# Re: Another stab at the universal present moment - a gedanken..

`On Mon, Jan 6, 2014 at 4:03 PM, Edgar L. Owen <edgaro...@att.net> wrote:`
```
> Jason,
>
> What clock measures your coordinate time? Apparently none. It's beginning
> to sound just like another name for Present time.
>

Hmmm... A Casio?

Does your theory feature some primitive God clock for "present time"? Does
it run on batteries, solar, self-winding? Where does it run?

Is the experience of "shaking hands" proof for its existence?

>
> What's the difference?
>

That's what is being asked of you! And you turn the question around.

This is starting to get circular because the different standard uses of
these terms have been shoved down this thread enough, so turning the
question around doesn't advance anything but circularity. PGC

> Edgar
>
>
>
> On Monday, January 6, 2014 9:47:36 AM UTC-5, Jason wrote:
>>
>>
>>
>> On Jan 6, 2014, at 6:55 AM, "Edgar L. Owen" <edga...@att.net> wrote:
>>
>> Brent,
>>
>> No it's not "an observation that the two twins are together at
>> particular spacetime coordinates" because the spacetime t coordinates are
>> different.
>>
>>
>> Their proper times are different, but not their coordinate times.
>>
>> A clock time is only a representation of how much speed (and accordingly
>> distance) had to be given up to travel through space. It is not an actual
>> coordinate in space time, for that you use coordinate time. All things
>> travel equal distances through space time in equal coordinate times, but
>> not all things travel equal distances through proper time (clock time) in
>> equal coordinate times.  It is when the coordinate times are equal that two
>> things can interact.
>>
>>
>>
>> Since the spacetime t coordinates are different WHEN are they together?
>>
>>
>> Their coordinate times are equal.
>>
>>
>> Certainly not in a simultaneous clock time as proved by their differing
>> clocks.
>>
>>
>> Right, their proper times are different.
>>
>>
>> When are they together Brent? Obviously in a present moment which is a
>> kind of time that clearly is not the same as clock time.
>>
>>
>> They are together when their spatial coordinates: x,y,z and coordinate
>> time t are the same. You are right this t is not the same as proper time.
>>
>> Your conclusion that there must be a global present for this to work is
>>  unneccessary.
>>
>> Jason
>>
>>
>> Edgar
>>
>>
>>
>> On Monday, January 6, 2014 12:18:16 AM UTC-5, Brent wrote:
>>>
>>> On 1/5/2014 12:00 PM, Edgar L. Owen wrote:
>>> > Brent,
>>> >
>>> > No, the present moment is NOT just a "label". It's an empirically
>>> verifiable observation
>>> > (measurement). And not only that both twins agree on that measurement,
>>> namely that they
>>> > have different clock times in the same shared present moment.
>>> >
>>> > There is simply no way around that....
>>> >
>>> > Edgar
>>>
>>> Of course it's an observation.  It's an observation that the two twins
>>> are together at
>>> particular spacetime coordinates.  I have no problem with you calling
>>> that a present
>>> moment (although everyone else calls it an event).  The problem is not
>>> that you can't
>>> define a global time at which they meet, it's that you can't define a
>>> *unique* global
>>> time.  There are infinitely many choices of coordinate time and they
>>> will all agree that
>>> the twins meet at the same coordinate time - but they will not agree as
>>> to which other
>>> distant events in the universe are at the same time as the meeting.
>>>
>>> Brent
>>>
>>  --
>> 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
>> To post to this group, send email to everyth...@googlegroups.com.
>>
>> Visit this group at <http://groups.google.com/group/everything-list>
>> For more options, visit <https://groups.google.com/groups/opt_out>
>>
>>  --
> 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
> To post to this group, send email to everything-list@googlegroups.com.
> Visit this group at http://groups.google.com/group/everything-list.
> For more options, visit https://groups.google.com/groups/opt_out.
>

--
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