Expanding Universe

[kendor]

Seeing as we havn't had a science topic recently.....
I was watching a programme the other day which said that with the aid of telescopes we are now seeing the galaxies at the far reaches of the universe the earliest matter expelled by the big bang.
A few thoughts entered my mind at this point.
If we are not at the centre of where the big bang happened then objects would be flying off both away and across from our viewpoint how do they know that these objects are the furthest away and have not been created by another big bang event elsewhere? why should there have only been one big bang anyway?
we could be looking at these far away objects from another big bang elsewhere that have crossed through our universe and may not be part of the matter that exists from "our" big bang (rather like an overlap where these accelerating objects are just faster moving than our own) Can any of the Cosmologists explain to me why there can only have been one big bang and why it can't be happening as we speak elsewhere if they say the proof is that all objects are moving away from us then that suggests we were at the centre of the bang, they say that the universe is actually accelerating so from that i deduct that...not all at the same rate otherwise we would not be able to observe it.
I have always had a theory since i was little that universes(notice the plural here) are scaled and that our universe could be part of something else in another larger universe, for us being so small time seems very long but in the larger universe of which we are a part our very existence may have been over in a flash ie we may have formed part of a nuclear explosion somewhere and our existence came into being and was extinguished in an instance but for us that instance is billions of years so far. same that small changes made by us may escalate the changes in the larger universe and we may be nothing more than part of a virus in a living creature?? ok i know this may be sounding a bit far fetched and i have no way to back up my theory but i also see the shortcomings of what some have said on the box and some of those theories i feel are flawed and speculative rather than backed by hard evidence(rather like mine ) has the maths, experimentation been done to explain why i might be talking out my backside?

 

[mildmanneredjanitor]

I have another hypophysis, if I could aliken the universe - to a packet of biscuits...

 

[kendor]

now you've complicated things, are they chocolate or plain?

 

[AdamW]

Take a jaffa cake...

There are ways to determine how far away something is in the universe and what way it is going.

1) Hubble's Law. Basically, the further away something is from us, the faster it is moving away from us. Take that Jaffa cake, put the spongey bit in a glass of milk. The outer edge expands faster than the bits nearer the middle. Now, things that are moving away from you faster will have a greater redshift (the Doppler effect, the reason that sirens sound lower when they travel away from you). So, we can judge how far away galaxies are.

2) Hubble's Law relies on Hubble's constant. If we have Hubble's constant we can work out how long the Universe has been expanding. However, we don't know what that is exactly, but every now and again someone works it out and it generally means the Universe is 14 billion years old, give or take a few hundred million years.

Now, that takes care of the one Universe. But how could we figure out if there were two Big Bangs within telescope range?

Well. We know roughly where the centre of the Universe would be. We know that the galaxies we see all come from roughly the same spot. If you can find one that comes from somewhere else, you will get the Nobel prize I guarantee!

So what about several Big Bangs happening in the same place, but say 4 billion years apart?

Well, when we look at a galaxy 13 billion light years away, we see stars that are about 1 billion years old. Those stars are now older of course, but the light we see shows them at an age of 1 billion. Whole galaxies full of relatively young, hydrogen burning stars. But, if we look at a galaxy say 3 billion light years away then we see much older stars, that look to be about 11 billion years old. They will be older, burning more complex elements (all the elements were created by stars through fusion of lighter elements).

We know what type of fuel a star is burning by it's colour (well, it's emission spectrum). So, by adding this information to knowing all the galaxies come from the same spot, we can also say they were created at the same time.

However, new galaxies are being created. What about this recent young'un?

 

[AdamW]

However all you really need to know is the Universe is big. Really big.

Of course, there could be other Universes out of telescope range, perhaps we are right on the cusp of seeing them, who knows? We may all wake up tomorrow and see a bright spot in the sky, where a Big Bang has occurred billions of light years away, billions of years ago, and the light has only just reached us.

Or perhaps it is already there, but to use some Star Trek style science "They are out of phase with our Universe", therefore we can't see them. If you think how much we know compared to 100 years ago, when many thought we knew pretty much everything, then there is a LOT of science we don't even have a clue about just yet. Perhaps there are multiple Universes laid over the top of one another, hence explaining some of the weird quantum effects that exist.

Maybe other Universes are created and disappear in such a short time that they never expand to any appreciable size. The life of a mayfly is a blip in the life of a tortoise, or a redwood. Perhaps we are the mayfly, perhaps we are the tortoise.

The short answer is, no-one knows if there is just one Universe.

 

[2scoops0406]

Seeing as we havn't had a science topic recently.....
I was watching a programme the other day which said that with the aid of telescopes we are now seeing the galaxies at the far reaches of the universe the earliest matter expelled by the big bang.
A few thoughts entered my mind at this point.
If we are not at the centre of where the big bang happened then objects would be flying off both away and across from our viewpoint how do they know that these objects are the furthest away and have not been created by another big bang event elsewhere? why should there have only been one big bang anyway? Think of yourself inside an expanding balloon, which ever point you are in, everything will appear to be moving away from you


we could be looking at these far away objects from another big bang elsewhere that have crossed through our universe and may not be part of the matter that exists from "our" big bang (rather like an overlap where these accelerating objects are just faster moving than our own) Can any of the Cosmologists explain to me why there can only have been one big bang and why it can't be happening as we speak elsewhere if they say the proof is that all objects are moving away from us then that suggests we were at the centre of the bang, they say that the universe is actually accelerating so from that i deduct that...not all at the same rate otherwise we would not be able to observe it.
I have always had a theory since i was little that universes(notice the plural here) are scaled and that our universe could be part of something else in another larger universe , for us being so small time seems very long but in the larger universe of which we are a part our very existence may have been over in a flash ie we may have formed part of a nuclear explosion somewhere and our existence came into being and was extinguished in an instance but for us that instance is billions of years so far Not current theory, though of course may well be other universes, but not in our dimensions therefore there is not such thing as scale outside a universe, we cannot have been part of some kind of nuclear explosion, as there are no nuclei prior to a big bang . same that small changes made by us may escalate the changes in the larger universe No not in the same dimension and we may be nothing more than part of a virus in a living creature?? Also might wish to consider that all we see experience feel etc might be one large computer simulation see here http://www.simulation-argument.com/ ok i know this may be sounding a bit far fetched and i have no way to back up my theory but i also see the shortcomings of what some have said on the box and some of those theories i feel are flawed and speculative rather than backed by hard evidence(rather like mine ) has the maths, experimentation been done to explain why i might be talking out my backside? Yes loads, but your "theory" is as good as anyone else's so far

 

[planenut]

Ah, I think i'm getting there now, are these biscuits sweet or savoury?

 

[mildmanneredjanitor]

If all the telescopes/radio telescopes are telling us that the universe is still expanding...

What they are 'seeing' is the universe expanding hundreds of millions of light years away.... Erm so doesn't that mean it might have already started springing back like a bungee? Just that It will take another few eons for us to actually see it?

Thinking about it... What if it springs back with such a force and velocity that it 'overtakes' the light it is emitting, therefore we wouldn't see it coming? But then I guess that if everything emulated from a singularity, then there are no forces to 'pull everything back' unless space time turns in on itself...

Heres another titbit, do all galaxies form a flattened spiral shape? and is this to do with the corriolis (spelling?) force? If so, are they all spinning in the same direction?

(corriolis force is what makes water rotate down around the plug hole)

Pass the aspirin

 

[AdamW]

Must be quick as I am meant to be working (to pay for my biscuits) but:

Not all galaxies are spiral shaped. In fact our own galaxy has two satellite galaxies orbiting it, these are ellipsoid galaxies (blob-shaped). You also get iregular galaxies that are just a big splat of stars. I am sure there are a few more but I can't remember.

We have a flattened out disc-shape not due to corriolis effect, but by virtue of our rotation. It takes about 235 million years for the sun to orbit galactic centre. Not so sure how a galaxy goes from being a blob to being a spiral, but I would imagine that gravity over a period of billions of years brings all the different orbits of stars around the system into alignment, hence the flattened disc.

The astronomical convention is that the north pole of something points upwards whilst the body rotates anticlockwise as you look down from the North (think how the Earth rotates). So in case you were wondering which way round the galaxy we go! Not sure how the Sun's north pole is aligned relative to the Milky Way's, perhaps someone else can answer that?

Corriolis effect is caused by virtue of rotation too, but this isn't what flattens the galaxy out. In fact it would even oppose the flattening out of the galaxy!

Talking of Corriolis, did you know that a snooker player from the UK would play badly in Australia because the balls would go the wrong way?

 

[Thermo]

E=MC2+1!

 

[AdamW]

did you know that a snooker player from the UK would play badly in Australia because the balls would go the wrong way?

Do you reckon this would explain cricket as well?

 

[kendor]

Just to elaborate: if everything is moving away from us then we must be in the EXACT centre where the bang occurred otherwise some of the objects would be heading towards us and not away am i right to suppose this?( indeed objects do head towards us, meteorites for one but that could just be the effects of gravity and not the forces from the bang)
I know of the doppler effect and the red/blue shift in light wavelengths but what i was originally thinking is how do we know that the oldest matter did originate from our centre and is not some remnants from a previous bang? it's these sort of unanswered questions that worry me when scientists make these theories have they gathered sufficient evidence to back up their theories or are they making assumptions based on a few pieces of evidence?
What i'm trying to say is that our knowledge has indeed moved forward in leaps and bounds but we can only base our future scienctific principles on hard evidence and the danger comes when we assume too much.

1) Hubble's Law. Basically, the further away something is from us, the faster it is moving away from us.

Adam what you are saying i think is that if an object is very far away then it needs to move a lot faster in order to look as though it is travelling at the same speed as a closer object relative to us? or do you mean that the first material expelled from the bang is moving faster and the stuff that expelled later in the instance is moving slower or is slowing?
now not being a scientist but a ponderer, something else comes to mind,
if before the bang there was a singularity and the bang itself was infinitely small in duration then wouldn't all the material have blasted out at once and therefore the universe would only be a ring with no matter at the centre or a hollow sphere?

 

[pipme]

From :- http://www.schoolsobservatory.org.uk/study/sci/cosmo/internal/hublaw.htm

Because galaxies in all directions seem to recede from our galaxy, it might appear that our galaxy is the centre of the universe. This is not the case, however. While Einstein and others were trying to wrestle with general relativity and force it to give a static universe, Alexander Friedmann took a different approach. He made two assumptions; the Universe looks the same in all directions, and this would be true wherever anyone looked from. From these assumptions he solved the equations for general relativity and showed, in 1922, that the Universe would not be static but would be expanding at a rate that was proportional to distance, exactly what Hubble later discovered.

One can imagine a balloon with evenly spaced dots painted on it. As the balloon is blown up, an observer on each spot would see all the other spots expanding away from it, just as observers see all the galaxies receding from our Galaxy. The analogy also provides a simple explanation for Hubble's law; the universe is expanding like a balloon.

 

[kendor]

so pip, from that i deduce that the universe is indeed hollow? and it is the "skin" that is expanding?
that is making me feel awkward now as it plays into the theory that the universe is flat and two dimensional albeit curved into a sphere like shape but nevertheless flat on the surface if you understand what i'm saying? if as i am given to understand that light doesn't travel in straight lines but gently curves over vast distances then in one direction ie outwards from the centre there would eventually be an edge but horizontally (curved) then in theory you should see matter for ever meaning that we should never see the earliest matter as there will always be matter beyond it! is this a fair comment? or flawed? if flawed could anyone show me where i'm going wrong?

 

[GRC]

Talking of Corriolis, did you know that a snooker player from the UK would play badly in Australia because the balls would go the wrong way?

OK, I'll bite; 'wrong' in what respect?

Regards, Graham