### Re: Measuring a system in a superposition of states vs in a mixed state

```On Wed, Dec 5, 2018 at 6:08 PM Philip Thrift  wrote:

> On Wednesday, December 5, 2018 at 12:53:45 AM UTC-6, Bruce wrote:
>>
>> On Wed, Dec 5, 2018 at 5:43 PM Philip Thrift  wrote:
>>
>>> On Wednesday, December 5, 2018 at 12:28:19 AM UTC-6, Bruce wrote:

On Wed, Dec 5, 2018 at 5:19 PM Philip Thrift
wrote:

> On Wednesday, December 5, 2018 at 12:00:18 AM UTC-6, Bruce wrote:
>>
>> On Wed, Dec 5, 2018 at 4:51 PM Philip Thrift
>> wrote:
>>
>>> On Tuesday, December 4, 2018 at 11:39:43 PM UTC-6, Bruce wrote:

On Wed, Dec 5, 2018 at 3:53 PM Philip Thrift
wrote:

> On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift
> wrote:
>>
>> On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:
>>>
>>> On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift
>>> wrote:
>>>

On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>
>
> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>
>
> 1. Histories originate at an emitter e and end at screen
> locations s on a screen S.
> 2. At each s there is a history bundle histories(s). A weight
> w(s) is computed from the bundle by summing the unit complex
> numbers of the
> histories and taking the modulus.
> 3. The weight w(s) is sent back in time over a single history
> h*(s) selected at random (uniformly) from histories(s).
> 4. At e, the weights w(s) on backchannel of h*(s) are received
> (in the "present" time)
> 5. A single history h*(s*) is then selected from the
> distribution in 4.
>
>
> How is it selected?  Above you said "at random".  But that
> implies there is already a probability measure defined on the
> histories.
> How is this probability measure determined?  Or put another way
> how do you
> determine what histories to consider to form the bundles in step
> 2?
>
> Brent
>

Selection happens via quantum Darwinism.

>>>
>>>
>>> Do you have even the faintest understanding of Quantum Darwinism?
>>>
>>> Bruce
>>>
>>
>> How is *sum over histories with Darwinian selection*  (as
>> defined) not quantum Darwinism?
>>
>> Operationally, what is different?
>>
>> - pt
>>
>
> *Sum over histories with Darwinian selection* is consistent with
> *Quantum
> Darwinism as a Darwinian process*  [
> https://arxiv.org/abs/1001.0745 ].
>

No, you clearly don't understand Quantum Darwinism! Zurek's
Darwinism is selection of pointer states, not one history from a
bundle.

Bruce

>>>
>>>  Histories are (hidden) states.
>>>
>>
>> It becomes obvious that you don't really understand consistent
>> histories, either.
>>
>> Bruce
>>
>
> I've never once mentioned *consistent histories*, only *sum over
> histories*.
>

Inconsistent histories?

> (Did you watch the lecture by Fay Dowker?)
>

No, I don't watch utube videos.

Pointer states [ https://arxiv.org/abs/1508.04101 ] can best be
> understood as related to histories via the *Reflective Path Integral*
> interpretation of the EPR experiment.
>

it seems to be required in your account, is simply a nonsense. Huw Price
lost the plot a long time ago.

There is no competition between the different paths between the initial
and final state -- which is what is used to calculate probabilities in the
path integral approach. So there is no Darwinian (or other) selection of
one such path over others. Quantum Darwinism is about something quite
different. Even Wikipedia agrees! Read Zurek's papers on this.

Bruce

>>>
>>>
>>> OK. As Kay Dowker stated in her presentation: The path integral
>>> interpretation is still under development.
>>>
>>
>> As has been pointed out, path integrals are a calculational tool, not an
>> interpretation.
>>
>
>
> Oh,* that* again. It's like Groundhog Day (the movie).
>

Given your repetitive harping on half-baked path integral ideas, I thought
repetition was the way forward.

Bruce

>> My (retrocausal) version of Darwinian selection w.r.t. multiple histories
>>>  *is* *the next
>>> development.*
>>>
>>
>> I see, it is not actually a coherent proposition at the ```

### Re: Measuring a system in a superposition of states vs in a mixed state

```

On Wednesday, December 5, 2018 at 12:53:45 AM UTC-6, Bruce wrote:
>
> On Wed, Dec 5, 2018 at 5:43 PM Philip Thrift  > wrote:
>
>> On Wednesday, December 5, 2018 at 12:28:19 AM UTC-6, Bruce wrote:
>>>
>>> On Wed, Dec 5, 2018 at 5:19 PM Philip Thrift  wrote:
>>>
On Wednesday, December 5, 2018 at 12:00:18 AM UTC-6, Bruce wrote:
>
> On Wed, Dec 5, 2018 at 4:51 PM Philip Thrift
> wrote:
>
>> On Tuesday, December 4, 2018 at 11:39:43 PM UTC-6, Bruce wrote:
>>>
>>> On Wed, Dec 5, 2018 at 3:53 PM Philip Thrift
>>> wrote:
>>>
On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift
wrote:
>
> On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:
>>
>> On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift
>> wrote:
>>
>>>
>>> On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:

On 12/4/2018 12:25 AM, Philip Thrift wrote:

1. Histories originate at an emitter e and end at screen
locations s on a screen S.
2. At each s there is a history bundle histories(s). A weight
w(s) is computed from the bundle by summing the unit complex
numbers of the
histories and taking the modulus.
3. The weight w(s) is sent back in time over a single history
h*(s) selected at random (uniformly) from histories(s).
4. At e, the weights w(s) on backchannel of h*(s) are received
(in the "present" time)
5. A single history h*(s*) is then selected from the
distribution in 4.

How is it selected?  Above you said "at random".  But that
implies there is already a probability measure defined on the
histories.
How is this probability measure determined?  Or put another way
how do you
determine what histories to consider to form the bundles in step 2?

Brent

>>>
>>> Selection happens via quantum Darwinism.
>>>
>>
>>
>> Do you have even the faintest understanding of Quantum Darwinism?
>>
>> Bruce
>>
>
> How is *sum over histories with Darwinian selection*  (as
> defined) not quantum Darwinism?
>
> Operationally, what is different?
>
> - pt
>

*Sum over histories with Darwinian selection* is consistent with
*Quantum
Darwinism as a Darwinian process*  [
https://arxiv.org/abs/1001.0745 ].

>>>
>>> No, you clearly don't understand Quantum Darwinism! Zurek's
>>> Darwinism is selection of pointer states, not one history from a bundle.
>>>
>>> Bruce
>>>
>>
>>  Histories are (hidden) states.
>>
>
> It becomes obvious that you don't really understand consistent
> histories, either.
>
> Bruce
>

I've never once mentioned *consistent histories*, only *sum over
histories*.

>>>
>>> Inconsistent histories?
>>>
>>>
(Did you watch the lecture by Fay Dowker?)

>>>
>>> No, I don't watch utube videos.
>>>
>>> Pointer states [ https://arxiv.org/abs/1508.04101 ] can best be
understood as related to histories via the *Reflective Path Integral*
interpretation of the EPR experiment.

>>>
>>> Your arxiv references do not support your case. Reverse causation, as it
>>> seems to be required in your account, is simply a nonsense. Huw Price lost
>>> the plot a long time ago.
>>>
>>> There is no competition between the different paths between the initial
>>> and final state -- which is what is used to calculate probabilities in the
>>> path integral approach. So there is no Darwinian (or other) selection of
>>> one such path over others. Quantum Darwinism is about something quite
>>> different. Even Wikipedia agrees! Read Zurek's papers on this.
>>>
>>> Bruce
>>>
>>
>>
>> OK. As Kay Dowker stated in her presentation: The path integral
>> interpretation is still under development.
>>
>
> As has been pointed out, path integrals are a calculational tool, not an
> interpretation.
>

Oh,* that* again. It's like Groundhog Day (the movie).

>
>> My (retrocausal) version of Darwinian selection w.r.t. multiple histories
>>  *is* *the next
>> development.*
>>
>
> I see, it is not actually a coherent proposition at the moment...
>
> Bruce
>

Coherency is overrated.

- pt

--
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To ```

### Re: Measuring a system in a superposition of states vs in a mixed state

```On Wed, Dec 5, 2018 at 5:43 PM Philip Thrift  wrote:

> On Wednesday, December 5, 2018 at 12:28:19 AM UTC-6, Bruce wrote:
>>
>> On Wed, Dec 5, 2018 at 5:19 PM Philip Thrift  wrote:
>>
>>> On Wednesday, December 5, 2018 at 12:00:18 AM UTC-6, Bruce wrote:

On Wed, Dec 5, 2018 at 4:51 PM Philip Thrift
wrote:

> On Tuesday, December 4, 2018 at 11:39:43 PM UTC-6, Bruce wrote:
>>
>> On Wed, Dec 5, 2018 at 3:53 PM Philip Thrift
>> wrote:
>>
>>> On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift
>>> wrote:

On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:
>
> On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift
> wrote:
>
>>
>> On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>>>
>>>
>>> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>>>
>>>
>>> 1. Histories originate at an emitter e and end at screen
>>> locations s on a screen S.
>>> 2. At each s there is a history bundle histories(s). A weight
>>> w(s) is computed from the bundle by summing the unit complex
>>> numbers of the
>>> histories and taking the modulus.
>>> 3. The weight w(s) is sent back in time over a single history
>>> h*(s) selected at random (uniformly) from histories(s).
>>> 4. At e, the weights w(s) on backchannel of h*(s) are received
>>> (in the "present" time)
>>> 5. A single history h*(s*) is then selected from the
>>> distribution in 4.
>>>
>>>
>>> How is it selected?  Above you said "at random".  But that
>>> implies there is already a probability measure defined on the
>>> histories.
>>> How is this probability measure determined?  Or put another way how
>>> do you
>>> determine what histories to consider to form the bundles in step 2?
>>>
>>> Brent
>>>
>>
>> Selection happens via quantum Darwinism.
>>
>
>
> Do you have even the faintest understanding of Quantum Darwinism?
>
> Bruce
>

How is *sum over histories with Darwinian selection*  (as defined)
not quantum Darwinism?

Operationally, what is different?

- pt

>>>
>>> *Sum over histories with Darwinian selection* is consistent with
>>> *Quantum
>>> Darwinism as a Darwinian process*  [ https://arxiv.org/abs/1001.0745
>>> ].
>>>
>>
>> No, you clearly don't understand Quantum Darwinism! Zurek's Darwinism
>> is selection of pointer states, not one history from a bundle.
>>
>> Bruce
>>
>
>  Histories are (hidden) states.
>

It becomes obvious that you don't really understand consistent
histories, either.

Bruce

>>>
>>> I've never once mentioned *consistent histories*, only *sum over
>>> histories*.
>>>
>>
>> Inconsistent histories?
>>
>>
>>> (Did you watch the lecture by Fay Dowker?)
>>>
>>
>> No, I don't watch utube videos.
>>
>> Pointer states [ https://arxiv.org/abs/1508.04101 ] can best be
>>> understood as related to histories via the *Reflective Path Integral*
>>> interpretation of the EPR experiment.
>>>
>>
>> Your arxiv references do not support your case. Reverse causation, as it
>> seems to be required in your account, is simply a nonsense. Huw Price lost
>> the plot a long time ago.
>>
>> There is no competition between the different paths between the initial
>> and final state -- which is what is used to calculate probabilities in the
>> path integral approach. So there is no Darwinian (or other) selection of
>> one such path over others. Quantum Darwinism is about something quite
>> different. Even Wikipedia agrees! Read Zurek's papers on this.
>>
>> Bruce
>>
>
>
> OK. As Kay Dowker stated in her presentation: The path integral
> interpretation is still under development.
>

As has been pointed out, path integrals are a calculational tool, not an
interpretation.

> My (retrocausal) version of Darwinian selection w.r.t. multiple histories
>  *is* *the next
> development.*
>

I see, it is not actually a coherent proposition at the moment...

Bruce

--
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To post to this group, send email to everything-list@googlegroups.com.

```

### Re: Measuring a system in a superposition of states vs in a mixed state

```

On Wednesday, December 5, 2018 at 12:28:19 AM UTC-6, Bruce wrote:
>
> On Wed, Dec 5, 2018 at 5:19 PM Philip Thrift  > wrote:
>
>> On Wednesday, December 5, 2018 at 12:00:18 AM UTC-6, Bruce wrote:
>>>
>>> On Wed, Dec 5, 2018 at 4:51 PM Philip Thrift  wrote:
>>>
On Tuesday, December 4, 2018 at 11:39:43 PM UTC-6, Bruce wrote:
>
> On Wed, Dec 5, 2018 at 3:53 PM Philip Thrift
> wrote:
>
>> On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift
>> wrote:
>>>
>>> On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:

On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift
wrote:

>
> On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>>
>>
>> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>>
>>
>> 1. Histories originate at an emitter e and end at screen
>> locations s on a screen S.
>> 2. At each s there is a history bundle histories(s). A weight
>> w(s) is computed from the bundle by summing the unit complex numbers
>> of the
>> histories and taking the modulus.
>> 3. The weight w(s) is sent back in time over a single history
>> h*(s) selected at random (uniformly) from histories(s).
>> 4. At e, the weights w(s) on backchannel of h*(s) are received
>> (in the "present" time)
>> 5. A single history h*(s*) is then selected from the distribution
>> in 4.
>>
>>
>> How is it selected?  Above you said "at random".  But that
>> implies there is already a probability measure defined on the
>> histories.
>> How is this probability measure determined?  Or put another way how
>> do you
>> determine what histories to consider to form the bundles in step 2?
>>
>> Brent
>>
>
> Selection happens via quantum Darwinism.
>

Do you have even the faintest understanding of Quantum Darwinism?

Bruce

>>>
>>> How is *sum over histories with Darwinian selection*  (as defined)
>>> not quantum Darwinism?
>>>
>>> Operationally, what is different?
>>>
>>> - pt
>>>
>>
>> *Sum over histories with Darwinian selection* is consistent with
>> *Quantum
>> Darwinism as a Darwinian process*  [ https://arxiv.org/abs/1001.0745
>> ].
>>
>
> No, you clearly don't understand Quantum Darwinism! Zurek's Darwinism
> is selection of pointer states, not one history from a bundle.
>
> Bruce
>

Histories are (hidden) states.

>>>
>>> It becomes obvious that you don't really understand consistent
>>> histories, either.
>>>
>>> Bruce
>>>
>>
>> I've never once mentioned *consistent histories*, only *sum over
>> histories*.
>>
>
> Inconsistent histories?
>
>
>> (Did you watch the lecture by Fay Dowker?)
>>
>
> No, I don't watch utube videos.
>
> Pointer states [ https://arxiv.org/abs/1508.04101 ] can best be
>> understood as related to histories via the *Reflective Path Integral*
>> interpretation of the EPR experiment.
>>
>
> Your arxiv references do not support your case. Reverse causation, as it
> seems to be required in your account, is simply a nonsense. Huw Price lost
> the plot a long time ago.
>
> There is no competition between the different paths between the initial
> and final state -- which is what is used to calculate probabilities in the
> path integral approach. So there is no Darwinian (or other) selection of
> one such path over others. Quantum Darwinism is about something quite
> different. Even Wikipedia agrees! Read Zurek's papers on this.
>
> Bruce
>

OK. As Kay Dowker stated in her presentation: The path integral
interpretation is still under development.

My (retrocausal) version of Darwinian selection w.r.t. multiple histories
*is* *the next
development.*

- pt

--
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```

### Re: Measuring a system in a superposition of states vs in a mixed state

```On Wed, Dec 5, 2018 at 5:19 PM Philip Thrift  wrote:

> On Wednesday, December 5, 2018 at 12:00:18 AM UTC-6, Bruce wrote:
>>
>> On Wed, Dec 5, 2018 at 4:51 PM Philip Thrift  wrote:
>>
>>> On Tuesday, December 4, 2018 at 11:39:43 PM UTC-6, Bruce wrote:

On Wed, Dec 5, 2018 at 3:53 PM Philip Thrift
wrote:

> On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift wrote:
>>
>> On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:
>>>
>>> On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift
>>> wrote:
>>>

On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>
>
> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>
>
> 1. Histories originate at an emitter e and end at screen locations
> s on a screen S.
> 2. At each s there is a history bundle histories(s). A weight w(s)
> is computed from the bundle by summing the unit complex numbers of the
> histories and taking the modulus.
> 3. The weight w(s) is sent back in time over a single history
> h*(s) selected at random (uniformly) from histories(s).
> 4. At e, the weights w(s) on backchannel of h*(s) are received (in
> the "present" time)
> 5. A single history h*(s*) is then selected from the distribution
> in 4.
>
>
> How is it selected?  Above you said "at random".  But that implies
> there is already a probability measure defined on the histories.  How
> is
> this probability measure determined?  Or put another way how do you
> determine what histories to consider to form the bundles in step 2?
>
> Brent
>

Selection happens via quantum Darwinism.

>>>
>>>
>>> Do you have even the faintest understanding of Quantum Darwinism?
>>>
>>> Bruce
>>>
>>
>> How is *sum over histories with Darwinian selection*  (as defined)
>> not quantum Darwinism?
>>
>> Operationally, what is different?
>>
>> - pt
>>
>
> *Sum over histories with Darwinian selection* is consistent with *Quantum
> Darwinism as a Darwinian process*  [ https://arxiv.org/abs/1001.0745
> ].
>

No, you clearly don't understand Quantum Darwinism! Zurek's Darwinism
is selection of pointer states, not one history from a bundle.

Bruce

>>>
>>>
>>>  Histories are (hidden) states.
>>>
>>
>> It becomes obvious that you don't really understand consistent histories,
>> either.
>>
>> Bruce
>>
>
> I've never once mentioned *consistent histories*, only *sum over
> histories*.
>

Inconsistent histories?

> (Did you watch the lecture by Fay Dowker?)
>

No, I don't watch utube videos.

Pointer states [ https://arxiv.org/abs/1508.04101 ] can best be understood
> as related to histories via the *Reflective Path Integral* interpretation
> of the EPR experiment.
>

Your arxiv references do not support your case. Reverse causation, as it
seems to be required in your account, is simply a nonsense. Huw Price lost
the plot a long time ago.

There is no competition between the different paths between the initial and
final state -- which is what is used to calculate probabilities in the path
integral approach. So there is no Darwinian (or other) selection of one
such path over others. Quantum Darwinism is about something quite
different. Even Wikipedia agrees! Read Zurek's papers on this.

Bruce

--
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To post to this group, send email to everything-list@googlegroups.com.

```

### Re: Measuring a system in a superposition of states vs in a mixed state

```

On Wednesday, December 5, 2018 at 12:00:18 AM UTC-6, Bruce wrote:
>
> On Wed, Dec 5, 2018 at 4:51 PM Philip Thrift  > wrote:
>
>> On Tuesday, December 4, 2018 at 11:39:43 PM UTC-6, Bruce wrote:
>>>
>>> On Wed, Dec 5, 2018 at 3:53 PM Philip Thrift  wrote:
>>>
On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift wrote:
>
> On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:
>>
>> On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift
>> wrote:
>>
>>>
>>> On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:

On 12/4/2018 12:25 AM, Philip Thrift wrote:

1. Histories originate at an emitter e and end at screen locations
s on a screen S.
2. At each s there is a history bundle histories(s). A weight w(s)
is computed from the bundle by summing the unit complex numbers of the
histories and taking the modulus.
3. The weight w(s) is sent back in time over a single history h*(s)
selected at random (uniformly) from histories(s).
4. At e, the weights w(s) on backchannel of h*(s) are received (in
the "present" time)
5. A single history h*(s*) is then selected from the distribution
in 4.

How is it selected?  Above you said "at random".  But that implies
there is already a probability measure defined on the histories.  How
is
this probability measure determined?  Or put another way how do you
determine what histories to consider to form the bundles in step 2?

Brent

>>>
>>> Selection happens via quantum Darwinism.
>>>
>>
>>
>> Do you have even the faintest understanding of Quantum Darwinism?
>>
>> Bruce
>>
>
> How is *sum over histories with Darwinian selection*  (as defined)
> not quantum Darwinism?
>
> Operationally, what is different?
>
> - pt
>

*Sum over histories with Darwinian selection* is consistent with *Quantum
Darwinism as a Darwinian process*  [ https://arxiv.org/abs/1001.0745 ].

>>>
>>> No, you clearly don't understand Quantum Darwinism! Zurek's Darwinism is
>>> selection of pointer states, not one history from a bundle.
>>>
>>> Bruce
>>>
>>
>>
>>  Histories are (hidden) states.
>>
>
> It becomes obvious that you don't really understand consistent histories,
> either.
>
> Bruce
>

I've never once mentioned *consistent histories*, only *sum over histories*.

(Did you watch the lecture by Fay Dowker?)

Pointer states [ https://arxiv.org/abs/1508.04101 ] can best be understood
as related to histories via the *Reflective Path Integral* interpretation
of the EPR experiment.

- pt

--
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To post to this group, send email to everything-list@googlegroups.com.

```

### Re: Measuring a system in a superposition of states vs in a mixed state

```On Wed, Dec 5, 2018 at 4:51 PM Philip Thrift  wrote:

> On Tuesday, December 4, 2018 at 11:39:43 PM UTC-6, Bruce wrote:
>>
>> On Wed, Dec 5, 2018 at 3:53 PM Philip Thrift  wrote:
>>
>>> On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift wrote:

On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:
>
> On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift
> wrote:
>
>>
>> On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>>>
>>>
>>> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>>>
>>>
>>> 1. Histories originate at an emitter e and end at screen locations s
>>> on a screen S.
>>> 2. At each s there is a history bundle histories(s). A weight w(s)
>>> is computed from the bundle by summing the unit complex numbers of the
>>> histories and taking the modulus.
>>> 3. The weight w(s) is sent back in time over a single history h*(s)
>>> selected at random (uniformly) from histories(s).
>>> 4. At e, the weights w(s) on backchannel of h*(s) are received (in
>>> the "present" time)
>>> 5. A single history h*(s*) is then selected from the distribution in
>>> 4.
>>>
>>>
>>> How is it selected?  Above you said "at random".  But that implies
>>> there is already a probability measure defined on the histories.  How is
>>> this probability measure determined?  Or put another way how do you
>>> determine what histories to consider to form the bundles in step 2?
>>>
>>> Brent
>>>
>>
>> Selection happens via quantum Darwinism.
>>
>
>
> Do you have even the faintest understanding of Quantum Darwinism?
>
> Bruce
>

How is *sum over histories with Darwinian selection*  (as defined) not
quantum Darwinism?

Operationally, what is different?

- pt

>>>
>>> *Sum over histories with Darwinian selection* is consistent with *Quantum
>>> Darwinism as a Darwinian process*  [ https://arxiv.org/abs/1001.0745 ].
>>>
>>
>> No, you clearly don't understand Quantum Darwinism! Zurek's Darwinism is
>> selection of pointer states, not one history from a bundle.
>>
>> Bruce
>>
>
>
>  Histories are (hidden) states.
>

It becomes obvious that you don't really understand consistent histories,
either.

Bruce

--
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```

### Re: Measuring a system in a superposition of states vs in a mixed state

```

On Tuesday, December 4, 2018 at 11:39:43 PM UTC-6, Bruce wrote:
>
> On Wed, Dec 5, 2018 at 3:53 PM Philip Thrift  > wrote:
>
>> On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift wrote:
>>>
>>> On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:

On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift
wrote:

>
> On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>>
>>
>> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>>
>>
>> 1. Histories originate at an emitter e and end at screen locations s
>> on a screen S.
>> 2. At each s there is a history bundle histories(s). A weight w(s) is
>> computed from the bundle by summing the unit complex numbers of the
>> histories and taking the modulus.
>> 3. The weight w(s) is sent back in time over a single history h*(s)
>> selected at random (uniformly) from histories(s).
>> 4. At e, the weights w(s) on backchannel of h*(s) are received (in
>> the "present" time)
>> 5. A single history h*(s*) is then selected from the distribution in
>> 4.
>>
>>
>> How is it selected?  Above you said "at random".  But that implies
>> there is already a probability measure defined on the histories.  How is
>> this probability measure determined?  Or put another way how do you
>> determine what histories to consider to form the bundles in step 2?
>>
>> Brent
>>
>
> Selection happens via quantum Darwinism.
>

Do you have even the faintest understanding of Quantum Darwinism?

Bruce

>>>
>>> How is *sum over histories with Darwinian selection*  (as defined) not
>>> quantum Darwinism?
>>>
>>> Operationally, what is different?
>>>
>>> - pt
>>>
>>
>> *Sum over histories with Darwinian selection* is consistent with *Quantum
>> Darwinism as a Darwinian process*  [ https://arxiv.org/abs/1001.0745 ].
>>
>
> No, you clearly don't understand Quantum Darwinism! Zurek's Darwinism is
> selection of pointer states, not one history from a bundle.
>
> Bruce
>

Histories are (hidden) states.

- pt

>
>

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### Re: Measuring a system in a superposition of states vs in a mixed state

```On Wed, Dec 5, 2018 at 3:53 PM Philip Thrift  wrote:

> On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift wrote:
>>
>> On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:
>>>
>>> On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift  wrote:
>>>

On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>
>
> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>
>
> 1. Histories originate at an emitter e and end at screen locations s
> on a screen S.
> 2. At each s there is a history bundle histories(s). A weight w(s) is
> computed from the bundle by summing the unit complex numbers of the
> histories and taking the modulus.
> 3. The weight w(s) is sent back in time over a single history h*(s)
> selected at random (uniformly) from histories(s).
> 4. At e, the weights w(s) on backchannel of h*(s) are received (in the
> "present" time)
> 5. A single history h*(s*) is then selected from the distribution in 4.
>
>
> How is it selected?  Above you said "at random".  But that implies
> there is already a probability measure defined on the histories.  How is
> this probability measure determined?  Or put another way how do you
> determine what histories to consider to form the bundles in step 2?
>
> Brent
>

Selection happens via quantum Darwinism.

>>>
>>>
>>> Do you have even the faintest understanding of Quantum Darwinism?
>>>
>>> Bruce
>>>
>>
>> How is *sum over histories with Darwinian selection*  (as defined) not
>> quantum Darwinism?
>>
>> Operationally, what is different?
>>
>> - pt
>>
>
> *Sum over histories with Darwinian selection* is consistent with *Quantum
> Darwinism as a Darwinian process*  [ https://arxiv.org/abs/1001.0745 ].
>

No, you clearly don't understand Quantum Darwinism! Zurek's Darwinism is
selection of pointer states, not one history from a bundle.

Bruce

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### Re: Measuring a system in a superposition of states vs in a mixed state

```

On Tuesday, December 4, 2018 at 10:28:39 PM UTC-6, Philip Thrift wrote:
>
>
>
> On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:
>>
>> On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift  wrote:
>>
>>>
>>> On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:

On 12/4/2018 12:25 AM, Philip Thrift wrote:

1. Histories originate at an emitter e and end at screen locations s on
a screen S.
2. At each s there is a history bundle histories(s). A weight w(s) is
computed from the bundle by summing the unit complex numbers of the
histories and taking the modulus.
3. The weight w(s) is sent back in time over a single history h*(s)
selected at random (uniformly) from histories(s).
4. At e, the weights w(s) on backchannel of h*(s) are received (in the
"present" time)
5. A single history h*(s*) is then selected from the distribution in 4.

How is it selected?  Above you said "at random".  But that implies
there is already a probability measure defined on the histories.  How is
this probability measure determined?  Or put another way how do you
determine what histories to consider to form the bundles in step 2?

Brent

>>>
>>> Selection happens via quantum Darwinism.
>>>
>>
>>
>> Do you have even the faintest understanding of Quantum Darwinism?
>>
>> Bruce
>>
>
>
>
>
> How is *sum over histories with Darwinian selection*  (as defined) not
> quantum Darwinism?
>
> Operationally, what is different?
>
> - pt
>

*Sum over histories with Darwinian selection* is consistent with *Quantum
Darwinism as a Darwinian process*  [ https://arxiv.org/abs/1001.0745 ].

- pt

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### Re: Where Max Tegmark is really wrong

```

On Tuesday, December 4, 2018 at 10:40:36 PM UTC-6, Philip Thrift wrote:
>
>
>
>
> On Tuesday, December 4, 2018 at 4:50:22 PM UTC-6, Brent wrote:
>>
>>
>>
>> On 12/4/2018 11:50 AM, Philip Thrift wrote:
>>
>>
>>
>> On Tuesday, December 4, 2018 at 1:46:44 PM UTC-6, Brent wrote:
>>>
>>>
>>>
>>> On 12/4/2018 12:06 AM, Philip Thrift wrote:
>>>
>>> Can you give an example of "truth in the programming" and how it differs
from the mathematical idea of true and the correspondence theory of truth?

Brent

>>>
>>>
>>>
>>> Truth in programming follows the Brouwerian concept of truth:
>>> [ https://plato.stanford.edu/entries/brouwer/ ]
>>>
>>>
>>>
>>> *There is no determinant of mathematical truth outside the activity of
>>> thinking; a proposition only becomes true when the subject has experienced
>>> its truth (by having carried out an appropriate mental construction);
>>> similarly, a proposition only becomes false when the subject has
>>> experienced its falsehood (by realizing that an appropriate mental
>>> construction is not possible).*
>>>
>>> *There is no determinant of mathematical truth outside the activity of
>>> computing;* a proposition only becomes true when the program has
>>> produced  its truth (by having carried out an appropriate computational
>>> construction); similarly, a proposition only becomes false when the program
>>> has produced its falsehood (by computing that an appropriate computational
>>> construction is not possible).
>>>
>>>
>>> I didn't ask for examples of circular definitions.
>>>
>>> Brent
>>>
>>
>>
>>
>> In what sense is type theory circular logic?
>>
>>
>> First, I didn't ask for a logic, I asked for examples to the different
>> ideas of truth.  Instead you provided some assertions about "where truth is
>> determined" and about becoming true...which were circular.
>>
>> "a proposition only becomes* true* when the subject has experienced its
>> *truth*"
>>
>> " a proposition only becomes *true* when the program has produced  its
>> *truth*"
>>
>> Third, neither your post nor the article on Brouwer said anything about
>> type theory.
>> https://plato.stanford.edu/entries/type-theory-intuitionistic/
>>
>> Brent
>>
>
>
> The simple way to put it:
>
>  Write a *Lisp* program *p*.
>
>  If *p* returns nil, pi is false.
>
If *p* returns nil, *p* is false.

>
>  If *p *returns anything else, *p* is true.
>
> That's all you need to know about truth.
>
> - pt
>

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### Re: Where Max Tegmark is really wrong

```

On Tuesday, December 4, 2018 at 4:50:22 PM UTC-6, Brent wrote:
>
>
>
> On 12/4/2018 11:50 AM, Philip Thrift wrote:
>
>
>
> On Tuesday, December 4, 2018 at 1:46:44 PM UTC-6, Brent wrote:
>>
>>
>>
>> On 12/4/2018 12:06 AM, Philip Thrift wrote:
>>
>> Can you give an example of "truth in the programming" and how it differs
>>> from the mathematical idea of true and the correspondence theory of truth?
>>>
>>> Brent
>>>
>>
>>
>>
>> Truth in programming follows the Brouwerian concept of truth:
>> [ https://plato.stanford.edu/entries/brouwer/ ]
>>
>>
>>
>> *There is no determinant of mathematical truth outside the activity of
>> thinking; a proposition only becomes true when the subject has experienced
>> its truth (by having carried out an appropriate mental construction);
>> similarly, a proposition only becomes false when the subject has
>> experienced its falsehood (by realizing that an appropriate mental
>> construction is not possible).*
>>
>> *There is no determinant of mathematical truth outside the activity of
>> computing;* a proposition only becomes true when the program has
>> produced  its truth (by having carried out an appropriate computational
>> construction); similarly, a proposition only becomes false when the program
>> has produced its falsehood (by computing that an appropriate computational
>> construction is not possible).
>>
>>
>> I didn't ask for examples of circular definitions.
>>
>> Brent
>>
>
>
>
> In what sense is type theory circular logic?
>
>
> First, I didn't ask for a logic, I asked for examples to the different
> ideas of truth.  Instead you provided some assertions about "where truth is
> determined" and about becoming true...which were circular.
>
> "a proposition only becomes* true* when the subject has experienced its
> *truth*"
>
> " a proposition only becomes *true* when the program has produced  its
> *truth*"
>
> Third, neither your post nor the article on Brouwer said anything about
> type theory.
> https://plato.stanford.edu/entries/type-theory-intuitionistic/
>
> Brent
>

The simple way to put it:

Write a *Lisp* program *p*.

If *p* returns nil, pi is false.

If *p *returns anything else, *p* is true.

That's all you need to know about truth.

- pt

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### Re: Measuring a system in a superposition of states vs in a mixed state

```

On Tuesday, December 4, 2018 at 3:45:32 PM UTC-6, Bruce wrote:
>
> On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift  > wrote:
>
>>
>> On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>>>
>>>
>>> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>>>
>>>
>>> 1. Histories originate at an emitter e and end at screen locations s on
>>> a screen S.
>>> 2. At each s there is a history bundle histories(s). A weight w(s) is
>>> computed from the bundle by summing the unit complex numbers of the
>>> histories and taking the modulus.
>>> 3. The weight w(s) is sent back in time over a single history h*(s)
>>> selected at random (uniformly) from histories(s).
>>> 4. At e, the weights w(s) on backchannel of h*(s) are received (in the
>>> "present" time)
>>> 5. A single history h*(s*) is then selected from the distribution in 4.
>>>
>>>
>>> How is it selected?  Above you said "at random".  But that implies there
>>> is already a probability measure defined on the histories.  How is this
>>> probability measure determined?  Or put another way how do you determine
>>> what histories to consider to form the bundles in step 2?
>>>
>>> Brent
>>>
>>
>> Selection happens via quantum Darwinism.
>>
>
>
> Do you have even the faintest understanding of Quantum Darwinism?
>
> Bruce
>

How is *sum over histories with Darwinian selection*  (as defined) not
quantum Darwinism?

Operationally, what is different?

- pt

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### Re: Extended Wigner’s Friend

```

On Tuesday, December 4, 2018 at 2:09:06 PM UTC-6, Brent wrote:
>
>
>
> On 12/4/2018 1:02 AM, Philip Thrift wrote:
> >
> > Fay Dowker [ https://en.wikipedia.org/wiki/Fay_Dowker ] gives a short
> > summary of "sum over histories" here (and why she prefers it to other
> > interpretations).
> >
>
> She says she prefers it to Copenhagen because Copenhagen doesn't give an
> picture of what happens between preparation and measurement. She says
> she prefers it to Bohmian QM because it doesn't conflict with
> relativity.  But she doesn't say anything about other interpretations
> such as Everett's relative state interpretation.
>
> Brent
>

Thank goodness.

- pt

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### Re: The most accurate clock ever

```Brent Meeker wrote:

> * finding the value of G depends on scaling the result by that ratio of
> masses (1.37e25 lbm/348 lbm). *
>

The mass of the Earth played no part in Cavendish's determination of G
because he was measuring gravitational attraction in a direction that
was parallel
to the Earth's surface.

> * The way you are looking at consider how far you would have to move the
> cesium clock from the surface of the 348lbm cannon ball in order to detect
> the change in gravitational time dilation affecting the clock. *
>

OK lets look at it like that, the new clock can detect the difference in
time dilation between 1g and 1.3g, so I'm sure it could detect the
time dilation caused by a 348 pound mass a foot or so away. But .3g
is so weak a force it would not have caused Cavendish's torsion balance to
move at all, air resistance and the rigidity of the wire holding it up
would have prevented it.

> *> It's the number I cited, far bigger than the 0.25mm Cavendish cited as
> the limit of his measurement.*
>

There is no way Cavendish could have placed the centers of two 248 pound

John K Clark

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### LIGO just announced 4 more Black Hole collisions

```https://www.space.com/42618-gravitational-waves-biggest-farthest-black-hole-crash.html

https://dcc.ligo.org/public/0156/P1800324/006/O2RandP.pdf

John K Clark

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### Re: Where Max Tegmark is really wrong

```

On 12/4/2018 11:50 AM, Philip Thrift wrote:

On Tuesday, December 4, 2018 at 1:46:44 PM UTC-6, Brent wrote:

On 12/4/2018 12:06 AM, Philip Thrift wrote:

Can you give an example of "truth in the programming" and how
it differs from the mathematical idea of true and the
correspondence theory of truth?

Brent

Truth in programming follows the Brouwerian concept of truth:
[ https://plato.stanford.edu/entries/brouwer/
]

/There is no determinant of mathematical truth outside the
activity of thinking; a proposition only becomes true when the
subject has experienced its truth (by having carried out an
appropriate mental construction); similarly, a proposition only
becomes false when the subject has experienced its falsehood (by
realizing that an appropriate mental construction is not possible)./

*There is no determinant of mathematical truth outside the
activity of computing;* a proposition only becomes true when the
program has produced  its truth (by having carried out an
appropriate computational construction); similarly, a proposition
only becomes false when the program has produced its falsehood
(by computing that an appropriate computational construction is
not possible).

I didn't ask for examples of circular definitions.

Brent

In what sense is type theory circular logic?

First, I didn't ask for a logic, I asked for examples to the different
is determined" and about becoming true...which were circular.

"a proposition only becomes*/true/* when the subject has experienced its
*/truth/*"

" a proposition only becomes /*true*/ when the program has produced  its
*/truth/*"

Third, neither your post nor the article on Brouwer said anything about
type theory.

https://plato.stanford.edu/entries/type-theory-intuitionistic/

Brent

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### Re: Coherent states of a superposition

```On Wed, Dec 5, 2018 at 2:36 AM  wrote:

>
> *Thanks, but I'm looking for a solution within the context of interference
> and coherence, without introducing your theory of consciousness. Mainstream
> thinking today is that decoherence does occur, but this seems to imply
> preexisting coherence, and therefore interference among the component
> states of a superposition. If the superposition is expressed using
> eigenfunctions, which are mutually orthogonal -- implying no mutual
> interference -- how is decoherence possible, insofar as coherence, IIUC,
> doesn't exist using this basis? AG*
>

I think you misunderstand the meaning of "coherence" when it is used off an
expansion in terms of a set of mutually orthogonal eigenvectors. The
expansion in some eigenvector basis is written as

|psi> = Sum_i (a_i |v_i>)

where |v_i> are the eigenvectors, and i ranges over the dimension of the
Hilbert space. The expansion coefficients are the complex numbers a_i.
Since these are complex coefficients, they contain inherent phases. It is
the preservation of these phases of the expansion coefficients that is
meant by "maintaining coherence". So it is the coherence of the particular
expansion that is implied, and this has noting to do with the mutual
orthogonality or otherwise of the basis vectors themselves. In decoherence,
the phase relationships between the terms in the original expansion are
lost.

Bruce

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### Re: Measuring a system in a superposition of states vs in a mixed state

```On Wed, Dec 5, 2018 at 6:58 AM Philip Thrift  wrote:

>
> On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>>
>>
>> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>>
>>
>> 1. Histories originate at an emitter e and end at screen locations s on a
>> screen S.
>> 2. At each s there is a history bundle histories(s). A weight w(s) is
>> computed from the bundle by summing the unit complex numbers of the
>> histories and taking the modulus.
>> 3. The weight w(s) is sent back in time over a single history h*(s)
>> selected at random (uniformly) from histories(s).
>> 4. At e, the weights w(s) on backchannel of h*(s) are received (in the
>> "present" time)
>> 5. A single history h*(s*) is then selected from the distribution in 4.
>>
>>
>> How is it selected?  Above you said "at random".  But that implies there
>> is already a probability measure defined on the histories.  How is this
>> probability measure determined?  Or put another way how do you determine
>> what histories to consider to form the bundles in step 2?
>>
>> Brent
>>
>
> Selection happens via quantum Darwinism.
>

Do you have even the faintest understanding of Quantum Darwinism?

Bruce

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### Re: Coherent states of a superposition

```
> Il 4 dicembre 2018 alle 16.36 agrayson2...@gmail.com ha scritto:
>
>
>
> On Tuesday, December 4, 2018 at 10:13:38 AM UTC, Bruno Marchal wrote:
>
> > >
> >
> > > > > On 3 Dec 2018, at 20:57, agrays...@gmail.com
> > wrote:
> > >
> > >
> > >
> > > On Sunday, November 18, 2018 at 1:05:26 PM UTC,
> > > agrays...@http://gmail.com wrote:
> > >
> > > > > > >
> > > >
> > > > On Saturday, November 17, 2018 at 7:39:14 PM UTC,
> > > > agrays...@gmail.com wrote:
> > > >
> > > > > > > > > If you write a
> > > > superposition as a sum of eigenstates, why is it important, or
> > > > relevant, or even true that the component states are coherent since
> > > > eigenstates with distinct eigenvalues are orthogonal. This means there
> > > > is no interference between the components of the superposition. AG
> > > > >
> > > > > > > > >
> > > > Put another way; from what I've read, coherence among
> > > > components of a superposition is necessary to guarantee interference,
> > > > but since an eigenstate expansion of the superposition consists of
> > > > orthogonal, non interfering eigenstates, the requirement of coherence
> > > > seems unnecessary. AG
> > > >
> > > > > > >
> > > For decoherence to occur, one needs, presumably, a coherent
> > > superposition. But when the wf is expressed as a sum of eigenstates with
> > > unique eigenvalues, those eigenstates are mutually orthogonal; hence,
> > > IIUC, there is no coherence. So, how can decoherence occur when the state
> > > function, expressed as a sum of eigenstates with unique eigenvalues, is
> > > not coherent? I must be missing something, but what it is I have no clue.
> > > AG
> > >
> > > > >
> >
> >
> > Decoherence never occurs, except in the mind or memory of the
> > observer. Take the state up + down (assuming a factor 1/sqrt(2)). And O is
> > an observer (its quantum state).
> >
> > >
> > >
> > O has the choice to measure in the base {up, down}, in which case
> > the Born rule says that he will see up, or down with a probability 1/2. He
> > will *believe* that decoherence has occurred, but if we long at the
> > evolution of the whole system O + the particle, all we get is
> >
> > O-up up + O-down down,
> >
> > And some other observer could in principle test this. (O-up means O
> > with the memory of having seen the particle in the up position).
> >
> > But O could measure that particle in the base {up+down, up-down).
> > He has just to rotate a little bit its polariser or Stern-Gerlach device.
> > In that case he obtains up+down with the probability one, which souls not
> > be the case with a mixture of up and down. In that case, coherence of up
> > and down do not disappear, even from the pot of the observer.
> >
> > Decoherence is just the contagion of the superposition to anything
> > interacting with it, including the observer, and if we wait long enough the
> > whole causal cone of the observer.
> >
> > Bruno
> >
> > >
> Thanks, but I'm looking for a solution within the context of interference
> and coherence, without introducing your theory of consciousness. Mainstream
> thinking today is that decoherence does occur, but this seems to imply
> preexisting coherence, and therefore interference among the component states
> of a superposition. If the superposition is expressed using eigenfunctions,
> which are mutually orthogonal -- implying no mutual interference -- how is
> decoherence possible, insofar as coherence, IIUC, doesn't exist using this
> basis? AG
>

There are instruments like the MZI (Mach-Zehnder Interferometer).. In this
insrtrument one (spli)amplitude goes through path A, the other (plit)amplitude
goes through par'th B. At the end of their travef both amplitudes recombine
interferentially giving *always a single* outome. As for the de-coherence
frankly i did not realize its conceptual meaning.

>
> > >
> > > > > -- You received this message because you are
> > subscribed to the Google Groups "Everything List" group.
> > > To unsubscribe from this group and stop receiving emails from
> > > it, send an email to everything-li...@googlegroups.com.
> > > To post to this group, send email to
> > > Visit this group at
> > > For more options, visit https://groups.google.com/d/optout
> > >
> > > > >
> >
> > >
>
>
> --
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> "Everything List" group.
> ```

### Re: The most accurate clock ever

```

On 12/4/2018 6:28 AM, John Clark wrote:

Brent Meekerwrote:

/> Neither does a cesium clock measure the change in strength of 2
large gravitational fields.  It measures the difference in
gravitational potential. /

Same thing, a gravitational field describes the gravitational
potential at every point.

/> //So I compared the change in gravitational potential when
moving the clock up 1cm to the change in potential when
Cavendish's torsion balance moved the sensing weights the smallest
change in distance he said he could measure 0.25mm with the
weights 9" (0.23m) from the cannon balls. The ratio of these two
potentials is the product of three terms: The ratio of masses
(1.37e25 lbm/348 lbm) The ratio distances squared
(0.23m/6.4e6m)^2. The ratio of smallest measurable changes
(0.01m/0.00025m).  Work it out yourself./

Brent, Cavendish's torsion balance was only sensitive enough to
measure the Gravitational constant to one part in 100, and even today
with the newest and best torsion balance money can buy you can only
get 11.6 parts per MILLION.

New Torsion Balance

To measure the difference in Earth's gravity at 2 points one
centimeter higher from the surface than the other you'd need to do
better than 3 parts per BILLION. This new clock can do that, 3,900
times better than the best modern torsion balance.

But that's because finding the value of G depends on scaling the result
by that ratio of masses (1.37e25 lbm/348 lbm).  The way you are looking
at consider how far you would have to move the cesium clock from the
surface of the 348lbm cannon ball in order to detect the change in
gravitational time dilation affecting the clock.  It's the number I
cited, far bigger than the 0.25mm Cavendish cited as the limit of his
measurement.

Brent

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### Re: Measuring a system in a superposition of states vs in a mixed state

```

On 12/4/2018 3:05 AM, Bruno Marchal wrote:

… where Omnès added “time to be irrational” ...

1. Histories originate at an emitter e and end at screen locations s
on a screen S.
2. At each s there is a history bundle histories(s). A weight w(s) is
computed from the bundle by summing the unit complex numbers of the
histories and taking the modulus.
3. The weight w(s) is sent back in time over a single history h*(s)
selected at random (uniformly) from histories(s).
4. At e, the weights w(s) on backchannel of h*(s) are received (in
the "present" time)

5. A single history h*(s*) is then selected from the distribution in 4.

"5.”  follows from mechanism as a first person view. No need of Omnès
mysterious selection.

The first person view is a view of the result of the sum over the
bundle; not of a single history. How would one perceive a history?

Brent

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### Re: Extended Wigner’s Friend

```

On 12/4/2018 1:02 AM, Philip Thrift wrote:

Fay Dowker [ https://en.wikipedia.org/wiki/Fay_Dowker ] gives a short
summary of "sum over histories" here (and why she prefers it to other
interpretations).

She says she prefers it to Copenhagen because Copenhagen doesn't give an
picture of what happens between preparation and measurement. She says
she prefers it to Bohmian QM because it doesn't conflict with
relativity.  But she doesn't say anything about other interpretations
such as Everett's relative state interpretation.

Brent

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### Re: Measuring a system in a superposition of states vs in a mixed state

```

On Tuesday, December 4, 2018 at 1:53:15 PM UTC-6, Brent wrote:
>
>
>
> On 12/4/2018 12:25 AM, Philip Thrift wrote:
>
>
>
> On Monday, December 3, 2018 at 9:00:26 PM UTC-6, Brent wrote:
>>
>>
>>
>> On 12/3/2018 8:50 AM, Bruno Marchal wrote:
>>
>>
>> On 3 Dec 2018, at 10:35, Philip Thrift  wrote:
>>
>>
>>
>> On Sunday, December 2, 2018 at 8:17:54 PM UTC-6, Brent wrote:
>>>
>>>
>>>
>>> On 12/2/2018 5:14 PM, Philip Thrift wrote:
>>>
>>>
>>>
>>> On Sunday, December 2, 2018 at 4:25:04 PM UTC-6, Brent wrote:

On 12/2/2018 11:42 AM, Philip Thrift wrote:

On Sunday, December 2, 2018 at 8:13:48 AM UTC-6, agrays...@gmail.com
wrote:
>
>
> *Obviously, from a one-world perspective, only one history survives
> for a single trial. But to even grossly approach anything describable as
> "Darwinian", you have to identify characteristics of histories which
> contribute positively or negatively wrt surviving but I don't see an
> inkling of that. IMO, Quantum Darwinism is at best a vacuous restatement
> of
> the measurement problemt; that we don't know why we get what we get. AG*
>
>>
>>
>>

In the *sum over histories* interpretation - of the double-slit
experiment, for example - each history carries a unit complex number -
like
a gene - and this gene reenforces (positively) or interferes (negatively)
with other history's genes in the sum.

But I thought you said the ontology was that only one history "popped
out of the Lottery machine"?  Here you seem to contemplate an ensemble of
histories, all those ending at the given spot, as being real.

Brent

>>>
>>>
>>>
>>>
>>> All are real until all but one dies.
>>> RIP: All those losing histories.
>>>
>>>
>>> The trouble with that is the Born probability doesn't apply to
>>> histories, it applies to results.  So your theory says nothing about the
>>> probability of the fundamental ontologies.
>>>
>>> Brent
>>>
>>
>>
>>
>>
>>
>> The probability distribution on the space of histories is provided by the
>> path integral.
>>
>>
>> Except that isn't true. A probability (or probability density) is
>> provided for a bundle of histories joining two events.  It doesn't not
>> provide a probability of a single history.
>>
>> Brent
>>
>>
> That's why you add to that "pick any history at random from the bundle":
>
>
> But the probability didn't apply to that history.  The Born rule gave the
> probability of the bundle.  To it is false that, "The probability
> distribution on the space of histories is provided by the path integral."
>
>
> 1. Histories originate at an emitter e and end at screen locations s on a
> screen S.
> 2. At each s there is a history bundle histories(s). A weight w(s) is
> computed from the bundle by summing the unit complex numbers of the
> histories and taking the modulus.
> 3. The weight w(s) is sent back in time over a single history h*(s)
> selected at random (uniformly) from histories(s).
> 4. At e, the weights w(s) on backchannel of h*(s) are received (in the
> "present" time)
> 5. A single history h*(s*) is then selected from the distribution in 4.
>
>
> How is it selected?  Above you said "at random".  But that implies there
> is already a probability measure defined on the histories.  How is this
> probability measure determined?  Or put another way how do you determine
> what histories to consider to form the bundles in step 2?
>
> Brent
>
>
> See the *Wheeler-Feynman computer*:
> [
> https://codicalist.wordpress.com/2018/09/25/retrosignaling-in-the-quantum-substrate/
>
> ]
>
> - p
>
>
>

Selection happens via quantum Darwinism.

- pt

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### Re: Measuring a system in a superposition of states vs in a mixed state

```

On 12/4/2018 12:25 AM, Philip Thrift wrote:

On Monday, December 3, 2018 at 9:00:26 PM UTC-6, Brent wrote:

On 12/3/2018 8:50 AM, Bruno Marchal wrote:

On 3 Dec 2018, at 10:35, Philip Thrift > wrote:

On Sunday, December 2, 2018 at 8:17:54 PM UTC-6, Brent wrote:

On 12/2/2018 5:14 PM, Philip Thrift wrote:

On Sunday, December 2, 2018 at 4:25:04 PM UTC-6, Brent wrote:

On 12/2/2018 11:42 AM, Philip Thrift wrote:

On Sunday, December 2, 2018 at 8:13:48 AM UTC-6,
agrays...@gmail.com wrote:

*
*
*Obviously, from a one-world perspective, only one
history survives for a single trial. But to even
grossly approach anything describable as
"Darwinian", you have to identify characteristics
of histories which contribute positively or
negatively wrt surviving but I don't see an
inkling of that. IMO, Quantum Darwinism is at best
a vacuous restatement of the measurement problemt;
that we don't know why we get what we get. AG*

In the *sum over histories* interpretation - of the
double-slit experiment, for example - each history
carries a unit complex number - like a gene - and this
gene reenforces (positively) or interferes
(negatively) with other history's genes in the sum.

But I thought you said the ontology was that only one
history "popped out of the Lottery machine"?  Here you
seem to contemplate an ensemble of histories, all those
ending at the given spot, as being real.

Brent

All are real until all but one dies.
RIP: All those losing histories.

The trouble with that is the Born probability doesn't apply
to histories, it applies to results.  So your theory says
nothing about the probability of the fundamental ontologies.

Brent

The probability distribution on the space of histories is
provided by the path integral.

Except that isn't true. A probability (or probability density) is
provided for a bundle of histories joining two events.  It doesn't
not provide a probability of a single history.

Brent

That's why you add to that "pick any history at random from the bundle":

But the probability didn't apply to that history.  The Born rule gave
the probability of the bundle.  To it is false that, "The probability
distribution on the space of histories is provided by the path integral."

1. Histories originate at an emitter e and end at screen locations s
on a screen S.
2. At each s there is a history bundle histories(s). A weight w(s) is
computed from the bundle by summing the unit complex numbers of the
histories and taking the modulus.
3. The weight w(s) is sent back in time over a single history h*(s)
selected at random (uniformly) from histories(s).
4. At e, the weights w(s) on backchannel of h*(s) are received (in the
"present" time)

5. A single history h*(s*) is then selected from the distribution in 4.

How is it selected?  Above you said "at random".  But that implies there
is already a probability measure defined on the histories. How is this
probability measure determined?  Or put another way how do you determine
what histories to consider to form the bundles in step 2?

Brent

See the *Wheeler-Feynman computer*:
[ https://codicalist.wordpress.com/2018/09/25/retrosignaling-in-the-quantum-substrate/
]

- pt
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### Re: Where Max Tegmark is really wrong

```

On Tuesday, December 4, 2018 at 1:46:44 PM UTC-6, Brent wrote:
>
>
>
> On 12/4/2018 12:06 AM, Philip Thrift wrote:
>
> Can you give an example of "truth in the programming" and how it differs
>> from the mathematical idea of true and the correspondence theory of truth?
>>
>> Brent
>>
>
>
>
> Truth in programming follows the Brouwerian concept of truth:
> [ https://plato.stanford.edu/entries/brouwer/ ]
>
>
>
> *There is no determinant of mathematical truth outside the activity of
> thinking; a proposition only becomes true when the subject has experienced
> its truth (by having carried out an appropriate mental construction);
> similarly, a proposition only becomes false when the subject has
> experienced its falsehood (by realizing that an appropriate mental
> construction is not possible).*
>
> *There is no determinant of mathematical truth outside the activity of
> computing;* a proposition only becomes true when the program has
> produced  its truth (by having carried out an appropriate computational
> construction); similarly, a proposition only becomes false when the program
> has produced its falsehood (by computing that an appropriate computational
> construction is not possible).
>
>
> I didn't ask for examples of circular definitions.
>
> Brent
>

In what sense is type theory circular logic?

- pt

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### Re: Where Max Tegmark is really wrong

```

On 12/4/2018 12:06 AM, Philip Thrift wrote:

Can you give an example of "truth in the programming" and how it
differs from the mathematical idea of true and the correspondence
theory of truth?

Brent

Truth in programming follows the Brouwerian concept of truth:
[ https://plato.stanford.edu/entries/brouwer/ ]

/There is no determinant of mathematical truth outside the activity of
thinking; a proposition only becomes true when the subject has
experienced its truth (by having carried out an appropriate mental
construction); similarly, a proposition only becomes false when the
subject has experienced its falsehood (by realizing that an
appropriate mental construction is not possible)./

*There is no determinant of mathematical truth outside the activity of
computing;* a proposition only becomes true when the program has
produced  its truth (by having carried out an appropriate
computational construction); similarly, a proposition only becomes
false when the program has produced its falsehood (by computing that
an appropriate computational construction is not possible).

I didn't ask for examples of circular definitions.

Brent

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### Fwd: tricolor consciousness compression

```

Forwarded Message

"That's teleportation for ya!"

http://smbc-comics.com/comic/teleporter

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### Re: Towards Conscious AI Systems (a symposium at the AAAI Stanford Spring Symposium 2019)

```On Mon, Dec 3, 2018 at 6:05 AM Bruno Marchal  wrote:

>* It is very simple. Never claim to have the truth, and always present a
> theory having verifiable consequences.*
>

Your theory is a working Turing Machine can be made without using matter or
physics, so don't show me more squiggles, show me a verifiable consequence
of that theory, show me  your mystical machine actually making a
calculation so I can verify  it is correct. Of course we both know you will
never EVER be able to do that, but that won't stop you from continuing to

>>show me a WORKING Turing Machine that doesn't make use of the laws of
>> physics so that I can observe it making a calculation.You insist such a
>> thing exists so put up or shut up.
>
>
> *> The existence is provable in Peano arithmet*ic.
>

If an observable Turing Machine that makes no use of matter or physics has
been proven to exist why is it that nobody has ever seen one and nobody
ever will? Because what Peano actually proved is that some squiggles that
humans (who are made of matter and obey the laws of physics) have assigned
meaning to is the same as other squiggles that humans have assigned
different meanings to. None of those squiggles are Turing Machines and none
of them are powerful enough to calculate 2+2.

>

In 1931 Godel knew nothing about Turing Machines.

>> Prove me wrong by producing a working machine that doesn't use matter or
>> physics.
>
>
> *>This is ambiguous.*
>

*Like hell it is!* My request is about as unambiguous as things get.

>

Like explaining why your observable Turing Machine, the one that works
without using using matter or physics, is totally unobservable

> > *or you ask me an example of a working machine, relatively to a
> universal machine, in arithmetic. *
>

I'm not picky, it can be relative to anything you want, all I ask is that
it be observable and able to make a calculation without using matter or
physics; and it need not be complicated, 2+2 would be good enough.

> >>And by "working" I mean one that changes in time or space or both.
>
>
> >OK. Then your laptop is an excellent example.
>

Correct, and unless Apple just came out with something new all laptops are
made of matter and they all obey the laws of physics.

*> People who says that theology or metaphysics cannot be done with the
> scientific method are those who want impose their personal conviction to
> others.*
>

Metaphysics with the scientific method is just physics, and theology with
the scientific method causes the entire area of study to evaporate.

> > *Religion has been separated from science for one reason only: to make
> it into an instrument of control of the others.*
>

Yes let's go back to the good old days of the inquisition when authorities
knew how to deal with blasphemers like Galileo.

> You can produce it anyway you like provided its observable.
>
>

> *We have to agree by what mean by observable.*
>

But before we can do that we must first agree on what we mean by "mean",
then we have to agree on what we mean by "mean by "mean"" then we have to
agree on what we mean by "mean by "mean by "mean""", then

I've noticed this phenomena before in debates when somebody is losing, they
start demanding definitions of words, and then demanding definitions of the
words in the definition, and then definitions of the words in the definitions
of the words in the definition, and then ...

> > *I have no clue what you mean by observable,*
>

Oh I think you do, I think you have a clue, you just can't produce what I

> > *you invoke your god-primary matter*  [...]  *Repeating a statement
> again and again does not make it valid.*
>

Very good, for once you say something I agree with completely.

>> I want to observe a working Turing Machine that is not made of matter
> and does not make use of the laws of physics.

> >  *{(q1 B 1 q1)}*
>

I tried that but it doesn't work, I've been shouting at {(q1 B 1 q1)} at
the top of my lungs "*HOW MUCH IS 2+2 ?*" but nothing changes,
the squiggles  just sit there.

>>You just said that pure arithmetic can do exactly that, so stop talking
>> about it and SHOW ME.
>
>
> > See my paper for the proof.
>

To hell with your idiotic "proof", don't tell me SHOW ME a Turing Machine
that is not made of matter that can calculate 2+2!

> >>I already told you that matter, or anything else, is real if you can
>> make a working Turing Machine out of it.
>
>
> > *“Working” is ambiguous.*
>

I guess "ambiguous" is you're new favorite word. I already said "working"
is something that changes in time or space or both, what the hell is

> > *How could a universal machine distinguish a physically working
> environment, and an arithmetically environment?*
>

Easy, if the environment changes in time or space then its physical, if it
doesn't then its arithmetical, and if the environment can't change then a
```

### Re: Towards Conscious AI Systems (a symposium at the AAAI Stanford Spring Symposium 2019)

```

On Tuesday, December 4, 2018 at 6:37:01 AM UTC-6, Bruno Marchal wrote:
>
>
> On 4 Dec 2018, at 11:39, Philip Thrift >
> wrote:
>
>
>
> On Tuesday, December 4, 2018 at 4:25:37 AM UTC-6, Bruno Marchal wrote:
>>
>>
>> On 3 Dec 2018, at 23:01, Philip Thrift  wrote:
>>
>>
>>
>> On Monday, December 3, 2018 at 1:24:30 PM UTC-6, Bruno Marchal wrote:
>>>
>>>
>>> On 2 Dec 2018, at 13:24, Philip Thrift  wrote:
>>>
>>>
>>>
>>> On Sunday, December 2, 2018 at 5:23:15 AM UTC-6, Bruno Marchal wrote:

On 29 Nov 2018, at 20:00, Philip Thrift  wrote:

On Thursday, November 29, 2018 at 10:27:00 AM UTC-6, Bruno Marchal
wrote:
>
>
> On 27 Nov 2018, at 18:50, Philip Thrift  wrote:
>
>
>
> On Tuesday, November 27, 2018 at 4:32:53 AM UTC-6, Bruno Marchal wrote:
>>
>>
>> On 24 Nov 2018, at 17:27, John Clark  wrote:
>>
>>
>>
>>
>> Turing explained how matter can behave intelligently,
>>
>>
>> No. He showed how a person can be attached to a computation, and also
>> that physics is Turing complete, so that we can use matter to implement
>> computations, like nature plausibly does. But it is not matter which
>> behave
>> intelligently: it is the person associated to the computation, and it
>> behaves as well relatively to numbers than to matter. You use of matter
>> is
>> “magical”.
>>
>>
>>
> If humans are matter (meaning of course that human brains are matter),
> then *humans behave intelligently* means that (at least some) *matter
> behaves intelligently*.
>
>
> Like with a computer: some arrangement of some matter can emulate a
> (universal) computation. That means that the physical laws are Turing
> complete.
>
> It does not mean that primary matter exists (see my reminding of what
> this means in my answer to Brent, soon enough!).
>
>
>
>
>
> It is not clear that Turing in his last ("morphogenesis") years
> thought that the Turing machine was a complete definition of computing in
> nature.
>
>
>
> If mechanism is true, in principle, nature has more powerful
> processing ability than any computer. Now, it could mean only that nature
> use a random oracle, which would come only from our ignorance about which
> computations run us, if I may say.
>
> Bruno
>
>
>
>

Going by something Barry Cooper wrote

*The intuition is that computational unconventionality certainly
entails higher-type computation, with a correspondingly enhanced respect
for embodied information. There is some understanding of the algorithmic
content of descriptions. But so far we have merely scratched the surface.*

"natural computing" may involve something that is non-Turing in a sense
that doesn't involve actual oracles in the hyperarithmetical processing
sense (but could involve topology: *We can say that topology is
precisely about the relation between finiteness and infiniteness that is
relevant to computation.* [
http://www.cs.bham.ac.uk/~mhe/papers/introduction-to-higher-order-computation-NLS-2017.pdf

]).

I posit that *experience processing* is a "natural computing" that is
non-Turing.

This new article may be of interest:

"there are now many signs that consciousness-like phenomena might exist
not just among humans or even great apes – but that insects might have
them, too"
]
https://aeon.co/essays/inside-the-mind-of-a-bee-is-a-hive-of-sensory-activity

]

I am OK with this. I am open that plants do think, somehow. What is
provably inconsistent with digital mechanism is that consciousness is
“natural” or a product of matter. That equates two different kind of
mysteries, without adding light on Matter nor Consciousness. That might be
true, but I don’t see any evidence for such a move.

Bruno

>>> That consciousness is an "intrinsic" property of patter will be the
>>> subject of
>>>
>>> Galileo's Error
>>> Foundations for a New Science of Consciousness
>>>
>>> by Philip Goff
>>> (coming from Penguin Random House)
>>>
>>>
>>>
>>>
>>> Please make an argument. Cite people only if you use an idea from them,
>>> but present the idea and use it.
>>>
>>>
>>>
>>>
>>>
>>> What higher-order computing matter does is an open question. But there
>>> is no evidence that there is any mathematical entity existing outside of
>>> matter (the subject of science).
>>>
>>>
>>> There is no evidence that matter is primary, physicists measure numbers,
>>> and then infer relation between those measurable numbers.
>>>
>>>
>>> Why limiting science to matter? Matter is vey interesting, but if you
>>> assume matter, you need indeed a non computationalist ```

### Re: Coherent states of a superposition

```

On Tuesday, December 4, 2018 at 10:13:38 AM UTC, Bruno Marchal wrote:
>
>
> On 3 Dec 2018, at 20:57, agrays...@gmail.com  wrote:
>
>
>
> On Sunday, November 18, 2018 at 1:05:26 PM UTC, agrays...@gmail.com wrote:
>>
>>
>>
>> On Saturday, November 17, 2018 at 7:39:14 PM UTC, agrays...@gmail.com
>> wrote:
>>>
>>> If you write a superposition as a sum of eigenstates, why is it
>>> important, or relevant, or even true that the component states are coherent
>>> since eigenstates with distinct eigenvalues are orthogonal. This means
>>> there is no interference between the components of the superposition. AG
>>>
>>
>> Put another way; from what I've read, coherence among components of a
>> superposition is necessary to guarantee interference, but since an
>> eigenstate expansion of the superposition consists of orthogonal, non
>> interfering eigenstates, the requirement of coherence seems unnecessary. AG
>>
>
> *For decoherence to occur, one needs, presumably, a coherent
> superposition. But when the wf is expressed as a sum of eigenstates with
> unique eigenvalues, those eigenstates are mutually orthogonal; hence, IIUC,
> there is no coherence. So, how can decoherence occur when the state
> function, expressed as a sum of eigenstates with unique eigenvalues, is not
> coherent? I must be missing something, but what it is I have no clue. AG *
>
>
>
>
> Decoherence never occurs, except in the mind or memory of the observer.
> Take the state up + down (assuming a factor 1/sqrt(2)). And O is an
> observer (its quantum state).
>

> O has the choice to measure in the base {up, down}, in which case the Born
> rule says that he will see up, or down with a probability 1/2. He will
> *believe* that decoherence has occurred, but if we long at the evolution of
> the whole system O + the particle, all we get is
>
> O-up up + O-down down,
>
> And some other observer could in principle test this. (O-up means O with
> the memory of having seen the particle in the up position).
>
> But O could measure that particle in the base {up+down, up-down). He has
> just to rotate a little bit its polariser or Stern-Gerlach device. In that
> case he obtains up+down with the probability one, which souls not be the
> case with a mixture of up and down. In that case, coherence of up and down
> do not disappear, even from the pot of the observer.
>
> Decoherence is just the contagion of the superposition to anything
> interacting with it, including the observer, and if we wait long enough the
> whole causal cone of the observer.
>
> Bruno
>

*Thanks, but I'm looking for a solution within the context of interference
and coherence, without introducing your theory of consciousness. Mainstream
thinking today is that decoherence does occur, but this seems to imply
preexisting coherence, and therefore interference among the component
states of a superposition. If the superposition is expressed using
eigenfunctions, which are mutually orthogonal -- implying no mutual
interference -- how is decoherence possible, insofar as coherence, IIUC,
doesn't exist using this basis? AG*

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### Re: The most accurate clock ever

```Given the Earth has a liquid core, is there any chance that turbulence in
the core would move the center of gravity around by some minute amount, but
large enough to throw off measurements of such tiny differences?

On Thu, Nov 29, 2018 at 9:29 AM John Clark  wrote:

> In yesterday's issue of the journal Nature Scientists at the National
> Institute of Standards and Technology (NIST) reported they have made a new
> type of clock that is the most accurate ever, it's called a Ytterbium
> Lattice Clock. It's about 100 times better than any previous clock, if set
> at the time of the Big Bang 13.8 billion years ago today it would be off by
> less than one second.
>
> https://www.nature.com/articles/s41586-018-0738-2
>
> It's so good the main source of error is due to General Relativity, if you
> lift the clock up by just one centimeter the Earth's gravitational field is
> slightly weaker and so the clock runs noticeably faster, that may be why
> NIST is now working on a portable version of their Ytterbium Lattice Clock.
> If GPS satellites had clocks this good they'd know where they were relative
> to the Earth to within a centimeter and so could tell users on the ground
> where they were within a centimeter; and that would be more than good
> enough for jet fighters to automatically land on aircraft carriers without
> a pilot, even at night in a heavy fog in a bad storm with the deck tossing
> up and down. It would be by far the best instrument ever made to detect
> tiny changes in the gravitational field, and that would make it much easier
> to find things buried deep underground. The Earth just became more
> transparent. It might even be used to detect Gravitational Waves and Dark
> Matter.
>
> John K Clark
>
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### Re: The most accurate clock ever

``` Brent Meeker wrote:

*> Neither does a cesium clock measure the change in strength of 2 large
> gravitational fields.  It measures the difference in gravitational
> potential. *

Same thing, a gravitational field describes the gravitational potential at
every point.

*> **So I compared the change in gravitational potential when moving the
> clock up 1cm to the change in potential when Cavendish's torsion balance
> moved the sensing weights the smallest change in distance he said he could
> measure 0.25mm with the weights 9" (0.23m) from the cannon balls. The ratio
> of these two potentials is the product of three terms: The ratio of masses
> (1.37e25 lbm/348 lbm)  The ratio distances squared (0.23m/6.4e6m)^2. The
> ratio of smallest measurable changes (0.01m/0.00025m).  Work it out
> yourself.*

Brent, Cavendish's torsion balance was only sensitive enough to measure the
Gravitational constant to one part in 100, and even today with the newest
and best torsion balance money can buy you can only get 11.6 parts per
MILLION.

New Torsion Balance

To measure the difference in Earth's gravity at 2 points one centimeter
higher from the surface than the other you'd need to do better than 3 parts
per BILLION. This new clock can do that, 3,900 times better than the best
modern torsion balance.

John K Clark

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### Re: Towards Conscious AI Systems (a symposium at the AAAI Stanford Spring Symposium 2019)

```
> On 4 Dec 2018, at 11:39, Philip Thrift  wrote:
>
>
>
> On Tuesday, December 4, 2018 at 4:25:37 AM UTC-6, Bruno Marchal wrote:
>
>> On 3 Dec 2018, at 23:01, Philip Thrift >
>> wrote:
>>
>>
>>
>> On Monday, December 3, 2018 at 1:24:30 PM UTC-6, Bruno Marchal wrote:
>>
>>> On 2 Dec 2018, at 13:24, Philip Thrift > wrote:
>>>
>>>
>>>
>>> On Sunday, December 2, 2018 at 5:23:15 AM UTC-6, Bruno Marchal wrote:
>>>
On 29 Nov 2018, at 20:00, Philip Thrift > wrote:

On Thursday, November 29, 2018 at 10:27:00 AM UTC-6, Bruno Marchal wrote:

> On 27 Nov 2018, at 18:50, Philip Thrift > wrote:
>
>
>
> On Tuesday, November 27, 2018 at 4:32:53 AM UTC-6, Bruno Marchal wrote:
>
>> On 24 Nov 2018, at 17:27, John Clark > wrote:
>
>
>
>> Turing explained how matter can behave intelligently,
>
> No. He showed how a person can be attached to a computation, and also
> that physics is Turing complete, so that we can use matter to implement
> computations, like nature plausibly does. But it is not matter which
> behave intelligently: it is the person associated to the computation, and
> it behaves as well relatively to numbers than to matter. You use of
> matter is “magical”.
>
>
>
> If humans are matter (meaning of course that human brains are matter),
> then humans behave intelligently means that (at least some) matter
> behaves intelligently.

Like with a computer: some arrangement of some matter can emulate a
(universal) computation. That means that the physical laws are Turing
complete.

It does not mean that primary matter exists (see my reminding of what this
means in my answer to Brent, soon enough!).

>
> It is not clear that Turing in his last ("morphogenesis") years thought
> that the Turing machine was a complete definition of computing in nature.

If mechanism is true, in principle, nature has more powerful processing
ability than any computer. Now, it could mean only that nature use a
random oracle, which would come only from our ignorance about which
computations run us, if I may say.

Bruno

Going by something Barry Cooper wrote

The intuition is that computational unconventionality certainly entails
higher-type computation, with a correspondingly enhanced respect for
embodied information. There is some understanding of the algorithmic
content of descriptions. But so far we have merely scratched the surface.

"natural computing" may involve something that is non-Turing in a sense
that doesn't involve actual oracles in the hyperarithmetical processing
sense (but could involve topology: We can say that topology is precisely
about the relation between finiteness and infiniteness that is relevant to
computation. [
http://www.cs.bham.ac.uk/~mhe/papers/introduction-to-higher-order-computation-NLS-2017.pdf

]).

I posit that experience processing is a "natural computing" that is
non-Turing.

This new article may be of interest:

"there are now many signs that consciousness-like phenomena might exist
not just among humans or even great apes – but that insects might have
them, too"
]
https://aeon.co/essays/inside-the-mind-of-a-bee-is-a-hive-of-sensory-activity

]
>>>
>>> I am OK with this. I am open that plants do think, somehow. What is
>>> provably inconsistent with digital mechanism is that consciousness is
>>> “natural” or a product of matter. That equates two different kind of
>>> mysteries, without adding light on Matter nor Consciousness. That might be
>>> true, but I don’t see any evidence for such a move.
>>>
>>> Bruno
>>>
>>>
>>>
>>> That consciousness is an "intrinsic" property of patter will be the subject
>>> of
>>>
>>> Galileo's Error
>>> Foundations for a New Science of Consciousness
>>>
>>> by Philip Goff
>>> (coming from Penguin Random House)
>>
>>
>>
>> Please make an argument. Cite people only if you use an idea from them, but
>> present the idea and use it.
>>
>>
>>
>>>
>>>
>>> What higher-order computing matter does is an open question. But there is
>>> no evidence that there is any mathematical entity existing outside of
>>> matter (the subject of science).
>>
>> There is no evidence that matter is primary, physicists measure numbers, and
>> then infer relation between those measurable numbers.
>>
>>
>> Why limiting science to matter? Matter is vey interesting, but if you assume
>> matter, you need indeed a non ```

### Re: Measuring a system in a superposition of states vs in a mixed state

```
> On 4 Dec 2018, at 09:25, Philip Thrift  wrote:
>
>
>
> On Monday, December 3, 2018 at 9:00:26 PM UTC-6, Brent wrote:
>
>
> On 12/3/2018 8:50 AM, Bruno Marchal wrote:
>>
>>> On 3 Dec 2018, at 10:35, Philip Thrift >
>>> wrote:
>>>
>>>
>>>
>>> On Sunday, December 2, 2018 at 8:17:54 PM UTC-6, Brent wrote:
>>>
>>>
>>> On 12/2/2018 5:14 PM, Philip Thrift wrote:

On Sunday, December 2, 2018 at 4:25:04 PM UTC-6, Brent wrote:

On 12/2/2018 11:42 AM, Philip Thrift wrote:
>
>
> On Sunday, December 2, 2018 at 8:13:48 AM UTC-6, agrays...@gmail.com <>
> wrote:
>
> Obviously, from a one-world perspective, only one history survives for a
> single trial. But to even grossly approach anything describable as
> "Darwinian", you have to identify characteristics of histories which
> contribute positively or negatively wrt surviving but I don't see an
> inkling of that. IMO, Quantum Darwinism is at best a vacuous restatement
> of the measurement problemt; that we don't know why we get what we get. AG
>
>
>
>
> In the sum over histories interpretation - of the double-slit experiment,
> for example - each history carries a unit complex number - like a gene -
> and this gene reenforces (positively) or interferes (negatively) with
> other history's genes in the sum.

But I thought you said the ontology was that only one history "popped out
of the Lottery machine"?  Here you seem to contemplate an ensemble of
histories, all those ending at the given spot, as being real.

Brent

All are real until all but one dies.
RIP: All those losing histories.
>>>
>>> The trouble with that is the Born probability doesn't apply to histories,
>>> it applies to results.  So your theory says nothing about the probability
>>> of the fundamental ontologies.
>>>
>>> Brent
>>>
>>>
>>>
>>>
>>>
>>> The probability distribution on the space of histories is provided by the
>>> path integral.
>
> Except that isn't true. A probability (or probability density) is provided
> for a bundle of histories joining two events.  It doesn't not provide a
> probability of a single history.
>
> Brent
>
>
> That's why you add to that "pick any history at random from the bundle”:

… where Omnès added “time to be irrational” ...

>
> 1. Histories originate at an emitter e and end at screen locations s on a
> screen S.
> 2. At each s there is a history bundle histories(s). A weight w(s) is
> computed from the bundle by summing the unit complex numbers of the histories
> and taking the modulus.
> 3. The weight w(s) is sent back in time over a single history h*(s) selected
> at random (uniformly) from histories(s).
> 4. At e, the weights w(s) on backchannel of h*(s) are received (in the
> "present" time)
> 5. A single history h*(s*) is then selected from the distribution in 4.

"5.”  follows from mechanism as a first person view. No need of Omnès
mysterious selection.

Bruno

>
> See the Wheeler-Feynman computer:
> [
> https://codicalist.wordpress.com/2018/09/25/retrosignaling-in-the-quantum-substrate/
>  ]
>
> - pt
>
> --
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### Re: Where Max Tegmark is really wrong

```
> On 4 Dec 2018, at 09:06, Philip Thrift  wrote:
>
>
>
> On Monday, December 3, 2018 at 7:46:22 PM UTC-6, Brent wrote:
>
>
> On 12/3/2018 9:59 AM, Philip Thrift wrote:
>> But that is close to the solipsist move. The fact that we cannot define
>> truth does not entail that some notion of truth does not make sense. In
>> particular, Peano arithmetic can already define an infinity of approximation
>> of truth, namely sigma_i and pi_i truth (the truth of the sentences will a
>> finite and fixed number of quantifier, as opposed to finite sentences with
>> an arbitrary finite number of quantifier).
>>
>> We can invoke truth, but we can develop meta-discourse relating truth to
>> theories, like we cannot invoke our own consciousness does not prevent us to
>> It is a bit like “I cannot study my own brain”, but I can still infer some
>> theories of my brain by looking at the brain of others and then assuming
>> that I am not different.
>
> So are do these theories produce true or false propositions?
>
>>
>> Bruno
>>
>>
>>
>>
>> A different perspective (!) of "truth" comes from - vs. PA (Peano
>> arithmetic) - PLT (programming language theory - the legacy to a large
>> extent of John C. Reynolds [ https://en.wikipedia.org/wiki/John_C._Reynolds
>>  - who was originally a
>> theoretical physicist ], and sort of in parallel the whole type-theory
>> gang). Rather than an external "god-like" notion of truth, truth is in the
>> programming.
>>
>> - pt
>>
>>
> Can you give an example of "truth in the programming" and how it differs from
> the mathematical idea of true and the correspondence theory of truth?
>
> Brent
>
>
>
> Truth in programming follows the Brouwerian concept of truth:
> [ https://plato.stanford.edu/entries/brouwer/ ]

OK, that is the first person truth, captured by the []p & p variant of []p,
allowed and imposed by incompleteness (we don’t have the provability of []p ->
p, but of course (([]p & p) -> p).

>
>
>
> There is no determinant of mathematical truth outside the activity of
> thinking; a proposition only becomes true when the subject has experienced
> its truth (by having carried out an appropriate mental construction);
> similarly, a proposition only becomes false when the subject has experienced
> its falsehood (by realizing that an appropriate mental construction is not
> possible).
>
> There is no determinant of mathematical truth outside the activity of
> computing; a proposition only becomes true when the program has produced  its
> truth (by having carried out an appropriate computational construction);
> similarly, a proposition only becomes false when the program has produced its
> falsehood (by computing that an appropriate computational construction is not
> possible).

Yes, []p & p is a bit solipsistic, like we all are from the exclusive first
person point of view. That is good psychology, but bad metaphysics. Brouwer
said once to his enthusiastic students “how can you appreciate a course given
by someone who does not believe in your existence?”. Good question!

Bruno

>
> - pt
>
> --
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### Re: Where Max Tegmark is really wrong

```

> On 4 Dec 2018, at 03:30, Brent Meeker  wrote:
>
>
>
> On 12/3/2018 7:31 AM, Bruno Marchal wrote:
>>> On 2 Dec 2018, at 21:06, Brent Meeker  wrote:
>>>
>>>
>>>
>>> On 12/2/2018 4:52 AM, Bruno Marchal wrote:
Language have no relation with truth a priori. Theories might have.
Semantics are truth “by definition”, by relativising it to the notion of
model/reality.

>>> Then what is this "true" and "false" which you attribute to the
>>> propositions of modal logic?
>> In  classical logic, truth is any object in a set of two objects, or it is
>> the supremum in a Boolean algebra. In propositional logic a “world” is
>> defined by any function from the set of atomic letters to {t, f}.
>
> Right.  T and F are just formal markers in logic and the rules of inference
> are supposed to preserve T.
>
>>
>> Then if the theory is “rich enough”, truth can be meta-defined by “satisfied
>> by the structure (N, 0, s, +, *).
>> Of course, this presuppose the intuitive understanding of 2+2=4, etc.
>>
>> In our case, as all modal formula are arithmetical formula, it is the usual
>> informal mathematical notion just above (arithmetical truth, satisfaction by
>> the usual standard model).
>
> That's satisfaction relative to some particular axioms and rules of inference.

OK, but the modal logic just sum up purely arithmetical theorem.

For example the fact that G proves <>t -> ~[]<>t really means that PA (or any
Löbian entity) proves

consistent(’t’) -> ~beweisbar(‘consistent(’t’)),

And the fact that G proves []p -> [][]p means that for all arithmetical
proposition p, PA proves

beweisbar(‘p’) -> beweisbar(‘beweisbar(‘p’)’).

The modal logic are imposed mathematically. G is the logic of (provable)
self-reference, like G* \ G gives the true non provable proposition. The fact
that G* \ G proves <>[]f means that the consistency of inconsistency is true,
and non provable by PA.

The entire theology, including physics, are constituted of true arithmetical
formula.

>
>>
>> That one can be define by V(‘p’) means the same as p. It is Tarski’s idea
>> that ‘p’ is true when p, or when it is the case that p. Like wise, to say
>> Provable-and-true(p) we use []p & p.
>
> That's the correspondence theory of truth, which is what ordinary discourse
> and physics assume.

Yes, except that with mechanism, the correspondence refers to the standard
model of arithmetic (the non axiomatisable structure (N, 0, s, +, *).

> So there are at least three kinds of "true”.

They all derive from the standard model of arithmetic, that is, the elementary
notions we learn in high school, although we don’t call it that way.

> To which we might add the Trump theory of truth, "If it makes me look good
> it's true.”

Better to not add this one :)

>
>>
>> I recommend the book by Torkel Franzen “Inexhaustibility” for a more
>> detailed explanation of the concept of truth.
>
> I have the book but I haven't read it (so many books, so little time).

I understand. Its other book on the misuse of Gödel’s incompleteness is also
very good, and simpler to read.

Bruno

>
> Brent
>
>
>>
>> We can come back, but I suggest to come back on this only when we need it,
>> as this is an very rich and complex subject by itself.
>>
>> Bruno
>>
>>
>>
>>
>>
>>> Brent
>>>
>>> --
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### Re: Where Max Tegmark is really wrong

```
> On 4 Dec 2018, at 02:46, Brent Meeker  wrote:
>
>
>
> On 12/3/2018 9:59 AM, Philip Thrift wrote:
>> But that is close to the solipsist move. The fact that we cannot define
>> truth does not entail that some notion of truth does not make sense. In
>> particular, Peano arithmetic can already define an infinity of approximation
>> of truth, namely sigma_i and pi_i truth (the truth of the sentences will a
>> finite and fixed number of quantifier, as opposed to finite sentences with
>> an arbitrary finite number of quantifier).
>>
>> We can invoke truth, but we can develop meta-discourse relating truth to
>> theories, like we cannot invoke our own consciousness does not prevent us to
>> It is a bit like “I cannot study my own brain”, but I can still infer some
>> theories of my brain by looking at the brain of others and then assuming
>> that I am not different.
>
> So are do these theories produce true or false propositions?

You quote me (Bruno), here.

You are the judge. In our (mechanist) case, this follows from elementary
arithmetic.

>
>>
>> Bruno
>>
>>
>>
>>
>> A different perspective (!) of "truth" comes from - vs. PA (Peano
>> arithmetic) - PLT (programming language theory - the legacy to a large
>> extent of John C. Reynolds [ https://en.wikipedia.org/wiki/John_C._Reynolds
>>  - who was originally a
>> theoretical physicist ], and sort of in parallel the whole type-theory
>> gang). Rather than an external "god-like" notion of truth, truth is in the
>> programming.
>>
>> - pt
>>
>>
> Can you give an example of "truth in the programming" and how it differs from
> the mathematical idea of true and the correspondence theory of truth?

I let Philip Thrift answer this one. I use always Tarski’s theory
(correspondence with respect to some model/reality assumed).

Bruno

>
> Brent
>
> --
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```

### Re: Towards Conscious AI Systems (a symposium at the AAAI Stanford Spring Symposium 2019)

```

On Tuesday, December 4, 2018 at 4:25:37 AM UTC-6, Bruno Marchal wrote:
>
>
> On 3 Dec 2018, at 23:01, Philip Thrift >
> wrote:
>
>
>
> On Monday, December 3, 2018 at 1:24:30 PM UTC-6, Bruno Marchal wrote:
>>
>>
>> On 2 Dec 2018, at 13:24, Philip Thrift  wrote:
>>
>>
>>
>> On Sunday, December 2, 2018 at 5:23:15 AM UTC-6, Bruno Marchal wrote:
>>>
>>>
>>> On 29 Nov 2018, at 20:00, Philip Thrift  wrote:
>>>
>>>
>>>
>>> On Thursday, November 29, 2018 at 10:27:00 AM UTC-6, Bruno Marchal wrote:

On 27 Nov 2018, at 18:50, Philip Thrift  wrote:

On Tuesday, November 27, 2018 at 4:32:53 AM UTC-6, Bruno Marchal wrote:
>
>
> On 24 Nov 2018, at 17:27, John Clark  wrote:
>
>
>
>
> Turing explained how matter can behave intelligently,
>
>
> No. He showed how a person can be attached to a computation, and also
> that physics is Turing complete, so that we can use matter to implement
> computations, like nature plausibly does. But it is not matter which
> behave
> intelligently: it is the person associated to the computation, and it
> behaves as well relatively to numbers than to matter. You use of matter
> is
> “magical”.
>
>
>
If humans are matter (meaning of course that human brains are matter),
then *humans behave intelligently* means that (at least some) *matter
behaves intelligently*.

Like with a computer: some arrangement of some matter can emulate a
(universal) computation. That means that the physical laws are Turing
complete.

It does not mean that primary matter exists (see my reminding of what
this means in my answer to Brent, soon enough!).

It is not clear that Turing in his last ("morphogenesis") years thought
that the Turing machine was a complete definition of computing in nature.

If mechanism is true, in principle, nature has more powerful processing
ability than any computer. Now, it could mean only that nature use a
random
oracle, which would come only from our ignorance about which computations
run us, if I may say.

Bruno

>>>
>>> Going by something Barry Cooper wrote
>>>
>>> *The intuition is that computational unconventionality certainly entails
>>> higher-type computation, with a correspondingly enhanced respect for
>>> embodied information. There is some understanding of the algorithmic
>>> content of descriptions. But so far we have merely scratched the surface.*
>>>
>>> "natural computing" may involve something that is non-Turing in a sense
>>> that doesn't involve actual oracles in the hyperarithmetical processing
>>> sense (but could involve topology: *We can say that topology is
>>> precisely about the relation between finiteness and infiniteness that is
>>> relevant to computation.* [
>>> http://www.cs.bham.ac.uk/~mhe/papers/introduction-to-higher-order-computation-NLS-2017.pdf
>>>
>>> ]).
>>>
>>>
>>> I posit that *experience processing* is a "natural computing" that is
>>> non-Turing.
>>>
>>> This new article may be of interest:
>>>
>>>
>>> "there are now many signs that consciousness-like phenomena might exist
>>> not just among humans or even great apes – but that insects might have
>>> them, too"
>>> ]
>>> https://aeon.co/essays/inside-the-mind-of-a-bee-is-a-hive-of-sensory-activity
>>>
>>> ]
>>>
>>>
>>> I am OK with this. I am open that plants do think, somehow. What is
>>> provably inconsistent with digital mechanism is that consciousness is
>>> “natural” or a product of matter. That equates two different kind of
>>> mysteries, without adding light on Matter nor Consciousness. That might be
>>> true, but I don’t see any evidence for such a move.
>>>
>>> Bruno
>>>
>>>
>>>
>> That consciousness is an "intrinsic" property of patter will be the
>> subject of
>>
>> Galileo's Error
>> Foundations for a New Science of Consciousness
>>
>> by Philip Goff
>> (coming from Penguin Random House)
>>
>>
>>
>>
>> Please make an argument. Cite people only if you use an idea from them,
>> but present the idea and use it.
>>
>>
>>
>>
>>
>> What higher-order computing matter does is an open question. But there is
>> no evidence that there is any mathematical entity existing outside of
>> matter (the subject of science).
>>
>>
>> There is no evidence that matter is primary, physicists measure numbers,
>> and then infer relation between those measurable numbers.
>>
>>
>> Why limiting science to matter? Matter is vey interesting, but if you
>> assume matter, you need indeed a non computationalist theory of matter and
>> of mind, which will need actual infinities, making hard to refute it
>> experimentally, which is not a good sign.
>>
>> All matter theories assumes elementary arithmetic, you cannot avoid
>> assuming it when doping physics, so there is no need of assuming it outside
```

### Re: Extended Wigner’s Friend

```

> On 4 Dec 2018, at 06:07, Brent Meeker  wrote:
>
>
>
> On 12/3/2018 5:47 PM, Mason Green wrote:
>> Here’s a recent editorial I found in the magazine arguing against
>> Many-Worlds on the grounds that it denies the reality of experience or the
>> self.
>> (https://www.quantamagazine.org/why-the-many-worlds-interpretation-of-quantum-mechanics-has-many-problems-20181018/)
>>
>> Well, if we don’t want many-worlds or subjectivism, than the only other
>> option looks like it’d be to modify QM itself. Some form of digital physics
>> might work, otherwise we could have objective collapse (either random, or
>> else there’s something/someone outside the universe choosing which path the
>> universe follows).
>
> Remember, QM is not compatible with general relativity.  It is often assumed
> that the problem is finding a quantum theory of spacetime. But the long
> sought theory may also require some modification of QM or otherwise throw
> light on the measurement problem.  For example, Penrose's gravitationally
> induced collapse might work out.

This, at least, postulates explicitly non-mechanism, which makes sense of its
materialism.

Unfortunately Penrose’s motivation from Gödel is invalid (and can be seen as a
confusion between []p and []p & p).

I am a priori open to his (non mechanist) theory of gravitation induced
collapse, except I still don’t make much sense of it (maybe due to my
incompetence).

Bruno

>
> Brent
>
> --
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### Re: Extended Wigner’s Friend

```
> On 4 Dec 2018, at 03:24, Stathis Papaioannou  wrote:
>
>
>
> On Tue, 4 Dec 2018 at 12:47, Mason Green  > wrote:
> Here’s a recent editorial I found in the magazine arguing against Many-Worlds
> on the grounds that it denies the reality of experience or the self.
> (https://www.quantamagazine.org/why-the-many-worlds-interpretation-of-quantum-mechanics-has-many-problems-20181018/
>
> )
>
> Well, if we don’t want many-worlds or subjectivism, than the only other
> option looks like it’d be to modify QM itself. Some form of digital physics
> might work, otherwise we could have objective collapse (either random, or
> else there’s something/someone outside the universe choosing which path the
> universe follows).
>
> That article just claims, without explanation, that it would be impossible to
> have consciousness if you were continually being duplicated. I don't think
> you should accept this without further thought.

This assumes non-mechanism, which is indeed not much convincing at least as an
hypothesis, unless they give a precise theory and how to test it.

Bruno

>
> --
> Stathis Papaioannou
>
>
>
> Virus-free. www.avast.com
>
>
>
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### Re: Towards Conscious AI Systems (a symposium at the AAAI Stanford Spring Symposium 2019)

```
> On 3 Dec 2018, at 23:01, Philip Thrift  wrote:
>
>
>
> On Monday, December 3, 2018 at 1:24:30 PM UTC-6, Bruno Marchal wrote:
>
>> On 2 Dec 2018, at 13:24, Philip Thrift >
>> wrote:
>>
>>
>>
>> On Sunday, December 2, 2018 at 5:23:15 AM UTC-6, Bruno Marchal wrote:
>>
>>> On 29 Nov 2018, at 20:00, Philip Thrift > wrote:
>>>
>>>
>>>
>>> On Thursday, November 29, 2018 at 10:27:00 AM UTC-6, Bruno Marchal wrote:
>>>
On 27 Nov 2018, at 18:50, Philip Thrift > wrote:

On Tuesday, November 27, 2018 at 4:32:53 AM UTC-6, Bruno Marchal wrote:

> On 24 Nov 2018, at 17:27, John Clark > wrote:

> Turing explained how matter can behave intelligently,

No. He showed how a person can be attached to a computation, and also that
physics is Turing complete, so that we can use matter to implement
computations, like nature plausibly does. But it is not matter which
behave intelligently: it is the person associated to the computation, and
it behaves as well relatively to numbers than to matter. You use of matter
is “magical”.

If humans are matter (meaning of course that human brains are matter),
then humans behave intelligently means that (at least some) matter behaves
intelligently.
>>>
>>> Like with a computer: some arrangement of some matter can emulate a
>>> (universal) computation. That means that the physical laws are Turing
>>> complete.
>>>
>>> It does not mean that primary matter exists (see my reminding of what this
>>> means in my answer to Brent, soon enough!).
>>>
>>>
>>>
>>>

It is not clear that Turing in his last ("morphogenesis") years thought
that the Turing machine was a complete definition of computing in nature.
>>>
>>>
>>> If mechanism is true, in principle, nature has more powerful processing
>>> ability than any computer. Now, it could mean only that nature use a random
>>> oracle, which would come only from our ignorance about which computations
>>> run us, if I may say.
>>>
>>> Bruno
>>>
>>>
>>>
>>>
>>>
>>> Going by something Barry Cooper wrote
>>>
>>> The intuition is that computational unconventionality certainly entails
>>> higher-type computation, with a correspondingly enhanced respect for
>>> embodied information. There is some understanding of the algorithmic
>>> content of descriptions. But so far we have merely scratched the surface.
>>>
>>> "natural computing" may involve something that is non-Turing in a sense
>>> that doesn't involve actual oracles in the hyperarithmetical processing
>>> sense (but could involve topology: We can say that topology is precisely
>>> about the relation between finiteness and infiniteness that is relevant to
>>> computation. [
>>> http://www.cs.bham.ac.uk/~mhe/papers/introduction-to-higher-order-computation-NLS-2017.pdf
>>>
>>>
>>>  ]).
>>>
>>>
>>> I posit that experience processing is a "natural computing" that is
>>> non-Turing.
>>>
>>> This new article may be of interest:
>>>
>>>
>>> "there are now many signs that consciousness-like phenomena might exist not
>>> just among humans or even great apes – but that insects might have them,
>>> too"
>>> ]
>>> https://aeon.co/essays/inside-the-mind-of-a-bee-is-a-hive-of-sensory-activity
>>>
>>>
>>>  ]
>>
>> I am OK with this. I am open that plants do think, somehow. What is provably
>> inconsistent with digital mechanism is that consciousness is “natural” or a
>> product of matter. That equates two different kind of mysteries, without
>> adding light on Matter nor Consciousness. That might be true, but I don’t
>> see any evidence for such a move.
>>
>> Bruno
>>
>>
>>
>> That consciousness is an "intrinsic" property of patter will be the subject
>> of
>>
>> Galileo's Error
>> Foundations for a New Science of Consciousness
>>
>> by Philip Goff
>> (coming from Penguin Random House)
>
>
>
> Please make an argument. Cite people only if you use an idea from them, but
> present the idea and use it.
>
>
>
>>
>>
>> What higher-order computing matter does is an open question. But there is no
>> evidence that there is any mathematical entity existing outside of matter
>> (the subject of science).
>
> There is no evidence that matter is primary, physicists measure numbers, and
> then infer relation between those measurable numbers.
>
>
> Why limiting science to matter? Matter is vey interesting, but if you assume
> matter, you need indeed a non computationalist theory of matter and of mind,
> which will need actual infinities, making hard to refute it experimentally,
> which is not a good sign.
>
> All matter theories assumes elementary arithmetic, you cannot avoid assuming
> it when doping physics, so there is no need of ```

### Re: Coherent states of a superposition

```
> On 3 Dec 2018, at 20:57, agrayson2...@gmail.com wrote:
>
>
>
> On Sunday, November 18, 2018 at 1:05:26 PM UTC, agrays...@gmail.com wrote:
>
>
> On Saturday, November 17, 2018 at 7:39:14 PM UTC, agrays...@gmail.com <>
> wrote:
> If you write a superposition as a sum of eigenstates, why is it important, or
> relevant, or even true that the component states are coherent since
> eigenstates with distinct eigenvalues are orthogonal. This means there is no
> interference between the components of the superposition. AG
>
> Put another way; from what I've read, coherence among components of a
> superposition is necessary to guarantee interference, but since an eigenstate
> expansion of the superposition consists of orthogonal, non interfering
> eigenstates, the requirement of coherence seems unnecessary. AG
>
> For decoherence to occur, one needs, presumably, a coherent superposition.
> But when the wf is expressed as a sum of eigenstates with unique eigenvalues,
> those eigenstates are mutually orthogonal; hence, IIUC, there is no
> coherence. So, how can decoherence occur when the state function, expressed
> as a sum of eigenstates with unique eigenvalues, is not coherent? I must be
> missing something, but what it is I have no clue. AG

Decoherence never occurs, except in the mind or memory of the observer. Take
the state up + down (assuming a factor 1/sqrt(2)). And O is an observer (its
quantum state).

O has the choice to measure in the base {up, down}, in which case the Born rule
says that he will see up, or down with a probability 1/2. He will *believe*
that decoherence has occurred, but if we long at the evolution of the whole
system O + the particle, all we get is

O-up up + O-down down,

And some other observer could in principle test this. (O-up means O with the
memory of having seen the particle in the up position).

But O could measure that particle in the base {up+down, up-down). He has just
to rotate a little bit its polariser or Stern-Gerlach device. In that case he
obtains up+down with the probability one, which souls not be the case with a
mixture of up and down. In that case, coherence of up and down do not
disappear, even from the pot of the observer.

Decoherence is just the contagion of the superposition to anything interacting
with it, including the observer, and if we wait long enough the whole causal
cone of the observer.

Bruno

>
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### Re: If Quantum Mechanics can be derived using arithmetic only, how would that derivation begin?

```
> On 3 Dec 2018, at 16:02, agrayson2...@gmail.com wrote:
>
>
>
> On Monday, December 3, 2018 at 2:42:26 PM UTC, Bruno Marchal wrote:
>
>> On 2 Dec 2018, at 15:00, agrays...@gmail.com  wrote:
>>
>>
>>
>> On Sunday, December 2, 2018 at 12:11:50 PM UTC, Bruno Marchal wrote:
>>
>>> On 30 Nov 2018, at 12:13, agrays...@gmail.com <> wrote:
>>>
>>>
>>>
>>> On Friday, November 30, 2018 at 12:34:13 AM UTC, Brent wrote:
>>> What can be inferred always depends on what you take as premises.  If you
>>> start from the Hilbert space formulation of QM or an equivalent formulation
>>> and you premise that there is a probability interpretation of  a state,
>>> then Gleason's theorem tells you that the Born rule provides the unique
>>> probability values.
>>>
>>> Brent
>>>
>>> So to get Born's Rule, Bruno would have to assume a huge amount IN ADDITION
>>> TO ARITHMETIC. I don't buy it. AG
>>
>> On the contrary, mechanism assumes less than any other theory. And Mechanism
>> is roughly the idea that the brain does not invoke magical things.
>>
>> The theory of everything, with mechanism assumed at the metalevel, assume
>> only S K, S≠K, and the axioms
>>
>> 1) If x = y and x = z, then y = z
>> 2) If x = y then xz = yz
>> 3) If x = y then zx = zy
>> 4) Kxy = x
>> 5) Sxyz = xz(yz)
>>
>> I doubt that you will find an easier theory.
>> (Exercice: prove that x = x)
>>
>> Bruno
>>
>> But you haven't replied to my objection. In addition to logic and the axioms
>> of arithmetic, you must ALSO assume such a thing as probability exists to
>> even approach QM. What you have above won't cut it, IMO. AG
>
>
> I do not assume any probabilities in the ontology. I justify them through the
> phenomenology. Here I was just making clear that I assume only the 5 rules
> and axioms above. There is three inference rules:
>
> 1) If x = y and x = z, then y = z
> 2) If x = y then xz = yz
> 3) If x = y then zx = zy
>
> And two axioms:
>
> 4) Kxy = x
> 5) Sxyz = xz(yz)
>
> Are the variables restricted to natural numbers, that is, the positive
> integers?

A combinatory algebra is any set with some law or operation verifying the
axioms above. That can be birds (Smullyan) or whatever you want, as long as the
formula above are satisfied.

And they can be numbers indeed. I will probably prove, soon, that if you take
the set N (the natural numbers), and fix some universal machinery phi_i (that
is an enumeration of the partial computable functions), then by defining (i j)
by phi_i(j) we make N into a combinatory algebra. So any universal
system/machine/number automatically endow N with a structure of (partial)
combinatory algebra. There are other more sophisticated models though.

phi_i(j) denotes the result of applying the ith program (of the fixed
enumeration of all programs in the fixed universal machinery) on the number j.

Kxy abbreviates ((K x) y) where (K x) denotes what is noted usually K(x), that
is K applied on x.

> What are these axioms, explicitly?

They are axioms defining the combinatory algebra, which captures the Turing
Universal system. Like the axioms of group theory defines the group. Not sure
of the meaning of your question, as it is hard to be more explicit than by
giving axioms.

> And No, I don't believe there's enough here to infer de Broglie matter waves,
> or the quantum interference pattern for, say, the double slit. AG

Being skeptical is good … as long as your skepticism does not prevent you to
verify the proof and perhaps to justify your disbelief with some specific
argument. If not, I will think that your disbelief is based on some personal
opinion (like believing in some ontological matter that we would have to
assume). In that case we are no more doing science.
And, yes, the axiom above capture basically the whole of computer science,
although we can add many axioms, to get more particular theories (Turing
complete or not). Of course, by incompleteness, to get the whole theoretical
computer truth, we would need a (non recursively enumerable) infinity of
axioms. Such truth are beyond *all* theories.

Note that I could use the numbers instead of combintaors; using Robinson

0 ≠ s(x) (0 is not the successor of a number)
s(x) = s(y) -> x = y (different numbers have different successors)
x = 0 v Ey(x = s(y))(except for 0, all numbers have a predecessor)
x+0 = x  (if you add zero to a number, you get that number)
x+s(y) = s(x+y)  (if you add a number x to the successor of a number y, you get
the successor of x added to y)
x*0=0   (if you multiply a number by 0, you get 0)
x*s(y)=(x*y)+x(if you multiply a number x by the successor of y, you get
the number x added to the multiplication of the number x with y)

OK?

That theory, amazingly, is also Turing complete, despite being very weak (it
cannot prove that 0 + x = x, for example).

Bruno

>
>
> Nothing else is assumed, ```

### Re: Extended Wigner’s Friend

```

On Monday, December 3, 2018 at 7:47:02 PM UTC-6, Mason Green wrote:
>
> Here’s a recent editorial I found in the magazine arguing against
> Many-Worlds on the grounds that it denies the reality of experience or the
> self. (
> https://www.quantamagazine.org/why-the-many-worlds-interpretation-of-quantum-mechanics-has-many-problems-20181018/)
>
>
>
> Well, if we don’t want many-worlds or subjectivism, than the only other
> option looks like it’d be to modify QM itself. Some form of digital physics
> might work, otherwise we could have objective collapse (either random, or
> else there’s something/someone outside the universe choosing which path the
> universe follows).
>
> -Mason

Keep in mind that "multiple histories" is (in a way) the time-reversed view
of "many worlds":

*In the same way that the many-worlds interpretation regards possible
futures as having a real existence of their own, the theory of multiple
histories reverses this in time to regard the many possible past histories
of a given event as having real existence.*
[ https://en.wikipedia.org/wiki/Multiple_histories ]

Fay Dowker [ https://en.wikipedia.org/wiki/Fay_Dowker ] gives a short
summary of "sum over histories" here (and why she prefers it to other
interpretations).

- pt

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### Re: Measuring a system in a superposition of states vs in a mixed state

```

On Monday, December 3, 2018 at 9:00:26 PM UTC-6, Brent wrote:
>
>
>
> On 12/3/2018 8:50 AM, Bruno Marchal wrote:
>
>
> On 3 Dec 2018, at 10:35, Philip Thrift >
> wrote:
>
>
>
> On Sunday, December 2, 2018 at 8:17:54 PM UTC-6, Brent wrote:
>>
>>
>>
>> On 12/2/2018 5:14 PM, Philip Thrift wrote:
>>
>>
>>
>> On Sunday, December 2, 2018 at 4:25:04 PM UTC-6, Brent wrote:
>>>
>>>
>>>
>>> On 12/2/2018 11:42 AM, Philip Thrift wrote:
>>>
>>>
>>>
>>> On Sunday, December 2, 2018 at 8:13:48 AM UTC-6, agrays...@gmail.com
>>> wrote:

*Obviously, from a one-world perspective, only one history survives for
a single trial. But to even grossly approach anything describable as
"Darwinian", you have to identify characteristics of histories which
contribute positively or negatively wrt surviving but I don't see an
inkling of that. IMO, Quantum Darwinism is at best a vacuous restatement
of
the measurement problemt; that we don't know why we get what we get. AG*

>
>
>
>>>
>>> In the *sum over histories* interpretation - of the double-slit
>>> experiment, for example - each history carries a unit complex number - like
>>> a gene - and this gene reenforces (positively) or interferes (negatively)
>>> with other history's genes in the sum.
>>>
>>>
>>> But I thought you said the ontology was that only one history "popped
>>> out of the Lottery machine"?  Here you seem to contemplate an ensemble of
>>> histories, all those ending at the given spot, as being real.
>>>
>>> Brent
>>>
>>
>>
>>
>>
>> All are real until all but one dies.
>> RIP: All those losing histories.
>>
>>
>> The trouble with that is the Born probability doesn't apply to histories,
>> it applies to results.  So your theory says nothing about the probability
>> of the fundamental ontologies.
>>
>> Brent
>>
>
>
>
>
>
> The probability distribution on the space of histories is provided by the
> path integral.
>
>
> Except that isn't true. A probability (or probability density) is provided
> for a bundle of histories joining two events.  It doesn't not provide a
> probability of a single history.
>
> Brent
>
>
That's why you add to that "pick any history at random from the bundle":

1. Histories originate at an emitter e and end at screen locations s on a
screen S.
2. At each s there is a history bundle histories(s). A weight w(s) is
computed from the bundle by summing the unit complex numbers of the
histories and taking the modulus.
3. The weight w(s) is sent back in time over a single history h*(s)
selected at random (uniformly) from histories(s).
4. At e, the weights w(s) on backchannel of h*(s) are received (in the
"present" time)
5. A single history h*(s*) is then selected from the distribution in 4.

See the *Wheeler-Feynman computer*:
[
https://codicalist.wordpress.com/2018/09/25/retrosignaling-in-the-quantum-substrate/

]

- pt

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### Re: Where Max Tegmark is really wrong

```

On Monday, December 3, 2018 at 7:46:22 PM UTC-6, Brent wrote:
>
>
>
> On 12/3/2018 9:59 AM, Philip Thrift wrote:
>
> But that is close to the solipsist move. The fact that we cannot define
>> truth does not entail that some notion of truth does not make sense. In
>> particular, Peano arithmetic can already define an infinity of
>> approximation of truth, namely sigma_i and pi_i truth (the truth of the
>> sentences will a finite and fixed number of quantifier, as opposed to
>> finite sentences with an arbitrary finite number of quantifier).
>>
>> We can invoke truth, but we can develop meta-discourse relating truth to
>> theories, like we cannot invoke our own consciousness does not prevent us
>> to try theories about it.
>> It is a bit like “I cannot study my own brain”, but I can still infer
>> some theories of my brain by looking at the brain of others and then
>> assuming that I am not different.
>>
>
> So are do these theories produce true or false propositions?
>
>
>> Bruno
>>
>>
>>
>
> A different perspective (!) of "truth" comes from - vs. PA (Peano
> arithmetic) - *PLT* (programming language theory - the legacy to a large
> extent of John C. Reynolds [
> https://en.wikipedia.org/wiki/John_C._Reynolds - who was originally a
> theoretical physicist ], and sort of in parallel the whole type-theory
> gang). Rather than an external "god-like" notion of truth, truth is in the
> programming.
>
> - pt
>
>
> Can you give an example of "truth in the programming" and how it differs
> from the mathematical idea of true and the correspondence theory of truth?
>
> Brent
>

Truth in programming follows the Brouwerian concept of truth:
[ https://plato.stanford.edu/entries/brouwer/ ]

*There is no determinant of mathematical truth outside the activity of
thinking; a proposition only becomes true when the subject has experienced
its truth (by having carried out an appropriate mental construction);
similarly, a proposition only becomes false when the subject has
experienced its falsehood (by realizing that an appropriate mental
construction is not possible).*

*There is no determinant of mathematical truth outside the activity of
computing;* a proposition only becomes true when the program has produced
its truth (by having carried out an appropriate computational
construction); similarly, a proposition only becomes false when the program
has produced its falsehood (by computing that an appropriate computational
construction is not possible).

- pt

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