Universe is one big galaxy???

[room16]

The Balloon skin is good in that it can show a 2d representation of relative movement of the observer to its surroundings using what we call inflation. But it is far from perfect as many have said.

Im still in my bubble, so to speak.

I have a hard time understanding how initial point of origin of the big bang, a singularity as we know it, is not the center of our ever expanding universe.

The vast majority of what we are made up of is bubble like, is it not? The smallest things like atoms and such are often represented as small bubbles and inside they have their own little universe. Even our solar system lives in a magnetic bubble which protects us from the interstellar winds.

For me, it's a bubble, until someone can show me otherwise....its the simplest of thoughts yet without finding the center (the initial point of the big bang) and accurate measurements of the most distant parts of the universe as far as we can see, to verify this idea of the continued expansion at the speed of light....this is all just more speculation/theory and still, atleast we make the effort to question.

[Budding Star Gazer]

The universe does not have a center. The main reason lots of people think that it must have one is because they think of the Big Bang as an explosion. It was not an explosion, let me explain.

So lets start with a empty void. Now imagine within this void is no space, no time and no energy. In fact it's empty then all of a sudden 14 billion years ago the big bang occurs.

Now it doesn't occur at a central point, it occurs everywhere at exactly the same time. Only thousands of a second after this Big bang did space come into existance.

I know there is already a post on " What was there before the Big Bang", And this brings it to light.

I say this because, If your statement is true even the empty void must be considered as Space; as it's impossible for something to expand into nothing, and if at the point of the big bang the Energy we call Time and Space came into existance that then occupies the void that was once there there must have been something beforehand.

There had to be catalyst ? which means something already existed.

[mark84]

Current theory suggests there was a singularity (a tiny point, like an electron) which went through the big bang (again, like others have said, no so much a bang, check out inflationary theory) I think the struggle to understand and comprehend that there was no space and time around this maybe more of a limit of our human minds and earthly experiences than of physics. Something that's well worth checking out is the multiverse theory and chaotic inflation, an idea that says we're just one of many universes and our universe can "spawn" other universes, like bubbles in a bath tub.

[Budding Star Gazer]

I'm no physicist but found that a very good read, However from what i just read and understand;i may be wrong! the Inflationary Theory still talks of inflation,expansion,into a void, a void that could contain energy (dark energy).

so if our universe as the current model and evidence suggests is flat to within a few degrees,symmetrical,has a horizon & expanding into a void that contains dark energy are we not just back to square One?.

Like i said i'm physicist & am probably wrong but reading that article would suggest a singularity or starting point,an end & an energy source that was there before, that is feeding the expansion or inflation of the universe.

I will read up on multiverse theories,i dont see why our universe has to be the only one out there but ``Pluralitas non est ponenda sine neccesitate'',(Ockham's razor)

will be kept in mind.

Thanks for that mark it has lit a fire under my curiosity and will give me something to think about while i'm on holiday, And i might add given me a bigger incentive to devote more of my time to Astonomy

[Space Bat]

I don't actually believe in the big bang...

I think for me time itself is perpetual constant with the universe the same where the beginning of time and the end of time are at the same place.

SO going with the ant analagy which does help to explain this, that if time were a perfect sphere you would have no beginning or end just different points in time.

And that the matter - galaxies / quasers etc are on the skin of the sphere or on the skin of time.

This then asks the question how big is the sphere? and is the sphere expanding...

For me - its infinite...

[mark84]

Thanks for that mark it has lit a fire under my curiosity and will give me something to think about while i'm on holiday, And i might add given me a bigger incentive to devote more of my time to Astonomy

No problem, I was much the same, I read the now slightly dated but still excellent 'brief history of time' by S Hawking 4 or 5 years back after someone left a copy round at my house by accident, I knocked it off the table and it fell open and began reading, and I have been hooked ever since! There's lots of stuff out there if you have time, some great physics books on amazon - stick with the ones with good reviews and you won't go far wrong, or if readings not your thing give youtube a try, have a search for 'relativity' oh, and,

fascinates everyone, it's a great and fun intro to quantum physics!

Not often you hear someone say they don't believe in the big bang nowadays spacebat, how about the big bounce?

[Space Bat]

Not often you hear someone say they don't believe in the big bang nowadays spacebat, how about the big bounce?

The utterances of a mad man perhaps?

My other theory is that there was a planet between Mars and Jupiter that got smashed to pieces - most of the bits are in the asteroid belt - but some bits are formed into moons such as our moon and mars's moons....

Chris

[wulfrunian]

I don't actually believe in the big bang...

I think for me time itself is perpetual constant with the universe the same where the beginning of time and the end of time are at the same place.

SO going with the ant analagy which does help to explain this, that if time were a perfect sphere you would have no beginning or end just different points in time.

And that the matter - galaxies / quasers etc are on the skin of the sphere or on the skin of time.

This then asks the question how big is the sphere? and is the sphere expanding...

For me - its infinite...

Can you explain this one a bit more Chris? How can "time" be at a "place"? How do your theories fit with the evidence?

[Permanent Midnight]

just a question.

do we, the mankind, know how it looks beyond the center of our milkyway?

Thanks

Teo

[Space Bat]

Basically that the physical size of the universe is infinite – that the start and end of time exist at the same point.

We perceive time based on OUR time frame and our technology. So before we could travel as we do now, the earth was seen as large and would take several weeks to circumnavigate – we can now do this in a matter of hours, so our modern perception of the size of earth is smaller due to being able to achieve things in less time. This is due to our perception of time that it has to have a start point and an elapsed period.

So at present our understanding of the universe is that it is incredibly huge if not never ending, so if our technology could take us to any point in the universe in a second then how would that effect mans perception of the physical size of the universe or indeed time? Or if we lived to trillions of years as a being – then taking a few million years to get somewhere – in perception of time would be brief.

The big bang theory was reinforced by the discovery of CMB and vice versa.

However if this radiation is uniformly distributed – I ask the question why if there was a big bang would this be uniform? it would have been difficult to distribute this relic radiation in a uniform manner as the velocity of the expanding universe would surely have meant the propagation of radiation would have been dispersed with a direct correlation of an expanding universe – we should be able to take this information and point direct to moment of expansion and where in space, and be able to truly age the universe. I would argue the point that CMB is there because there was no big bang and that it shows no discernable change in shape or pattern to suggest expansion but more that this radiation is the remnant decay of fusion due to the formation of our galaxy.

So getting back to the original question time in the same place…

I tried to drop a picture in but couldn't

If you draw two circles and and connect them together (like a cylander) and place a dot on the circumferance of the first circle and call it A - you will see it can be anywhere on that circle as there is no beginning or end.

Now if you put a dot on one of the lines between the two circles it shows that there is a start point and there is an end point - where this line joins the second circle. Now depending on how far the circles are apart defines how big our perception or how long we think there is between the two circles or age.

A is positioned in actual time where it can be anywhere at any point

B is positioned in what I believe is a perceived time or time reality based on our reference of a beginning and end of time scenario.

If you could manipulate time and bring the two circles together as one so there is no line or perception of time exists - you could then be anywhere in time and space at anyone time.

Now I am not an expert -so will accept that this could be totally wrong and that I am talking a load of rubbish.

[batmanflyer]

Hi,

Recently in physics, we have started cosomology, which has fasanated me from the start, please forgive me but i didnt really know which section to post this under...but anyway back to my point/question.

My teacher was unable to answer the question, "are the galaxys in the univese in fact one big galaxy where smaller galaxys (the milkyway) orbit around a central point, as the earth does around the sun?"

I understand this could be contridicted as the universe is ever expanding, supporting the big bang, but i was just looking for some expertise on this area.

Ben,

Hello

I am not an expert on this but I think that there is a difference between the earth's orbit around the sun and the milkyway's orbit around its axe.

The difference is that the earth has its orbit destined by gravity while the galaxies have their orbits destined by a black hole centre. Though that the second example also involves gravity there is a major difference here. We do not know how the black hole gravity works on long distances, nor what happens to light and matter that gravitates into the centre.

[narrowbandpaul]

'black hole gravity' is the same gravity that keeps the earth in orbit round the sun.....

infact replace the sun with a 1 solar mass black hole (radius 3km) and guess what happens.....nothing! the earth continues merrily in its orbit, unaware that someone switched the source of gravitation. Its dark now as photons cannot escape the gravitation potential created by a black hole for r<3km

what we dont know is what happens beyond the event horizon, r<Rs. Thats an unknown....but for r>Rs the gravitational field is well understood.

[ollypenrice]

The balloon analogy is a good one but you always need to stress that the SURFACE of the balloon represents the universe. When it's a balloon it is spherical. When it's an analogy it isn't!

Ollly

[shakyl008]

Yah... You know, that question's a bit dumb...

Like it's the same as asking what is energy made of? It might be possible in the same way that an ailien mothership could land on Earth tomorrow and make my brain better(80'000IQ)

It's not the type of question to which we have concreet answers, yet.

My adivce to you(is you still remember about your question) is: use your imagination!

My say: Can imagine it, can do it.

hope I was of any help

[narrowbandpaul]

it was in the 1910's and 20's when we thought that all there was was this galaxy, and the other spiral nebulae were located within our galaxy....

so they thought the universe contained only one galaxy, whereas this question asks whether the entire universe is just on galaxy.....

maybe thats a question of metaphysics, as we can never know the answer...to do so we would have to step outside the universe, where space/time no longer exists (ie there is no coordinate frame (x,y,z,t) to specify a point.....

but the question isnt dumb....there are no dumb questions, just dumb answers!

[drollere]

some basic points got lost along the twist of this thread.

going back to the original post: the current comoving breadth of the universe is about 91 billion light years. the galaxies are not rotating around a singe point, simply because gravitation can't sustain centripetal motion across that kind of distance. orbits, such as orbits within a galaxy cluster, are a fraction of that.

the singularity did not expand *into* anything, including a pre-existing void: it expanded entirely into itself, and it still is. there was no pre-existing void; time started with the universe, so there was no "before time" to explain. it's not that we don't have an explanation, it's that no explanation is necessary.

that's all in terms of science, but the same point appears as the regression fallacy in philosophy. it's pointless to say that something must have been "before" the universe in order to create the universe, because then you have to explain what created that thing that came before.

if you *see* something that was before the universe, then that's different; but our "seeing" back in time stops at the cosmic microwave radiation, which is at around 380,000 years *after* the singularity.

finally, it's already been explained that the universe has no inherent center, and one way to visualize that is to think of *each point* in the metric universe expanding in all directions at the same time. matter in the universe doesn't expand, only space does as the "hubble flow". the distances between galaxies grow larger, and their light is red shifted as a result. objects that are gravitationally bound do not expand, but maintain local attraction -- as stars in a galaxy or galaxies in a galaxy cluster.

the fact that most galaxies are not bound in a single cluster but instead are receding from each other demonstrates that gravity is too weak at those distances to create a single "galaxy".