This is the classic Q page&A (Questions and answers) but it is open to all kinds of questions, even off topic, because sometimes ideas can come from the most unpredictable things.
Write any ideas you can think of in the messages, not just questions, but also requests and advice and we will try to follow them. In case of questions that go beyond our mathematical skills we will ask for help from prof. Anselmi.
A classic sequence of questions on determinism.
What you will read here is a good example of the doubts that come to everyone more or less when they collide with indeterminism.
REQUEST
The message that seems to come out is that everything comes out at random and therefore no responsibility for anything since everything is determined by “roll the dice” and this is unacceptable to me.
REPLY
What we find unacceptable has zero influence on the functioning of particles, energy and spacetime. We are but a tiny speck in an infinite space, a grain of nothing between two eternities that we call before and after. So it would be good to try to understand how these things work (as far as possible), without playing at the gods who dictate what is acceptable or unacceptable.
REQUEST
We are small but made of particles, so how we are is due to their behavior. But there is something definite, for example the cub that goes to look for the mother's udder or the lion that feeds on meat and hunts for it, evidently something definite exists.
REPLY
Of course, something definite in living beings exists. The Q2 zone that becomes loaded with memories and experiences over the years makes some reactions highly probable than others. You should listen this video, from the minute 3 on, which explains it better than me.
For which, as you rightly say, the lion usually hunts etc.. And even the baby goes to look for the breast because there are structures inherited through the DNA that characterize it already at birth.
But the nondeterminism we are talking about does not refer to this, but to the decisions at the basis of everything. That is those decisions that, if you're careful, you are not the one to take but they come from within. They are instant choices arriving from the unconscious and only after they have arrived does reason to speak “I chose for this reason or another”. Another example of these choices are the solutions that come after sleep to problems that seemed unsolvable the previous day. If you are careful, they are not decisions made by an elusive one “free will” but from something that acted while you were totally unconscious.
And above all by nondeterminism we mean what happens at the subatomic level. Events that every possible experiment has proved to be totally indeterministic, that is, not determined by anything previous. And since we are composed of subatomic particles, it is inevitable that those choices are at the root of every decision. The choices, which we call random, made by subatomic particles, they determine to some extent all that follows, there is no other possibility.
Then the decisions are filtered by the Q2 layer which suppresses some reactions and favors others, thus determining behavior in a way that we normally refer to as character, or personality, or even free will. These are names we give to the characteristics of the Q2 structure.
The “character” of an individual determines fairly predictable behaviors, but this does not mean that all his decisions are determined by previous conditions.
In conclusion, some of what the living are doing can be predictable with a good chance. But not everything can be foreseen, with absolute determinism, starting from the previous conditions.
REQUEST
I understand what you are saying but I context it as it gives the impression of wanting “to justify”in the sense of saying “Ok, things work in a deterministic way but at the base there is the case” and for me it is not like that…
There is a huge paradox between what is apparently the subatomic world and tactile reality and it is precisely the crux of the matter, let's leave human and animal beings aside and take something material, a bullet for example, we know that it is not possible to determine the position and trajectories of the particles, which in theory determine what will do what they themselves compose and therefore according to this theory it is not predictable how the bullet will behave, which is an inanimate object and devoid of any will of its own or consciousness or whatever you want…
Yet every bullet will behave in exactly the same way, it will be possible to predict its trajectory, the speed, and where it will go, but according to “roll of the dice” it would not be possible as the particles that compose it, and which therefore determine its behavior, they do not meet any specifications “law” but I am in fact a “roll of the dice”… And it doesn't come back eh, but not even a little…
REPLY
The bullet is too, minimally, unpredictable. It is perhaps a few billionth of a billionth of a micron but it is. And this inevitably leads to variations that become more and more amplified over time, just as it happens that the flapping of a butterfly's wings in New York will inevitably bring, after some time, to changes in the climate even in Paris.
Of course when you go to measure the trajectory of a bullet with a tape measure or other macroscopic instruments you will find it predictable.. But if you experiment with greater precision, you will find that there is always unpredictability. These experiments have been done, they have been doing all kinds of them for a hundred years and they always inevitably lead everyone to the same conclusion, that is, subatomic particles do what they want, without any dependence on previous conditions.
And the experiments, especially Bell's inequalities, they have also shown that there is no way to predict, not even theoretically, what choices will the particles make.
Two generations of physicists have been looking for loopholes from this and no one has found them. Of course, if you don't know the experiments that have been done, you have reason to doubt. Even my intuition told me that it is not possible that “god you play dice”, but then I studied the problem better and I realized that this is the case. I therefore advise you to read and study these topics because in science what matters is the evidence. The intuition of us humans can help but the results of the experiments have the last word.
The predictability that we experience exists but it is only the collective probability due to a large number of particles that, in measurable and known percentages, they do what we expect. This is the statistical law of large numbers, just as by flipping a coin a thousand times you can predict that it will come more or less half the times heads. But that “more or less” it is only an approximation when thinking on macroscopic scales. While when you go to see the details, anything can happen, also the 100% of heads for ten consecutive throws.
REQUEST
I do not question the experiments or the various theories, I wouldn't be able to, but my reasoning is based on objective data concerning the world in which we live, because according to the unpredictability of the particles there are percentages that vary and above all we are not able to predict in any way, so what is the point of making plans to say about a bridge if I already know from the start that seven or eight times it will stand up and another two or three times it will come down due to the unpredictability of the subatomic particles?
Because we can turn it as we want but matter, all, it is made up of particles that make up atoms which in turn make up molecules, so either there is something that “then he tidies up”, the intuitive one, the particles so that “play” to their liking on a micro scale but at some point they all put themselves in order and therefore the materials, which are composed of matter and blah blah blah and blah blah blah are what we have designed, or more simply we have not understood anything…
Because it is true that subatomic measurements would show imperfections and more, but it is just as good as except for manufacturing defects, the bullet will make the bullet and I will only and exclusively be a bullet, never an antacid tablet or a comb, I don't know if I can explain myself…
If I design a machine, I do it without measuring the infinitely small, trusting that such material will have such reaction or behavior, according to “roll of the dice” however this is not the case, because if the quantum x goes to the right instead of to the left, everything changes… understand what I mean?
REPLY
At macroscopic dimensions and with approximate measurements, what you say is right. Bridges do not come down because in everything we do we always give a good margin of safety. A margin that is billions of billions of times greater than the small differences that could be caused by the microscopic behavior of matter.
But if you go into the details and the sub-microscopic, what you say is no longer valid. To continue along the path of knowledge, as well as to make satellites, electronic components, computer and all the rest, it is now necessary to take into account even these non-deterministic details, otherwise the satellites come down and the computers don't work.
Furthermore, once it is understood that even life originates from non-deterministic randomness, the great questions about life (consciousness, free will, death etc ..) they change shape and finally become understandable for what they are.
REQUEST
It makes no sense to distinguish between macro and micro, unless we conclude that they are two separate worlds. That is, what happens at the micro level, the famous “roll of the dice”, it is what then affects the atomic structures and from these the molecular ones, if the roll of the dice goes five times in one direction, and five on the opposite, causes the atom to be once x and the other y, and this is not the same as the molecules made up of those atoms could not be the same so why make plans if we do not know what structural behavior to expect?
So let's say that some things always happen and repeat themselves in the same way, we are unable to say why but only to exploit its potential, but between the roll of the dice and the next step that causes things to always happen the same way there must be an unknown level, otherwise the behavior of matter would be of an anarchic type. Two black parents will always give birth to a black child and not a blonde with blue eyes and this is determined by the genes., which in turn are determined by molecules which are made up of atoms, if the dice were rolled randomly by two blacks, a blond could come out.
REPLY
It's probably best to let it go. E’ right that you can think as you like. And after all it is not even important, we are just monkeys who use words to talk about the branches of their trees.
REQUEST
No problem, on the other hand the approach “religious”, and I say this not with derogatory intent eh, be clear, it's just my feeling but utmost respect, in the end everyone has to believe in something.
REPLY
Religious approach, but when ever, there is not a shred of religion in these words, rather! E’ just a realization of the proportions between us and everything else. And how much what we can experience and understand is deformed by physical limits. While many believe that we are who knows what, the pinnacle of evolution, supreme intelligence, free arbitrators, holy spirits, etc…
REQUEST
No, do not misunderstand, religious not that you have used religious terminology or anything else in the classical sense of religion, in the sense, however, that many, including you, and my personal opinion which therefore counts zero split, you seem to have that kind of approach towards quantum science but I repeat, that's my impression, to skin.
And I don't think it is who knows what and not even the culmination of evolution, I believe, however, that it is right to ask questions, and God forbid, a bit’ less wanting to find answers at any cost too “forcing things”. I was reading just now that CERN is evaluating the results, anomaly, of some experiments that at the moment, pending appropriate checks, they give discoveries unknown particles and who knows, maybe something new might come up.
REPLY
Of course it is right to ask questions! Indeed thank you for your questions which are a magnificent example of the doubts that come to everyone when they collide with these strange behaviors of the matter.. These are the same questions that Einstein asked himself and he too, exactly like you, he didn't want to believe it.
Einstein thought that all this was unacceptable and he sought for a long time some explanation that did not conflict with common sense and that would allow to keep alive the concept of determinism.. Arguing with Bohr he got so heated up to exclaim: “God doesn't play dice !”, to which Bohr replied: “Stop telling God what to do”.
In the following hundred years, four generations of physicists have asked the same questions and all, at first glance, they had the same disbelief reaction you write in your messages. It took me years to convince myself and certainly Damiano also asked himself if there were other more reasonable explanations when he started studying physics.. Explanations that do not clash with the logic we are used to using. But no one has been able to find these explanations for her.
To try to understand these strange behaviors, experiments of all kinds have been made. And all the experiments, not one against, led to the same conclusion, that is, that God plays dice. Or better, than subatomic particles (for example photons and electrons) they make choices “their own way”, choices that are not conditioned or conditioned in any way, choices not determined by any previous condition. And from this descend concepts that also modify our way of seeing life, conscience, will and free will.
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