Q&A: Determinism and Statistics
Determinism and Statistics
Question
Hello Rabbi Michi,
The central scientific claim in physics is that the laws of nature are deterministic. I would like to ask several questions about this:
1) Is it, in principle, the case that even the most complex and chaotic system is deterministic, and therefore predictable in advance, and that this is only our inability to account for all the data and all the interactions between them, with statistics merely expressing that inability?
2) What is the relationship between the laws and the probability that something will actually happen? That is, the fact that the laws are fixed still does not mean that things will happen. For example, given such-and-such data and a certain amount of time, life may arise on a certain planet, but things can still go wrong, such as a comet colliding with it. And even if we assume that the comet entered a collision course a million years earlier, for example, additional variables could still arise along the way that did not exist when it set out, and so even if the laws of physics determined that something could happen, there is still a possibility that it will not happen.
3) What is the relationship between the laws and the human soul, and social and historical laws (for example, cyclical patterns of nations)? After all, free choice is not necessitated by the determinism of physics in the brain. Can this be said about the entire psychological structure of the human being? And does physics affect social and historical processes (or regularities), such that they too are deterministic?
I hope I didn't ask too many things in one question 🙂
Answer
Hello.
- The laws of physics are deterministic, except in quantum theory (choice will be discussed below). There, according to the accepted interpretation, there is randomness, but only at very small scales (very tiny particles). Therefore it is commonly thought that inability to predict expresses nothing more than inability.
- The relationship is 1:1. What you call unexpected things (a comet) is also a result of the laws of nature.
- When human choice is involved, that of course can change what happens in the world (unless you are a determinist). Therefore laws that deal with events involving human beings are laws of probability, not deterministic laws. But even there, of course, we are not dealing with randomness but with choice. Those are different things.
Discussion on Answer
Hello. I already answered both questions, and from your words it is clear that you understood the answer well. I do not see what would be gained by repeating what I wrote.
N,
If you ignore randomness (quantum, or something else if it exists and is not known) and choice (and again, someone might argue that choice exists not only for human beings, while someone else will argue that there is no choice at all), and if you had information about all the particles in the universe (mass and velocity), complete information about all the forces that exist (that is, you would know physics completely, including what is still unknown), and unlimited computing power, you could predict a future state (and also past states) at any time.
Thank you for the answer.
1) So statistics is our expression of the inability? For example, when we say that a certain medicine helps in 70% of cases, does that basically mean it is suitable for 100% of cases of the disease, except that because we do not have the ability to be precise about the exact characteristics of the disease, in practice it only helps in 70% of cases (in other words, the 30% are really subtypes of the disease for which the medicine does not work)?
2) The first question leads to the second. It is clear that the unexpected things are also subject to the laws of nature. The question is whether the outcome is subject to them. Let me try to sharpen the example. Suppose one person is standing opposite another person and aiming a gun at him. If we freeze the moment and examine the data (angle, wind speed, distance, stability, etc. etc., and assuming we have the precise ability to measure), we will reach the conclusion that the shot should hit the center of the other person's heart and kill him. Now the first person fires. If nothing changes, the second person will die. But if during those 0.02 seconds of the bullet's flight the wind suddenly changes slightly (which of course is also subject to laws), and the bullet hits 0.01 mm to the right of the heart and does not kill the second person—then even in such a case, is the claim that if we had unlimited ability, we should have predicted that in advance? And in the example of the comet, over long periods of time, with unlimited ability would we also be supposed to foresee what would arise over time that would cause, say, the comet to hit the planet and destroy the emergence of life?