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Author Topic:   Is space flat?
purplecorndog
Inactive Member


Message 1 of 28 (297425)
03-22-2006 7:50 PM


Hey there everyone.
I've gone through these posts for awhile now and it's evident that everyone knows what they're talking about!
The one thing I just can't seem to wrap my head around is space: is it flat or three-dimensional? I suppose 'dememsional' was a bad word to use. Diagrams I've found while roaming around show a pit, for lack of a better term, in space. To me, that means that there's a literal fabric.
I don't know if I even made myself clear, but I tried.
Thanks in advanced for clarifications.

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AdminNWR
Inactive Member


Message 2 of 28 (297440)
03-22-2006 8:23 PM


Thread moved here from the Proposed New Topics forum.

  
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 3 of 28 (297444)
03-22-2006 8:39 PM
Reply to: Message 1 by purplecorndog
03-22-2006 7:50 PM


Wow, so many new folk. Hi purplecorndog!
space: is it flat or three-dimensional?
3d? Yes, but we don't like to separate it from time, which gives us 4d.
Flat? Well, it depends. Over small distances it is, to a very good approximation, flat. However, as you look on larger length scales you realise (using incredibly sensitve instrumentation) that around the earth, it is not totally flat. On sufficiently large scales the curvature can be quitepronounced, such as the whole universe being possibly curved into a (hyper)sphere, or around a black hole where things appear to curve the wrong way because the curvature is so extreme.
Diagrams I've found while roaming around show a pit, for lack of a better term, in space.
The pit is space. This is a very common misconception with depictions of space(time). The pit shows that space is being stretched and distorted (by some mass such as a planet, star, black hole, etc)
To me, that means that there's a literal fabric.
Yes, in quite a close sense, space(time) is a fabric.

This message is a reply to:
 Message 1 by purplecorndog, posted 03-22-2006 7:50 PM purplecorndog has not replied

Replies to this message:
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Gary
Inactive Member


Message 4 of 28 (297475)
03-22-2006 11:52 PM
Reply to: Message 1 by purplecorndog
03-22-2006 7:50 PM


I think you're referring to pictures that show a massive object like a black hole distorting spacetime, maybe with a ball rolling around the edge of a pit. They are usually drawn that way because it is easier to get the point across in two dimensions than three. Really, the "pit" exists in all directions, so the ball would roll around in any plane about the object in the middle.
Here's a picture of a gravitational lens, which illustrates that point.
APOD: 2001 October 7 - Abell 2218: A Galaxy Cluster Lens

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Xeriar
Inactive Member


Message 5 of 28 (304846)
04-17-2006 9:31 PM
Reply to: Message 1 by purplecorndog
03-22-2006 7:50 PM


Unfortunately this isn't a question with a single answer.
As mentioned, on extremely small scales, the Universe is pretty flat. Gravity wells are modelled as the warping of spacetime, however, so what we perceive as gravity is, actually, us being interrupted in our otherwise 'straight' motion in spacetime. This is more of a compression of space, however, rather than curvature into a higher dimension (well, at least as I understand it).
----
If you are asking 'Is the Universe a hypertorus or hypersphere', we only have the WMAP results to go by, which suggest that, at least on the scale of the visible Universe, it is flat to measurement error. There may be some large-scale structure to the Universe, but it suggests that the Universe is either
1: Really, really forking huge
2: Infinite
I consider both #1 and #2 to be equally mindboggling, personally

This message is a reply to:
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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 6 of 28 (304897)
04-18-2006 6:07 AM
Reply to: Message 5 by Xeriar
04-17-2006 9:31 PM


This is more of a compression of space, however, rather than curvature into a higher dimension (well, at least as I understand it).
Outside mathematics, it is a common misconception that a "higher dimension" is required for curvature. This is not true. Often a higher dimension is required for us to visualise curvature, e.g. a sphere (such as the surface of a snooker ball) is 2-dimensional, yet for us to appreciate that curavture we require a 3 dimensions in which to view it. The sphere itself requires no such higher dimension.
we only have the WMAP results to go by, which suggest that, at least on the scale of the visible Universe, it is flat to measurement error
Flat here refers to space and not space-time. We say spatially flat to be unambiguous. Space-time on the other hand is very curved.

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1.61803
Member (Idle past 1504 days)
Posts: 2928
From: Lone Star State USA
Joined: 02-19-2004


Message 7 of 28 (305001)
04-18-2006 1:30 PM
Reply to: Message 1 by purplecorndog
03-22-2006 7:50 PM


god's change purse
Space is where god keeps his pocket change and pocket watch. Space is full of quantum activity; without space there is no movement, no movement, no change. No change, no time. And the only reason for time is so that it everything does not happen at once.

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john6zx
Member (Idle past 4821 days)
Posts: 66
Joined: 01-27-2007


Message 8 of 28 (380517)
01-27-2007 4:44 PM
Reply to: Message 3 by cavediver
03-22-2006 8:39 PM


Yes, in quite a close sense, space(time) is a fabric.
A fabric that can stretch, things can move through it w/o tearing it. It never wears out? How much would a square foot of it weigh?
What is this fabric made of? How far can it stretch before breaking? What is it stretching into? How would someone grab this fabric to stretch it? Has anyone recreated this stretching?

This message is a reply to:
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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 9 of 28 (380523)
01-27-2007 5:13 PM
Reply to: Message 8 by john6zx
01-27-2007 4:44 PM


Hi, welcome to EvC
A fabric that can stretch
Yes
things can move through it w/o tearing it
No. 'things' as we think of them are actually ripples and bumps in the fabric. There is only the fabric.
It never wears out? How much would a square foot of it weigh?
Those concepts don't have much meaning
What is this fabric made of?
It just is. Everything that we think of is an aspect of the fabric. The fabric is existence.
How far can it stretch before breaking? What is it stretching into?
By stretching, we simply mean there is a concept of distance associated with pairs of points on the fabric, and distances can grow (or shrink) Thus the fabric doesn't tear nor stretch into something.
How would someone grab this fabric to stretch it?
See above
Has anyone recreated this stretching?
What we think of as gravity is an effect of this stretching. We can see it in astronomical observations. But for us to strecth space-time would require manipulating immense energies - something for the far future.

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zcoder
Member (Idle past 6208 days)
Posts: 66
Joined: 03-19-2007


Message 10 of 28 (390191)
03-19-2007 9:57 AM
Reply to: Message 9 by cavediver
01-27-2007 5:13 PM


quote:
Has anyone recreated this stretching?
I maybe wrong here, but when a object of any mass is in space
the space does not exist where the mass object is.
space and mass can not take up the same space. so in a sence, mass
does stretch space around it distorting it, and this is on top
of the fact that space is also stretching in all derections away
from a mass object.
zcoder....

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Replies to this message:
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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 11 of 28 (390237)
03-19-2007 2:05 PM
Reply to: Message 10 by zcoder
03-19-2007 9:57 AM


I maybe wrong here, but when a object of any mass is in space
the space does not exist where the mass object is.
No 'maybe' about it
A physical object does not preclude space, it just occludes it - i.e. the object hides the background space.
You have to understand that a 'physical object' is just a concentration of excitations of the underlying matter and force quantum fields. These fields overlap the space-time field perfectly - it is not a case of either/or. All the fields exist everywhere.

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zcoder
Member (Idle past 6208 days)
Posts: 66
Joined: 03-19-2007


Message 12 of 28 (390309)
03-19-2007 6:32 PM
Reply to: Message 11 by cavediver
03-19-2007 2:05 PM


I don't know much about theorys, I just try to think it out
logicly.
So if it's true that space can not exist where mass is, then what
makes gravity on mass objects that don't spin?
The main thing I noticed was that when you watch the astronauts
playing with liquids. and what I noticed was that the liquids would
ball up together into a ball.
And the larger clumbs would draw the smaller ones into it,
if they got close enough to them.
And as the clump got bigger it could draw in alot more. which means
that it is growing in mass, and gaining in gravity, enough to pull
in more.
But, what in space is making gravity on objects that are not
spinning?? Like our moon, which really has no spin to say, but
turns once every lunar month, which is such a slow spin that
that could not account for the gravity that the moon has , so
I had to conclude that the moon's mass created most of it's
gravity.
But I still needed to explain how mass makes gravity.
and this is what I came up with.
Picture a ball in space, and as space expands in all directions
away from the ball, the effects on the ball is as if it was
falling into it's self.
This also puts the effects of gravity on the ball which is related
to the balls mass. in other words the ball is falling into it's self
in all directions, while space is rushing away from it in all directions
and it's this effect that couse's a inward force onto the ball hence gravity.
and the amount of gravity asserted is in relation to it's mass.
Is this idea flawed? is there something I did not consider?
Zcoder....

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Taz
Member (Idle past 3291 days)
Posts: 5069
From: Zerus
Joined: 07-18-2006


Message 13 of 28 (390375)
03-19-2007 11:40 PM
Reply to: Message 12 by zcoder
03-19-2007 6:32 PM


zcoder writes:
I don't know much about theorys, I just try to think it out
logicly.
First of all, this isn't AIM chat. Stop pressing the enter button unless you want to start a new paragraph.
Did you know that logic is actually a field of it's own in colleges? Did you know that you can major in logic? Did you know that you can get a Ph.D in logic and become a logician? In other words, logic ain't common sense. Allow me to show you why your common sense is far from logic.
So if it's true that space can not exist where mass is, then what
makes gravity on mass objects that don't spin?
Can you give me a reference where it says the current gravity theories state that "spinning" creates gravity? I honestly don't know where this came from.
The main thing I noticed was that when you watch the astronauts
playing with liquids. and what I noticed was that the liquids would
ball up together into a ball.
Liquids ball up together into a ball because of hydrogen bonding not because of gravity. What hydrogen bonding is should have been covered in your high school chemistry class.
And the larger clumbs would draw the smaller ones into it,
if they got close enough to them.
No, larger clumps don't draw the smaller ones toward them. It's just an illusion. What happens is they coincidently float into each other and hydrogen bonding takes over.
And as the clump got bigger it could draw in alot more. which means
that it is growing in mass, and gaining in gravity, enough to pull
in more.
No, as the clump got bigger, it has more volume which gives it more and more chances to encounter other clumps.
Yes, those clumps of liquid do have their own gravitational fields, but they are so minute that you might as well think it's zero.
But, what in space is making gravity on objects that are not
spinning?? Like our moon, which really has no spin to say, but
turns once every lunar month, which is such a slow spin that
that could not account for the gravity that the moon has , so
I had to conclude that the moon's mass created most of it's
gravity.
I don't get it. Where did you get the idea that gravity comes from the spin of an object?
Picture a ball in space, and as space expands in all directions
away from the ball, the effects on the ball is as if it was
falling into it's self.
This also puts the effects of gravity on the ball which is related
to the balls mass. in other words the ball is falling into it's self
in all directions, while space is rushing away from it in all directions
and it's this effect that couse's a inward force onto the ball hence gravity.
and the amount of gravity asserted is in relation to it's mass.
Ok, let's go with what you just described. If space is rushing away from an object to make the object "fall" into itself, how come more massive objects exert more gravitational force on other objects?
Is this idea flawed? is there something I did not consider?
Perhaps you forgot to consider that we're not in the dark ages anymore and that our understanding of the natural world isn't like how dark ages science worked: witches burn-->wood burns-->wood floats-->duck floats... or something along that nonsense.

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Replies to this message:
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zcoder
Member (Idle past 6208 days)
Posts: 66
Joined: 03-19-2007


Message 14 of 28 (390387)
03-20-2007 1:53 AM
Reply to: Message 13 by Taz
03-19-2007 11:40 PM


I will ignore the insalt.
like I said I don't have a degree in all this.
But I am feeling I was wrong to think I would
get answers in a polite manner to the correct
meaning of what creates gravity.
"how come more massive objects exert more gravitational force on other objects?"
the effect I described is in relation to the objects mass
so the greater the mass the more gravity it has, so it will
exert more gravitational force on other objects.
Zcoder....

This message is a reply to:
 Message 13 by Taz, posted 03-19-2007 11:40 PM Taz has replied

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zcoder
Member (Idle past 6208 days)
Posts: 66
Joined: 03-19-2007


Message 15 of 28 (390392)
03-20-2007 4:31 AM
Reply to: Message 14 by zcoder
03-20-2007 1:53 AM


Never mind,
I wanted in my later years to try out some science
as a hobby sence I now have the time in my life to do so.
I spent most of my life as a electronics engineer and
programmer.
I know first hand how a programmer can use his imagination
to create in the computer, worlds that don't really exist
and set laws, which he knows can not ever exist, and when
the program is started it can create, detroy, worlds and
systems all while following the laws set forth by the programmer.
once set in motion even the programmer(the creator) does not know
where at the program is at, in any instance, nore what will come next.
even though he is the creator. I have even been surprised at some
of the things I have seen happen, even though I was the creator.
And all the different laws or realms I made was pure imagination
not basted on real models of real worlds.
I also know that taking theorys and building programs to follow
those theorys to a tea can also be done.
So with evolution and creation both being theorys and the fact
that doing them in a computer or in your mind does not make them
so. and a theory is just a theory not a fact, nore is it provin.
infact it is more of an adoption of an idea, mostly based on appeal
becouse it sounded logical, If this is not the case then it would
have to be a fact that you believe it, otherwise it is just a
theory.
This leads me to then believe that if you adopt a theory which is
not proven in real life, then it has to be on faith.
for instance, In physics, the term theory is generally used for a
mathematical framework, derived from a small set of basic principles.
the theory in present time can not be confirmed, but is
adopted as doctrine base only on it's fiting into a mathematical model
or it's basic principles.
same goes for creation, all is faith, so now this leaves only one
difference between the two believe systems. Why each individual will
accept one system over another can not be fully explained.
So if one believe system is false then so is the other. becouse they
are both alike in more then one way.
But this will never even get fair thought by a evolutionist after all
they believe that the word theory is a science fact, becouse they
learned it in school, and other scientists believe it also, so it has
to be true. after all the mathematical model proves it, infact just
for shits and giggles, a group of us back in the 80's made a mathematical
model that proved god existed, yet we did not believe it. and we used
also christian basic principles, only thing we lacked was an einstein or
darwin to prove it.
like my experience making world models in a computer, so can a creator
and watch his creation turn out surpizes after surpizes.
but that too is just a theory.
So why do I see in this forum, which says they have good scientists but
are unwilling to say the truth that at this time in mans journey, we
really have no idea what the hell kind of realm we live in.
why must it be one sided? why so many attacts on believers, would a
believer threaten your theory? I believe not, whould it threaten your
mathematical model, I believe not.
So why can't there be real honest diversity in these forums from the so
called scientists, and a real respectful discussion on these theorys?
I believe the theory of string theorys, I believe in the expansion of
space, I believe alot that you do, but I don't on all things. is this
not healthy? what is the problem?
When I came here I was excited, I just knew that what ever I may have
believed would be shown to me to be wrong, with explanations so I could
wrap my head around it all, but what I got was attacted for being wrong
I never even got to rebuttal back. it's not like a got into a post that
lasted along while before getting insulted, it was right away.
then when I ended my post with, is there something I am flawed at
in my thought?
It's a shame of none-academic honest diversity from a community
I have ever seen, not even in collage have I ever seen this.
Zcoder....

This message is a reply to:
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