[hyperpallium]

Mechanical: the contact theory, that one thing can only affect another by being in contact with it e.g. the teeth of gears.

Unfortunately, gravity ("spooky action at a distance") does not require contact, so the mechanical theory fails. Which can be stated figuratively as "the world is not a machine".

"The machine, the ghost, and the limits of understanding: Newton's contributions to the study of mind" at the University of Oslo, September 2011 https://youtube.com/watch?v=D5in5EdjhD0

[ealloc]

I've read Chomsky's opinion on this before in his essay ""Science, Mind, and Limits of Understanding", and I think he misunderstands the physics.

He seems to think Newton accidentally disproved the concept of locality through his theory of gravity. It's true that philosophers largely gave up on locality in the 18th century because of Newton, but that was only temporary: In the 19th century the principle of locality came back with a vengance after Maxwell.

Today the principle of locality is a key component of the Standard model: The Hamiltonian of the standard model is local, meaning you can compute what happens at a point in spacetime knowing only what is going on in an infinitesimal region around it. Even outside the standard model, LIGO proved that graviational waves exist, and therefore gravity is a local phenomenon.

Einstein was famously prepared to give up on quantum mechanics because it seemed to violate the principle of locality, which he thought was more important. That is still debated sometimes, though whether quantum nonlocality exists seems to be a matter of interpretation and is also different from the kind of locality chomsky is talking about. Locality is still a key principle in physics.

[hyperpallium]

> what is going on in an infinitesimal region around it

A "field" is just a name for spooky action at a distance. It's a description, not an explanation. There is no mechanical contact, only "locality" of a field.

Or are you saying that fields are really mediated by particles... so there is mechanical contact?

[sgt101]

People call these thing gravitons but they are particles in the sense that light and electricity are particle based - which is to say that in the limit it turns out that a discrete particle doesn't describe everything that's happening and some wave like properties in space and time are a good fit too. The particles are sort of like a manifestation or a partial mathematical description of the thing that's underneath. The particle is an excitation of a field - all particles are, so mechanical interactions reduce to fields. The thing to remember is that your intuitive and perceptual apparatus was largely evolved to help you get fruit in a forest, and later to help you catch rabbits and shell fish. The ideas that are obvious are approximations that allow you to navigate the world of the past - but they are not "right".

[ealloc]

Yes, forces transmitted through fields act "at a distance", but is that really "spooky"? Do you think it is "spooky" that if you make a wave at one end of a pond, the wave reaches the other end? I don't. I consider the propagation of waves to be a "local" non-spooky phenomenon.

Disturbances in a field propagate through space similarly. A disturbance of the field at a point only affects the value of the field in the immediate spacetime surroundings, just like a water wave. I would call that "local" and non-spooky. Whether or not there is "mechanical contact", whatever that means, is irrelevant.

This is in contrast to Newton's theory of gravity, where the force of gravity was spookily felt instantaneously across space.

[hyperpallium]

> A disturbance of the field at a point only affects the value of the field in the immediate spacetime surroundings, just like a water wave.

Ok, I see that's local (though not mechanical, as you say).

I think a magnetic field (as from a magnet, not a wave) is not local though? So, the transmissiin of modulation is "local", but the field itself is "at a distance"?

[meikos]

When you move the magnet, the field change takes a while to propogate outwards. So, yes also local

[TheOtherHobbes]

Non-locality in QM is directly implied by Bell’s inequality.

https://en.m.wikipedia.org/wiki/Bell%27s_theorem

[ealloc]

No it isn't. There is still plenty of debate about the philosophical implications of Bells' inequality.

See for example this 2014 PNAS article "Quantum nonlocality does not exist": http://www.pnas.org/content/111/31/11281

You can find plenty more if you google. I personally agree with the ideas of that paper in a broad sense if not in detail, as do many people.

Second, if you are trying to argue that locality is no longer a guiding principle, note how the standard model is quantum-mechanical so obeys bell's inequality, yet we still call it "local". Locality was a key guiding principle of the standard model.

[sgt101]

Gravity is not spooky action at a distance, Einstein showed us how the fabric of space time implements Gravity in a mechanistic way. Some quantum processes (I don't dare to elaborate - read Wikipedia and then do 6 years of physics to find out more!) are referred to as "spooky action as a distance" or non locality. This is simply not understood - hence the bloody bloody Copenhagen interpretation and the bloody bloody people who chant "look at my sums it's all fine and I have no responsibility to understand and because I can't I will try and stop anyone who wants to".

I feel bad about all of this. And ignorant, but I am confident that Gravity is a mechanistic force. And I think that the jury is out about the world as a machine, but as far as I know everything that we understand about it is mechanistic. The other bits may be non-mechanistic, but we may never understand that.