Mechanistic view of the universe

Question

I was chatgpting and found Encouragement of the Mechanistic View The mechanistic view in physics is driven by several key principles:

Determinism: The idea that the future behavior of a system can be predicted with complete accuracy if its initial conditions and the laws of motion governing it are known.

Reductionism: The belief that complex phenomena can be understood by breaking them down into their simpler constituent parts and studying these parts individually.

Causality: The principle that every effect has a specific cause and that the laws of physics govern these cause-effect relationships.

Locality: The notion that interactions between objects occur at specific points in space and time, without instantaneous action at a distance.

My question is: What encourages a mechanistic view and how its related to reductionism and determinism ?

One blow to mechanical view was I think was action at a distance but does the concept of fields kept the concept of mechanistic view by introducing the concept of locality and answer to action at a distance ? Please explain to me the intricate relationship between causality and locality .

Anyone interested must read https://dn720201.ca.archive.org/0/items/evolutionofphysi033254mbp/evolutionofphysi033254mbp.pdf

Answer 1

An additional (perhaps minor) point: Maxwell himself spent his later years hypothesizing various mechanistic models for electromagnetic wave propagation in which space was filled with submicroscopic gear wheels and springs which transmitted movement by direct contact between machine elements, eliminating the need for fields as we conceptualize then today. This approach fell flat, for the following reasons:

To get the measured speed of light to come out correctly required that those little gear wheels and whatnot be almost massless and the springs and whatnot be almost infinitely stiff- ruling out any form of ordinary matter to make them out of.

Then you have the problem that ordinary matter can pass straight through that infinite array of space-filling gear wheels without any resistance. Hmm...

Finally you have the problem that to mechanically propagate waves in space through physical contact between gear wheels in three dimensions required those little gear wheels to mechanically engage one another in three dimensions in physically impossible ways.

Answer 2

The term mechanistic is outdated. It characterizes Newtonian mechanics. Already in the 19th century Maxwell’s electrodynamics is a theory which cannot be understood in mechanical terms.

1. The principle of causality holds for the physical theories of Newton, Maxwell, Boltzmann (thermodynamics and statistical mechanics) and Einstein (Special and General Theory of Relativity). The principle does not hold for quantum mechanics and quantum field theories.

2. The principal of locality should be restricted to the first part of the definition in the OP's post. Then it holds for all of the above theories with the exception of quantum mechanics and quantum field theories: In general, the state of a quantum system has to be considered a field of probabilities (psi-function), and therefore the interaction via interference cannot be localized.

3. The principle of separability states that physical systems which are separated in spacetime can be considered as separated systems. The principle holds for all of the above theories with exception of quantum theory: The phenomenon of entanglement in quantum theory contradicts the principle of separability.

4. Different from the principle of locality is the principle “no instantaneous action at distance”: This principle is violated by Newton’s mechanics and afterwards Boltzmann's thermodynamics and statistical mechanics. But it is satisfied by the other physical theories above. An upper bound for the propagation of the causal effect is the speed of light.

5. The question of reduction of theories is quite a different subject. A textbook example is Boltzmann’s and Gibbs’ reduction of thermodynamics to statistical mechanics. But the possibility of general reduction is restricted. In general, distinct sciences work with additional specific laws, which will not be reduced to the deepest layer of elementary particles.

This short overview from the history of physics shows which of the above principles were successfully incorporated into which physical theories, while other principles had to be abandoned.

Answer 3

As you have probably understood from the book, the mechanical view of the universe is a thing of the past. Nowadays, how things works, is described (by physics) in terms of fields.

With regards to locality in a machine-like universe, you expect a specific part not to depend on, or affect another (except nearby); after all, that's what a machine is like: parts are not dependent on other parts, except if they are explicitly connected.

In regards to causality, although this concept can be "interpreted" in many ways, one thing is for sure: you expect a cause to precede the effect.

Both these concepts are challenged by the phenomenon of quantum entanglement, where a system is exchanging information with another, violating locality, while at the same time, makes cause and effect indistinguishable.

In fact the Nobel price 2022 was about this process.

Answer 4

What encourages a mechanistic view...

I've already argued in a comment that a mechanistic model attempts to answer a "how" question, e.g. how does the observed motion of the planets arise? Ptolemy attempted to answer this question, and Newton produced a simpler model. This led to the discovery of the planet Neptune.

1. Herschel discovered Uranus by good, old fashioned, observation.
2. Initially Newton's model didn't fit the data for Uranus terribly well, but John Adams and Urbain Le Verrier realized that the model could be made to fit if there were yet another planet out there. They independently calculated the position of their hypothetical planet, which was duly observed.

Getting back to your question: a mechanistic model may predict phenomena which may or may not be observed. Mechanistic models are encouraged by this possibility.