The universe may not be expanding.

What I have always wondered is if the universe is expanding then why can't we calculate the point of origin from which it is expanding?

In other words, find the centre.
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reply to post by Gools

There is no center (correct spelling). The universe is not expanding from a center outward. The big bang was not an explosion. The expansion is the expansion of existence and it is happening everywhere at once. It is getting bigger everywhere and it's happening faster all the time.

It's a tough concept...to say the least. Another way to look at it is that the big bang happened everywhere. Does that help?


[edit on 9/18/2009 by Phage]

Originally posted by Gools
What I have always wondered is if the universe is expanding then why can't we calculate the point of origin from which it is expanding?

In other words, find the centre.
.

That's not easy task and it's comaparable to you standing inside a very large circle trying to find its center. You need to see the perimeter of the circle to reference the central point. We can't see the "ending parts" of the universe clearly enough.

The hypothetical center of the universe hardly contains any features that would provide substantial evidence of the Big Bang taking place there anyway -- no ground zero smelling after gun powder.

reply to post by Gools


From our perspective we are at the center of it.

Originally posted by Phage
There is no center (correct spelling).

Unless you're in the UK, where we use "centre" and "metre". I think it has something to do with you guys driving on the wrong side of the road.

Just wondering if you've come across the work of Julian Barbour, Phage? He has come up with an explanation of the nature of time, or rather gets around the need for any such concept in GR, and argues that our concept of the arrow of time is illusory. He's a brilliant writer, for the layman, and even managed to get me thinking in a 4 dimensional Minkowski configuration space, where the instant that we perceive is the result of probability waves.

One side effect of his theory is that even if the universe is constantly expanding then contracting, we would only ever actually perceive it as expanding.

I need to re-read it in light of this tired-light, to see whether that fits.

Intuitively, a static universe in which there is a mechanism for constant creation sits easier in my fuddled brain than big bang cosmology, for exactly the reason of the misapprehension of a universe expanding from a singularity having a centre when it actually doesn't.

Ok, I have steam coming from my ears now.

Here is an article on the natutre of time by Barbour. Well worth a read.

[edit on 19-9-2009 by Karilla]

Originally posted by Phage
... it is happening everywhere at once.

In that case we would be moving away from the moon and the moon from us and from the sun and the sun from us, and the same for every other object etc.

In fact it would look to us like everything was moving away from us unless we are getting bigger to compensate.
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reply to post by Gools


Well actually the Moon is moving away from us but it has nothing to do with the expansion of the universe, it's a localized tidal effect.

Our little neighborhood is expanding but the rate of expansion is small. For example, the space between us and Alpha Centauri (4.3 light years) is expanding at the rate of 10cm/sec. Space in the Solar System is getting bigger, but the Moon and other planets swim upstream against the expansion, held together locally by gravity.

It is when we look at the expansion over truly vast distances that it becomes apparent.

[edit on 9/19/2009 by Phage]

reply to post by Phage


Ok Socratic method approach. How do we know the distance between the stars is increasing with actually being able to cover that space?

reply to post by Phage

The big bang was not an explosion.

Wouldnt this possibly lend credence to the theory that the universe was
created by someone or something at some point?
After all, the amount of power needed would be immense to say the least.
Just a thought.
I am sure the theories abound. Good stuff! Thanks!

reply to post by Watcher-In-The-Shadows

First, a correction. The distance between stars is not increasing. That is too small a scale. Some stars are moving toward each other, some are moving away. The same applies to "local" galaxies, the distance between us and Andromeda is decreasing. In these "small" scales, local motions exceed the rate of expansion so relative velocities vary quite a bit.

We can determine relative velocities by determining the red shift (or blue shift, which is simply a negative red shift value) of the light coming from the stars. The is an experimentally proven method.

Ashmore has come to the conclusion, that because of a coincidental relationship between two unrelated quantities, the observed red shift of distant galaxies is not caused by their motion but by "lazy light". I've given some of my objections to his theory. In reading other criticisms by those much more versed the pertinent aspects of photoemission than I am, I've come the the conclusion that his theory has no merit.

reply to post by Phage


Yet you did not answer my question. I ask again, how do you know any object's in spaces distance from us?

reply to post by Watcher-In-The-Shadows

I'm sorry, you asked about distance increasing, not about absolute distance.

There are several methods used to determine the distance of objects in space.

We use parallax, the apparent shift in position of an object when the observer's viewpoint changes.

For more distant objects this does not work so we use the magnitude (brightness) of the object. Since brightness decreases with distance we can judge the distance by the amount of dimming. Of course, different stars and galaxies do not all produce the same amount of light but by the use of spectroscopy we can determine the "original" amount of light being emitted.

A third method, which for the purposes of this topic would be a circular argument, is that the distance can be determined by the amount of red shift.

[edit on 9/19/2009 by Phage]

reply to post by Phage


Remeber Socratic method. So we know how light behaves over vast differences? And if so how do we know this?

reply to post by Karilla


I'll have to go with the obvious, which you're already aware of, that km/-s are SI based derived units (tied to physically defined observable comparatives) while Mpc are not (though no less legitimate). Measuring the distances in km or m would be unwieldy though easily converted. Even if the system appears to be arbitrary the important fundamental aspect is that there is widespread acceptance, agreement and recognition of the system of measurement.

It's fine to debate the value of the comparatives and ultimately replacements will be found as methods are refined.

I don't think it's so bizarre that there is a term for velocity derived from the comparatives and a term for the distance based on angles and lengths of a right triangle. Oh well.

reply to post by Watcher-In-The-Shadows

Albert told us and he hasn't been shown wrong yet.

It's awfully easy to play the "we don't really know anything" game. But I don't do that.

reply to post by Phage


Considering the fact we cannot even travel that distance what makes you think he could be shown wrong? I mean realistically. And I am not going to try to turn this into a conversation about that. Socratic method I mean.

[edit on 19-9-2009 by Watcher-In-The-Shadows]

Originally posted by Phage
It's awfully easy to play the "we don't really know anything" game. But I don't do that.

It's awfully easy to play the "I know everything" game too.

Despite my B.Sc. (in biochem) and a knowledge of physics up to second year university science, there is something that intuitively has never added up for me about this whole the universe is expanding thing, but I can never seem to express it in words.
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reply to post by Gools

Who claims we know everything? We don't. But that doesn't mean we know nothing.

The expansion of space is difficult to understand, and express.


[edit on 9/19/2009 by Phage]

reply to post by Phage


I would argue that "know" is simply a illusion. But that is me derailing. And as for Albert, well, not everything he says has to be correct. I remember him not being able to find any problem with the Copenhagen Intrepretation yet rejecting it because he was a Determinist. With an honesty I GREATLY respect him for.
And lastly, try me.

[edit on 19-9-2009 by Watcher-In-The-Shadows]

Originally posted by Watcher-In-The-Shadows
And as for Albert, well, not everything he says has to be correct. I remember him not being able to find any problem with the Copenhagen Intrepretation yet rejecting it because he was a Determinist. With an honesty I GREATLY respect him for.

He thought of the fudging of relativity to produce a static universe by the introduction of the Cosmological Constant as his greatest mistake. Mind you, it's being looked at in a new light these days as it explains the fact that we can see stars that are older than the universe is supposed to be.

He didn't do bad, though, did he?

Here's another paper arguing that it might be time to look again at the idea of a static universe.

The Three Empirical Pillars of Big Bang
Theory
The tenants of the Big Bang theory interpret the
redshift as a Doppler effect indicating the expansion
of the universe. They interpret the cosmic
background radiation as an echo of the initial explosion.
The third empirical pillar of the theory is
called “Big Bang nucleosynthesis”, which claims to
predict the abundances of the four light elements:
deuterium, helium-3, helium-4, and lithium-7.
The much-trumpeted alleged concordance of
Big Bang predictions with observations goes essentially
as follows. What is called the abundance
of a chemical element is the ratio of the amount
of this element in the universe to that of hydrogen,
which is the most prevalent. In his 1989 review
of Big Bang nucleosynthesis, Gary Steigman
of Ohio State University [18] explains that the only
parameter on which the predicted abundances depend
is ´, the universal ratio of nucleons to photons.
For a narrow interval of values of ´ tightly
constrained by the observed abundances, “the
standard hot Big Bang model predicts the individual
abundances to lie precisely in this range.”
But, as Steigman says, “Abundances are not observed.
Abundances are derived from the observational
data, often following a long and tortuous
path involving theory.…Errors (or uncertainties),
often systematic, may be introduced at many steps
in the overall process of deriving abundances
from observational data. Furthermore we are here
concerned with primordial abundances. Even if
present day universal abundances were known to
arbitrary accuracy (which they are not!), we still
would have to employ theory and observation to
extrapolate back to obtain primordial (or at least
pregalactic) abundances. Additional errors (uncertainties)
are surely introduced here too.”