# Re: The Nature of Contingency: Quantum Physics as Modal Realism

```On 08-04-2022 07:28, Bruce Kellett wrote:
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`On Fri, Apr 8, 2022 at 1:42 PM smitra <smi...@zonnet.nl> wrote:`
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```
```On 08-04-2022 00:45, Bruce Kellett wrote:
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```
It has nothing to do with realism. Local physics is completely
```
```defined
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```by what happens at the individual spacetime points. But that does
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```not
```
```imply that variables have definite values before they are
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```measured. We
```
```allow for stochastic dependence on the physics at local spacetime
points and also allow for MWI -- the operation of the
```
```deterministic
```
```Schrodinger equation giving every possible outcome on  every
interaction. If you are not careful, you are going to make MWI
realistic. The Humean assumption underlies any local theory,
```
```including
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```MWI if that can be shown to be local. It is not intrinsically
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```realist.
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```
Locality implies separability. If you disagree, show me the
mathematics of a local state (referring to distinct spacetime
```
```points)
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```that is not separable -- without begging the question, that is!

```
```
Locality refers to the dynamics of a theory, not to properties of
some
particular state.
```
```
The properties of the state refer to the dynamics of the underlying
interactions. In quantum mechanics, the state vector tells you
everything that can be known about the consequences of the underlying
dynamics.

```
```
A Hamiltonian must be specified.

```
```In classical physics, you don't have non-separable
states, but you can get to non-local correlations using only local
dynamics.
```
```
Only in the trivial, everyday, sense of Bertlmann's socks.

```
```In QM you can get to non-separable states using only local
dynamics.
```
```
The non-separable state may be created at a single spacetime point,
but that is not a relevant consideration if the parts then move apart.

```
```The mere fact that you can have non-classical entangled states
does not imply that the dynamics of the theory is non-local
```
```
The fact of non-separable entangled states, which are unique to
quantum mechanics, does imply non-locality.
Vide above....
You still have not shown me this magical local state that is
non-separable.

```
```
What matters is that the Hamiltonian is local.

```
```Bruce

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