You might not be able to predict what the machine does in the infinite future, and you might not be able to determine what will happen with less complexity than just running the machine, but that doesn't contradict determinism. A deterministic universe doesn't require that someone from within be able to collect all of the necessary information and to perform enough computation to predict their experiment's future with certainty.
"You're thought experiment has been debunked by reality, and any non-trivial example of Bell's inequality"
No it hasn't. Bell makes an assumption that detecting=sets, creates an example of where setting one particle must also set another according to QM, then the proof measures both and says "well thats as predicted by QM hence its proof"
So if he assumes QM is correct, then X cannot be true, Y must be true, measures Y and says QM is true.
if (QM)
{
y= true;
x = false;
}
else
{
x = ??
y = ??
}
(measurement says y=true)
What does that say about x? Nothing.
You collapsed the wave function.
Dark Reflection
You don't even need to predict infinitely far ahead... for example:
if this program's else clause will execute, then take branch A, else take branch B.
Regardless of what information you allegedly have about the program's future state will be incorrect, so it is trivially provable that no amount of information can be sufficient to even predict the future in a simple closed experiment such as this, and if even a single experiment can be designed where the result is not predictable, the universe cannot be deterministic.
File under 'M' for 'Manic ranting'
If I lock up Einstein, Schrodinger and Heisenberg in a room with a capsule of cyanide gas and a time release mechanism for the gas, would I be sent to jail? Or to the mental institution?
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Einstein was both wrong and not wrong. Schrodinger was just gauche enough to evaluate the wave function.
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
As I said.... "if this program will take branch A after executing this statement then take branch B, else take branch A" where branches A and B are mutually exclusive is an extremely simple example of a system where no amount of information will be sufficient to predict its conclusion, and if an experiment can be derived whose outcome cannot be predicted by any amount of information, then the universe cannot be deterministic either.
File under 'M' for 'Manic ranting'
1. if detecting a particle *determines* its state vs *observes* it state, (the main point of conflict) then:
2. There is no perfect isolation, a vacuum is not perfect, and does not shield magnetic fields or other effects.
3. Interactions with other stuff *IS* detection. That other stuff does get influenced depending on the state of the particle. The magnetic field does influence the world around it.
4. Your photon has a magnetic field, and that influences the matter around it, depending on its wave function.
5. And thus it is detected ALL THE TIME BY EVERYTHING AROUND IT, long before you put it through a diffraction grating, or whatever test you dream up.
6. Thus your Quantum uncertainty theory can never work, the particle/photon/whatever's state MUST be determined BEFORE *you* detect it by its interactions with other matter.
Interesting argument, but I'm not sure that I agree on point 3. We've got a number of very subtle experiments that have tried to tease out exactly where the observer effect starts and ends. Bell's Theorem and EPR prove that no hidden variables exist, so these properties are not things that are stored and just discovered when we check - the behavior that's observed can only be explained if they "decide" what to be when we make a measurement.
Also, consider things like the quantum eraser, and delayed-choice quantum eraser - it seems like the universe is keeping track of what we are looking for and how, such that we can "detect" a particle, destroying the wave-nature and interference pattern, but then "erase" our knowledge of the detection, and see the wave-nature restored.
Finally, with your point about the bricks, you seem to be saying that maybe half-particles exist but we can't detect them because of limitations of our instruments - but discrete, quantum-mechanical behavior extends to far more than just particle counts and even positions. The Stern-Gerlach apparatus being a clear counterexample to your point. The behavior observed there doesn't depend on dealing with any particular number of particles - it just shows that particle spin is entirely quantized, since the particles passing through are deflected entirely one direction or another. We could readily detect particles which were deflected partially, according to continuous, classical behavior - if they existed.
Ultimately, you've got a good argument if all your suppositions are true, but we've got experiments that prove quantum uncertainty as well as anything has ever been proven. In the words of Feynman: "It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong."
The halting probability is much more interesting; a number within the set of real numbers which can never be found by any algorithm or computation. Its proof that the set of real numbers is larger than the set of natural numbers. All natural numbers can be found by computation.
aleph null does not equal aleph one.
In the free world the media isn't government run; the government is media run.
Schroedinger should have chosen a different animal than cats, you know, 9 lives and so.
Not really. When you measure something you change it, so your information would no longer be accurate, and thus you could never have the type of data to make that kind of prediction.
This is a statement of your faith in QM. It is a religious statement not a factual one.
No actually it is a factual statement which has been tested to a precision better than one part in a trillion. In fact it is one of the most precisely tested scientific theories ever discovered. Have you tested you theory on how things work to that level of precision? Have you even figured out what the predictions of your theory are to that level? In fact have you ever done any experiment whatsoever which has agreed with your ideas and disagreed with QM? If not then I think it is extremely clear who is taking things on faith rather than scientific fact.
That field is not confined by a vacuum, it may be tiny but it is there, and thus the particle *IS* detected because it MUST have an influence depending on its spin.
Go and read - and understand - a book on quantum field theory and then we can talk. Fields are quantized which is why photons have a chance to pass through matter without any interaction. The more matter there is the smaller the chance but it is not zero as you suggest...and if you understood QFT, and QED in particular, you would be able to calculate the chance of the interaction via the various possible channels.
There is nothing wrong with criticizing current scientific understanding - indeed that is often how we make progress - but to do so you must understand the current thinking first and then show how it is wrong and/or do an experiment to show that it is wrong. You cannot just dream up some theory off the top of your head and expect anyone to take it seriously. Established scientific thinking has had a lot of effort spent on testing and confirming it. Anything which will replace it needs to have a similar amount of care and attention to detail spent on it.
Something can have influence, and the effects of that influence can be undetected. If an electron can exist with indeterminate spin, why can't the effects of its electromagnetic field be indeterminate?
Let's look at the two-slit experiment. If we try it in ordinary life with a machine gun, so we're putting things known to be particles through, the hit distribution is the sum of the distributions from each slit. If we try it in ordinary life by putting it in water and making waves through it, we get an interference pattern.
Now, let's try it with electrons. We send electrons through (the slits have to be smaller and closer together for this to work) and get an interference pattern. We send one electron at a time through the slits, and we still get an interference pattern, as if the electron were somehow passing through both slits at the same time. This seems odd, so we set up detectors to see which slot an electron goes through. We then see that each electron goes through only one slot, and the interference pattern disappears, being replaced by the machine-gun pattern.
This has been observationally verified many, many times. Would you care to explain where the interference pattern comes from, or how it's consistent with what you've been saying? If you can't, then you've got nothing.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
You can ask whether the else clause will be executed within the next N steps, N being any finite number and "step" being one basic computational step or some other finite and nonzero measurement. (If nothing else, you run it for N steps, and see.) You cannot in general know whether that else clause will ever be executed. If you have a reasonable definition of complexity, you can probably show that, in general, you can't predict N steps into the future with a method less complex than the machine itself.
If you name a number of years, however high, the Universe can be deterministic up to that number of years. I'm not sure what more you want.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
If he misrepresents the explanation, what is a better representation?
The existence of the Halting Problem disproves determinism.
The existence of the Halting Problem REQUIRES determinism. The Halting machine itself is deterministic. Given the current state of the machine, you can perfectly predict the next step of the machine. You just can't predict whether it will ever finish running without walking through the steps until it stops (assuming it does, and you'll never know if you ran it long enough).
Determinism is more about knowledge of the current state and the rules the game operates by.
You don't even need to predict infinitely far ahead... for example:
if this program's else clause will execute, then take branch A, else take branch B.
Regardless of what information you allegedly have about the program's future state will be incorrect, so it is trivially provable that no amount of information can be sufficient to even predict the future in a simple closed experiment such as this, and if even a single experiment can be designed where the result is not predictable, the universe cannot be deterministic.
The machine is still deterministic. You can predict with 100% certainty that if the condition on the evaluation is true, it will do A, and if not it will do B. You can even determine what the condition will be by running all the steps of the program until you get to that statement. That is determinism.
The only way you could have a "computer" that wasn't deterministic would be if its operation were influenced by randomness (true randomness - not algorithmic pseudo-randomness). Such a device would not be a Turing Machine.
In fact, whether it is possible to really build a finite Turing Machine depends on whether the universe is actually deterministic. Any computer exists in the physical world, and is subject to things like cosmic rays that can impact logic decisions apart from the content of memory, or for that matter change the content of memory apart from the program design, etc. So, if the cosmic rays are non-deterministic then it is not possible to build true a finite Turing Machine. (By "finite" I mean a machine with only limited tape length - a true Turing machine requires limitless memory.)
http://xkcd.com/224/
Table-ized A.I.
I didn't put the word ever in there because I didn't mean ever... I meant the results of *THIS* test, and no other. I don't care what happens any other time I run the test, I want to know the results of *THIS* test. If the universe is deterministic, then at any point in time, then it must contain sufficient information in its state to predict some future state, and that information is the only input to the algorithm. The fact that any such agent which tries to examine such a state may never stop trying to gather information about the current state to make the prediction is irrelevant... if the universe is genuinely deterministic, then the state exists and is sufficient to predict the universe's future state, even if it takes an infinite amount of time to actually do... and the definition of determinism itself is sufficient to illustrate the point.
And my point is that it is, by definition, impossible for any current state at the point in time that we try to predict the outcome of even that single experiment to correctly predict its outcome, and without such state, the universe cannot be deterministic either.
File under 'M' for 'Manic ranting'
Again, the ability for the agent to gather the information that would predict its outcome is superfluous... if the the universe is deterministic, then the information to predict the state exists, but in this extremely simple experiment, it is illustrated that not even an infinite amount of information can be sufficient to predict the outcome of the experiment because it contains an inherent contradiction, and if information about the universe's current state is insufficient to predict a future state of *ANY* experiment, then the universe is non-deterministic.
File under 'M' for 'Manic ranting'
A universe being nondeterministic does not mean it is impossible to construct smaller entirely deterministic systems within that framework... "if A then B" can be entirely determistic, even if the universe which runs it is not, if no aspects of the universe's non-determinism impact the execution of the statement. However, a determistic universe means that it *IS* impossible to construct a non-deterministic system. above, I show how such a system can be constructed, however, which suggests the universe cannot be determistic (even though it may possess many deterministic qualities).
File under 'M' for 'Manic ranting'
A universe being nondeterministic does not mean it is impossible to construct smaller entirely deterministic systems within that framework... "if A then B" can be entirely determistic, even if the universe which runs it is not, if no aspects of the universe's non-determinism impact the execution of the statement.
Sure, I'll buy that. However, in practice if the universe contains elements that are non-deterministic, it seems extremely likely that the physical construction of a computer would not be entirely free of those elements.
"Wrong. Not all interactions collapse the wave function, and that's one of the great mysteries still being explored."
That's faith in mysteries not proof.
No it's not, it's a perfectly factual statement.
It's magnetic influence is dependent on its spin, and thus it already determined because it has an influence before you detect it.
No. You can establish the location of an electron - detecting it - without determining its spin.
"Your reasoning seems to amount to "
You misrepresent the explanation.
You haven't offered any explanation. Of anything.
" But it won't be long before someone comes up with a simpler one that better fits the observations"
Indeed, and that simpler equation will meet opposition from believers in the old equation. That's you.
How can it "be me"? You haven't offered a simpler explanation for me to consider. Your "simpler explanation" - which apparently amounts to a simple pig-headed insistence that there are hidden variables, in direct contradiction to oft-repeated experimental results - has no evidence in its favour. Simple it may be, but it also has to explain observations. Hidden variables can not account for what is observed.
You have not debunked my simple thought experiment.
Your thought experiment doesn't need debunking, because it doesn't actually make any difference to what has already been observed in reality. Your vague thoughts about half-bricks don't make any difference to the observed facts, which, so far, are only explicable by theories which include quanta of light.
The problem here is a theory is either "right" or "is right but needs tweeking"
No. A theory is either proven false, or not yet proven false. If you think you're the guy to prove quantum theory false, go for out - but given the apparent level of your understanding of physics and the scientific method, I won't be holding my breath.
systemd is Roko's Basilisk.
Deterministic machines build by man don't encompass everything, the way the universe does.
File under 'M' for 'Manic ranting'
The halting problem requires a deterministic system, it does not require that the universe itself to be deterministic. The universe encompasses everything that ever was, is, or will be... including all deterministic systems. My main point is that in a deterministic universe you should be able to contrive a deterministic thought experiment which will always be able to correctly predict the outcome of the experiment, but if you design the experiment so that its output is always the opposite of whatever was predicted, then it becomes evident that there can never be sufficient information at the beginning of the experiment to predict its conclusion, and if the current state of the universe is not sufficient to predict a future state, then the universe is not deterministic.
File under 'M' for 'Manic ranting'
The halting problem requires a deterministic system, it does not require that the universe itself to be deterministic. The universe encompasses everything that ever was, is, or will be... including all deterministic systems.
I'll accept that definition of the universe, but recognizing that "all deterministic systems" might be an empty set.
My main point is that in a deterministic universe you should be able to contrive a deterministic thought experiment which will always be able to correctly predict the outcome of the experiment, but if you design the experiment so that its output is always the opposite of whatever was predicted, then it becomes evident that there can never be sufficient information at the beginning of the experiment to predict its conclusion, and if the current state of the universe is not sufficient to predict a future state, then the universe is not deterministic.
You're basically trying a proof by contradiction here, I believe. However, your wording is really loose.
First, what do you mean by "predict the outcome of the experiment?" What experiment?
Then you say that you "should be able to contrive" an "experiment" that can predict the outcome of the "experiment," but that it will have the "output" that is the opposite of whatever was predicted. What does this statement even mean, since it appears self-contradictory, like saying let the set A contain the number 5 and not contain the number 5. I can't tell whether your conclusions follow from your premise as your premise seems confusing at best.
It seems like you're trying to do something like this: Let f(x) = x + 3. So, f(5) = 8. So let's redefine f(x) = x + 3 if x5, and it equals 9 if x=5. You haven't made a contradiction, you've just swapped one deterministic function out with another.
You also brought up the halting problem, and it isn't obvious to me how that relates. The halting problem has nothing to do with determinism, just predictability. The behavior of a halting machine is completely deterministic - it has a finitely definable starting state, and given that starting state will always end up executing the same series of steps. However, it is unpredictable in the sense that you can't tell what the result will be with certainty without actually running through all the steps to get there.
Well SG always bugged me because the magnetic field only affects the spin that is in the axis relative to the field, yet even if it was quantized why would it nicely have spin related to the field? So even if it was quantized, if you were actually measuring the spin you'd still expect it to deflect by different smooth amounts, depending on the orientation of the spin to the field. The fact its a fixed amount surely means you are not measuring a spin effect AT ALL. Quantized or not.
The most provocative thing about Stern-Gerlach is that it suggests spin orientation itself is quantized, not just magnitude. You seem to object to this interpretation, but I don't see you providing any alternative. I'm inclined to go with the established consensus among quantum physicists.
I equate deterministic with predictable... that's all.... It seems reasonable to me to conclude that if one has information at hand, this information can be utilized to take a course of action. I suggest implementing this process within a deterministic system such as a theoretical computing machine to illustrate that there is no possible way for the system to fail to perform its function However, since there can never exist enough information about the future at the time that such information is being analyzed to exclude that possibility from occurring, the universe cannot be entirely deterministic, and there is no possible way for it to be... just as certainly as if a black-box halting problem solver would be a non-deterministic system as well.
File under 'M' for 'Manic ranting'
Really? What happens if you ask it to tell you if a function will terminate when the function does the opposite of whatever the halting machine says the function will do?
Still think it's deterministic?
The behavior of a halting machine can only be deterministic for certain types of functions.
File under 'M' for 'Manic ranting'
Really? What happens if you ask it to tell you if a function will terminate when the function does the opposite of whatever the halting machine says the function will do?
Turing machines only support a few instructions. It can move left, move right, stay in the same place, change state, and write something in the current position.
There is no instruction called "terminate when the function does the opposite of whatever the halting machine says the function will do." I don't even know what that means. Turing machines don't say anything - they just execute instructions.
The behavior of a Turing machine is completely deterministic. If the instruction table says to move left given the current conditions, it will move left.
I'm suggesting that with such an experiment, it wouldn't matter how much resources it required... even if the amount of resources were infinite, the results of the prediction would *always* be wrong, because the experiment is explicitly designed to contradict whatever is to be expected for its output. This thought experiment shows that it can be possible for there to exist insufficient information to predict the future, and so it follows that the universe cannot be wholly deterministic.
And there is, in fact, no compelling reason beyond so-called aesthetic appeal *why* the universe needs to have deterministic behavior anyways.... further, the fact that it might not be entirely predictable does not mean that deterministic systems cannot exist at all, so we don't need to lose our precious determinism entirely even if we accept that the universe is, at its core, inherently unpredictable.
File under 'M' for 'Manic ranting'
But if the instruction table says to move left when an alleged so-called analysis of the future says it will move right, or vice versa, assuming that analysis of the future were a magical black box, it will still do one or the other, quite predictably, as a deterministic system should, but it will still always produce a result inconsistent with that prediction, which shows that the future cannot be predicted with 100% certainty from a given state... where determinism suggests that everything about the future *CAN* be determined from its current state. Whether such information were even knowable in the first place is irrelevant, no quantity of information (even an infinite amount) can ever be sufficient to accurately predict the result, which means that the universe cannot be wholly deterministic, and thus contains at least some non-deterministic components.
File under 'M' for 'Manic ranting'
But if the instruction table says to move left when an alleged so-called analysis of the future says it will move right
What does that even mean? The instruction table says that if the condition is A, move left, if the condition is B, move left, if the condition is C, move right, and so on. A Turing machine operates entirely in the now (just like any other conventional computer). It doesn't have to guess what it might do - it just looks at the current state, looks it up in a table, and does what it says.
If you're saying that it should try to figure out what it will do 10 steps in the future, then that is basically the halting problem and it is not possible. Nor is it necessary for its behavior to be deterministic. The only thing determinism requires is that given a current state there is only one correct immediate future state. That is exactly what a Turing machine is - a mathematical construct that is perfectly deterministic.
It doesn't have to "figure out" anything... if the sufficient state to predict the future exists, then you could at least theoretically use some alleged "magical" black box to say whatever a future state is going to be based on the universe's current state, and just have the deterministic turing machine query that. My point is that when the turing machine is programmed to do the opposite of whatever the black box says is going to happen, absolutely no amount of information, even an infinite amount, will actually ever be sufficient for such a black box to actually correctly predict the future. If insufficient information to predict the future exists at the present time, then the universe cannot be deterministic.
In fact, the *only* real reasons that I know of to rigidly hold onto the notion that the universe is deterministic are either out of a subjective sense of aesthetic appeal (but bear in mind that while a deterministic universe cannot contain any non-deterministic components, even a universe with non-deterministic components can still have deterministic components inside of it as well, so the aesthetic appeal of determinism for many practical purposes is not actually lost in a non-deterministic universe), or out of a sense of a no less subjective religious (or anti-religious) world-view that is actually simply founded on the principles of materialistic determinism, and is being adhered to out of a sense of blind-faith dogma.
File under 'M' for 'Manic ranting'
It doesn't have to "figure out" anything... if the sufficient state to predict the future exists, then you could at least theoretically use some alleged "magical" black box to say whatever a future state is going to be based on the universe's current state, and just have the deterministic turing machine query that.
The problem with such an approach is that your machine is part of the universe, and therefore must modify it as part of performing its evaluation of the future state of the universe. The machine must also be larger than the universe to do this, since it needs to maintain in its memory the entire current state of the universe and some number of future states to perform the calculation.
Such a machine cannot exist. The fact that it can't exist doesn't mean the universe isn't deterministic. It just means that you can't write down the state of the entire universe using only the matter present inside of it.
You can't build a machine that perfectly models itself for the same reason that you can't build a box that can fit itself inside unmodified.
And Turing machines execute the instructions they're told to execute. They don't figure out what they'd do and then do the opposite, unless you just invert the programming. A hand-waving argument about doing such a thing doesn't prove anything about the universe.
In fact, the *only* real reasons that I know of to rigidly hold onto the notion that the universe is deterministic are...
I have no idea whether the universe is deterministic. I'm just pointing out that neither does anybody else.
Again, there is nothing that the Turing machine would ever need to figure out... it simply needs to just blindly do the opposite of whatever some black box says is supposed to happen... there is no "intelligence" behind this decision, it is simply flawlessly executing the instructions that would have been programmed into it, and the only way the box could ever be correct is if the machine were malfunctioning... a malfunction is not outside of the realm of possibility, but a malfunction is also generally outside of the scope of any thought experiment that involves a Turing machine in the first place. The only "thinking" that might arguably be involved is inside of the black box, which reports whatever it is that is about to happen.. But the only thing the Turing machine does is take the information the bllack box provides as its input and outputs the inverse. So in theory, the Turing machine would simply always do the opposite of whatever the black box said is going to happen happen, and in theory, the black box will always say what is about to happen.
Except of course... the black box *CAN'T* always say what is going to happen... as the thought experiment illustrates. The fact that no such black box could ever be constructed does not change the fact that no possible quantity of information would ever be sufficient to predict a future where information about the future would ever be used to produce its opposite. The universe's current state is insufficient to predict the future and simply cannot be entirely deterministic.
Except that's generally understood to be what materialistic determinism *IS*... so I'm not sure if you meant to or not, but you've really just sort of agreed with me there.
But of course...
For someone who is professing to have no idea, you seem to be abnormally determined to convince me that my conclusions are invalid... perhaps you should try to figure out why you believe what you do.... or if you don't know what you believe, I might suggest you should stop trying to point out what you think may be wrong with another person's ideas just because you don't happen to agree with their conclusions, because otherwise you just come across as somebody who wants to disagree for the sake of being disagreeable, and not somebody who has actually made any real attempt to rationally think through their beliefs.
File under 'M' for 'Manic ranting'
Again, there is nothing that the Turing machine would ever need to figure out... it simply needs to just blindly do the opposite of whatever some black box says is supposed to happen...
A Turing machine is a mathematical construction. You're trying to use the halting problem as a rationale for the universe being non-deterministic. However, the halting problem only applies to Turing machines. A Turing machine can't contain a black box, because that isn't part of the definition of a Turing machine.
It is a bit like proving that there are a countable number of integers and then trying to say that there must be a countable number of irrational numbers by just redefining the meaning of "integer." You're playing word games, but that doesn't prove anything.
To be honest, I'm not really sure how you could prove anything about the universe using an argument purely from discrete mathematics, unless it is a proof that there is no such thing as determinism at all (which certainly would be an interesting claim for a mathematician to make). Math is a world all its own, and while it can be used to describe the physical world, it has an existence apart from it in a sense.
Except that's generally understood to be what materialistic determinism *IS*... so I'm not sure if you meant to or not, but you've really just sort of agreed with me there.
Again, you're playing word games. Determinism requires that the universe has some state, and some set of rules that determines what its next state will be (which is a really rough way of putting it when time isn't discrete and is relative, but I don't think we're arguing about that). If you're arguing that determinism means something else, then we're just talking past each other.
For someone who is professing to have no idea, you seem to be abnormally determined to convince me that my conclusions are invalid... perhaps you should try to figure out why you believe what you do.... or if you don't know what you believe, I might suggest you should stop trying to point out what you think may be wrong with another person's ideas just because you don't happen to agree with their conclusions, because otherwise you just come across as somebody who wants to disagree for the sake of being disagreeable, and not somebody who has actually made any real attempt to rationally think through their beliefs.
Honestly, the only reason I'm continuing this discussion is because I thought you might have an interesting argument for determinism based on the halting problem, which was your original point. I wasn't sure if you were just having trouble communicating your ideas, or if they were not established in rigor.
I don't really care whether I convince you. I don't intend to be disagreeable for its own sake. I'm just skeptical. If you're going to assert that the universe is non-deterministic that is a really bold statement, and I'm not going to simply accept it at face value.
The only stand I'm taking is that I don't believe anybody has shown conclusively whether the universe is deterministic or not. I'm open to arguments one way or the other. I'm fine with thought experiments and hand-waving arguments, but I'm not going to accept them as some kind of conclusive proof.
The halting problem illustrates the underlying principle that is generalized by the thought experiment. If the universe were genuinely deterministic, then its current state is sufficient to predict a future state... except the thought experiment shows that the current state cannot ever be sufficient to predict a future state where any possible alleged-future state that might be predicted from the current state will always be wrong. Even if the predictor it were wrapped up in a neat little magical black box that didn't really care what was being done with its information, but simply blindly presented a prediction that was supposedly accurate based on the universe's current state, there is no possibility that it could ever be correct if it were ever utilized in this fashion, and since insufficient information exists to predict a future in this scenario, the universe apparently cannot be deterministic.
File under 'M' for 'Manic ranting'