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Author Topic:   Universe Race
Percy
Member
Posts: 22606
From: New Hampshire
Joined: 12-23-2000
Member Rating: 4.9


Message 331 of 410 (459643)
03-09-2008 8:23 AM
Reply to: Message 325 by Agobot
03-08-2008 7:53 PM


Agobot writes:
And how come some of the experts speak with such great authority about the Big Bang, its phases, how it started, how it proceeded, how matter came to be, when, in fact, the Big bang itself is not proven to be a fact?
As theories go, that the universe was once in a very hot, dense state is something in which we have a high degree of confidence because of the strong empirical support in the form of observational evidence of things like recession speed of galaxies increasing with distance, the decreasing proportion of heavy elements with increasing distance, the cosmic microwave background radiation arriving with (almost) equal intensity from all directions, etc., and the equally strong theoretical support from general relativity that rules out a static universe.
It's just one of the proposed theories/albeit the best one, so far/. As time goes by, new theories will arise and replace older ones, as we gather more knowledge and evidence of the world.
Absolutely true, but you fail to note that the evidence upon which older theories were based is not replaced. New theories must still be consistent with old data. This is why, for example, theories of the shape of earth went from flat to spherical to oblate spheroid, and not from flat to spherical to cubical. Any theory that replaces the Big Bang must still explain the original hot, dense state for which the observational evidence is so strong.
--Percy

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 Message 325 by Agobot, posted 03-08-2008 7:53 PM Agobot has not replied

fallacycop
Member (Idle past 5599 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 332 of 410 (459647)
03-09-2008 8:48 AM
Reply to: Message 329 by Zucadragon
03-09-2008 7:28 AM


Re: Pea size
Is this correct ?
Yes. Except for the word surface.

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cavediver
Member (Idle past 3722 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 333 of 410 (459659)
03-09-2008 10:25 AM
Reply to: Message 329 by Zucadragon
03-09-2008 7:28 AM


Re: Pea size
Yes, and I'm not sure why Fallacycop is objecting to the word 'surface' - that's eactly the word we use. Though we are dealing with a 3d surface, not a 2d surface. The only correction is that stars are gravitationally bound into galaxies and are thus unaffected by the expansion. Similarly, the galaxies are bound into clusters - it is only once you rech the scale of clusters that the expansion starts to become apparent.

This message is a reply to:
 Message 329 by Zucadragon, posted 03-09-2008 7:28 AM Zucadragon has not replied

Replies to this message:
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Chiroptera
Inactive Member


Message 334 of 410 (459660)
03-09-2008 10:43 AM
Reply to: Message 329 by Zucadragon
03-09-2008 7:28 AM


Re: Pea size
If I understand correctly, and I'm trying to even though its a hard way to think for me, the universe shouldn't be seen as an actuall ball thats expanding but more or less a surface that is expanding in all directions.
What may be confusing to some is that we have been using two different analogies to express two different aspects of our expanding universe.
One analogy is, as you have said, the expanding 2-sphere -- a spherical surface that is expanding. This represents a two-dimensional universe in analogy to our three dimensions. All the galaxies are on this surface. As this surface expands, the galaxies will move further apart, and the farther apart the galaxies begin, the greater the rate at which the distance between them increases -- in other words, galaxies in this two dimensional universe will see greater red shifts associated with galaxies that are farther away. To a two dimensional person living in this sphere, nothing else exists except the surface -- there is no inside the sphere, nor is there any outside the sphere.
The other analogy that we have been using is a static spherical surface. This represents not our three dimensional universe, but our 4 dimensional space-time, which, in GR models, exists "all at once" and is not changing. In this model, a line of longitude represents the "time" direction, and just as we are always moving forward in time, so a person on this sphere always moves along a line of longitude. Here, though, since the sphere has only two dimensions, and one of them is time, there is only one other dimension that serves as space -- hence the person believes she lives in a one-dimensional universe. The space that she sees is at right angles to the line of longitude, so her universe (at least the spatial part) is a circle of latitude. Assuming that she is moving toward the equator, when she measures the size of her universe, the circle of latitude is bigger at later times than earlier times -- hence she sees her universe as expanding. Her spatial universe is a circle of latitude that is moving toward the equator, and so getting bigger. Again, all that exists is the surface -- there is no "inside the sphere" or "outside the sphere."
So, a 2-sphere is being used in two separate analogies to illustrate two different aspects of the phenomenon. I hope that people weren't getting confused, and if they were I hope this clears some of the confusion up.

...Onward to Victory is the last great illusion the Republican Party has left to sell in this country, even to its own followers. They can't sell fiscal responsibility, they can't sell "values," they can't sell competence, they can't sell small government, they can't even sell the economy. -- Matt Taibbi

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tesla
Member (Idle past 1671 days)
Posts: 1199
Joined: 12-22-2007


Message 335 of 410 (459674)
03-09-2008 12:29 PM
Reply to: Message 333 by cavediver
03-09-2008 10:25 AM


Re: Pea size
Astrophysicists have determined speed by this point of view, although the expansion is apparent; I wish to ask you a question.
If a car is moving 30 miles an hr, And passes another car that is moving 30 miles an hr, There is an appearance of 60 miles per hr.
In the math, Has the speed of our own cluster, Our own galaxy and our own rotation, Been taken into account when determining the speed of expansion?
The relative speed from our point of view as being "faster than light speed" Is more than likely a trick of the eye, If we do not have the proper math to evaluate the true speed relative to our own.
The idea that "nothing is moving" and just "the fabric expanding" does not seem to be supported by meteors and planets.
Is it possible that what i have proposed is just as likely?
Dense object value 80 =O
Dense object value 80 implode/explodes with a force of 20/60
Dense object releases value 60 in 3 parts of value 20, and retains 20.
..O
O O
....O
The attraction of the masses back to themselves does not equal the force of the explosion/implosion, So it remains moving away, Yet the paths are affected by the relation of the other dense objects.
The dense objects are black holes which begin to build under matter production, And explode implode forming many bodies who all interact with each other and become the formed galaxies.
Is this not as potential the truth? Or what data do you have that would prove this model wrong?

keep your mind from this way of enquiry, for never will you show that not-being is
~parmenides

This message is a reply to:
 Message 333 by cavediver, posted 03-09-2008 10:25 AM cavediver has replied

Replies to this message:
 Message 338 by fallacycop, posted 03-09-2008 1:04 PM tesla has replied
 Message 339 by Percy, posted 03-09-2008 1:12 PM tesla has not replied
 Message 340 by cavediver, posted 03-09-2008 1:13 PM tesla has replied

fallacycop
Member (Idle past 5599 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 336 of 410 (459676)
03-09-2008 12:36 PM
Reply to: Message 333 by cavediver
03-09-2008 10:25 AM


Re: Pea size
I objected to the word surface because it can give the false impression that there is a bulk of empty space bounded by that surface. In the often used analogy where the universe is a globe and time is the north-south direction, the use of the word surface might give the impression that the interior of the globe has some significance.

This message is a reply to:
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Replies to this message:
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cavediver
Member (Idle past 3722 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 337 of 410 (459680)
03-09-2008 1:02 PM
Reply to: Message 336 by fallacycop
03-09-2008 12:36 PM


Re: Pea size
We emphasise the word 'surface' to signal that the analogies do not use the interior of the balloon or the globe. This is intimately connected with the mathematics of topology, where we refer to spheres as surfaces and balls as solids. For example, S2 is the 2-sphere, what the layman would call the surface of a ball. It has no boundary, no edge. B2 is the 2-ball, and is the common idea of a ball - a solid object. It does have a boundary, which is S2. We write dS2=0 and dB2=S2, where d is the boundary operator. It is a beautiful result of topology that a boundary of an object itself has no boundary, as seen in this example. Thus d2=0. We see the same in lower dimensions. S1 is the 1-sphere or circle where-as B1 is the 1-Ball or disc. Again, the boundary of the disc is the circle and the circle has no boundary.
If the Universe is closed, then space has the topology of S3, which again has no boundary.

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fallacycop
Member (Idle past 5599 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 338 of 410 (459681)
03-09-2008 1:04 PM
Reply to: Message 335 by tesla
03-09-2008 12:29 PM


Re: Pea size
The idea that "nothing is moving" and just "the fabric expanding" does not seem to be supported by meteors and planets.
You are right. Meteors, Planets, Stars, Galaxies, etc..., everything is moving. That is not the kind of movement that is explained by the expansion of the universe. The expansion explains the movement in a much larger scale. As cavediver explained above, only in the scale of galaxy clusters the expansion of the universe becomes aparent.
The relative speed from our point of view as being "faster than light speed" Is more than likely a trick of the eye, If we do not have the proper math to evaluate the true speed relative to our own.
You are still traped inside a non-relativistic frame of mind. That's not how things work. There is no such thing as true velocity. All velocities are measured relative to something else.
Besides, even if you compound two movements, the final observed speed is never larger then the speed of light.

This message is a reply to:
 Message 335 by tesla, posted 03-09-2008 12:29 PM tesla has replied

Replies to this message:
 Message 341 by tesla, posted 03-09-2008 1:16 PM fallacycop has replied

Percy
Member
Posts: 22606
From: New Hampshire
Joined: 12-23-2000
Member Rating: 4.9


Message 339 of 410 (459682)
03-09-2008 1:12 PM
Reply to: Message 335 by tesla
03-09-2008 12:29 PM


Re: Pea size
You're just asking the same question over and over again. We keep giving you the same answer over and over again. Do you think the answer is going to change? No, the data cannot be interpreted as an explosion into pre-existing space.
tesla writes:
In the math, Has the speed of our own cluster, Our own galaxy and our own rotation, Been taken into account when determining the speed of expansion?
Our local reference frame is considered stationary. There is no such thing as an absolute reference frame to measure against.
The relative speed from our point of view as being "faster than light speed" Is more than likely a trick of the eye, If we do not have the proper math to evaluate the true speed relative to our own.
The amount of red shift provides an extremely accurate measure of relative speed.
The idea that "nothing is moving" and just "the fabric expanding" does not seem to be supported by meteors and planets.
You're pulling the "nothing is moving" comment out of context. In the scenario under consideration in that prior discussion, nothing is moving. Obviously everything in the universe has local motions, but these are dwarfed by the recession velocities of objects a great distance apart.
Is this not as potential the truth? Or what data do you have that would prove this model wrong?
How many times do we have to mention the cosmic microwave background radiation (CMBR)? It proved your model wrong a half century ago.
--Percy

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cavediver
Member (Idle past 3722 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 340 of 410 (459683)
03-09-2008 1:13 PM
Reply to: Message 335 by tesla
03-09-2008 12:29 PM


Re: Pea size
In the math, Has the speed of our own cluster, Our own galaxy and our own rotation, Been taken into account when determining the speed of expansion?
Cosmologists, on the whole, are fairly bright guys and girls, and when you take a community of several thousand of them, they don't tend to miss these 'subtle' points.
The idea that "nothing is moving" and just "the fabric expanding" does not seem to be supported by meteors and planets.
In the same way that when you claim that you are stationary, I can damn well see your eyeballs moving, your hair rustling, and your finger nails growing. How can you possibly be stationary?
Is it possible that what i have proposed is just as likely?
Hmmm, tens of thousands of PhDs and professors over the past 100 years, spending their lifetimes working towards the current theory of cosmology...
vs
Tesla, with no training whatoever, having a deep think about these things on a Sunday afternoon...
I don't know, you tell me...
Perhaps next Sunday you should get out your clubs and knock a few balls around. And then tell us that you've as likely a chance of winning the Open as Tiger.

This message is a reply to:
 Message 335 by tesla, posted 03-09-2008 12:29 PM tesla has replied

Replies to this message:
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tesla
Member (Idle past 1671 days)
Posts: 1199
Joined: 12-22-2007


Message 341 of 410 (459684)
03-09-2008 1:16 PM
Reply to: Message 338 by fallacycop
03-09-2008 1:04 PM


Re: Pea size
You are right. Meteors, Planets, Stars, Galaxies, etc..., everything is moving. That is not the kind of movement that is explained by the expansion of the universe. The expansion explains the movement in a much larger scale. As cavediver explained above, only in the scale of galaxy clusters the expansion of the universe becomes aparent.
Why would clusters moving be any different than the lesser bodies movement just because of its scale?
You are still traped inside a non-relativistic frame of mind. That's not how things work. There is no such thing as true velocity. All velocities are measured relative to something else.
Just because measurement is impossible without two points to measure from does not mean there is no movement. There is movement, but all the variables have not been observed. If we find the "center" of the galaxy what is there? Can you say it is not moving? If yes, your being dogmatic. Who can tell with our viewpoint? There is velocity, but we cannot measure it without two points. In general relativity, we found that a lightning bolt can appear differently by the relation of the viewer. Any attempt to find its location without first putting our own location in an understood relativity to the object, The objects appearance will be a trick of the eye.
Besides, even if you compound two movements, the final observed speed is never larger then the speed of light.
Then why is it taught that the universe is expanding faster than light speed? From what viewpoint is this being viewed for its validity in relativity?

keep your mind from this way of enquiry, for never will you show that not-being is
~parmenides

This message is a reply to:
 Message 338 by fallacycop, posted 03-09-2008 1:04 PM fallacycop has replied

Replies to this message:
 Message 344 by fallacycop, posted 03-09-2008 1:33 PM tesla has replied
 Message 345 by Percy, posted 03-09-2008 1:35 PM tesla has not replied

tesla
Member (Idle past 1671 days)
Posts: 1199
Joined: 12-22-2007


Message 342 of 410 (459689)
03-09-2008 1:25 PM
Reply to: Message 340 by cavediver
03-09-2008 1:13 PM


Re: Pea size
That's your data?
10'000 people saying the world is flat cannot be wrong huh.
What data exists that makes what i have proposed any less viable than current theory?

keep your mind from this way of enquiry, for never will you show that not-being is
~parmenides

This message is a reply to:
 Message 340 by cavediver, posted 03-09-2008 1:13 PM cavediver has replied

Replies to this message:
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cavediver
Member (Idle past 3722 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 343 of 410 (459690)
03-09-2008 1:25 PM
Reply to: Message 342 by tesla
03-09-2008 1:25 PM


Re: Pea size
No, you misunderstand me. I think you are entirely correct.

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Replies to this message:
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fallacycop
Member (Idle past 5599 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 344 of 410 (459692)
03-09-2008 1:33 PM
Reply to: Message 341 by tesla
03-09-2008 1:16 PM


Re: Pea size
Then why is it taught that the universe is expanding faster than light speed? From what viewpoint is this being viewed for its validity in relativity?
A universe expanding faster then the speed of light is not in contradiction with relativity because, as we explained above, what we are observing is the expansion of space itself, as oposed to relative movement of two objects.

This message is a reply to:
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Replies to this message:
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Percy
Member
Posts: 22606
From: New Hampshire
Joined: 12-23-2000
Member Rating: 4.9


Message 345 of 410 (459694)
03-09-2008 1:35 PM
Reply to: Message 341 by tesla
03-09-2008 1:16 PM


Re: Pea size
tesla writes:
Why would clusters moving be any different than the lesser bodies movement just because of its scale?
Space is expanding at the same rate everywhere, but objects that are gravitationally bound to each other do not expand away from one another with the expanding space. Gravity diminishes by the square of the distance, so at the largest scales, larger than galactic clusters, objects are so distant from one another and their mutual gravitational attraction so weak that they are carried away from each other by the expansion of space.
Just because measurement is impossible without two points to measure from does not mean there is no movement.
No one said measurement is impossible. We said that there's no such thing as an absolute reference frame. It is equally valid to make measurements from any inertial (non-accelerating) reference frame you choose, so we choose our own local reference frame for convenience, which by definition is stationary since we're not moving relative to ourself. I would guess that it is also common to adjust cosmological measurements to be relative to our sun or to the Milky Way galaxy in which our sun resides, but you'd have to ask Cavediver or Son Goku to find out for sure.
Then why is it taught that the universe is expanding faster than light speed? From what viewpoint is this being viewed for its validity in relativity?
The Hubble constant, the rate of expansion of the universe, is approximately 71 kilometers/second/megaparsec. The speed of light is approximately 300,000 kilometers/second. Since recession velocity is proportional to distance, doing the math tells us that objects separated from each other by more than 4,222 megaparsecs (8 1022 miles or 1.3 1010 light years) are receding from each other at a speed greater than that of light.
--Percy
Edited by Percy, : Correct values in last paragraph, must have accidentally hit a number one row off on the number pad.

This message is a reply to:
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Replies to this message:
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