Everything in the universe is deterministic

[ramollari]

I used to believe that everything in the universe is deterministic because it obeys physical laws. So we could theoretically predict events. But does the quantum theory undermine this idea? To which extent does uncertainty with the behaviour of the tiniest particles affect bigger events?

 

[lalbatros]

Physical laws are essentially not deterministic.

Quantum mechanics is not and is the most fundamental theory.

Statistical mechanics is deterministic only on the averages but it deals essentially with the effects of large numbers of particles that cannot be studied or observed in a deterministic way (practically impossible on a detailled level).

Determinism even in classical theory is limited by experimental precision. In many circonstances experimental precision is limited by the system being studied. This applies to statistical mechanics. This applies also to the well known three-body system for which long-term unpredictability is the rule. Chaotic systems and turbulence are other examples.

Determinism is the exception apparently. It is limited to classical and simple systems well prepared and defined (there are always limits on preparation). Even then, it applies usually only on "short" periods of time. (when the experiment is switched who can predict what follows? what the scientists will do for example)

 

[R0man]

The concept of determinism in the universe has been a topic of debate for centuries. On one hand, some argue that everything in the universe is predetermined and follows a set of predetermined physical laws, making it possible to predict events. On the other hand, the quantum theory, which explains the behavior of the tiniest particles, has raised questions about the extent to which determinism can be applied to the universe.

While it is true that the physical laws governing the behavior of larger objects can be predicted with a high degree of accuracy, the same cannot be said for the behavior of particles at the quantum level. According to the Heisenberg uncertainty principle, it is impossible to simultaneously know the exact position and momentum of a particle. This means that there will always be a level of uncertainty in predicting the behavior of these particles, which can have a cascading effect on larger events.

Furthermore, the concept of quantum entanglement, where particles can be connected and influence each other's behavior instantaneously regardless of distance, challenges the idea of determinism in the universe. This phenomenon suggests that there is a level of randomness in the universe that cannot be predicted or controlled.

In conclusion, while determinism may hold true for larger objects in the universe, the uncertainty and randomness at the quantum level suggest that not everything in the universe can be predicted. The behavior of tiny particles can have a significant impact on larger events, making it impossible to have complete determinism in the universe.