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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. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-18 05:34 -0700
          Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-18 17:02 -0700
            Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-18 17:08 -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. 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. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-20 11:56 -0700
        Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-18 20:17 -0700
    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. mitchrae3323@gmail.com - 2018-04-18 12:26 -0700
      Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-18 12:30 -0700
        Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-18 12:39 -0700
      Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-18 12:37 -0700
    Re: The Shape of the Universe. casagiannoni@optonline.net - 2018-04-20 07:38 -0400
      Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-20 07:52 -0700
      Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-20 10:07 -0700
        Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-20 10:40 -0700
          Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-20 10:43 -0700
            Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-20 10:50 -0700
              Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-20 11:20 -0700
                Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-22 17:40 -0700
              Re: The Shape of the Universe. The Starmaker <starmaker@ix.netcom.com> - 2018-04-20 23:49 -0700
    Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-23 10:31 -0500
      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. Adam Stefaniak <adam.stefaniak@hotmail.co.uk> - 2018-04-24 04:51 -0700
          Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-24 23:44 -0500
            Re: The Shape of the Universe. mlwozniak@wp.pl - 2018-04-25 00:17 -0700
            Re: The Shape of the Universe. Erálnì Histickému <no@ovmwk.gn> - 2018-04-25 09:48 +0000
            Re: The Shape of the Universe. Adam Stefaniak <adam.stefaniak@hotmail.co.uk> - 2018-04-25 04:46 -0700
        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. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-25 14:05 -0700
                Re: The Shape of the Universe. Odd Bodkin <bodkinodd@gmail.com> - 2018-04-25 21:45 +0000
                  Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-25 15:11 -0700
                    Re: The Shape of the Universe. Odd Bodkin <bodkinodd@gmail.com> - 2018-04-25 22:25 +0000
                      Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-25 15:43 -0700
                        Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-25 15:46 -0700
                          Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-25 16:05 -0700
                            Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-25 16:57 -0700
                              Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-25 17:22 -0700
                                Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-25 17:24 -0700
                            Re: The Shape of the Universe. Odd Bodkin <bodkinodd@gmail.com> - 2018-04-26 13:01 +0000
                              Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-26 06:39 -0700
                                Re: The Shape of the Universe. Odd Bodkin <bodkinodd@gmail.com> - 2018-04-26 14:29 +0000
                                  Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-26 07:58 -0700
                                    Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-26 08:16 -0700
                                    Re: The Shape of the Universe. Odd Bodkin <bodkinodd@gmail.com> - 2018-04-26 16:08 +0000
                                      Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-26 10:38 -0700
                                        Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-26 11:01 -0700
                              Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-26 06:40 -0700
                                Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-26 07:12 -0700
              Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-25 22:53 -0500
                Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-25 21:13 -0700
                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. benj <benj@nobody.net> - 2018-04-27 19:05 -0400
                    Toss a rock up, and it "remembers" to come down. Jeff-Relf.Me  @. - 2018-04-27 16:23 -0700
                    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: Where/When is there no Energy/Matter ? moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-05-03 16:53 +0000
                              Re: Where/When is there no Energy/Matter ? benj <benj@nobody.net> - 2018-05-04 11:38 -0400
                                Re: Where/When is there no Energy/Matter ? Tom Roberts <tjroberts137@sbcglobal.net> - 2018-05-04 09:07 -0700
                                  Re: Where/When is there no Energy/Matter ? Otto Wahl <tlow@wtiwor.oc> - 2018-05-04 17:53 +0000
                                    Re: Where/When is there no Energy/Matter ? Edward Prochak <edprochak@gmail.com> - 2018-05-04 19:06 -0700
                                      Re: Where/When is there no Energy/Matter ? Otto Wahl <tlow@wtiwor.oc> - 2018-05-05 11:22 +0000
                  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. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-27 15:01 -0700
                      Re: The Shape of the Universe. mitchrae3323@gmail.com - 2018-04-28 11:31 -0700
                        Re: The Shape of the Universe. Erin Koff <umhn@cniwwe.im> - 2018-05-01 11:10 +0000
                    Re: The Shape of the Universe. mlwozniak@wp.pl - 2018-04-27 21:41 -0700
                    Re: The Shape of the Universe. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-29 03:27 +0200
                      Re: The Shape of the Universe. benj <benj@nobody.net> - 2018-04-28 22:51 -0400
                Re: The Shape of the Universe. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-29 03:06 +0200
                  Re: The Shape of the Universe. mlwozniak@wp.pl - 2018-04-28 22:30 -0700
                  Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-30 09:31 -0500
                    Re: The Shape of the Universe. Erin Koff <umhn@cniwwe.im> - 2018-04-30 16:23 +0000
                      Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-30 09:25 -0700
                    Re: The Shape of the Universe. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-05-01 01:27 +0100
                      Re: The Shape of the Universe. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-05-01 13:12 -0700
                        Re: The Shape of the Universe. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-05-24 21:01 +0200
                          Re: The Shape of the Universe. Oslovné Ritmickeho <uiq@oichewo.th> - 2018-05-24 19:35 +0000
                            Re: The Shape of the Universe. mitchrae3323@gmail.com - 2018-05-24 19:04 -0700
                              Re: The Shape of the Universe. Oslovné Ritmickeho <uiq@oichewo.th> - 2018-05-25 08:43 +0000
              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. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-28 12:00 -0700
                      Re: The Shape of the Universe. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-28 12:01 -0700
                    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. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-28 10:55 -0700
                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. mlwozniak@wp.pl - 2018-04-28 22:33 -0700
                    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. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-27 13:25 -0700
          Re: The Shape of the Universe. "Chris M. Thomasson" <invalid_chris_thomasson@invalid.invalid> - 2018-04-25 15:33 -0700

Page 3 of 7 — ← Prev page 1 2 [3] 4 5 6 7  Next page →

#456796

Tom Roberts wrote on 24/04/18 01:31:
> [I rarely read your posts or reply to you because it seems that all you 
> do is post nonsense. But I happened to see this one, and noticed that 
> your usual nonsense 'just happens' to be correct, in a way that is worth 
> responding to as it may surprise some readers.]
> 
> On 4/18/18 1:36 AM, The Starmaker wrote:
>> the universe is both flat and curved.
> 
> Yes, this is so, in a way you clearly do not realize or understand. This 
> happens because you speak so loosely, without specifying what you mean 
> by "the universe" -- that ambiguity can sensibly be interpreted two 
> ways, which makes this seemingly silly statement actually be correct.
> 
> In our current best cosmological models, spaceTIME is curved, but space 
> is flat.
> 
>      [I won't bore you with the details, as you clearly don't care,
>       and won't understand anyway.]
> 
> Tom Roberts

How can space possibly be "flat"??

Seems to me, here on Earth, I can go North-South, and I can go East-West 
and I can go Up-Down ... three dimensions!!

In the Milky Way Galaxy, one day I might be able to go directly towards 
the Galaxy Centre, or follow our spiral arm, or go up, out of the 
Galactic disk .... three dimensions!!

And other Galaxies aren't all in the same plane ... three dimensions!!

And, of course, the Universe is expanding ... in all directions ... 
three dimensions!!
-- 
Daniel

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#456801

@Daniel60

> How can space possibly be "flat"??
> 
> Seems to me, here on Earth, I can go North-South, and I can go East-West 
> and I can go Up-Down ... three dimensions!!


The statements about curvature (or lack thereof) of the universe have a specific meaning. They're statements about topology, not about the number of dimensions. Furthermore, they are limited to intrinsic curvature.

Space is flat if parallel lines drawn in it neither converge nor diverge. They stay parallel forever. Equivalently, internal angles of triangles drawn in such a space add up to 180 degrees.

So, a 2-dimensional plane is flat, but a 2-dimensional surface of a sphere is positivelly curved (parallel lines drawn e.g. at the equator will meet at the poles; triangles have more than 180 degrees of internal angles).
A 2-dimensional hyperbolic space (looks like a saddle, or a Pringles crisp, when embedded in 3 dimensions) is negativelly curved. Parallel lines will diverge, and triangles have less than 180 degrees.

But, for example, a cylyndrical space (the surface of an infinitely long cylinder) is also intrinsically flat, even though when we embed it in 3D our intuition would want to call it curved.
And yet, parallel lines stay parallel, and triangles keep having 180 degrees.
Some hypothetical 2-dimensional creatures living on the cylinder's surface could not discern it from a flat sheet - unless they travelled far enough to return to where they came from (or made equivalent observations).

In none of those cases is the embedding in the higher dimension necessary. It's just a tool to help us intuitivelly visualise what's going on. The space is fully described as curved or flat without the need to invoke higher dimensions.


Curvature of the universe is analogous. Only now we don't have the luxury of visualising embedding it in a higher dimension (our minds work with 3D). Still, the relationships stay the same.
You can measure whether triangles in the 3D universe add up to 180 degrees to determine its intrinsic spatial curvature.

Since any curvature will approximate to flatness if looked at from close enough (we don't have perfect instruments) the triangles must be large. The larger the better. So what is looked at in practice, is the scale of acoustic oscillations in the cosmic microwave background. The expected scale can be calculated, and then compared with observations.
So far, looks indistinguishable from flat.

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#456891

On 4/24/18 6:51 AM, Adam Stefaniak wrote:
> The statements about curvature (or lack thereof) of the universe have
> a specific meaning. They're statements about topology, not about the
> number of dimensions. Furthermore, they are limited to intrinsic
> curvature.

Close, but not quite. Curvature applies to geometry, not topology. 
Topology is a lower level of structure than geometry. Topology only 
defines which points of the manifold are "near" to each other, i.e. what 
"continuous" means. In particular, topology has no concept of distance, 
while distance is the essence of geometry.

> Space is flat if parallel lines drawn in it neither converge nor
> diverge. They stay parallel forever. Equivalently, internal angles of
> triangles drawn in such a space add up to 180 degrees.

This is true for Euclidean spaces, but not necessarily for all flat 
spaces [#]. The difficult is that these are non-local descriptions, 
while curvature is inherently local -- it applies separately to each 
point, in a neighborhood of the point in question.

	[#] Some non-orientable spaces can have no pair of lines
	that never intersect, and still be flat. This is a case
	where an unusual topology makes your non-local criteria
	invalid.

> But, for example, a cylyndrical space (the surface of an infinitely
> long cylinder) is also intrinsically flat, even though when we embed
> it in 3D our intuition would want to call it curved. And yet,
> parallel lines stay parallel, and triangles keep having 180 degrees. 
> Some hypothetical 2-dimensional creatures living on the cylinder's
> surface could not discern it from a flat sheet - unless they
> travelled far enough to return to where they came from (or made
> equivalent observations).

A cylinder differs from a plane in TOPOLOGY, not geometry. But every 
manifold must have a topology and geometry that are consistent with each 
other; for flat geometry the choice of topology is limited.

	Indeed for most if not all geometries the topological
	choices are limited.

> [... further discussion that is basically correct]

Tom Roberts

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#456902

On Wednesday, 25 April 2018 06:44:44 UTC+2, tjrob137  wrote:

> This is true for Euclidean spaces, but not necessarily for all flat 
> spaces [#].

Samely, we can assume that 2+2 is equal 4 only when mrucving of
mimayka isn't involved. Common sense would say it's stupid, but
who cares about common sense.

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#456903

Tom Roberts wrote:

> On 4/24/18 6:51 AM, Adam Stefaniak wrote:
>> The statements about curvature (or lack thereof) of the universe have a
>> specific meaning. They're statements about topology, not about the
>> number of dimensions. Furthermore, they are limited to intrinsic
>> curvature.
> 
> Close, but not quite. Curvature applies to geometry, not topology.
> Topology is a lower level of structure than geometry. Topology only
> defines which points of the manifold are "near" to each other, i.e. what
> "continuous" means. In particular, topology has no concept of distance,
> while distance is the essence of geometry.

I disproof your "geometry" approach in a few seconds. An earth radius 
rigid empty sphere will match an exactly 1g, normal negative oriented at 
the of surface. I can't prove that it does, hence your geometry arguments 
for the "curvature" of timespace falls down precipice.

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#456908

@tjrob137

Thanks for the corrections!

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#456816

Daniel60 wrote:
> 
> Tom Roberts wrote on 24/04/18 01:31:
> > [I rarely read your posts or reply to you because it seems that all you
> > do is post nonsense. But I happened to see this one, and noticed that
> > your usual nonsense 'just happens' to be correct, in a way that is worth
> > responding to as it may surprise some readers.]
> >
> > On 4/18/18 1:36 AM, The Starmaker wrote:
> >> the universe is both flat and curved.
> >
> > Yes, this is so, in a way you clearly do not realize or understand. This
> > happens because you speak so loosely, without specifying what you mean
> > by "the universe" -- that ambiguity can sensibly be interpreted two
> > ways, which makes this seemingly silly statement actually be correct.
> >
> > In our current best cosmological models, spaceTIME is curved, but space
> > is flat.
> >
> >  Â Â Â Â [I won't bore you with the details, as you clearly don't care,
> >  Â Â Â Â  and won't understand anyway.]
> >
> > Tom Roberts
> 
> How can space possibly be "flat"??
> 
> Seems to me, here on Earth, I can go North-South, and I can go East-West
> and I can go Up-Down ... three dimensions!!
> 
> In the Milky Way Galaxy, one day I might be able to go directly towards
> the Galaxy Centre, or follow our spiral arm, or go up, out of the
> Galactic disk .... three dimensions!!
> 
> And other Galaxies aren't all in the same plane ... three dimensions!!
> 
> And, of course, the Universe is expanding ... in all directions ...
> three dimensions!!
> --
> Daniel

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#456817

Daniel60 wrote:
> 
> Tom Roberts wrote on 24/04/18 01:31:
> > [I rarely read your posts or reply to you because it seems that all you
> > do is post nonsense. But I happened to see this one, and noticed that
> > your usual nonsense 'just happens' to be correct, in a way that is worth
> > responding to as it may surprise some readers.]
> >
> > On 4/18/18 1:36 AM, The Starmaker wrote:
> >> the universe is both flat and curved.
> >
> > Yes, this is so, in a way you clearly do not realize or understand. This
> > happens because you speak so loosely, without specifying what you mean
> > by "the universe" -- that ambiguity can sensibly be interpreted two
> > ways, which makes this seemingly silly statement actually be correct.
> >
> > In our current best cosmological models, spaceTIME is curved, but space
> > is flat.
> >
> >  Â Â Â Â [I won't bore you with the details, as you clearly don't care,
> >  Â Â Â Â  and won't understand anyway.]
> >
> > Tom Roberts
> 
> How can space possibly be "flat"??
> 
> Seems to me, here on Earth, I can go North-South, and I can go East-West
> and I can go Up-Down ... three dimensions!!
> 
> In the Milky Way Galaxy, one day I might be able to go directly towards
> the Galaxy Centre, or follow our spiral arm, or go up, out of the
> Galactic disk .... three dimensions!!
> 
> And other Galaxies aren't all in the same plane ... three dimensions!!
> 
> And, of course, the Universe is expanding ... in all directions ...
> three dimensions!!
> --
> Daniel

Based on my observations...that which you call the big bang..the stars spread out in all directions because the top was flat and
they had to go in all directions because they needed to spread out some more.

Down...is where they came from. Up is where they went. But, there was was not much room Up, so they went 
this way and that way....that which you call...spread out.

I mean, really...if you go inside a pizza box...there is not much room up or down. It's flat!

The pizza is flat! The box it comes in is flat!!

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#456886

On 4/24/18 5:48 AM, Daniel60 wrote:
> Tom Roberts wrote on 24/04/18 01:31:
>> In our current best cosmological models, spaceTIME is curved, but 
>> space is flat.
> 
> How can space possibly be "flat"??

Here "flat" is a technical term meaning that the Riemann curvature 
tensor is identically zero.

> Seems to me, here on Earth, I can go North-South, and I can go East-West 
> and I can go Up-Down ... three dimensions!!

Sure.

> [...] three dimensions!

My use of "flat" does not imply 2 dimensions, as you seem to think. 
Indeed it can apply to manifolds of any dimension greater than 1.

Tom Roberts

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#456905

Tom Roberts wrote on 25/04/18 14:21:
> On 4/24/18 5:48 AM, Daniel60 wrote:
>> Tom Roberts wrote on 24/04/18 01:31:
>>> In our current best cosmological models, spaceTIME is curved, but 
>>> space is flat.
>>
>> How can space possibly be "flat"??
> 
> Here "flat" is a technical term meaning that the Riemann curvature 
> tensor is identically zero.
> 
>> Seems to me, here on Earth, I can go North-South, and I can go 
>> East-West and I can go Up-Down ... three dimensions!!
> 
> Sure.
> 
>> [...] three dimensions!
> 
> My use of "flat" does not imply 2 dimensions, as you seem to think. 
> Indeed it can apply to manifolds of any dimension greater than 1.
> 
> Tom Roberts

Well, why didn't you say so?? ;-P

-- 
Daniel

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#456898

Hallo Daniel60,

> And, of course, the Universe is expanding ... in all directions ... 
> three dimensions!!

ahem - 4?



-- 
Mit freundlichen Grüßen,

Klaus Meinhard

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#456906

Klaus Meinhard wrote on 25/04/18 16:53:
> Hallo Daniel60,
> 
>> And, of course, the Universe is expanding ... in all directions ...
>> three dimensions!!
> 
> ahem - 4?
> 
as, I think, Time is the fourth dimension ... yes, I'll give you that!!

-- 
Daniel

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#456928

On 4/25/18 1:53 AM, Klaus Meinhard wrote:
>> And, of course, the Universe is expanding ... in all directions ...
>> three dimensions!!
> 
> ahem - 4?

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.

Tom Roberts

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#456951

"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.
>
> Tom Roberts:
>
hanson wrote:
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!

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#456957

hanson wrote: 

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! 

We’re inside an evaporating black hole. 

“The red shifted Expansion illusion”  is mimicking  the loss of Planck Pressure, which lowers the kinetic energy of the Higgs field as evaporation progresses. 

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#456962

David (Kronos Prime) Fuller <fuller.david@hotmail.com> wrote:
> hanson wrote: 
> 
> So, if "space is expanding" what is space expanding into? 

Nothing. Is that a problem?

> 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! 
> 
> We’re inside an evaporating black hole. 
> 
> “The red shifted Expansion illusion”  is mimicking  the loss of Planck
> Pressure, which lowers the kinetic energy of the Higgs field as evaporation progresses. 
> 
> 
> 



-- 
Odd Bodkin — Maker of fine toys, tools, tables

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#456963

Odd Bodkin obfuscated

David (Kronos Prime) Fuller <fuller...@hotmail.com> wrote: 
> hanson wrote: 
> 
> So, if "space is expanding" what is space expanding into? 

Nothing. Is that a problem? 

Obfuscate Much??

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#456964

David (Kronos Prime) Fuller <fuller.david@hotmail.com> wrote:
> 
> Odd Bodkin obfuscated
> 
> David (Kronos Prime) Fuller <fuller...@hotmail.com> wrote: 
>> hanson wrote: 
>> 
>> So, if "space is expanding" what is space expanding into? 
> 
> Nothing. Is that a problem? 
> 
> Obfuscate Much??
> 

Not really. What’s happening is that a concept does not meet your
expectations, and so there is a dissonance, and you blame the answerer for
your confusion, when the real problem is internal. 

Here, you have imagined that expansion is a term that can only apply to
something with an outer boundary, and so you imagine that expansion is
visualized by watching that boundary move outward. This is what leads to
the question of “expanding into what?” But the reality is that expansion is
a perfectly understandable concept with or without an outer boundary.
Without an outer boundary, the meaning of expansion is simple: things in
the space are getting further apart. Period. So there is no outer boundary
involved and in fact there does not even need to be ANY outer boundary,
involved or not. And if there is no outer boundary, then “expanding into
what?” Is a meaningless question. 

Watch your internal unspoken assumptions. They are likely wrong. 

-- 
Odd Bodkin — Maker of fine toys, tools, tables

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#456967

Odd Bodkin
David (Kronos Prime) Fuller <fuller...@hotmail.com> wrote: 
> 
> Odd Bodkin obfuscated 
> 
> David (Kronos Prime) Fuller <fuller...@hotmail.com> wrote: 
>> hanson wrote: 
>> 
>> So, if "space is expanding" what is space expanding into? 
> 
> Nothing. Is that a problem? 
> 
> Obfuscate Much?? 
> 

Not really. What’s happening is that a concept does not meet your 
expectations, and so there is a dissonance, and you blame the answerer for 
your confusion, when the real problem is internal. 

No ... I’ve studied for long enough to know “Your No Aether Magic” is exactly as Valid as “My Aether Magic”

You guys are just playing Word Games & making Assumptions with your Aether-less Vacuum Mystery Math.

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#456968

Odd Bodkin scribbled 

David (Kronos Prime) Fuller <fuller...@hotmail.com> wrote: 
> 
> Odd Bodkin obfuscated 
> 
> David (Kronos Prime) Fuller <fuller...@hotmail.com> wrote: 
>> hanson wrote: 
>> 
>> So, if "space is expanding" what is space expanding into? 
> 
> Nothing. Is that a problem? 
> 
> Obfuscate Much?? 
> 

Not really. What’s happening is that a concept does not meet your 
expectations, and so there is a dissonance, and you blame the answerer for 
your confusion, when the real problem is internal. 

No ... I’ve studied for long enough to know “Your No Aether Magic” is exactly as Valid as “My Aether Magic” 

You guys are just playing Word Games & making Assumptions with your Aether-less Vacuum Mystery Math. 

Just because the “SR/GR of Einstein” is a self canceling Möbius Transformation doesn’t make your Aether-less Vacuum True

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