### Re: Questions about the Equivalence Principle (EP) and GR

```

On Thursday, February 21, 2019 at 8:38:12 PM UTC-7, Brent wrote:
>
>
>
> On 2/21/2019 4:05 PM, agrays...@gmail.com  wrote:
>
>
>
> On Thursday, February 21, 2019 at 1:35:17 PM UTC-7, Brent wrote:
>>
>>
>>
>> On 2/21/2019 5:27 AM, agrays...@gmail.com wrote:
>>
>>
>>
>> On Wednesday, February 20, 2019 at 7:50:51 PM UTC-7, Brent wrote:
>>>
>>>
>>>
>>> On 2/20/2019 1:23 PM, agrays...@gmail.com wrote:
>>>
>>>
>>>
>>> On Wednesday, February 20, 2019 at 12:16:31 PM UTC-7, Brent wrote:

On 2/20/2019 8:42 AM, agrays...@gmail.com wrote:

On Wednesday, February 20, 2019 at 7:09:10 AM UTC-7, John Clark wrote:
>
>
> >* Newton "explained" *
>
>
> Why did you put explained in quotation marks? If you can predict what
> something is going to do then you've explained it, the better the
> prediction the better the explanation. I don't know what else the word
> could possibly mean. And in science no explanation is perfect, but some
> are
> less wrong than others.
>

*QM better illustrates the justification for quotes. Many
interpretations that make the same predictions. AG *

>
> *> why a body at "rest" can start moving, via the application of
>> "force"*
>
>
> And Einstein explained that a body moving in a geodesic through 4D
> spacetime will take a path that is not a geodesic if a force is applied.
> The Earth is moving in a straight line (aka a geodesic) through curved
> spacetime; the reason Earth's orbit looks elliptical to us is due to map
> distortion, the same reason that in a flat map of the curved surface of
> the
> Earth Greenland looks larger than South America and is almost as large as
> Africa. Except that it's even worse, in one we're projecting the 2 D
> curved surface of the Earth into the flat 2D surface of the map, but with
> Einstein we're projecting a curved 4D volume into a flat 3D volume.
>
> *> What does "rest" mean in GR *
>
>
> In General Relativity moving in a geodesic is as close as you can get
> to the traditional idea of rest, but as long as time passes you're going
> to
> be moving through 4D spacetime.
>

*If you're at spatial rest in spacetime in the presence of a
gravitational source, how does GR explain the subsequent spatial motion?
AG
*

When you were at "spatial rest" you had a force applied to you.
Removing it allowed you to follow a geodesics path through
spacetimealso known as "falling".

Brent

>>>
>>> *So it seems that GR doesn't explain motion; rather, it assumes motion
>>> is a natural state of things. AG *
>>>
>>>
>>> So called "standing still" is just motion in the time direction
>>> only...in Newtonian and special relativity as well. Just as there is no
>>> absolute motion, there's no absolution motionless either...it's called
>>> "relativity" for a reason.
>>>
>>> Brent
>>>
>>
>>
>> *Other than gravity, the remaining known forces are moderated, or shall
>> we say "caused by" particles. Doesn't GR remain an exception; that is,
>> wouldn't it preclude the existence of a graviton? TIA, AG *
>>
>>
>> Gravitons, the weak-field limit quanta of the gravitational field, aren't
>> precluded.  They are implicit in string-theory; which is why string theory
>> is a candidate for the quantum theory of gravity.  The problem is there's
>> no mathematically consistent way to extend the graviton, weak field,
>> picture to the strong field limit and predict what happens in a black hole
>> where GR predicts a singularity.
>>
>> Brent
>>
>
> *ISTM that gravitons would be inconsistent with GR, which derives
> gravitating motion from geometry, not mediating particles.  AG*
>
>
> It is conceptually inconsistent, just as GR is conceptually inconsistent
> with Newtonian gravity.  But that doesn't mean the theories make detectably
> different predictions in the domain where we can test them.  Notice how
> difficult it was to test GR vs Newton.
>
> Brent
>

*Even if gravitons are detected, and they account for "force" consistent
with the other three forces, wouldn't there remain the task of changing the
form of gravity to make it covariant? Would that require tensors? AG*

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### Re: Questions about the Equivalence Principle (EP) and GR

```

On 2/21/2019 4:05 PM, agrayson2...@gmail.com wrote:

On Thursday, February 21, 2019 at 1:35:17 PM UTC-7, Brent wrote:

On 2/21/2019 5:27 AM, agrays...@gmail.com  wrote:

On Wednesday, February 20, 2019 at 7:50:51 PM UTC-7, Brent wrote:

On 2/20/2019 1:23 PM, agrays...@gmail.com wrote:

On Wednesday, February 20, 2019 at 12:16:31 PM UTC-7, Brent
wrote:

On 2/20/2019 8:42 AM, agrays...@gmail.com wrote:

On Wednesday, February 20, 2019 at 7:09:10 AM UTC-7,
John Clark wrote:

>/Newton "explained" /

Why did you put explained in quotation marks? If
you can predict what something is going to do then
you've explained it, the better the prediction the
better the explanation. I don't know what else the
word could possibly mean. And in science no
explanation is perfect, but some are less wrong
than others.

*QM better illustrates the justification for quotes.
Many interpretations that make the same predictions. AG *

/> why a body at "rest" can start moving, via
the application of "force"/

And Einstein explained that a body moving in a
geodesic through 4D spacetime will take a path that
is not a geodesic if a force is applied. The Earth
is moving in a straight line (aka a geodesic)
through curved spacetime; the reason Earth's orbit
looks elliptical to us is due to map distortion,
the same reason that in a flat map of the curved
surface of the Earth Greenland looks larger than
South America and is almost as large as Africa.
Except that it's even worse, in one we're
projecting the 2 D curved surface of the Earth into
the flat 2D surface of the map, but with Einstein
we're projecting a curved 4D volume into a flat 3D
volume.

/> What does "rest" mean in GR /

In General Relativity moving in a geodesic is as
close as you can get to the traditional idea of
rest, but as long as time passes you're going to be
moving through 4D spacetime.

*If you're at spatial rest in spacetime in the presence
of a gravitational source, how does GR explain the
subsequent spatial motion? AG
*

When you were at "spatial rest" you had a force applied
to you.  Removing it allowed you to follow a geodesics
path through spacetimealso known as "falling".

Brent

*So it seems that GR doesn't explain motion; rather, it
assumes motion is a natural state of things. AG
*

So called "standing still" is just motion in the time
direction only...in Newtonian and special relativity as well.
Just as there is no absolute motion, there's no absolution
motionless either...it's called "relativity" for a reason.

Brent

*Other than gravity, the remaining known forces are moderated, or
shall we say "caused by" particles. Doesn't GR remain an
exception; that is, wouldn't it preclude the existence of a
graviton? TIA, AG
*

Gravitons, the weak-field limit quanta of the gravitational field,
aren't precluded.  They are implicit in string-theory; which is
why string theory is a candidate for the quantum theory of
gravity.  The problem is there's no mathematically consistent way
to extend the graviton, weak field, picture to the strong field
limit and predict what happens in a black hole where GR predicts a
singularity.

Brent

*ISTM that gravitons would be inconsistent with GR, which derives
gravitating motion from geometry, not mediating particles.  AG*

It is conceptually inconsistent, just as GR is conceptually inconsistent
with Newtonian gravity.  But that doesn't mean the theories make
detectably different predictions in the domain where we can test them.
Notice how difficult it was to test GR vs Newton.

Brent

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```

### Re: Test 20190218

```Mysterious? No! Lobian? Yes!

-Original Message-
From: Bruno Marchal
To: everything-list
Sent: Thu, Feb 21, 2019 9:24 am
Subject: Re: Test 20190218

On 18 Feb 2019, at 23:22, spudboy100 via Everything List
wrote:

Thanks. Eventually I got the older messages. I don’t understand why they have
taken so long. Machines are mysterious :)
Best,
Bruno

-Original Message-
From: Bruno Marchal
To: everything-list
Sent: Mon, Feb 18, 2019 4:10 am
Subject: Test 20190218

Hi,

This is a test. I did not get my last answers back. I guess some problem with

Sorry, I will try to send them again. I will see on the web google pages.

Bruno

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```

### Re: Questions about the Equivalence Principle (EP) and GR

```

On Thursday, February 21, 2019 at 1:35:17 PM UTC-7, Brent wrote:
>
>
>
> On 2/21/2019 5:27 AM, agrays...@gmail.com  wrote:
>
>
>
> On Wednesday, February 20, 2019 at 7:50:51 PM UTC-7, Brent wrote:
>>
>>
>>
>> On 2/20/2019 1:23 PM, agrays...@gmail.com wrote:
>>
>>
>>
>> On Wednesday, February 20, 2019 at 12:16:31 PM UTC-7, Brent wrote:
>>>
>>>
>>>
>>> On 2/20/2019 8:42 AM, agrays...@gmail.com wrote:
>>>
>>>
>>>
>>> On Wednesday, February 20, 2019 at 7:09:10 AM UTC-7, John Clark wrote:

>* Newton "explained" *

Why did you put explained in quotation marks? If you can predict what
something is going to do then you've explained it, the better the
prediction the better the explanation. I don't know what else the word
could possibly mean. And in science no explanation is perfect, but some
are
less wrong than others.

>>>
>>> *QM better illustrates the justification for quotes. Many
>>> interpretations that make the same predictions. AG *
>>>

*> why a body at "rest" can start moving, via the application of
> "force"*

And Einstein explained that a body moving in a geodesic through 4D
spacetime will take a path that is not a geodesic if a force is applied.
The Earth is moving in a straight line (aka a geodesic) through curved
spacetime; the reason Earth's orbit looks elliptical to us is due to map
distortion, the same reason that in a flat map of the curved surface of
the
Earth Greenland looks larger than South America and is almost as large as
Africa. Except that it's even worse, in one we're projecting the 2 D
curved surface of the Earth into the flat 2D surface of the map, but with
Einstein we're projecting a curved 4D volume into a flat 3D volume.

*> What does "rest" mean in GR *

In General Relativity moving in a geodesic is as close as you can get
to the traditional idea of rest, but as long as time passes you're going
to
be moving through 4D spacetime.

>>>
>>>
>>> *If you're at spatial rest in spacetime in the presence of a
>>> gravitational source, how does GR explain the subsequent spatial motion? AG
>>> *
>>>
>>>
>>> When you were at "spatial rest" you had a force applied to you.
>>> Removing it allowed you to follow a geodesics path through
>>> spacetimealso known as "falling".
>>>
>>> Brent
>>>
>>>
>>
>> *So it seems that GR doesn't explain motion; rather, it assumes motion is
>> a natural state of things. AG *
>>
>>
>> So called "standing still" is just motion in the time direction only...in
>> Newtonian and special relativity as well. Just as there is no absolute
>> motion, there's no absolution motionless either...it's called "relativity"
>> for a reason.
>>
>> Brent
>>
>
>
> *Other than gravity, the remaining known forces are moderated, or shall we
> say "caused by" particles. Doesn't GR remain an exception; that is,
> wouldn't it preclude the existence of a graviton? TIA, AG *
>
>
> Gravitons, the weak-field limit quanta of the gravitational field, aren't
> precluded.  They are implicit in string-theory; which is why string theory
> is a candidate for the quantum theory of gravity.  The problem is there's
> no mathematically consistent way to extend the graviton, weak field,
> picture to the strong field limit and predict what happens in a black hole
> where GR predicts a singularity.
>
> Brent
>

*ISTM that gravitons would be inconsistent with GR, which derives
gravitating motion from geometry, not mediating particles.  AG*

>
>
>
>>
>>
*>  what causes "motion" from that pov?*

Force, same as with Newton.

John K Clark

>>> --
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>>> Groups "Everything List" group.
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>>> To post to this group, send email to everyth...@googlegroups.com.
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>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>>
>>> --
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>> Visit this group at https://groups.google.com/group/everything-list.
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>>
>>
>> --
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> .
> Visit this group at ```

### Re: Questions about the Equivalence Principle (EP) and GR

```On Thu, Feb 21, 2019 at 8:27 AM  wrote:

*> Other than gravity, the remaining known forces are moderated, or shall
> we say "caused by" particles. Doesn't GR remain an exception; that is,
> wouldn't it preclude the existence of a graviton? TIA, AG *

3 of the 4 fundamental forces of nature are explained by Quantum Mechanics
and all 3 are moderated by particles; General Relativity alone deals with
gravity, so far at least Quantum Mechanics  has proved itself useless there
and we can't even get these 2 very successful theories to talk to each
other much less merge. If space and time are quantized then the graviton
could exist but due to its elusive nature even if it does exist it is quite
likely nobody will ever be able to detect a graviton.

As far as I know the first person to point this out was Freeman Dyson in  a
brilliant  talk he gave in 2014 (on his 90th birthday!!) and shows that
something like LIGO could never detect one and other methods have little
chance either:

Freeman Dyson: Is a Graviton Detectable?

In rebuttal to Dyson some say graviton might be datatable in theory but not
in practice:

Can Gravitons Be Detected?

John K Clark

>

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```

### Re: Questions about the Equivalence Principle (EP) and GR

```

On 2/21/2019 5:27 AM, agrayson2...@gmail.com wrote:

On Wednesday, February 20, 2019 at 7:50:51 PM UTC-7, Brent wrote:

On 2/20/2019 1:23 PM, agrays...@gmail.com  wrote:

On Wednesday, February 20, 2019 at 12:16:31 PM UTC-7, Brent wrote:

On 2/20/2019 8:42 AM, agrays...@gmail.com wrote:

On Wednesday, February 20, 2019 at 7:09:10 AM UTC-7, John
Clark wrote:

>/Newton "explained" /

Why did you put explained in quotation marks? If you can
predict what something is going to do then you've
explained it, the better the prediction the better the
explanation. I don't know what else the word could
possibly mean. And in science no explanation is perfect,
but some are less wrong than others.

*QM better illustrates the justification for quotes. Many
interpretations that make the same predictions. AG *

/> why a body at "rest" can start moving, via the
application of "force"/

And Einstein explained that a body moving in a geodesic
through 4D spacetime will take a path that is not a
geodesic if a force is applied. The Earth is moving in a
straight line (aka a geodesic) through curved spacetime;
the reason Earth's orbit looks elliptical to us is due
to map distortion, the same reason that in a flat map of
the curved surface of the Earth Greenland looks larger
than South America and is almost as large as Africa.
Except that it's even worse, in one we're projecting the
2 D curved surface of the Earth into the flat 2D surface
of the map, but with Einstein we're projecting a curved
4D volume into a flat 3D volume.

/> What does "rest" mean in GR /

In General Relativity moving in a geodesic is as close
as you can get to the traditional idea of rest, but as
long as time passes you're going to be moving through 4D
spacetime.

*If you're at spatial rest in spacetime in the presence of a
gravitational source, how does GR explain the subsequent
spatial motion? AG
*

When you were at "spatial rest" you had a force applied to
you.  Removing it allowed you to follow a geodesics path
through spacetimealso known as "falling".

Brent

*So it seems that GR doesn't explain motion; rather, it assumes
motion is a natural state of things. AG
*

So called "standing still" is just motion in the time direction
only...in Newtonian and special relativity as well. Just as there
is no absolute motion, there's no absolution motionless
either...it's called "relativity" for a reason.

Brent

*Other than gravity, the remaining known forces are moderated, or
shall we say "caused by" particles. Doesn't GR remain an exception;
that is, wouldn't it preclude the existence of a graviton? TIA, AG

*

Gravitons, the weak-field limit quanta of the gravitational field,
aren't precluded.  They are implicit in string-theory; which is why
string theory is a candidate for the quantum theory of gravity.  The
problem is there's no mathematically consistent way to extend the
graviton, weak field, picture to the strong field limit and predict what
happens in a black hole where GR predicts a singularity.

Brent

/>  what causes "motion" from that pov?/

Force, same as with Newton.

John K Clark

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from it, send an email to everything-li...@googlegroups.com.
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Visit this group at
.
.

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.
Visit this group at
.
.

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To unsubscribe from this group and stop receiving emails from it, send
an email to ```

### Re: Modal logic, consciousness, and matter

```

On Thursday, February 21, 2019 at 8:23:15 AM UTC-6, Bruno Marchal wrote:
>
>
> On 18 Feb 2019, at 20:18, Philip Thrift >
> wrote:
>
> On Monday, February 18, 2019 at 9:14:38 AM UTC-6, Bruno Marchal wrote:
>
> This is the link to the reply in the topic "When Did Consciousness Begin?"
> As I have said before, the modal logic and numerical semantics written
> there is one way to approach the science of experience. But I think
> ultimately this is a logical semantics (not a material semantics), but of
> course belief in an actual numerical reality makes a difference.
>
> Here is something more along those lines:
>
> On modal logic and consciousness:
>
> *A Modal Logic for Gödelian Intuition*
> Hasen Khudairi
> https://philarchive.org/archive/KHUAML
>
> *Towards an Axiomatic Theory of Consciousness*
> Jim Cunningham [ https://www.doc.ic.ac.uk/~rjc/ ]
> https://www.doc.ic.ac.uk/~rjc/Cunningham.pdf
>
>
> However I think that there is ultimately a material semantics.
>
>
> I can imagine a semantic for some theory of matter, but matter itself
> cannot be semantical. What would that mean? Even without mechanism, I have
> no idea what that could mean.
>
>
>
>
I define material semantics here:

*Material Semantics for Unconventional Programming*
https://codicalist.wordpress.com/2018/12/14/material-semantics-for-unconventional-programming/

material semantics =

physical (*incl.* chemical+biological)
+
psychical (or experiential) semantics

>
>
>
> As for the ancient Greeks, forget Aristotle and look to Epicurus.
>
>
> I assume mechanism, and I just listen to the universal machine, with
> machine taken in the sense of Church and Turing. The notion of matter is
> not assumed in such definition, and we know, basically since Gödel, that
> they exist in arithmetic (semantically, of course).
>
>
>
>
>
>
> Some "offbeat" materialism I just came across that my be of interest:
>
> Terry Eagleton
> *Materialism*, Yale University Press
> excerpt 2:
> http://blog.yalebooks.com/2017/02/09/material-theology-and-christian-religion/
>
>
> Very nice. I would not have dare to suggest that christianism is so much
> materialist. I am not sure this was true during the five first hundreds
> years, but it is dogmatically so after 529 (closure of Plato’s academy).
>
>
>
>
>
>
> *Matter is an aggregation of cuisines whose recipes arise and combine to
> form the cookbook of nature.*
>
>
> No problem with this, on the contrary. A recipe is another name for an
> algorithm, which is typically not made of matter, but exist in arithmetic.
>
> And for the cooking, there is no need distinguish primary matter, which
> cannot exist with Mechanism, and matter, which obviously exist
> phenomenologically.
>
> Bruno
>
>

Of course all algorithms (technically) are made of matter:

They are arrangements of glyphs of ink on paper  (like in a book), or are
electronic dots on a screen (like you are looking at right now) or are
magnetic polarities stored on a hard drive, etc.

That matter "has" recipes (or algorithms) is the dialectics of Codicalism.

- pt

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### Re: Questions about the Equivalence Principle (EP) and GR

```

On Thursday, February 21, 2019 at 7:27:27 AM UTC-6, agrays...@gmail.com
wrote:
>
>
> *Other than gravity, the remaining known forces are moderated, or shall we
> say "caused by" particles. Doesn't GR remain an exception; that is,
> wouldn't it preclude the existence of a graviton? TIA, AG*
>

Just my opinion: There are at least two possibilities for gravity people
are considering.

1. Gravity is "mediated" by particles: *gravitons*.  Here, all particles
(including gravitons) "move" in a conventional spacetime background.
2. Space (or spacetime) *itself* is composed in some way as a collection of
"particles" ("cells", "tiles", ...). This is the approach of LQG and CDT.
There is no background "space" that things move in anymore in the
conventional sense: just a bunch of *spacicles* and particles interacting.

There could be others of course (e.g. HOPE - Histories of Phenomenally
Everything, ...).

- pt

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### Re: Modal logic, consciousness, and matter

```
> On 18 Feb 2019, at 20:18, Philip Thrift  wrote:
>
> On Monday, February 18, 2019 at 9:14:38 AM UTC-6, Bruno Marchal wrote:
>
> This is the link to the reply in the topic "When Did Consciousness Begin?" As
> I have said before, the modal logic and numerical semantics written there is
> one way to approach the science of experience. But I think ultimately this is
> a logical semantics (not a material semantics), but of course belief in an
> actual numerical reality makes a difference.
>
> Here is something more along those lines:
>
> On modal logic and consciousness:
>
> A Modal Logic for Gödelian Intuition
> Hasen Khudairi
> https://philarchive.org/archive/KHUAML
>
> Towards an Axiomatic Theory of Consciousness
> Jim Cunningham [ https://www.doc.ic.ac.uk/~rjc/ ]
> https://www.doc.ic.ac.uk/~rjc/Cunningham.pdf
>
>
> However I think that there is ultimately a material semantics.

I can imagine a semantic for some theory of matter, but matter itself cannot be
semantical. What would that mean? Even without mechanism, I have no idea what
that could mean.

>
> As for the ancient Greeks, forget Aristotle and look to Epicurus.

I assume mechanism, and I just listen to the universal machine, with machine
taken in the sense of Church and Turing. The notion of matter is not assumed in
such definition, and we know, basically since Gödel, that they exist in
arithmetic (semantically, of course).

>
>
>
> Some "offbeat" materialism I just came across that my be of interest:
>
> Terry Eagleton
> Materialism, Yale University Press
> excerpt 2:
> http://blog.yalebooks.com/2017/02/09/material-theology-and-christian-religion/

Very nice. I would not have dare to suggest that christianism is so much
materialist. I am not sure this was true during the five first hundreds years,
but it is dogmatically so after 529 (closure of Plato’s academy).

>
>
>
> Matter is an aggregation of cuisines whose recipes arise and combine to form
> the cookbook of nature.

No problem with this, on the contrary. A recipe is another name for an
algorithm, which is typically not made of matter, but exist in arithmetic.

And for the cooking, there is no need distinguish primary matter, which cannot
exist with Mechanism, and matter, which obviously exist phenomenologically.

Bruno

>
> - pt
>
> --
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> "Everything List" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> .
> To post to this group, send email to everything-list@googlegroups.com
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### Re: Test 20190218

```
> On 18 Feb 2019, at 23:22, spudboy100 via Everything List
>  wrote:
>

Thanks. Eventually I got the older messages. I don’t understand why they have
taken so long. Machines are mysterious :)

Best,

Bruno

>
>
> -Original Message-
> From: Bruno Marchal
> To: everything-list
> Sent: Mon, Feb 18, 2019 4:10 am
> Subject: Test 20190218
>
> Hi,
>
> This is a test. I did not get my last answers back. I guess some problem with
>
> Sorry, I will try to send them again. I will see on the web google pages.
>
> Bruno
>
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```

### Re: Questions about the Equivalence Principle (EP) and GR

```

On Wednesday, February 20, 2019 at 7:50:51 PM UTC-7, Brent wrote:
>
>
>
> On 2/20/2019 1:23 PM, agrays...@gmail.com  wrote:
>
>
>
> On Wednesday, February 20, 2019 at 12:16:31 PM UTC-7, Brent wrote:
>>
>>
>>
>> On 2/20/2019 8:42 AM, agrays...@gmail.com wrote:
>>
>>
>>
>> On Wednesday, February 20, 2019 at 7:09:10 AM UTC-7, John Clark wrote:
>>>
>>>
>>> >* Newton "explained" *
>>>
>>>
>>> Why did you put explained in quotation marks? If you can predict what
>>> something is going to do then you've explained it, the better the
>>> prediction the better the explanation. I don't know what else the word
>>> could possibly mean. And in science no explanation is perfect, but some are
>>> less wrong than others.
>>>
>>
>> *QM better illustrates the justification for quotes. Many interpretations
>> that make the same predictions. AG *
>>
>>>
>>> *> why a body at "rest" can start moving, via the application of "force"*
>>>
>>>
>>> And Einstein explained that a body moving in a geodesic through 4D
>>> spacetime will take a path that is not a geodesic if a force is applied.
>>> The Earth is moving in a straight line (aka a geodesic) through curved
>>> spacetime; the reason Earth's orbit looks elliptical to us is due to map
>>> distortion, the same reason that in a flat map of the curved surface of the
>>> Earth Greenland looks larger than South America and is almost as large as
>>> Africa. Except that it's even worse, in one we're projecting the 2 D
>>> curved surface of the Earth into the flat 2D surface of the map, but with
>>> Einstein we're projecting a curved 4D volume into a flat 3D volume.
>>>
>>> *> What does "rest" mean in GR *
>>>
>>>
>>> In General Relativity moving in a geodesic is as close as you can get
>>> to the traditional idea of rest, but as long as time passes you're going to
>>> be moving through 4D spacetime.
>>>
>>
>>
>> *If you're at spatial rest in spacetime in the presence of a
>> gravitational source, how does GR explain the subsequent spatial motion? AG
>> *
>>
>>
>> When you were at "spatial rest" you had a force applied to you.  Removing
>> it allowed you to follow a geodesics path through spacetimealso known
>> as "falling".
>>
>> Brent
>>
>>
>
> *So it seems that GR doesn't explain motion; rather, it assumes motion is
> a natural state of things. AG *
>
>
> So called "standing still" is just motion in the time direction only...in
> Newtonian and special relativity as well. Just as there is no absolute
> motion, there's no absolution motionless either...it's called "relativity"
> for a reason.
>
> Brent
>

*Other than gravity, the remaining known forces are moderated, or shall we
say "caused by" particles. Doesn't GR remain an exception; that is,
wouldn't it preclude the existence of a graviton? TIA, AG *

>
>
>
>>> *>  what causes "motion" from that pov?*
>>>
>>>
>>> Force, same as with Newton.
>>>
>>> John K Clark
>>>
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### HoTT: The programing language of space

```
HoTT (Homotopy Type Theory) is re-expressed here as a programming language
to encode mathematics.

[
https://www.researchgate.net/publication/326645835_HoTT_The_Language_of_Space
]

[ https://github.com/groupoid/cafe) github.com/groupoid/cafe ]

Abstract
Homotopy Type Theory (HoTT) is the most advanced programming language in
the domain of intersection of several theories: algebraic topology,
homological algebra, higher category theory, mathematical logic, and
theoretical computer science. That is why it can be considered as a
language of space, as it can encode any existent mathematics.

Speaker: Maxim Sokhatsky is an author of Privat24 deposits, 20 years of
working experience as a programmer, one of the 30 top-commiters in Ukraine
in Open Source, author of N2O, the best Erlang Web Framework, CEO of Synrc
Research Center, author of several embedded operating system runtimes and
production programming languages. Maxim is familiar with any programming
language on the planet and had seen sources of all operating systems.

Now Maxim is doing his Ph.D. research (the second year of education) in
HoTT, trying to encode as much mathematics in the programming language as
possible along the way.

During this lecture, Maxim will try to smoothly guide you from the
programming perspective to the pure space of mathematics and will show the
evolution of mathematical provers from AUTOMATH to the family of Cubical
Type Checkers. Also, this lecture is considered as a general introduction
to HoTT course Maxim is preparing for his friends.

cf. [ http://groupoid.space) groupoid.space ]

- pt

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