Physicist: With very few exceptions, yes. What we normally call “random” is not truly random, but only appears so. The randomness is a reflection of our ignorance about the thing being observed, rather than something inherent to it.
For example: If you know everything about a craps table, and everything about the dice being thrown, and everything about the air around the table, then you will be able to predict the outcome.
Not actually random.
If, on the other hand, you try to predict something like the moment that a radioactive atom will radioact, then you’ll find yourself at the corner of Poo Creek and No. Einstein and many others believed that the randomness of things like radioactive decay, photons going through polarizers, and other bizarre quantum effects could be explained and predicted if only we knew the “hidden variables” involved. Not surprisingly, this became known as “hidden variable theory”, and it turns out to be wrong.
If outcomes can be determined (by hidden variables or whatever), then any experiment will have a result. More importantly, any experiment will have a result whether or not you choose to do that experiment, because the result is written into the hidden variables before the experiment is even done. Like the dice, if you know all the variables in advance, then you don’t need to do the experiment (roll the dice, turn on the accelerator, etc.). The idea that every experiment has an outcome, regardless of whether or not you choose to do that experiment is called “the reality assumption”, and it should make a lot of sense. If you flip a coin, but don’t look at it, then it’ll land either heads or tails (this is an unobserved result) and it doesn’t make any difference if you look at it or not. In this case the hidden variable is “heads” or “tails”, and it’s only hidden because you haven’t looked at it.
It took a while, but hidden variable theory was eventually disproved by John Bell, who showed that there are lots of experiments that cannot have unmeasured results. Thus the results cannot be determined ahead of time, so there are no hidden variables, and the results are truly random. That is, if it is physically and mathematically impossible to predict the results, then the results are truly, fundamentally random.
What follows is answer gravy: a description of one of the experiments that demonstrates Bell’s inequality and shows that the reality assumption is false. If you’re already satisfied that true randomness exists, then there’s no reason to read on. Here’s the experiment:
The set up: A photon is fired at a down-converter, which converts it into two entangled photons. These photons then go through polarizers that are set at two different angles. Finally, photo-detectors measure whether a photon passes through their polarizer or not.
1) Generate a pair of entangled photons (you can do this with a down converter, which splits one photon into an entangled pair of photons).
2) Fire them at two polarizers.
3) Randomly change the angle of the polarizers after the photons are emitted. This prevents information about one measurement to affect the other, since that would require that the information travels faster than light.
4) Measure both photons (do they go through the polarizers (1) or not (0)?) and record the results.
The amazing thing about entangled photons is that they always give the same result when you measure them at the same angle. Entangled particles are in fact in a single state shared between the two particles. So by making a measurement with the polarizers at different angles we can measure what one photon would do at two different angles.
It has been experimentally verified that if the polarizers are set at angles 
We can do two experiments at 0°, 22.5°, 45°, 67.5°, and 90°. The reality assumption says that the results of all of these experiments exist, but unfortunately we can only do two at a time. So C(0°, 22.5°) = C(22.5°, 45°) = C(45°, 67.5°) = C(67.5°, 90°) = cos2(22.5°) = 0.85. Now based only on this, and the reality assumption, we know that if we were to do all of these experiments (instead of only two) then:
C(0°, 22.5°) = 0.85
C(0°, 45°) ≥ C(0°, 22.5°) + C(22.5°, 45°) -1 = 0.70
C(0°, 67.5°) ≥ C(0°, 45°) + C(45°, 67.5°) -1 = 0.55
C(0°, 90°) ≥ C(0°, 67.5°) + C(67.5°, 90°) – 1 = 0.40
That is, if we could hypothetically do all of the experiments at the same time we would find that the measurement at 0° and the measurement at 90° are the same at least 40% of the time. However, we find that C(0°, 90°) = cos2(90°) = 0 (they never give the same result).
Therefore, the result of an experiment only exists if the experiment is actually done.
Therefore, you can’t predict the result of the experiment before it’s done.
Therefore, true randomness exists.
As an aside, it turns out that the absolute randomness comes from the fact that every result of every interaction is expressed in parallel universes (you can’t predict two or more mutually exclusive, yet simultaneous results). “Parallel universes” are not nearly as exciting as they sound. Things are defined to be in different universes if they can’t coexist or interact. For example: in the double slit experiment a single photon goes through two slits. These two versions of the same photon exist in different universes from their own points of view (since they are mutually exclusive), but they are in the same universe from our perspective (since we can’t tell which slit they went through, and probably don’t care). Don’t worry about it too much all at once. You gotta pace your swearing.
As another aside, Bell’s Inequality only proves that the reality assumption and locality (nothing can travel faster then light) can’t both be true. However, locality (and relativity) work perfectly, and there are almost no physicists who are willing to give it up.
“Randomness is a condition when you don’t know the outcome of an experiment.”
I disagree with this statement – not knowing is not the same thing as it being impossible to know. True randomness is when effects occur that could ever be traced to any cause, even if one was omniscient and could trace all causal paths. In other words, when an outcome cannot in principle be predicted.
You’re right that there is no way to know what science will discover in the future. We could learn that all things are deterministic, all things are causal, and everything there is is one big clockwork. However, that is not my speculation.
My speculation is that there are multiple avenues of science, mathematics, and philosophy that already point towards the phenomenon of emergent behavior as being a real, legitimate aspect of our cosmos. In other words, that there truly are effects that cannot be traced back to any cause, in principle. In other words, true randomness.
I don’t see why that is so hard to accept. Frankly, it seems to me to be a simpler solution to certain problems that the tortured idea that every single effect has a cause, tracing all the way back to the big bang (and then what caused that?). Occam’s Razor.
“…In other words, that there truly are effects that cannot be traced back to any cause, in principle. In other words, true randomness…”
When you prove that something is “impossible to know/predict”, you base yourself on some assumptions. It can be that in the future it will be discovered (like it already happened) that your assumptions are limited to some specific conditions and outside these conditions do not hold. For example, Newtonian mechanics is limited to speeds much bellow the speed of light.
An effect, which cannot be traced now, perhaps will be traced in the future?
Can you prove that scientists will never be able to trace what happened before the big bang? Based on modern physics, nothing can escape black holes, so we will never trace what happens there. But maybe future physics will give us some clue? Maybe some currently unknown particles/fields/dimensions will allow to get information about what is inside a black hole?
Yes, some people do accept that there are things that cannot be traced; other people try to trace those things… It depends on the person’s character.
Sorry, I am writing a lot in this thread, but I am really interested in the topic.
I have a question to those who wrote here:
Why should we distinguish between ‘true’ and ‘not true’ randomness and can they always be distinguished?
(1). We cannot predict when a radioactive atom will decay (true randomness).
(2). But we also cannot predict the tomorrow’s British pound rate to USD (thought not true randomness by physicists).
Can you prove that (2) is really true randomness? What if someone on Earth is now observing some atom and once that atom decays, she runs to exchange her 10,000,000 USD to GBP?
So it means that USD/GBP rate can possibly depend on an atom decay and so (2) is also “true random”.
In this way virtually any event can be true random.
I think what it means is that her actions were triggered by a random event. After the random event has happened we can presumably predict that she will run to the exchange. The randomness is still within the quantum realm.
The atom randomly decays, then she predictably runs.
“I think what it means is that her actions were triggered by a random event…”
Which means the dollar-pound rate is truly random.
…and cannot be predicted in principle
“Yes, some people do accept that there are things that cannot be traced; other people try to trace those things… It depends on the person’s character.”
And it should be no other way. The scientific method depends on people challenging theory and measuring empirically.
Likewise, there are mathematicians and physicists and philosophers who are looking for rigorous ways to demonstrate that randomness is a real phenomenon, both in nature and on paper. John Bell and Kurt Godel are good examples of people who investigated things in this direction.
One thing we can agree on: it is a fascinating topic, and I think one that is pretty fundamental to our world.
“If this is the case, then how can “randomness” be proven?”
It’s difficult, that’s for certain. It’s almost akin to proving a negative. One direction science has taken is to put bounds on how deterministic a system can be. John Bell did this with QM with his inequalities, which showed that QM really must either be indeterministic, or locality cannot hold – in other words, there must be a universal frame of reference of some kind that guides all QM outcomes, an idea that many physicists dislike deeply.
And the Bell Inequalities have survived many, many experimental verifications, which show that as best we can measure, they are indeed correct.
So it’s not impossible to conduct experiments or perform rigorous math that support the idea of randomness. Just very tricky. It is perhaps unlikely we will ever be able to exclude all alternatives, of course. 🙂
Pingback: Why creativity is special and infinity and monkeys cant't crush it - Peter Rey's Blog
Everything that happens, or that can happen, has an equation.
Every equation has an automatic solution.
Whether we take the time to look at an equation and try to solve it or not, the equation is solved regardless.
Whether we experiment on a theory and see results or not,
The experiment always has results.
Everything that can happen, has already happened.
The first clause of step 3 of the experimental proof seems to require the conclusion that “random” is already know to be true: “Randomly change the angle of the polarizers after the photons are emitted.”
@Doug Carter
. The rest is just hidden-variable paranoia.
That has been a significant sticking point for a long time and ensuring that it is random has been a whole thing. The results of this experiment are exactly the same regardless of how the polarizers are randomized. In fact, if you just do each of the four experiments one at a time, thousands of times in a row, the results are still the same.
Fundamentally, the important result is that the correlation probability is
Yes, agreed, but as has already been mentioned, when we do something “randomnly” its only “random” because we cant see a sequence or association?
@jon
Sometimes. When you flip a coin and cover it, the result is still random because you don’t know what it is. Quantum randomness is entirely different. The result literally cannot be known or predicted because it literally doesn’t exist in a definite state. That’s what this post (and Bell’s theorem) attempts to demonstrate: if something is merely unknown, then it can be described with probabilities. But in this experiment we find that the results cannot be described with probabilities.
So what happens from here on in?
How do you know you’ve accounted for all the variables?
@Annese Wehbe
The idea of hidden variables is “the system is in a definite state, we just can’t predict it because there are things going on that we don’t know about (hidden variables)”. The approach here is to say, if the system is in a definite state, it can be described by probabilities and must obey all of the mathematical laws of probability. Bell’s theorem shows that certain experiments do not obey the laws of probability, and therefore the assumption that the system is in a definite state is false.
There could definitely be hidden variables we’re not taking into account, but that doesn’t change the nature of the randomness (which is due to the system not being in a definite state).
Allow me to interviene, but Bell’s Theorem, in my opinion, does not prove or disprove anything. It only shows another paradox in which logic rules get broken if information travels faster than light, and thats it.
The fact that a quantum entangled particle can instantly communicate with its mirrored part corrupts the statistical odds because it messes up with the favorable cases and therefore probability changes.
This doubious premise that quantum entaglement true, is behind all the confusion. If Quantum entaglement is wrong, then Bell’s experiment is just another paradox like many others. If it is true, then Bell’s experiment could be real and the “Theoretical” C(a,c) = 0,5 that you have mentioned before is wrong, because if in fact particles can communicate faster than light, the theoretical probability would be the one calculated by Bell and not the common statistical 0.5 you have pointed out as a real theoretical value (because in this context the so called “reality” would be the quantum entanglement, and not the conventional world statistics).
This way, the hidden variable theory was NOT disproved, because we can deterministically show how the whole system would behave if we started from the hypothetical correct premise (and with that I mean the premise in which quantum entanglement is real) and using logical argumentation. If the system would behave ” truly randomly” as you claimed, you wouldnt have been able to explain it using logical rules, such as coherent language, because the results would have none! True randomness means “lack of cause-effect or pattern”.
If we do adulterate physic rules like this, and use it as a fallacy (like this experiment was), when information travels faster than light, logic rules will get broken, and math, being the language that describes logic, starts to not make sense. If math doesnt work, time sequence events do not make sense either, since math and time order are intrinsically related. Therefore, random events may seem to take place.
Whether you believe it or not, true randomness were never proven to be right or wrong and the evidences for both sides are very interesting to study.
P.s Sorry for any english mistake or typo
Why do so many people describe superimposition as TWO particles?
To me they do not possess the property of “two-ness” but only “one-ness” UNTIL the observation at which time the ONE breaks into two. Seams to me that makes a lot of the mysteries disappear and reasoning to be better.
It’s ALWAYS about asking the right question while suppressing “common sense” which Einstein described as “prejudices” and with which I agree.
If the concept of ‘hidden variables’ is correct, then would it not follow that there can be no parallel universes? All outcomes are always predetermined, therefore there can be no alternate realities. Comments?
Just because it isn’t predictable doesn’t necessarily mean it’s random. In Copenhagen quantum mechanics one could easily imagine all the results coming out of some kind of cosmic PRNG (though probably not literally).
Furthermore the many-worlds interpretation doesn’t allow randomness at all, every possible result inevitably happens, each in its own universe
Furthermore four-dimensionalism implies that both the details and the results of the experiment are fixed. Something not having happened yet or having happened in the past is no different than it being far away. The future is as real and as solid as the moon.
I can’t accept that every single thing in the universe – past, present, and future – is determined from an initial set of conditions, with the single exception of quantum uncertainty. *That* is somehow allowed to be random, but absolutely nothing else is. Smells like fine tuning to me.
Seems like the simplest explanation is that either a). the universe is wholly deterministic, or b). randomness is a true feature of our universe, and quantum mechanics does not have a monopoly on it. In my view, science will have to explain why the current model is to be accepted without question, because it’s not the simplest answer.
Of course the hard part is proving any of this. We may be into unfalsifiable territory, at least with the current state of the art. Still, my suspicion remains.
This is entirely misleading.
There is no such thing as randomness. What Quantum tells us that there’s a limit on how much information that can be obtained about a particles position and momentum simultaneously.
That’s it. The universe is indeed quite deterministic. There is no true randomness. A truly or inherently random process actually violates the second law of thermodynamics.
“If you know all the variables in advance, then you don’t need to do the experiment”.
I can’t agree to this. Human beings are clearly flawed. Every theory/experiment is flawed. I believe in determinism but we still need to do experiments to get closer to the cause that generated the effect. Experiment is still needed. You also used “if”, but can we know all the variables. Let us hypothetically assume we know all the variables, are they countably infinite? Or uncountable? If uncountably infinite, then how can we determine the outcome?
I suggest intrinsic randomness doesn’t exist. However, for all practical purposes, we will make someone (who believes in randomness) happy today and tell
Them it exists.
Humans are indeed flawed, but I don’t understand how that in principle has anything to do with whether nature is deterministic or not. Unless you are suggesting nature is also itself flawed?
I don’t accept anthropics as an answer to anything, nor do I believe that an observer participates in a system. All of that seems like theology to me.
Much more likely to me is that nature is largely deterministic but includes randomness as a valid cause for many events. Of course, neither of us can prove our point, so this is just intellectual speculation. But still fun. 🙂
Humans perceive. Our perception is flawed.
I don’t think nature is flawed.
I was always curious to know: when physicists say in quantum mechanics that it is impossible to know/measure the position and speed of a small particle simultaneously with high precision (Uncertainty principle).
Does this mean it is not possible because for measurement we always use some particle (say, photon or electron) which will change the original particle’s position/speed?
In analogy: suppose there is a submarine weighing 10 ton somewhere in the sea and we want to measure its location and speed, but our only instruments are metal balls 5 tons each. We send such a ball towards the approximate location of the submarine and then we by checking the angle of inclination and change of velocity of the ball we conclude about the submarine location/speed. It is obvious that in this case we cannot be accurate just because each ball will cause the submarine change of location and/or speed. But we can use smaller balls and increase the precision.
Is it the same when we speak of particles?
If people would discover a new kind of particle that does interact with electrons and photons, but does not change their location/speed significantly, would this change the the Uncertainty principle?
Well, I realize my mistake and can answer my own question: for small objects the uncertainty comes from the fact that smaller objects have larger wavelength and so they are less like particles and more like waves, that’s why their location/speed cannot be determined.
@Leo
You’re exactly right, but the situation is a bit more profound. The uncertainty principle is fundamental in very much the same way that randomness is fundamental. The exact nature of a particular particle interaction is not the issue, it’s that things genuinely don’t have the highly simultaneously specific position and momentum that we want to measure.
I am not a physicist but I think the laws of quantum mechanics apply to quantum scales.
It is utterly astounding to me that concepts (or more accurately constructs) such as randomness or free will are so widely adopted as fact and seemingly without a single shred of evidence to support them. Both Randomness and Free Will are equally lazy attempts to account for large gaps in our understanding. Both free will and randomness require a miraculous departure from the otherwise ubiquitous causal nature of our physical reality. Somehow people are totally fine with these illogical impositions. I have met incredibly intelligent thinkers say things like “i refuse to believe that all events are predetermined” or “i refuse to accept that im not the author of my actions”…WHY? I dont refute randomness because i refuse to believe that its possible, but because THERES NO GODDAMN REASON TO MAKE THAT LEAP JUST BECAUSE WE DONT KNOW HOW TO TRACE THE CAUSALITY OF QUANTUM EVENTS YET?
interesting discussion as expected.. but mostly all of this is about the false equivalence of different terms, in an attempt to mix and match “science” with “mathematics” and both with “philosophy”…. terms such as… probability vs possibility… observation vs measurement… knowledge vs assumption…. unpredictability vs randomness… ultimately all of science is a methodology which begins with observation, and depends on measurement for validation, yet there simply is no such thing as human observation and/or measurement to ABSOLUTE precision.. the one and only form of true knowledge humans are capable of is that based on PURE CONCEPTS, which mathematics is based upon, specifically because all of pure math is fundamentally based on pure Concepts which are absolutely true “by definition”.. such as…zero, unity, infinity, positive, negative, the square root of minus one, and.. (you guessed it).. randomness.. nothing in scientific Methodology, based on observation and measurement, can ever be said to represent an ABSOLUTE Scientific Law.. every scientific law is just a theory which has not YET been disproven, and the proper purpose of science to not to prove, but to disprove, find the flaw, improve the state of the art, make progress.. learning is a journey, not a destination.. but no experimentation model can ever test an infinite number of trials.. (and who said the cosmos was finite, anyway, there is simply no reason to leap to such an assumption, much less conclusion).. you cannot prove randomness any more that you can measure (with absolute accuracy) quantity zero, unity, or infinity.. my answer is, yes, randomness does exist, but only as a mathematical concept (same as zero or unity or infinity)… but none such thing exists in physical reality, it is merely a concept defined to be true by definition.. there is simply no reason to ever assume that chaos is random, nor that the cosmos is finite.. everything is cause and effect, and just because you cannot pinch it between your fingers is no reason to leap blindly into a priori mysticism… so, YES, randomness is an absolutely true mathematical concept, same as infinity.. NO, there is no true randomness in the physical cosmos, all is cause and effect… but, hey guys, as soon as you discover what quarks are really made of, and what dark matter and dark energy really are, get back to us.. in the meantime, enjoy the day you have in front of you
Yes, interesting discussion. The relationship of science, mathematics, and philosophy is an interesting one for sure. I’m glad to see that there is significant overlap between them all.
As to randomness, I’ll simply point out that the best empirically-verified scientific models say that true randomness exists at the quantum level. Is this true or not? Beyond my capability to say. But I find it highly suspicious that science thinks the only place true randomness can exist is at the quantum level. Why is it so special? Smells like fine tuning.
I suspect that pure determinism cannot possibly explain the universe as we see it. I tend to believe in strong emergence, in that I believe there are phenomena that cannot be reduced, even in principle, down to the quantum level. This is not belief in magic. I suspect there are natural forces in our universe beyond the basic 4 we know of today, forces that exist at scales beyond the quantum, and that one day science will find them. Idle speculation. but time will tell.
Excellent reply, Darren.. but.. “pure determinism cannot possibly explain the universe as we see it”.. therein is the eternal paradox in just 4 words.. “as we see it”…no amount of observation can, by definition, ever be infinite; and proof of randomness would require infinite powers of observation. Fair enough to call it philosophy rather than science, at your option, but the pure mathematical concepts of infinity and randomness are simply not subject to dispute or fine tuning by either science or philosophy … like yourself, I see no reason to assume there are only 4 natural forces at work.. perhaps we may one day, if we are lucky enough to survive both cosmic catastrophe and our own enthusiasm for self-genocide, come to understand what such things as dark matter and dark energy truly are, as opposed to merely observing the symptoms of which they are the driving force cause .. (some folks already have speculative notions about what quarks are made of)….but not today…no magic, just a continuing journey…we have come a long way in the last 4 centuries, but have yet a very, very long way to go.. enjoy the trip.. it sure beats fear of falling off the edge of a flat earth.. the only true obstacle in our path is a closed mind
one last thought, Darrell ..
(sorry for misspelling your name on that last one)…
“Frankly, it seems to me to be a simpler solution to certain problems that the tortured idea that every single effect has a cause, tracing all the way back to the big bang (and then what caused that?). Occam’s Razor.”
Who said there was only one big bang, or that the cosmos (far larger than our “known” universe) was finite, or that there have been only a finite number of big bangs, much less only one, or that the space-time continuum, for lack of a better term, has finite limits ?? Infinity is a really, really big thing, and 13 billion years or so is a really, really short time.
Although you could, I suppose, call that “emergence” , which I suppose you to mean order evolving from not just chaos, but true randomness, yet that strikes me as a far less simple assumption than cause and effect
Nothing happens without cause, whether we are here to observe it or not.
Occam’s Razor.
(or maybe it’s just an “engineer thing”, LOL)
As much as I am a truly unrepentant advocate of science, I confess that my most fundamental beliefs remain more driven by philosophy and mathematics, which I see as inseparably intertwined.
Occam’s Razor is a great guide. To my knowledge, it has never steered science wrong – although it may have delayed acceptance of some discoveries. When quantum mechanics was first announced, many physicists at first considered it to be much less simple than classical mechanics. Same for relativity.
In any event, I find it simpler to believe that there are undiscovered forces above the quantum level that help explain the phenomena of life and consciousness, rather than assume that somehow these incredibly complex things can be explained as nothing more than wiggling strings. Likewise that freedom of choice is real and not illusion versus the idea that Maxwell’s Demon can foresee the entire future universe. But it hardly matters what I believe.
Why on earth would anybody need undiscovered forces for explaining the evolution of life? Biology together with genetics and paleontology and embriology explain it very well.
Similar as we don’t need undiscovered forces to explain evolution of computers.
Not for evolution. That is a simple process. I’m talking abiogenesis. Explain to me how something as exquisitely intricate and ordered as a single cell can emerge – deterministically – from quantum mechanics or whatever is more fundamental. Now explain how life leapt from that single cell to what we see today. Now explain how consciousness emerged from *that*.
I simply do not believe that chaotic behavior is enough to explain this, no matter how many strange feedback loops one imagines. I cannot accept that consciousness is reducible to particle physics. There must be more to the story than that. Yes, idle speculation on my part.
Pingback: Q: What is the “monogamy of entanglement”? | Ask a Mathematician / Ask a Physicist
Darrell, the second law is why life is favoured it disperses energy. Religious groups push some stupid idea that life violates the second law it doesn’t all you need to do is track the energy of a lifeform, life is not a perpetual motion machine. Complex structures are allowed to arise they do also in natural non life situations like solar system, sun and galaxy mechanics and large scale universe features. In your example why do you treat a complex solar system as different to a complex life, they are both by definition complex structures.
The other confusion by many posts is Quantum mechanics is not a deterministic theory at all. QM denies you being able to fully observe all states of a system, so how are you going to determine anything in absolute certainty. The best QM allows is you to predict a probability of a casual relationship.
As to randomness that is in the eye of the beholder. As you can never know all the states in QM there is no way to ever prove such a thing as true randomness. Random in QM thus falls to the same definition as the classical coin toss or dice roll being a lack of complete observation information.
Darrell, cell did not emerge, it evolved. Very slowly, step-by-step-by-step. Life did not leap, it evolved. Show savage an airplane or a computer and he will ask: oh, how could such a thing emerge? But we know that airplanes and computer did not emerge, they evolved by a slow process of trial-and-error. This way any evolution: biological, technological, chemical, planetary etc. goes.
I have no clue what is going on in the comments.
“Randomly change the angle of the polarizers…”
You are presupposing that the thing you want to prove exists, already does.
The you utilize it’s assumed existence as part of your experiment to prove it exists.
One of you guys/gals probably already pointed that out. You seem a clever bunch.
I suspect there is no experiment that can answer this question. There are a large number of stumbling blocks.
In order to prove randomness exists using a piece of matter, you first have to prove that you are accounting for every force that affects it. This requires absolute knowledge of the composition of the universe. Bummer.
In order for a random event to occur, it would have to occur at a random time, otherwise it’s occurrence would be predictable. But since time does not repeat itself, everything that happens (at a given time) happens only once. In order for something to be “random”, there has to exist the possibility of a different outcome. But there can be no other outcome for something that has already happened. Trippy.
You can never be certain that something is happening randomly since the act of observation (detection) affects what happens. Some would say it actually forces a state of existence. But these are people who choose to exist in the state of perpetual geekdom, so bear that in mind.
Comments please!!
Peace-Pot-Microdot
Hi, as the person who originally asked this question would you be good enough to explain how/why observation effects outcome? I am learning so if you could put it in laymans terms I would be most grateful.
I have read about this many times before but I do not understand it.
Thanks.
I don’t know what it says about us, but this thread has been going since 2009. What are the chances of that 😉
“I don’t know what it says about us, but this thread has been going since 2009. What are the chances of that 😉”
I’d say no better than random chances … 😛
I think, randomness is a thing which is purely relative. For one observer a process can be purely random, as he or she does not know the law behind the process or does not have access to information which allows to predict the process. But for another observer who does have the information, the same process can be purely deterministic.
We, humans, at the current state of the science believe that particles behave randomly based on a known probability distribution. But there can be other “creatures” who can interact with the particles of our world using fields or forces that we don’t have the access to. Example, like dark matter or some other fields or means.
And so perhaps those creatures do have information to fully predict the behavior of the particles that we think are random.
Maybe all our universe is a simulation in a computer and each particle in our world is simulated in it. Then in that computer our particles can be pure deterministic.
So you can never prove that for some process which you believe is purely random, there is no some (hidden for you) information that makes it not random for another observer who does have access to that information.
Pingback: Q: Can free will exist in our deterministic universe? | Ask a Mathematician / Ask a Physicist
@Jon Waterman
This post talks about what measurements do. In a nutshell, a measurement is anything that conveys information back and forth between the interacting systems.
The very short answer to your question is that a series of measurements must always be consistent with each other, so one measurement restricts what the possible results of future measurements may be. For example, if you find that a particular particle is here on Earth, then a subsequent measurement will not find it on Mars in the next five seconds.