Re: expansion

On Jan 30, 10:39 am, john280109 <vega...@xxxxxxxxxxxxx> wrote:
On Jan 30, 7:51 am, PD <TheDraperFam...@xxxxxxxxx> wrote:



On Jan 30, 7:48 am, john280109 <vega...@xxxxxxxxxxxxx> wrote:

On Jan 30, 7:34 am, PD <TheDraperFam...@xxxxxxxxx> wrote:

On Jan 29, 10:40 pm, john280109 <vega...@xxxxxxxxxxxxx> wrote:

On Jan 29, 3:12 pm, PD <TheDraperFam...@xxxxxxxxx> wrote:

On Jan 29, 2:52 pm, moro...@xxxxxxxxxxxxxxxxxxxxxxx (Michael Moroney)
wrote:

john280109 <vega...@xxxxxxxxxxxxx> writes:
On Jan 29, 11:04 am, moro...@xxxxxxxxxxxxxxxxxxxxxxx (Michael Moroney)

Use your imagination, John.  I mentioned the balloon surface since it is
the most common example of something that is expanding, with no center
and no edge.  A physical object that everyone has seen, the balloon.

Now, if the nozzle bothers you, imagine a perfect sphere that is
expanding.  There is no center of the surface.   There is no edge of the
surface.  Yet dots on the surface will retreat away from each other,
and the speed they retreat from each other is proportional to their
distance along the surface.

Now, if you paint spots
on your sphere's surface and then expand the
sphere, all the spots *do not* distance themselves equally;
spots directly opposite each other, i.e. the two
axes, will go at the rate of growth of the diameter-
points closer than half circumference will separate
faster.

Now you're cheating.  The balloon surface world is two dimensional, but
now you're talking about the third dimension, which doesn't exist for
the two dimensional balloon surface world.

OK, wait, in order to explain the greater
universe, which we assume to be real, you want to
equate it with something having no center, and also you want
it to have no edge- neither of which conditions has been seen
in anything real to my knowledge.

I just gave an example.

Plus, you say there's no edge, but you say it's expanding-
expanding with relation to what? Is the whole universe expanding?
And if not, then what?

Take the balloon analogy into another dimension.  A 3 dimensional
"surface" of a 4 dimensional hypersphere.  Now, this is much harder
to imagine than the balloon, since it's not easy to think in 4 dimensions,
as we humans are confined to 3 dimensions.  All "dots" (3D objects instead
of 2D paint dots) "painted" on the hypersurface will retreat from each
other, at a rate proportional to their distance.  Just like we see in our
universe!  You may mention how you could go all the way around and come
back to the starting point.  There are speed of light limitations, but I
see no reason why one of the extremely distant galaxies we see out there
may be our very own Milky Way, or a progenitor, as it existed billions of
years ago.

Now you may want to bring up the analogy of moving from the surface of the
balloon, through the balloon to the other side - clear across the
universe, you may say.  Maybe so, but that involves the 4th dimension,
which is not accessible to us.  "Cheating", just like you talked about
leaving the surface of the balloon, going through it to the other side.
It's still pretty far away, for the perfect sphere with the 2D surface
universe, it's "d" away instead of "pi*d/2" away.  Now if you get even
more imaginative, we can think of pinching a partially inflated balloon so
that opposite surfaces touch. Opposite sides of the balloon universe
become very close, but still require travel through the extra dimension.
In our 3D surface universe, the "wormholes" of science fiction become
possible.  I don't think such wormholes have anything to do with black
holes, and are probably impossible, since they require access to an extra
dimension, as well as "something" "pinching" the whole universe.

Many call time the extra dimension.  I consider the extra dimension to
be spacelike but inaccessible to us.  However, the universe expands at
a constant rate in this dimension so it is proportional to time, so
time has some of the characteristics of the extra dimension.

Gobbledegook-

Now, if we want to talk about gobbledegook, we can start talking about
all the gobbledegook you post on spin here.
So cruel!!
But listen to your argument. An expanding
sphere's surface with dots- only the distance
along the surface between the dots is
considered- the sphere's surface itself is
imagined to be flat.
Humph.

Nowhere in my reply did I use the word "flat".  It is not flat.  Over a
very short distance things will appear flat, but over a long distance
there will be noticeable distortion.  This is nothing new.  Consider the
Earth.  I can draw small squares and triangles just fine.  But over a
longer distance, things happen.  "Rectangular" Wyoming has a different
length for its northern and southern borders.  Even larger, if I use the
Equator, the Prime Meridian and the 90 degree meridian, I have a triangle
with 3 right angles.

And this is remarkable because it demonstrates that you can discover
that a space (in this case, a surface is a 2D space) is curved WITHOUT
stepping far enough off the surface to see the whole closed space or
surmise the center of the earth. It is easy to tell that the surface
of the earth is curved with precision measurements ON THE SURFACE.

Now you can ask the same question about the 3 spatial dimensions we
live in. If they are curved around some center, that center doesn't
live in these 3 dimensions, any more than the center of the earth
lives on the curved surface of the earth. Moreover, we don't have to
move away from these 3 dimensions to determine (with precision
measurements) that these 3 dimensions are curved.

The extrapolation is straightforward:
1. Center of earth not on curved 2D surface of earth => center of
universe not on curved 3D space of universe.
2. There is no center of expansion on 2D surface of sphere => there is
no center of expansion in 3D space of universe.
3. Curvature of 2D measurable ON surface without moving OFF surface =>
curvature of 3D space measurable IN space without moving OFF 3D space.

A flat sphere's surface. OK, you take away
a dimension but it's still a sphere? A flat
sphere?

The dimension is still there, but inaccessible.  Like we humans live in
only 3 dimensions, we cannot access any others.

[snip rest of misplaced attack on "flat"]

All I can say is wow!
The book 'Flatlander' has got people imagining dimensions can
be added and subtracted from reality.
Not true.
Reality has 3 dimensions.
The center of a sphere is at the sphere's center.
Dots on a sphere's surface are on a curved surface.

Some of your last statements are just incredible gibberish.
 Curved 2D? Sorry, doesn't happen.

I'm sorry, John, you don't think the 2D surface of a sphere is curved?

Wow.

John

No-oh!!
In order to describe any construct
containing a curve, you need three
dimensions. Including the *shell* of zero
thickness of the sphere that I suppose you're
thinking of.
You know that zero thickness is also a fictional animal,
do you not?
john

So, John, you are so entrenched in the material world that you cannot
even tolerate Euclidean ideas of 1D and 2D constructs? Euclid's ideas
have been around for some time, you know.

For you, unless it has shape, finite extent, boundaries, and volume,
it isn't real?

PD

for everyone, not just me

I respectfully disagree. Please do not project your own biases and
limitations on the populace in general.

The reality is that our discovery of how nature works has outstripped
both our familiar concept set, which we've derived over the centuries
from our senses, and our vocabulary, which again is based on centuries-
old usage. It really should not be a surprise that neither of these
things have been able to keep up with what has been discovered in
nature in the last 100 years.

It is also not reasonable for you to demand that all this slow down
until the concept sets and the vocabulary catch up, just so that it is
more accessible to you.

I do not deny that most of the universe is unfamiliar and difficult to
describe. There is no requirement that the universe be accessible and
easily understood. It is interesting *precisely because* it is
difficult to understand.


these concepts are tools for
understanding ideas that can't be expressed otherwise

unfortunately, if you can't explain your idea every which
way from sunday, you don't have an idea. and this is
how it is right now (except for my idea, of course :-))

john

.

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