Thread: Looking into space

First off i would like someone to clarify something for me, Does the universe have a centre?? if so and indeed it is far enough away isnt it possible that if we look to that point for evidance of the begging of the univers or as close as possable. It's just if the big bang theory is true then shouldnt there be one point in the univers in wich it occured and this is obviously going to be the centre of the univers because everything came out of one place. (unless of corse unless more particles went one way instead of the other causeing the the universe to be bigger on one side from the point of 'big bang')

I know it probably sounds confusing i mean i doen't even realy understand it???

Where is the center of the Universe?
Here, there, and everywhere.
by Paul Doherty, Exploratorium Teacher Institute


When astronomers look at distant galaxies to determine how fast they're moving, it looks like they're all moving away from us. Does that mean we're at the center of the universe? Well, no. It turns out that every point in the universe sees itself as the center! You can show yourself why with this activity.


More here:

Link here

Mod edit: Fixed long link to prevent page distortions. IS

Originally Posted by ssj4dave

First off i would like someone to clarify something for me, Does the universe have a centre??

This is an excellent question. Most physicists seem to believe that the universe has no center. I believe that it most likely does. The question is far from answered, I believe, because the site of the big bang is most likely not visible from this part of the universe.

The universe does not have a centre. Big Bang wasn't an explosion in spacetime, it was an expansion of spacetime itself.

Originally Posted by cosmictraveler

Where is the center of the Universe?
Here, there, and everywhere.
by Paul Doherty, Exploratorium Teacher Institute


When astronomers look at distant galaxies to determine how fast they're moving, it looks like they're all moving away from us. Does that mean we're at the center of the universe? Well, no. It turns out that every point in the universe sees itself as the center! You can show yourself why with this activity.


More here:

Link here

Mod edit: Fixed long link to prevent page distortions. IS

so what ur saying is that because the universe is infataly big there is no centure so there could be many centures through it from each position of an object??

Originally Posted by Stargazer

The universe does not have a centre. Big Bang wasn't an explosion in spacetime, it was an expansion of spacetime itself.

could you express the big bang part in a different way please?

so what ur saying is that because the universe is infataly big there is no centure so there could be many centures through it from each position of an object??

That's what I think as well as some scientists. The link explains about it in more detail, did you check out the link I provided?

Thank you whoever made the link smaller!

i don't know wether the universe has a centre because for one there are many spacetime distortions around the place and second of all there is no definitive measurement of spacetime which we can say is the smallest and hence make up a measuring system. without that we can't find the center.

we don't even know if the universe has a shape let alone center.

Originally Posted by Stargazer

The universe does not have a centre. Big Bang wasn't an explosion in spacetime, it was an expansion of spacetime itself.

It is so easy to make such statements, isn't it? Can you back this up, or did you just read it somewhere?

As far as I can understand, it is the universe itself that is expanding, in all directions - not the distribution of matter within the universe. Currently, the big bang says that the universe was incredibly small and dense about 14 billion years ago, and for some reason it started to expand rapidly, and still is today. It expands at an accelerating rate, it seems. I thought that this was the current consensus among scientists, that the universe was expanding.

Originally Posted by Stargazer

As far as I can understand, it is the universe itself that is expanding, in all directions - not the distribution of matter within the universe.

The balloon analogy is not good for this. As a balloon expands, all parts of the balloon, if the balloon is perfectly round, expand at the exact same rate. As the universe expands, the distribution of matter is clearly different. Furthermore, not all matter is expanding only outward, such that there are indeed relative differences in direction of expansion of matter. For example, how might galaxies collide if they are only moving outward and away from each other?

The average movement is outward. This does not rule out the movement of some matter being towards other matter.
To write "The Universe has no centre", is as you suggest very easy. It can be read in any elementary, intermediate or advanced text on cosmology. This means it can be written not only easily, but with a reasonable measure of confidence.

right that is a lot of information thanks!
So going bye what you said that 'The average movement is outward.' does this mean that is also moving inward? Becaue if it is then surely you could state that the universe is actually just moving to a destination in many different directions? And also i suppose you could say that at some stage The average movement could be inward causing the destruction of the universe??? I know it sounds a bit far fetched but isn't it a possibility?

And also if the universe is continuing to expand the one theory behind it could be that it is just continuing going and cloning its self out of what ever it can find any matter or any force, so if this is one theory and can be done, and we found out how to do it, then this would be an ideal way to explore space, by sending one probe out and as it lands it creates say 3 more of its self and then they go out and each create 3 more of them selves and so on. Is this all possible or am talking a load improbable nonsense??

Originally Posted by Ophiolite

To write "The Universe has no centre", is as you suggest very easy. It can be read in any elementary, intermediate or advanced text on cosmology. This means it can be written not only easily, but with a reasonable measure of confidence.

The problem is not with the writing, but with the reading. Nothing in cosmology should be taken with such confidence that we believe that it is surely true in its present form. Science is about current theory and degrees of probability, not about truth and not about confidence in the surety of what we read.

I said that the universe is expanding because that is what the current theories say. I wouldn't deliberately bring up old theories that has been revised or discarded, and I can't bring up theories that we might come up with in the future.

Originally Posted by Hermes

Originally Posted by Ophiolite

To write "The Universe has no centre", is as you suggest very easy. It can be read in any elementary, intermediate or advanced text on cosmology. This means it can be written not only easily, but with a reasonable measure of confidence.

The problem is not with the writing, but with the reading. Nothing in cosmology should be taken with such confidence that we believe that it is surely true in its present form. Science is about current theory and degrees of probability, not about truth and not about confidence in the surety of what we read.

I am at a loss to see what in my statements, quoted above, is at odds with your subsequent staement. If you agree, why did you bother making it? If you diagree, why?
As Stargazer points out we are discussing current theo . ries. Within them the Universe does not have a centre. It is therefore appropriate to explain this point in terms of current theories.
You note " Nothing in cosmology should be taken with such confidence that we believe that it is surely true in its present form."
Agreed. I happen not to believe in the Big Bang, but when someone asks on a science forum does the Universe have a centre I will reply within a scientific context in as scientific a manner as I am able.
I sense that you had something important to say in relation to you apparent rather snide attack on Stargazer. "It is so easy to make such statements, isn't it? Can you back this up, or did you just read it somewhere?" Please say it and stop beating around the bush.

Originally Posted by Ophiolite

As Stargazer points out we are discussing current theo . ries. Within them the Universe does not have a centre.

You used the word theory in the plural. There certainly exists current theories wherein the universe is postulated to have a center. Even though perhaps not the most popular, there are such theories that have been proposed by prominent scientists.

You note " Nothing in cosmology should be taken with such confidence that we believe that it is surely true in its present form."
Agreed. I happen not to believe in the Big Bang, but when someone asks on a science forum does the Universe have a centre I will reply within a scientific context in as scientific a manner as I am able.

No one really knows what about current theories is true and will stand the test of time. Much of modern copsmological theory is just placeholders waiting to be replaced with something else, such as "dark matter" for example. I feel no compulsion to tell people what the majority of scientists believe unless specifically asked that question. Instead, I prefer to feel free to develop my own opinion within the bounds of reason, in which there is tremendous latitude, as evidenced by the wide range of opinions among prominent scientists today.

I sense that you had something important to say in relation to you apparent rather snide attack on Stargazer. "It is so easy to make such statements, isn't it? Can you back this up, or did you just read it somewhere?" Please say it and stop beating around the bush.

When responding to a question as open as this one was, I think that it is not useful to respond with one prominent theory, even if the theory that currently enjoys the most support, as though it is somehow truth and the listener should accept it as truth. Such statements should be phrased in such a way that the speaker makes it clear that this is not to be accepted at face value as the unequivocal and unchallengable truth. My point was to question whether the person who wrote it recognized that such a statement should never be stated as though it is obvious fact, but rather should be stated as what it is, one prominent but far from universally accepted theory.

Originally Posted by Ophiolite

You note " Nothing in cosmology should be taken with such confidence that we believe that it is surely true in its present form."
Agreed. I happen not to believe in the Big Bang, but when someone asks on a science forum does the Universe have a centre I will reply within a scientific context in as scientific a manner as I am able.

The Big Bang is not a perfect theory, true, but what exactly is it that you do not believe?

Originally Posted by Stargazer

The Big Bang is not a perfect theory, true, but what exactly is it that you do not believe?

Since it's introduction the underlying theory has gone through increasingly contorted adaptations to squeeze it so that it fits the observed facts.
Now many, perhaps most, theories go through apparently comparable adaptations, but I suggest that these changes typically involve simplification or elegance. That has not been the case with the Big Bang.
Secondly, it has become a matter of extreme heresy to offer alternative views to the Big Bang. Even highlighting weaknesses in the theory is usually only 'safe' to do if you are an established name, otherwise your career might be expected to take a sudden nose dive. This atmosphere ensures that serious weaknesses are not properly investigated and alternative theories are not entertained. A paradigm so firmly entrenched yet with so many question makrs around it looks like a weak paradigm to me.
My objection to the theory is thus a meta-objection: I expect the theory to fall when internal inconsistencies have built to such a level that cosmologists are forced to consider alternatives. I base this belief not on an understanding of physics (which is at first year undergraduate level), but on an understanding of how science actually functions.
Since it is a belief (and a matter of faith as much as anything) I would not normally even mention it these forums, but you did ask.

Originally Posted by Ophiolite

I happen not to believe in the Big Bang, but when someone asks on a science forum does the Universe have a centre I will reply within a scientific context in as scientific a manner as I am able.

Originally Posted by Ophiolite

it has become a matter of extreme heresy to offer alternative views to the Big Bang.

You say that you do not believe in the big bang. You also say that it has become a matter of extreme heresy to offer alternative views. You seem to prefer to call your own views heretical rather than consider them to have any scientific value. Others of us do not consider our own ideas to be so devoid of potential value.

Originally Posted by Hermes

You say that you do not believe in the big bang. You also say that it has become a matter of extreme heresy to offer alternative views. You seem to prefer to call your own views heretical rather than consider them to have any scientific value.

Absolutely. That is an objective assessment of them. I do not have specific objections to the substance of current Big Bang theory. I do not have an alternative cosmological theory that would deliver superior explanations for the observed facts than the current theory. Consequently my views do indeed have very limited scientific value. It would be wholly unscientific of me to claim otherwise, and totally add odds with the principles by which I live.

Originally Posted by Hermes

Others of us do not consider our own ideas to be so devoid of potential value.

Well, modesty was always one of my strong points.