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The Shape of the Universe.

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  The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-17 23:36 -0700
    Re: The Shape of the Universe. "Chris M. Thomasson" <invalid_chris_thomasson@invalid.invalid> - 2018-04-18 00:12 -0700
      Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-18 00:42 -0700
        Re: The Shape of the Universe. Daniel60 <daniel47@eternal-september.org> - 2018-04-18 22:26 +1000
          Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-18 17:02 -0700
    Re: The Shape of the Universe. SolomonW <SolomonW@citi.com> - 2018-04-18 17:33 +1000
      Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-18 10:27 -0700
        Re: The Shape of the Universe. SolomonW <SolomonW@citi.com> - 2018-04-19 12:19 +1000
          Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-19 23:51 -0700
            Re: The Shape of the Universe. SolomonW <SolomonW@citi.com> - 2018-04-21 22:02 +1000
              Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-21 09:25 -0700
                Re: The Shape of the Universe. SolomonW <SolomonW@citi.com> - 2018-04-22 16:23 +1000
                  Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-22 13:48 -0700
                    Re: The Shape of the Universe. SolomonW <SoloomonW@citi.com.au> - 2018-04-23 10:35 +1000
                      Re: The Shape of the Universe. "reber G=emc^2" <herbertglazier0@gmail.com> - 2018-04-22 17:55 -0700
                        Re: The Shape of the Universe. "hanson" <hanson@quick.net> - 2018-04-22 18:29 -0700
                      Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-22 21:13 -0700
                        Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-22 23:23 -0700
                          Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-22 23:31 -0700
                        Re: The Shape of the Universe. SolomonW <SolomonW@citi.com> - 2018-04-23 20:04 +1000
    Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-18 10:18 -0700
    Re: The Shape of the Universe. benj <benj@nobody.net> - 2018-04-18 13:33 -0400
      Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-19 23:53 -0700
    Re: The Shape of the Universe. casagiannoni@optonline.net - 2018-04-20 07:38 -0400
      Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-20 10:07 -0700
    Re: The Shape of the Universe. "reber G=emc^2" <herbertglazier0@gmail.com> - 2018-04-21 19:33 -0700
      Re: The Shape of the Universe. "hanson" <hanson@quick.net> - 2018-04-21 20:40 -0700
    Re: The Shape of the Universe. mitchrae3323@gmail.com - 2018-04-22 20:21 -0700
    Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-23 10:31 -0500
      Re: The Shape of the Universe. Double-A <double-a3@hush.com> - 2018-04-23 14:16 -0700
      Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-23 22:50 -0700
      Re: The Shape of the Universe. Daniel60 <daniel47@eternal-september.org> - 2018-04-24 20:48 +1000
        Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-24 08:49 -0700
        Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-24 08:50 -0700
        Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-24 23:21 -0500
          Re: The Shape of the Universe. Daniel60 <daniel47@eternal-september.org> - 2018-04-25 20:25 +1000
        Re: The Shape of the Universe. Klaus Meinhard <k_meinhard@gmx.de> - 2018-04-25 08:53 +0200
          Re: The Shape of the Universe. Daniel60 <daniel47@eternal-september.org> - 2018-04-25 20:28 +1000
          Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-25 10:42 -0500
            Re: The Shape of the Universe. "hanson" <hanson@quick.net> - 2018-04-25 13:33 -0700
              Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-25 22:53 -0500
                Re: The Shape of the Universe. "hanson" <hanson@quick.net> - 2018-04-26 00:00 -0700
                Re: The Shape of the Universe. Erin Koff <umhn@cniwwe.im> - 2018-04-27 21:18 +0000
                  Gravity is the "memory" of where the stuff was. Jeff-Relf.Me  @. - 2018-04-27 14:36 -0700
                    Re: Gravity is the "memory" of where the stuff was. Erin Koff <umhn@cniwwe.im> - 2018-04-27 21:44 +0000
                      You're a consumer. Jeff-Relf.Me  @. - 2018-04-27 14:52 -0700
                        Re: You're a consumer. benj <benj@nobody.net> - 2018-04-27 19:07 -0400
                    Re: Gravity is the "memory" of where the stuff was. Double-A <double-a3@hush.com> - 2018-04-27 15:54 -0700
                      Toss a rock up, and it "remembers" to come down. Jeff-Relf.Me  @. - 2018-04-27 16:23 -0700
                        Re: Toss a rock up, and it "remembers" to come down. Double-A <double-a3@hush.com> - 2018-04-28 15:09 -0700
                    Re: Gravity is the "memory" of where the stuff was. benj <benj@nobody.net> - 2018-04-27 19:05 -0400
                    Re: Gravity is the "memory" of where the stuff was. Sergio <invalid@invalid.com> - 2018-05-02 15:47 -0500
                      Gravity is SpaceTime, the 4D TimeScape; it's everywhere, always. Jeff-Relf.Me  @. - 2018-05-02 14:30 -0700
                        Re: Gravity is SpaceTime, the 4D TimeScape; it's everywhere, always. moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-05-03 06:53 +0000
                          Where/When is there no Energy/Matter ? Jeff-Relf.Me  @. - 2018-05-03 01:11 -0700
                  Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-27 16:38 -0500
                    Re: The Shape of the Universe. Erin Koff <umhn@cniwwe.im> - 2018-04-27 21:53 +0000
                    Re: The Shape of the Universe. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-29 03:27 +0200
                Re: The Shape of the Universe. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-29 03:06 +0200
              Re: The Shape of the Universe. Daniel60 <daniel47@eternal-september.org> - 2018-04-26 19:44 +1000
                Re: The Shape of the Universe. "hanson" <hanson@quick.net> - 2018-04-26 08:18 -0700
                  Re: The Shape of the Universe. Daniel60 <daniel47@eternal-september.org> - 2018-04-28 00:16 +1000
                    Re: The Shape of the Universe. "hanson" <hanson@quick.net> - 2018-04-27 07:46 -0700
                Re: The Shape of the Universe. Erin Koff <umhn@cniwwe.im> - 2018-04-28 11:52 +0000
                  Re: The Shape of the Universe. benj <benj@nobody.net> - 2018-04-28 14:23 -0400
                    Re: The Shape of the Universe. Erin Koff <umhn@cniwwe.im> - 2018-05-01 11:07 +0000
              Re: The Shape of the Universe. Lofty Goat <rlwatkins@gmail.com> - 2018-04-28 12:33 -0500
                Re: The Shape of the Universe. benj <benj@nobody.net> - 2018-04-28 14:34 -0400
                  Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-28 22:33 -0500
                    Re: The Shape of the Universe. benj <benj@nobody.net> - 2018-04-29 03:17 -0400
                    Re: The Shape of the Universe. "Sea Wasp (Ryk E. Spoor)" <seawasp@sgeinc.invalid.com> - 2018-04-29 09:21 -0400
                      Re: The Shape of the Universe. "hanson" <hanson@quick.net> - 2018-04-29 07:26 -0700
                Re: The Shape of the Universe. "hanson" <hanson@quick.net> - 2018-04-28 11:44 -0700
            Re: The Shape of the Universe. Klaus Meinhard <k_meinhard@gmx.de> - 2018-04-27 09:47 +0200
              Re: The Shape of the Universe. Helmut Wabnig <hwabnig@.- --- -.dotat> - 2018-04-27 21:39 +0200
          Re: The Shape of the Universe. "Chris M. Thomasson" <invalid_chris_thomasson@invalid.invalid> - 2018-04-25 15:33 -0700
    Re: The Shape of the Universe. jasinski.ryszard.21@gmail.com - 2018-04-26 01:24 -0700
    The Shape of the Universe. swormley1@gmail.com - 2018-04-27 16:39 -0700
      Re: The Shape of the Universe. benj <benj@nobody.net> - 2018-04-27 20:46 -0400

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#682398

On 4/25/18 3:33 PM, hanson wrote:
> So, if "space is expanding" what is space expanding into?

There is nothing (no thing) into which space is expanding. This is an 
expansion of the entire universe, so there can be nothing outside of it.

> Has anybody ever observed, measured and recorded the
> "thing" that our 3D space is embedding in?

The question makes no sense, as nothing (no thing) cannot be measured or 
recorded.

> Modeling nature is just palavering about observations.

No. In physics it is generalizing and abstracting from measurements to a 
more general set of mathematical relationships among appropriate quantities.

> Modeling is not physics. Modeling is Philosophy!

Not at all! Science is the process of formulating models of the world we 
inhabit, testing them via experiment, and improving them successively to 
be more accurate and/or cover a wider domain of applicability.

Tom Roberts

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#682411

"Tom Roberts" <tjroberts137@sbcglobal.net> wrote:
>
hanson wrote:
>> So, if "space is expanding" what is space expanding into?
>
Tom Roberts wrote:
> There is nothing (no thing) into which space is expanding. This is an 
> expansion of the entire universe, so there can be nothing outside of it.
>
hanson wrote:
So, what is your entire universe expanding into?
What is that non-existent "outside" that your are referring to?
>
hanson earlier wrote:
>> Has anybody ever observed, measured and recorded the
>> "thing" that our 3D space is embedding in?
>
Tom Roberts wrote:
> The question makes no sense, as nothing (no thing) cannot be measured or 
> recorded.
>
hanson wrote:
So, if "nothing (no thing) cannot be measured recorded"
then why do you assert that the Universe expands?

hanson earlier wrote:
> Modeling nature is just palavering about observations.
>
Tom Roberts wrote:
> No. In physics it is generalizing and abstracting from measurements to a 
> more general set of mathematical relationships among appropriate 
> quantities.
>
hanson wrote:
Roberts, your 2-liner is NOT physics. It is philosophical
palaver about "generalizing and abstracting your nothing"

hanson earlier wrote:
>> Modeling is not physics. Modeling is Philosophy!
>
Tom Roberts wrote:
> Not at all! Science is the process of formulating models of the world we 
> inhabit, testing them via experiment, and improving them successively to 
> be more accurate and/or cover a wider domain of applicability.
>
hanson wrote:
Yes, it is the "Science of philosophy" about the Universe
that you just modeled, which gave raise to the
<http://tinyurl.com/Tears-for-Einsteins-Misery> [1].

You, Roberts, are mentionned in one of the links
in [1] wherein you sang a very different tune then
you presented above.
>
<snicker>...<chortle>...ahahahAHAHA...ROTFLMAO 

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#682643

Tom Roberts wrote:

> On 4/25/18 3:33 PM, hanson wrote:
>> So, if "space is expanding" what is space expanding into?
> 
> There is nothing (no thing) into which space is expanding. This is an
> expansion of the entire universe, so there can be nothing outside of it.

I can't believe what I'm reading here, on this platform, in this forum. It 
has to be another paradox. Your "nothing" stands for the ABSENCE of time 
and space. You can't expand anything along that.

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#682647 — Gravity is the "memory" of where the stuff was.

> > There is nothing (no thing) into which space is expanding. This is an
> > expansion of the entire universe, so there can be nothing outside of it.
> 
> I can't believe what I'm reading here, on this platform, in this forum.
> It has to be another paradox.  Your "nothing" stands for 
> the ABSENCE of time and space.  You can't expand anything along that.

13.8 billion years ago, everything in the (subjectively) Known Universe
was in the same location; i.e. zero entropy and infinite density/exergy.
[ eXergy is a type of energy that can do physical work, force * distance ]

Eventually, this eXergy will be consumed away, replaced with entropy;
leaving us with a uniform heat bath that has all of the energy
but none of the eXergy.

Gravity is the "memory" of where the stuff was.

All of history, every lesson ever, every advance, tells us:
  Randomness is ignorance, nothing more.

General Relativity's four dimensional TimeScape is static, eternal, 
perfectly causal... it is, at once, everything _and_ nothing.

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#682652 — Re: Gravity is the "memory" of where the stuff was.

Jeff-Relf.Me wrote:

>> > There is nothing (no thing) into which space is expanding. This is an
>> > expansion of the entire universe, so there can be nothing outside of
>> > it.
>> 
>> I can't believe what I'm reading here, on this platform, in this forum.
>> It has to be another paradox.  Your "nothing" stands for the ABSENCE of
>> time and space.  You can't expand anything along that.
> 
> 13.8 billion years ago, everything in the (subjectively) Known Universe
> was in the same location; i.e. zero entropy and infinite density/exergy.[
> eXergy is a type of energy that can do physical work, force * distance ]
> Eventually, this eXergy will be consumed away, replaced with entropy;
> leaving us with a uniform heat bath that has all of the energy but none
> of the eXergy. Gravity is the "memory" of where the stuff was.
> All of history, every lesson ever, every advance, tells us:
>   Randomness is ignorance, nothing more.
> General Relativity's four dimensional TimeScape is static, eternal,
> perfectly causal... it is, at once, everything _and_ nothing.

Thanks. What to do next?

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#682655 — You're a consumer.

> > Eventually, this eXergy will be consumed away, replaced with entropy;
> > leaving us with a uniform heat bath that has all of the energy but
> > none of the eXergy.  Gravity is the "memory" of where the stuff was.
> 
> Thanks.  What to do next?

You're a consumer.
The only difference between you can sun is what you consume. when and how.

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#682681 — Re: You're a consumer.

On 4/27/2018 5:52 PM, Jeff-Relf.Me@. wrote:
>>> Eventually, this eXergy will be consumed away, replaced with entropy;
>>> leaving us with a uniform heat bath that has all of the energy but
>>> none of the eXergy.  Gravity is the "memory" of where the stuff was.
>>
>> Thanks.  What to do next?
> 
> You're a consumer.
> The only difference between you can sun is what you consume. when and how.
> 
The ONLY difference? Um, Rolf I can think of a few more differences 
between me and the sun. You are STILL an idiot!

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#682679 — Re: Gravity is the "memory" of where the stuff was.

On Friday, April 27, 2018 at 2:36:50 PM UTC-7, Jeff-Relf.Me wrote:
> > > There is nothing (no thing) into which space is expanding. This is an
> > > expansion of the entire universe, so there can be nothing outside of it.
> > 
> > I can't believe what I'm reading here, on this platform, in this forum.
> > It has to be another paradox.  Your "nothing" stands for 
> > the ABSENCE of time and space.  You can't expand anything along that.
> 
> 13.8 billion years ago, everything in the (subjectively) Known Universe
> was in the same location; i.e. zero entropy and infinite density/exergy.
> [ eXergy is a type of energy that can do physical work, force * distance ]
> 
> Eventually, this eXergy will be consumed away, replaced with entropy;
> leaving us with a uniform heat bath that has all of the energy
> but none of the eXergy.
> 
> Gravity is the "memory" of where the stuff was.
> 
> All of history, every lesson ever, every advance, tells us:
>   Randomness is ignorance, nothing more.
> 
> General Relativity's four dimensional TimeScape is static, eternal, 
> perfectly causal... it is, at once, everything _and_ nothing.


The universe has no memory.

Double-A

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#682685 — Toss a rock up, and it "remembers" to come down.

MrAA replied ( to me ):
> > Gravity is the "memory" of where the stuff was.
> 
> The universe has no memory.

Figuratively speaking, 
toss a rock up, and it "remembers" to come down.

You think gravity is a sucking force, like a vacuum cleaner, no ?

> > We're consumers.  The only difference between us and the sun
> > is what we consume, when and how.

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#682804 — Re: Toss a rock up, and it "remembers" to come down.

On Friday, April 27, 2018 at 4:23:53 PM UTC-7, Jeff-Relf.Me wrote:
> MrAA replied ( to me ):
> > > Gravity is the "memory" of where the stuff was.
> > 
> > The universe has no memory.
> 
> Figuratively speaking, 
> toss a rock up, and it "remembers" to come down.
> 
> You think gravity is a sucking force, like a vacuum cleaner, no ?


I go with the flow, Jeff.

Double-A

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#682680 — Re: Gravity is the "memory" of where the stuff was.

On 4/27/2018 5:36 PM, Jeff-Relf.Me@. wrote:
>>> There is nothing (no thing) into which space is expanding. This is an
>>> expansion of the entire universe, so there can be nothing outside of it.
>>
>> I can't believe what I'm reading here, on this platform, in this forum.
>> It has to be another paradox.  Your "nothing" stands for
>> the ABSENCE of time and space.  You can't expand anything along that.
> 
> 13.8 billion years ago, everything in the (subjectively) Known Universe
> was in the same location; i.e. zero entropy and infinite density/exergy.
> [ eXergy is a type of energy that can do physical work, force * distance ]
> 
> Eventually, this eXergy will be consumed away, replaced with entropy;
> leaving us with a uniform heat bath that has all of the energy
> but none of the eXergy.
> 
> Gravity is the "memory" of where the stuff was.
> 
> All of history, every lesson ever, every advance, tells us:
>    Randomness is ignorance, nothing more.

Rolf, there is no doubt that you are VERY random!

> General Relativity's four dimensional TimeScape is static, eternal,
> perfectly causal... it is, at once, everything _and_ nothing.
> 

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#683387 — Re: Gravity is the "memory" of where the stuff was.

On 4/27/2018 4:36 PM, Jeff-Relf.Me@. wrote:
>>> There is nothing (no thing) into which space is expanding. This is an
>>> expansion of the entire universe, so there can be nothing outside of it.
>>
>> I can't believe what I'm reading here, on this platform, in this forum.
>> It has to be another paradox.  Your "nothing" stands for 
>> the ABSENCE of time and space.  You can't expand anything along that.
> 
> 13.8 billion years ago, everything in the (subjectively) Known Universe
> was in the same location; i.e. zero entropy and infinite density/exergy.
> [ eXergy is a type of energy that can do physical work, force * distance ]
> 
> Eventually, this eXergy will be consumed away, replaced with entropy;
> leaving us with a uniform heat bath that has all of the energy
> but none of the eXergy.
> 
> Gravity is the "memory" of where the stuff was.

so, where there is no gravity,
there is no memory where stuff is,
it is Lost in Space.

> 
> All of history, every lesson ever, every advance, tells us:
>   Randomness is ignorance, nothing more.

randomness is a human concept, only humans decide what is random.

> 
> General Relativity's four dimensional TimeScape is static, eternal, 
> perfectly causal... it is, at once, everything _and_ nothing.
> 

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#683405 — Gravity is SpaceTime, the 4D TimeScape; it's everywhere, always.

> > 13.8 billion years ago, everything in the (subjectively) Known Universe
> > was in the same location; i.e. zero entropy and infinite density/exergy.
> > [ eXergy is a type of energy that can do physical work, force * distance ]
> > 
> > Eventually, this eXergy will be consumed away, replaced with entropy;
> > leaving us with a uniform heat bath that has all of the energy
> > but none of the eXergy.
> > 
> > Gravity is the "memory" of where the stuff was.
> 
> so, where there is no gravity,
> there is no memory where stuff is; it's Lost in Space.

Gravity is SpaceTime, the 4D TimeScape; it's everywhere, always.

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#683466 — Re: Gravity is SpaceTime, the 4D TimeScape; it's everywhere, always.

Jeff-Relf.Me  @. writes:

<snip exergy obsession>

>Gravity is SpaceTime, the 4D TimeScape; it's everywhere, always.

Wrong. Gravity is the curvature of spacetime, caused by mass-energy
present.

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#683468 — Where/When is there no Energy/Matter ?

> > Gravity is SpaceTime, the 4D TimeScape; it's everywhere, always.
> 
> Wrong.  Gravity is the curvature of spacetime, 
> caused by mass-energy present.

Where/When is there no Energy/Matter ?

Einstein wrote:

  Time and space and gravitation have no separate existence from matter.

13.8 billion years ago, everything in the (subjectively) Known Universe
was in the same location; i.e. zero entropy and infinite density/exergy.

Eventually, this eXergy will be consumed away, replaced with entropy;
leaving us with a uniform heat bath that has all of the energy
but none of the eXergy.

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#682649

On 4/27/18 4:18 PM, Erin Koff wrote:
> Tom Roberts wrote:
>> On 4/25/18 3:33 PM, hanson wrote:
>>> So, if "space is expanding" what is space expanding into?
>> There is nothing (no thing) into which space is expanding. This is an
>> expansion of the entire universe, so there can be nothing outside of it.
> 
> Your "nothing" stands for the ABSENCE of time
> and space. You can't expand anything along that.

In our current cosmological models, space is NOT "expanding into nothing", it is 
just expanding. There is no "into" or "along", just expansion -- an intrinsic 
increase in size.

This is different from any ordinary expansion. When you blow up a balloon, it 
clearly expands into the surrounding air. Geometrically, the balloon is embedded 
in the 3-d space containing the air and balloon. But the geometry of the 
universe is QUITE different -- it is not embedded in anything (any manifold).

	Please note I am discussing our MODELS. But, of course, models
	are all we can discuss....

Tom Roberts

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#682656

Tom Roberts wrote:

> On 4/27/18 4:18 PM, Erin Koff wrote:
>> Tom Roberts wrote:
>>> On 4/25/18 3:33 PM, hanson wrote:
>>>> So, if "space is expanding" what is space expanding into?
>>> There is nothing (no thing) into which space is expanding. This is an
>>> expansion of the entire universe, so there can be nothing outside of
>>> it.
>> 
>> Your "nothing" stands for the ABSENCE of time and space. You can't
>> expand anything along that.
> 
> In our current cosmological models, space is NOT "expanding into
> nothing", it is just expanding. There is no "into" or "along", just
> expansion -- an intrinsic increase in size.
> This is different from any ordinary expansion. When you blow up a
> balloon, it clearly expands into the surrounding air. Geometrically, the
> balloon is embedded in the 3-d space containing the air and balloon. But
> the geometry of the universe is QUITE different -- it is not embedded in
> anything (any manifold).Please note I am discussing our MODELS. But, of
> course, models are all we can discuss....

eXACTLY, the absence of geometry "outside" this universe is absurd. Hence 
a paradox.

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#682831

Tom Roberts wrote:

> On 4/27/18 4:18 PM, Erin Koff wrote:
>> Tom Roberts wrote:
>>> On 4/25/18 3:33 PM, hanson wrote:
>>>> So, if "space is expanding" what is space expanding into?
>>> There is nothing (no thing) into which space is expanding. This is an
>>> expansion of the entire universe, so there can be nothing outside of it.
>> Your "nothing" stands for the ABSENCE of time
>> and space. You can't expand anything along that.
> 
> In our current cosmological models, space is NOT "expanding into nothing",
> it is just expanding.

Correct.

> There is no "into" or "along", […]

Incorrect.  Our current cosmological models *include* the possibility of a 
multiverse.  See my other follow-up for details.


PointedEars
-- 
“Science is empirical: knowing the answer means nothing;
 testing your knowledge means everything.”
   —Dr. Lawrence M. Krauss, theoretical physicist,
    in “A Universe from Nothing” (2009)

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#682829

Tom Roberts wrote:

> On 4/25/18 3:33 PM, hanson wrote:
>> So, if "space is expanding" what is space expanding into?
> 
> There is nothing (no thing) into which space is expanding. This is an
> expansion of the entire universe, so there can be nothing outside of it.

Not true, because there might not be only “*the* universe”.

*Our* universe could be part of, and expanding into, a multiverse, where 
there are other universes; but while there are theories that predict this 
(WMAP/ “Planck”-supported inflation theory being one of them), there is no 
experiment yet that confirmed it.

One difficulty of an experiment is that those other universes would be 
moving away from ours faster than the speed of light (Lawrence Krauss at 
AAI, 2009 [1]):

<https://youtu.be/7ImvlS8PLIo?t=3454>

However, *if* there is a multiverse, then we must assume that *it* is not 
expanding into anything.

See also: <https://en.wikipedia.org/wiki/Multiverse>

(the “Proponents and Skeptics” section features remarkable lists for both 
categories)


F’up2 sci.physics.relativity

PointedEars
-- 
Q: What did the female magnet say to the male magnet?  
A: From the back, I found you repulsive, but from the front
   I find myself very attracted to you.
(from: WolframAlpha)

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#682413

hanson wrote on 26/04/18 06:33:
> "Tom Roberts" <tjroberts137@sbcglobal.net> wrote:
> "Daniel60" <daniel47@eternal-september.org> wrote:
>>>> And, of course, the Universe is expanding ... in all directions  
>>>> three dimensions!!
> "Klaus Meinhard" <k_meinhard@gmx.de> wrote
>>> ahem - 4?
>>
> "Tom Roberts" wrote:
>> No. At least not in the usual modeling of the world as a 4-d 
>> Lorentzian manifold. In such a model, we analysts are outside the 
>> model [#], and we can (necessarily) examine the model at any time or 
>> place (where those words refer to time and place in the model, not our 
>> analysts' world). So over analysts' time the model is fixed (i.e. not 
>> 'expanding').
>>
>> [#] Even if we are modeling the universe we inhabit. We humans
>> cannot possibly be part of the model, but we are part of the
>> universe.
>>
>> This is the origin of the MISLEADING and PUNFUL claim "nothing moves 
>> in spacetime". That phrase conflates time in the model to time to us 
>> analysts. Yes, as analysts' time advances the model does not change 
>> (or 'move'). But for objects in the universe being modeled, motion 
>> certainly is possible.
>>
>> Back to the original issue: to us in the universe, space is expanding 
>> over time. But it makes no sense to claim "time is expanding", so our 
>> universe is expanding in 3 dimensions, not 4.
>>
> So, if "space is expanding" what is space expanding into?
> Has anybody ever observed, measured and recorded the
> "thing" that our 3D space is embedding in?
> Modeling nature is just palavering about observations.
> Modeling is not physics. Modeling is Philosophy!
> 
When you blow up a balloon, does the inside of the balloon know what it 
is expanding into??

-- 
Daniel

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