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david_phil
2006-Mar-27, 06:25 PM
Hi, could you guys help a lowly amatur please? I can get my head around most things to do with the universe but I am still having a problem with one thing.You know when NASA and all say that they have been observing galaxies from very early on in the universe, say with the hubble telescope.
1) Which way phisically are they looking? ( e.g. North, South, East or west etc.)
2) Is the milkyway further out in the universe than them or not?
3) Is the milkyway older than them or not?
4) Is the milkyway moving faster than them?

Because as far as I can understand it, if those were among the first galaxies to be born and the universe is expanding, they would be on the outer edge of the universe and if the milkyway is younger, we would be made of interstellar dust further in towards the centre of the universe. So are they looking at them towards the out boundry where the would be really old and most likely non-exsistant any more or are they looking inwards towards the big bang itself where they are mostly likely to be actually young galaxies made from old dust.
I find this quite confusing. If it is easier to e-mail me the details then that would be fine.
If there happens to be someone in Wltshire, uk that might have a little time to explain this to me, great! But that would be very unlikely I suppose.

Thanks for reading.

antoniseb
2006-Mar-27, 07:17 PM
I moved this thread to Q&A from ATM. It is straight-forward questions, not an alternative theory.

Hi david_phil, thanks for joining the BAUT forum.

Let me take the first stab at answering your questions.

What we see is light from distant galaxies. It has taken millions and in some case billions (thousands of millions) of years for that light to get here. That is true in every direction we look. The mainstream way to think about this is that the universe is expanding, so the space between the galaxies is getting bigger.

The Milky Way is just another galaxy. From our perspective we are not moving very fast. Perhaps we are falling toward the galaxy M31, but this is at a slow speed compared to the apparent speed of the distant galaxies. No obeserver in one of those distant galaxies would see themselves as moving either. Most large galaxies are about the same age, probably forming in the first 500 million years of the universe, and perhaps combining with some of their neighbors along the way.
If that doesn't help, ask some specific questions in this thread, and people here will be happy to answer them to the best of their ability, or point you to good websites with the answers you seek.

Bob
2006-Mar-27, 07:57 PM
One question you asked is very insightful. When viewing very distant and very faint galaxies, astronomers look out towards regions near the Galaxy's north or south poles. If they tried to look out along the Galaxy's equator, their view would be spoiled by dust clouds. The Galaxy's north pole is not aligned with the Earth's north pole, but it is overheard in the northern hemisphere.

Irishman
2006-Mar-27, 09:38 PM
I can get my head around most things to do with the universe but I am still having a problem with one thing...
1) Which way phisically are they looking? ( e.g. North, South, East or west etc.)
2) Is the milkyway further out in the universe than them or not?
3) Is the milkyway older than them or not?
4) Is the milkyway moving faster than them?

Counting? ;)

1) Theoretically, direction is irrelevant. They are looking out. All directions go out distances, and light takes time to travel distances, ergo, looking farther away is looking back in time. Practically, they look galactic north and south as Bob said, because galactic dust blocks the light from farther away.

2) This question doesn't make much sense. Further out in what way? Are you asking if the Universe is spherical, and are those galaxies now farther away on the outside, or conversely collected in the middle? Time is orthogonal to space - it is the "4th Dimension" - it is perpendicular to all three dimensions of space. Those other Galaxies are outward from us if you project our view as a visible center. Like standing on a ship in the ocean, you can turn around in a full circle and see as far as you can in each direction, a nice circular horizon all the way around. However, if you traveled as far as you can see in one direction and repeated the exercise, you would still see a circular horizon all the way around. Are they closer to the "edge" of the Universe? That's a philosophical question about the meaning of the words "edge of the universe".

3) The Milky Way is actually probably younger than the galaxies we see far out there. We are seeing them as they were farther back in time than we see the stars of the Milky Way.

4) Moving compared to what? Relative motion says that you have to define the reference point before you can compare velocities.

Jeff Root
2006-Mar-28, 11:53 AM
1) Which way phisically are they looking? ( e.g. North, South,
East or west etc.)
Hello, David!

I'd be interested to know what you meant by that question.

I think you could benefit from a full-blown introductory-level
college course in astronomy, with visits to a planetarium and
some actual night sky observing time included. Along with a
good general astronomy textbook.

-- Jeff, in Minneapolis

david_phil
2006-Mar-28, 05:37 PM
Yea. Sorry. About the way question one is put. I'm trying to ask it in layman terms. My son asked me this question. So, if you stood at the north pole which way would you point to say "The big bang came from that direction so we are going in this direction.". If everything came from one point why do galaxies collid into each other?

Thanks for this. I have asked these sort of questions before to other places ans people and usually get no answer at all. I hope you don't mind this. Books do not explain everything properly. Can't beat getting it from the astronomers mouth so to speak.

01101001
2006-Mar-28, 06:12 PM
Yea. Sorry. About the way question one is put. I'm trying to ask it in layman terms. My son asked me this question. So, if you stood at the north pole which way would you point to say "The big bang came from that direction so we are going in this direction.". If everything came from one point why do galaxies collid into each other?

Any direction. All directions. It even happened where your head is at now. It happened everywhere -- and all space is the result of it.

Some galaxies collide because the happen to have motion, within the expanding space, toward each other.

The Milky Way is not moving away from the location of the big bang. It is moving away from most matter as space continues to get bigger, as, on the large scale, all matter is moving away from all other matter.

Jeff Root
2006-Mar-28, 08:25 PM
My son asked me this question. So, if you stood at the north
pole which way would you point to say "The big bang came from
that direction so we are going in this direction.".
If everything came from one point why do galaxies collide
into each other?

Thanks for this. I have asked these sort of questions before
to other places and people and usually get no answer at all.
I hope you don't mind this. Books do not explain everything
properly. Can't beat getting it from the astronomers mouth
so to speak.
David,

First, just to be sure I'm not misleading you or anyone else,
I'm not an astronomer, nor are most of the people who are likely
to reply to your questions, but many of us know enough about the
subject to give useful answers to at least some questions.

If you can find the right books, they will explain everything
properly, but I agree: I can't think of a book to recommend that
definitely answers your question. Stephen Hawking's 'A Brief
History of Time' attempts to answer it. So does his more recent
picture book, 'The Universe in a Nutshell'. I didn't care much
for either book, but you may like them.

A fairly decent summary of the various theories is presented in
John D. Barrow's 'The Origin of the Universe'. This book is from
1994, before the acceleration of the expansion was discovered,
but I'd bet it has been updated. I think it is a good book for
someone going to a party where you will be surrounded by
cosmologists all evening, and want to know what they are talking
about, and you only have 24 hours to learn cosmology. :-) Or
for someone who studied cosmology years ago and needs a quick
refresher. It isn't a terrific intro to the subject. But it
does try to answer your question, as will any general book on
modern cosmology.

Another pre-acceleration book is 'The Big Bang' by George Silk.
It goes into more detail than Barrow's book, and covers a wider
range of topics. Whether you would consider it easy to read
depends a lot on how you read, I think. Moreso than most books.
It is easier than a typical textbook, but requires a bit of
concentration. An astronomy professor described it to me well:
Silk only goes over an idea once, then moves on to the next idea.
That method of exposition isn't for everyone. This book may also
have been updated since my 1989 edition.

The reason you are having trouble getting an answer to your
question is that it is far, far more involved than it seems.
To give an adequate answer to it, I would have to spend several
hours writing, at least. And that's assuming that I didn't run
into any problems requiring me to do reasearch, which is likely.
You need a broad understanding of a wide range of ideas in
physics, relativity, astronomy, and cosmology to make sense of
the answer.

My recommendation is to learn as much as you can about all these
subjects so that you and your son can puzzle out the answer
together.

But please-- Keep asking questions!

-- Jeff, in Minneapolis

Kaptain K
2006-Mar-28, 09:14 PM
So, if you stood at the north pole which way would you point to say "The big bang came from that direction so we are going in this direction.".
As has been said, there is no one direction you can point to and say; "The big bang occured over there." The big bang was the creation of the universe. It occured everywhere. A 2-D analogy is to think of a balloon the that is being inflated. You cannot point to one point on the surface of the balloon and say "this is the center". Every point on the surface has an equally valid (or invalid) claim to be the center.


If everything came from one point why do galaxies collid into each other?
Short answer: Gravity.
Longer answer: Over local distances, gravity overwhelms expansion. Some galaxies are approaching others for the same reason that the Earth orbits the Sun instead of flying off into intersteller space. Locally, gravity is stronger than the universal expansion.

david_phil
2006-Mar-29, 06:03 PM
Thanks! This is great. Now then, what if the expansion of the universe wasn't due to a big bang from nothing but a big suck! I just can't get my head around the idea of absolute nothing! Not even a blank void. There wouldn't even be blackness! So, (this is my idea, thinking logically) if there was just say, a huge vacuum type void, but that void was actually full of something, something that we can't detect at the moment, we haven't the technology yet, to us now it's just blank space. Some where, lets say at the centre of this void some form of force from the outer part of the void changed the "something" into literally something that then chain-reacted to form the elements etc and bang! I have called the "something" element Zero. Dark energy to you, you could say. A particle so small that we can't detect it but is literally everywhere! It so small that it goes through everything else. Right through atoms, everything. We are swimming in it. And I think that the universe does re-cycle its self. Black holes act like giant vacuum cleaners that turn something into nothing!
You can all have a good chuckle now.
I know it seems a crazy idea but I like.
You may now go forth and blow my idea to millions of pieces!
Prove me wrong remembering that all the other THEORIES are theories but with a lot of scientific experimention where mine hasn't. Yet?
P.S. Sorry about the "Thumbs down" icon, I thought it was a Question mark. Wasn't wearing my glasses.

hhEb09'1
2006-Mar-29, 06:14 PM
So, (this is my idea, thinking logically) if there was just say, a huge vacuum type void, but that void was actually full of something, something that we can't detect at the moment, we haven't the technology yet, to us now it's just blank space. Some where, lets say at the centre of this void some form of force from the outer part of the void changed the "something" into literally something that then chain-reacted to form the elements etc and bang! I have called the "something" element Zero. Dark energy to you, you could say. A particle so small that we can't detect it but is literally everywhere! It so small that it goes through everything else. Right through atoms, everything. We are swimming in it. And I think that the universe does re-cycle its self. Black holes act like giant vacuum cleaners that turn something into nothing!Do we move the thread back to ATM now? :)

antoniseb
2006-Mar-29, 06:34 PM
Do we move the thread back to ATM now? :)

Only if he's willing to defend his idea against the questioning of anyone who enjoys taking such ideas apart (like me).

On the other hand, we can't really address his idea here.

hhEb09'1
2006-Mar-29, 06:39 PM
On the other hand, we can't really address his idea here.Right, it seems the original intent was ATM, the reason the thread was started there.

david_phil
2006-Mar-31, 01:47 PM
Yes. Go for it guys!

dvb
2006-Mar-31, 04:28 PM
So, (this is my idea, thinking logically) if there was just say, a huge vacuum type void, but that void was actually full of something, something that we can't detect at the moment, we haven't the technology yet, to us now it's just blank space. We call that void space, and it's full of lots of stuff, including stuff that we can't see, or detect.


Some where, lets say at the centre of this void some form of force from the outer part of the void changed the "something" into literally something that then chain-reacted to form the elements etc and bang! I have called the "something" element Zero. As far as we can detect, there is no centre of the universe, unless we consider ourselves to be the centre. The thing is, no matter where we look, we can see that galaxies are traveling away from us in every direction. All the evidence that's been gathered so far leads us to this conclusion. We also have a perfectly good explanation of how matter formed into heavier elements.


Dark energy to you, you could say. A particle so small that we can't detect it but is literally everywhere! It so small that it goes through everything else. Right through atoms, everything. We are swimming in it. And I think that the universe does re-cycle its self. Black holes act like giant vacuum cleaners that turn something into nothing! We have particles like that already, and we call them neutrinos (http://www.ps.uci.edu/%7Esuperk/neutrino.html). About black holes though, we have little evidence to suggest such a thing is happening. To give you a better understanding, a black hole, isn't really a hole at all. It's just an infinately dense collapsed star, where the gravity is so strong, that not even light can escape it. This isn't to say that the light disappears into some void, just that we can't see the light once it passes the event horizon of the black hole, since it would have to travel faster than light to escape the gravity.


Prove me wrong remembering that all the other THEORIES are theories but with a lot of scientific experimention where mine hasn't. Yet? The first thing you need to understand, is that in a scientific discussion, the burden of proof is on the claimant. It's you're job to give us a model, and it's our job to poke holes in your model, until you have something solid enough to make accurate predictions based on our current observational data.

Alnair
2006-Mar-31, 09:46 PM
Hi, could you guys help a lowly amatur please? I can get my head around most things to do with the universe but I am still having a problem with one thing.You know when NASA and all say that they have been observing galaxies from very early on in the universe, say with the hubble telescope.
1) Which way phisically are they looking? ( e.g. North, South, East or west etc.)
2) Is the milkyway further out in the universe than them or not?
3) Is the milkyway older than them or not?
4) Is the milkyway moving faster than them?

Because as far as I can understand it, if those were among the first galaxies to be born and the universe is expanding, they would be on the outer edge of the universe and if the milkyway is younger, we would be made of interstellar dust further in towards the centre of the universe. So are they looking at them towards the out boundry where the would be really old and most likely non-exsistant any more or are they looking inwards towards the big bang itself where they are mostly likely to be actually young galaxies made from old dust.
I find this quite confusing. If it is easier to e-mail me the details then that would be fine.
If there happens to be someone in Wltshire, uk that might have a little time to explain this to me, great! But that would be very unlikely I suppose.

Thanks for reading.

[ - ] I am an Elementary School Teacher, and I think I can explain these. Please check my answers.

1) Which way physically are they looking? ( e.g. North, South, East or west etc.)
First, looking into the sky is looking back in time. In all direction, light travels to us from an earlier times. The stars we see may not be there in our time.

2) Is the milky-way further out in the universe than them or not?
YES, it is in the concept we are seeing them at an earlier time and not where they are at this time.

3) Is the milky-way older than them or not?
NO, we are just seeing them at an earlier time.

4) Is the milky-way moving faster than them?
The cute thing here is some we see are blue shifted, but most we see are red shifted.

david_phil
2006-Apr-08, 03:06 PM
Sorry that I haven't got back to you guys sooner as I have been on holiday.
Thanks for all of the replies.
Firstly, you are right, yes there are neutrino's but aren't they deficult to produce? Not the sort of particles that the rest of the universe might be "floating" in or help make up the missing mass of the universe?
My idea of the particle would be a bit like a deep sea fish swimming around in its watery world. As far as it's concerned the water is like space, everywhere around it, supporting it as it swims. It doesn't know where the centre is or the ends. It could swim around for years and not know that if it swam upwards in a sort time it would feel the temperature from the sun warming the water and so on.

If the big bang didn't actually come from one specific place why doesn't the scientific community give the scientific programs that pictorialy show the big bang as a typical explosion,hell!

Here is a question for you, would it theoretically, be possible for light to travel faster in deep space, say, in between galaxies where the main forces of gravity and electro-magnetism are at their minimum? Even if by one 100th of 1 percent would make our calulations for age and distance of objects out by quite some amount?
Got to go now.
Cheers!

Kaptain K
2006-Apr-08, 05:35 PM
...aren't [neutrinos] deficult to produce?
No! Neutrinos are very easy to produce. They are just very hard to detect!

Jeff Root
2006-Apr-08, 07:18 PM
If the big bang didn't actually come from one specific place
why doesn't the scientific community give the scientific programs
that pictorialy show the big bang as a typical explosion, hell!
They do the best they can. Scientists understand that. If you
want something more accurate, suggest an alternative.



would it theoretically be possible for light to travel faster
in deep space, say, in between galaxies where the main forces
of gravity and electro-magnetism are at their minimum? Even if
by one 100th of 1 percent would make our calulations for age
and distance of objects out by quite some amount?
If the difference in speed is one hundredth of one percent,
then the difference in calculated distances and ages would be
less than one hundredth of one percent. Which is quite a bit
less than the uncertainty in measurements of distances and
redshifts.

On the other hand, the speed of light has been measured to
considerably better precision than one hundredth of one percent.
The speed of light in vacuum is the value you generally see:
299,792,458 meters/second. This speed is different if the light
being measured is in a different gravity from the observer.
It is a known effect and is described mathematically by the
general theory of relativity.

-- Jeff, in Minneapolis

david_phil
2006-Apr-10, 08:59 PM
Yes Kaptain K I do apologise. Your right. My mistake about the neutrinos. As an alternative big bang, how about showing nothing and then everything, the whole universe for those first few nanoseconds as all matter be what ever matter they think it is and once gravity starts the matter starts to turn to the elements and everthing then divides into seperate clouds to make the galaxies which then continues to move away from each other as the do now.

For Jef, could neutrinos (if there were plenty of them) have an effect on photons? Vacuum on earth could be still full of neutrinos where in deepest space there maybe a lot less?

skyline5k
2006-Apr-11, 02:16 PM
The hardest part about picturing the big bang is the fact that just about every illustration out there suggests that the universe went from the size of an atom to a golf ball to a beach ball, to Earth, to Geidi Prime... in size. Yet that's not "really" the case, is it.

Of this I'm no expert, but after image googling "big bang" those are the best types of representations that could be given. The question always goes back to, if the universe was the size of a beach ball at one point, what was outside of the beach ball? Nothing they say. What's nothing?

Kaptain K
2006-Apr-11, 03:24 PM
Yes it is hard to wrap one's mind around it, but by definition, the Universe is everything that there is. To talk about what was before the big bang or what is outside the Universe is meaningless.

david_phil
2006-Apr-11, 09:27 PM
Yes Kaptain K but "nothing" mathmaticly speaking is the middle of everything!
-1, "0",1 etc.

Jeff Root
2006-Apr-11, 09:28 PM
Yes it is hard to wrap one's mind around it, but by definition,
the Universe is everything that there is.
I prefer a different, more limited definition, but I can go
with that one.



To talk about what was before the big bang or what is outside
the Universe is meaningless.
Using your definition, the second assertion is true, but the
first is not. The Big Bang didn't necessarily involve the
whole Universe. There's no reason to the think that the
Universe didn't exist before the Big Bang.

-- Jeff, in Minneapolis

davidhw
2006-Apr-12, 02:46 AM
to visualize the expansion of space in the Big Bang was never the balloon model, but rather the "raisins in the cake" one, i.e., if you imagine raisins in a dough being cooked, all the raisins move away from one another, not from some "central" starting point.

The appeal is both astronomical and gastronomical. :-)

skyline5k
2006-Apr-12, 03:54 AM
and Tasty too!

Perhaps we'll just have to add a few more dimensions to the fold to more easily explain where we are in the universe, and what's "around" it.

But it won't be me doing it. My math is horrible!

Darrrius
2006-Apr-12, 09:22 AM
As an alternative big bang, how about showing nothing and then everything

But how do you show nothing?

Kaptain K
2006-Apr-12, 02:56 PM
But how do you show nothing?
With great difficulty! ;)

Zamise
2006-Apr-12, 08:13 PM
Those questions do seem kind of funny, but also big ones. I think all the answers that I've seen so far are cop outs for explaining where one could point to and say that there is a direction where everything came from in our universe. There probably is information out there somewhere, some folks somewhere out there have had to have done the math by now, just hard to find out where to get that kind of information since it is much easier for people who don't really know the answer to just say it is nowhere and everywhere at the same time. How are you supposed to agree or disagree with that? Itís a cop out to not really knowing.

Jeff Root
2006-Apr-12, 09:09 PM
Zamise,

There is no cop-out. You want to know in which direction the
Big Bang occurred? Light from shortly after the Big Bang is
reaching us right now. It is the cosmic microwave background
radiation (CMBR). It comes from the entire sky. It comes from
13.7 billion years in the past. 13.7 billion years ago, that
light was being emitted from everywhere. It is still
travelling from where it started.

We know the distance and direction of the Big Bang: 13.7 billion
years in the past.

-- Jeff, in Minneapolis

Zamise
2006-Apr-13, 12:07 AM
Zamise,

There is no cop-out. You want to know in which direction the
Big Bang occurred? Light from shortly after the Big Bang is
reaching us right now. It is the cosmic microwave background
radiation (CMBR). It comes from the entire sky. It comes from
13.7 billion years in the past. 13.7 billion years ago, that
light was being emitted from everywhere. It is still
travelling from where it started.

We know the distance and direction of the Big Bang: 13.7 billion
years in the past.

-- Jeff, in Minneapolis

Um, what direction and distance is 13.7 billion years ago? Thats a time I thought, sorry. I was thinking if somebody could measure the direction and distance of things such as galaxies and deturman if they are all moving outward or away from each other, then perhaps they could also average those measurements to some point in outer space by which then they'd be able to roughly point to it. Maybe it wouldn't be where the start of the big bang occured, but they could say "Thats the point where everything is moving away from" like being in an explosion. Seems like that could be done, no? Even on televison, when they show a representation of the big bang you can see and point to where it started expanding outward and point to it. Maybe I'm just another victum of Bad Astronomy then. Thanks for trying to explain again, hope I don't seem too sarcastic to respond to, its only like my 3rd post here in 3 years heh.

Jeff Root
2006-Apr-13, 02:06 AM
Um, what direction and distance is 13.7 billion years ago?
The direction is toward the past (time is one-dimensional so
there are only two possible directions), and the distance is
13.7 billion years.



I was thinking if somebody could measure the direction and distance
of things such as galaxies and determine if they are all moving
outward or away from each other, then perhaps they could also average
those measurements to some point in outer space by which then they'd
be able to roughly point to it.
I presume you've seen the balloon analogy. It is flawed, but
for the limited purpose of showing that there is no center to
the expansion, it works fine.

Glue little bits of paper all over the surface of a balloon.
They represent galaxies, or clusters of galaxies. The distance
across the surface of the balloon represents distance between
galaxies or clusters. When you blow up the balloon, the pieces
of paper move away from each other. The farther apart two bits
of paper are, the faster they move away from each other.

No point on the surface of the balloon is the center of the
expansion. The only point that can be considered the center of
the expansion is at the center of the balloon. But that point
represents a point in the past, before the balloon started to
inflate, and the balloon and all the bits of paper were at one
point. After you blow up the balloon, there is no direction in
space you can point back to that location. The direction to
the beginning is toward the center of the balloon, and that is
a direction in time, not space. That time no longer exists.
The place is everywhere.

It sounds stupid, but it is an accurate description. Details
of the Big Bang may change a lot with new observations and new
theories, but the fact that it happened everywhere we can see,
with no center, is something that isn't going to change.

-- Jeff, in Minneapolis

Zamise
2006-Apr-13, 04:46 AM
What about the nozel on the surface of the balloon? Wouldn't it expand at the same time? And then that would be where one could point to, since that is where all the matter, energy and time it would take to expand it outward in a measurable direction and distance originate from initially? Maybe I'm just making things too complex, and that simple of an answer everyone gives just don't fly well with my rationalization. I want coordinats I can point to, for my kids or they will keep bugging me dang it! Kidding :)

Jeff Root
2006-Apr-13, 06:56 AM
I want coordinates I can point to, for my kids or they will keep
bugging me dang it!
If they are over ten years old, telling them that the direction
is backwards in time and the distance is 13.7 billion years will
probably impress them and they will be delighted. If they are
under ten, such an answer would probably only confuse them.

In any case you can say that the cosmic background radiation
comes to us from every direction-- from all over the entire sky--
and it has travelled 13.7 billion years to get here. Likewise,
light from the atoms that we are made of was given off at the
same time, and is now being seen by creatures 13.7 billion
light-years away from us, and they are probably struggling to
understand it, too.

-- Jeff, in Minneapolis

Irishman
2006-Apr-13, 03:28 PM
davidhw said:
to visualize the expansion of space in the Big Bang was never the balloon model, but rather the "raisins in the cake" one, i.e., if you imagine raisins in a dough being cooked, all the raisins move away from one another, not from some "central" starting point.

I never liked the "raisin cake" model, quite independent of my dislike for raisins in cake. The problem is that raisins do move away from a geometric center. They are pushed apart by the expanding dough in between, but there is a geometric center to the lump of dough, and there is a geometric center to the finished cake. There is also the bottom of the cake that sits against the pan and doesn't go anywhere, and the raisins spread away from the center of the bottom of the cake.

That analogy isn't really meant to show expanding without a center - that is what the balloon analogy is for. The raisin cake analogy is meant to show how spacetime itself expands between the galaxies/stars, not just the stars/galaxies moving apart in spacetime.


skyline5k said:
The hardest part about picturing the big bang is the fact that just about every illustration out there suggests that the universe went from the size of an atom to a golf ball to a beach ball, to Earth, to Geidi Prime... in size. Yet that's not "really" the case, is it.

Yes, that is in fact "really" the case. What that means from a standpoint of what was outside the Universe, what the Universe was expanding into, etc, is the 2 dollar question. But the expanse of existence we define as our Universe (the "local Hubble Volume, the expanse where all the galaxies and stars we see exists, everything created int he Big Bang, the field where our universal laws apply, etc) is belieded (based on evidence and reasoning) to have been physically the size of an atom, a golf ball, a beach ball, etc.


Of this I'm no expert, but after image googling "big bang" those are the best types of representations that could be given. The question always goes back to, if the universe was the size of a beach ball at one point, what was outside of the beach ball? Nothing they say. What's nothing?

Again, that's the big head scratcher. Most people define the Universe to include everything in existence. However, we also describe the Universe as beginning in the Big Bang. It is entirely possible that those two definitions are not the same thing. That is what Jeff Root means by his statement, "There's no reason to the think that the Universe didn't exist before the Big Bang." He's using the first definition and not the second (based upon his reading of what Kaptain K said).

Is there an existence, a something, larger than the Big Bang volume? How could we tell? We discuss the Big Bang as expanding, and in a lot of cases we say it is expanding but not expanding into anything. That is conceptually not-graspable by most people. Our experience of expanding is 3 dimensions, and expanding into empty space (or air, or water, pushing something out of the way to fill that space). The typical use for the Big Bang is that there is nothing there, including empty space. That just does not compute.

Ergo the philosophical debates over is there something outside the "universe", etc.

Zamise
2006-Apr-13, 04:09 PM
I think I'm getting what Irishman is saying a little better than whats been mentioned so far, it seems to make a little more sense to me the way he is putting it. Also, 13.7 seems not very old in comparison to the age of other things we supposed to know the age of too, I can't argue if thats the generally accepted age of the universe though which is probably a whole nother topic, but I don't think that is right either, something smells fishy and I cant put a finger on it, or point to it.

Tensor
2006-Apr-13, 04:38 PM
Also, 13.7 seems not very old in comparison to the age of other things we supposed to know the age of too, I can't argue if thats the generally excepted age of the universe though, but I don't think that is right either, something don't smell right and I cant put a finger on it, or point to it.

Here (http://www.astro.ucla.edu/~wright/age.html) is how that figure is arrived at.

Zamise
2006-Apr-13, 05:02 PM
Here (http://www.astro.ucla.edu/~wright/age.html) is how that figure is arrived at.

Funny, I was just looking at that page right before I came back here.

Tensor
2006-Apr-13, 05:06 PM
Funny, I was just looking at that page right before I came back here.

LOL, well, I guess that didn't help much then. If you want a good kinda, sorta, elementry intro to cosmology, the rest of the site that page is on, would be it.

david_phil
2006-Apr-13, 06:34 PM
Hi all, been working, missing out on all the fun.
If the universe is like an expanding balloon what is the air of the balloon then?
Are you saying that the entire universe is on that little thin membrane only?
Did you ever do the experiment in school where you put the deflated and tied ballon into a small vacuum chamber? As the air is sucked out, the ballon expands until it bursts or fills the chamber. The small amount of air that was inside the ballon expands too so not only do you get expansion of the balloon but everything inside expands too! So the total volume of the balloon is the universe and not just the outside. This means you could work out an actual distance in lightyears and not time. And any rate if the light from the big bang came before the galaxies and light( radiation) travels basicly in a straight line then it would have gone way before now or it bouced off something and come back! That then would give you false readings and a whole lot of other questions???????

Kaptain K
2006-Apr-13, 06:52 PM
The balloon analogy is just that, an analogy. It is a way to help visualise a difficult problem. It is not an exact representation, but a guide or model.

Are you saying that the entire universe is on that little thin membrane only?
Yes! The 2-D surface is a representation of the 4-D spacetime universe.

If the universe is like an expanding balloon what is the air of the balloon then?
It is irrelevant.

So the total volume of the balloon is the universe and not just the outside.
No! In the balloon analogy, the universe is the surface of the balloon, by definition!

david_phil
2006-Apr-13, 07:53 PM
In that case K I see it more as an Orange with its pips as the galaxies and dark matter as its flesh supporting the pips. As it grows the pips grow and move apart evenly with it. I look to nature itself for mimicing signs of larger more complex things. Such as huricanes on earth mimic spiral galaxies.

Tensor
2006-Apr-14, 01:14 AM
...Such as huricanes on earth mimic spiral galaxies.

But that is just another analogy, and incomplete at that. How many barred spiral or eliptical hurricanes have you seen?

Zamise
2006-Apr-14, 01:18 AM
Hey, check this out, this really helps visualize an explaining of the balloon model for an expanding universe from a link above that I did a little more browsing around on...

http://www.astro.ucla.edu/~wright/balloons.gif

I noticed that there is one dot almost in the center, you can see the rest expand outward, and actually so is that dot, but its moving directly toward or away from the line of site. It might be easy to conclude that the center dot would be near the center of the universe, but wait. Thing is, if you turned the balloon so that one of the other dots where closest to the line of site, it would look the same as the the other dot as the rest expanded around it. This sort of helped me visualize whats supposed to be going on and why we could not pin point a center to the universe based on the ballon model of the universe. However, I still think its flawed, which has been mention already, and I think somehow a center could still be found where some sort of nozel existed at least at one time like at the beging of the expansion of the universe, that somehow allowed a bit of another universe into this one and now like a balloon tied off in a vacume would keep expaning after that. I'm just not sure how that would be done, at least not using the model of a tied off balloon. This model would also seem to mean that if we traveled far enough in one direction we would wind up where we started too I think, goofy?

Don't know if that will help anyone else, but it sort does me, even if its not correct, at least I think I can grasp the concept of what everyone is saying now. Hope Ned Write don't mind me hotlinking that animation. If its against the rules or something, I hope a mod or admin can take care of it for me.

Thanks all,

Zam

david_phil
2006-Apr-14, 11:51 AM
Nice one Zamise! Well found.
Now is it right to say that energy cannot be destroyed but only changed into other energies. My idea is that as the universe expands all the different energies end up changing eventually into one energy, dark energy or as I like to call it potential energy. Then it collapses in on itself a bit like a star turning into a singlarity which re-starts the process over again. BANG!

Zamise
2006-Apr-14, 01:30 PM
Sounds intresting David. I don't know what to think exactly about that, but the latest I've heard is that the folks who know this stuff well don't think the universe will collapse, but will keep expanding until it fades out. It'll fade to dark matter or what I don't know. Maybe they've changed their minds since last I heard or heard wrong or told wrong, but anyway I've never understood much of what dark matter might supposed to be, maybe something intresting for me to read and learn more about next.

david_phil
2006-Apr-15, 11:23 AM
Well thats is what I mean. All the energies will turn to dark energy and the process will start again. A re-cylcing universe! If the general public thought that , it would really help in encouraging people to re-cycle wouldn't it! I have had this idea for a number of years. I do think that the experts look a bit too close and complex things sometimes. I think they need to take a few steps back sometimes and look at the bigger picture a bit more. As a engineer who does bespoke design work on occassions I find looking at the process as a whole helps to find a way of improving that part of the process. Well, works for me!

antoniseb
2006-Apr-15, 11:33 AM
A re-cylcing universe! If the general public thought that , it would really help in encouraging people to re-cycle wouldn't it!

I'm not sure that follows. I'd expect most people would take it as a sign that they don't have to recycle because the universe will do it for them. More to the astronomical point: I'm understanding from what you wrote that you think that the formation of black holes creates dark energy, and that this will somehow cause the whole universe to collapse.

If this is what you meant, I think perhaps you don't understand either black holes or dark energy. Every once in a while, we get someone here who wants to talk about the recycling universe, and they write some very non-mainstream things. Is there a website you guys are getting this from, or do you each re-invent it independently?

trinitree88
2006-Apr-15, 12:10 PM
Zamise,

There is no cop-out. You want to know in which direction the
Big Bang occurred? Light from shortly after the Big Bang is
reaching us right now. It is the cosmic microwave background
radiation (CMBR). It comes from the entire sky. It comes from
13.7 billion years in the past. 13.7 billion years ago, that
light was being emitted from everywhere. It is still
travelling from where it started.

We know the distance and direction of the Big Bang: 13.7 billion
years in the past.

-- Jeff, in Minneapolis

We need to remind ourselves, too, that the universal boundary conditions for the Big Bang need to include in them specific instructions so that after 13.7 billion years, the polarization of the CMB microwaves will line up with the ecliptic plane of the solar system in the Milky Way galaxy, in the Local Group of Galaxies.....not with most of the stars in the millions of all the other galaxies in the universe....our humble little sun. :shifty: This present anomaly will be the subject of much conjecture, and possibly a very unique insight in the next few years.

I remeber going to Tufts University in Medford, MA., to hear Steven Hawking speak. Someone in the audience asked him at the end about boundary conditions for the universe. Through his interpreter he replied "The boundary conditions of the universe are....there are no boundary conditions for the universe...and everybody laughed, because that's such a tricky question, then and now. But, if the polarization data hold up, and they seem to be....there's going to have to be a defined axis to the BB, and at least one boundary condition for both inflation, and post inflationary models. Pete.

david_phil
2006-Apr-15, 12:37 PM
If black holes suck in all matter, from stars, planets etc, where does all this matter and energy go to then? My idea of dark energy is a bit different to the general idea. That is why I call it potential energy. Energy waiting to happen so to speak. And I don't think it will colapse, just all matter turns back to their basic state and eventually to energy, then potential energy.
And as for re-cylcing universes, if more people are thinking on that line then that can't be bad. can it?

antoniseb
2006-Apr-15, 01:31 PM
If black holes suck in all matter, from stars, planets etc, where does all this matter and energy go to then?

Based on the gravitational attraction that things have toward these black holes, I think it is pretty obvious where this matter goes. It gets added to the mass of the object we call the black hole. It doesn't go anywhere else.

One other note, black holes don't "suck in" all matter. They attract matter the same way a star or planet attracts matter. Does Jupiter "suck in" its moons? No. They just keep orbiting it. Does the Earth suck in an asteroid that zips passed it? No, but it does change the path of the asteroid.

david_phil
2006-Apr-16, 12:23 PM
Sorry, suck wasn't the right word to use but you know what I meant. As for where you say the matter goes, that is just one of many theories of which I think is one of the less logical ones. If that was the case then for every ton of matter that is pulled in by the BH then the gravitational force would increase. The amounts that go in would exponentially increase the force pulling in more material until the galaxy is gone. I have yet to see a largely swallowed galaxy. If the power is so great that not even photons escape it then they must turn into energy and not matter. Why not?

antoniseb
2006-Apr-16, 12:37 PM
The amounts that go in would exponentially increase the force pulling in more material until the galaxy is gone. I have yet to see a largely swallowed galaxy. If the power is so great that not even photons escape it then they must turn into energy and not matter. Why not?

You are kind of waving your hands and saying it must be so, when it isn't. As far as anything more than a few hundred thousand miles from a stellar mass black hole is concerned gravitationally, it is just a small dense star. The planet Mercury does not get swallowed by our Sun, and it would not get swallowed by a one Solar Mass black hole that was suddenly exchanged for the Sun. Things don't pass near a black hole and magically change the laws of physics to change their trajectory to go into the black hole.

Similarly, if we were to add an extra ton to the mass of the Sun, it would increase in mass slightly, and the planets would orbit slightly more quickly, but that wouldn't exponentially increase the amount of stuff going into the Sun.

I'm not sure why you think that a large black hole in the center of a galaxy can somehow take away enough of the angular momentum of things orbiting in the galaxy so that they can find their way to the center. This just isn't the way things work.

david_phil
2006-Apr-16, 07:06 PM
Some scientists think that dark matter is all around galaxies a bit like roots in soil holding it together. If this too cannot escape the black hole then all might eventaully go in. It doesn't have to be a big hole. Like grains of sand in an egg timer the outer grains seem perfectly safe but eventually they all fall through.

Zamise
2006-Apr-16, 11:23 PM
I just cought the end of a show on the science channel, and it was saying that something, I didn't catch what, does escape black holes, and paraphraseing but it also said on a long enough time scale even black holes fade into nothing. Then it minamally went into the gravitational forces of black holes mergeing, which has always intregued me, but it didn't say much on the subject. I'd like to find out if its possible for black holes to orbit each other like binary stars, and if so could an unseen universe exist inbetween the two where everything is expanding outward except at the very center where the gravity may be perfectly in ballance, or if thats just not possible. Could stars with planets exist in that area? Would there be an outer boundry? Could there be a center of that, and could this idea be applied to a larger scale? Too many questions...

Tensor
2006-Apr-17, 03:07 AM
Zamise and david-phil, a lot of your questions here could be answered by this book (http://www.amazon.com/gp/product/0393312763/sr=8-1/qid=1145242522/ref=pd_bbs_1/104-7453934-6391148?%5Fencoding=UTF8). It's understandable without the math. For layman, I can't recommend it enough.

david_phil
2006-Apr-17, 05:59 PM
I understand the general opinion of how the universe is suppose to work. I know about Inflation, cosmic strings, Hawkings' turn around about the information paradox and yes they all give very valid possible explinations for things. I am trying to see things by starting with a clean slate with just the solid facts that man has now. All the rest still is theory, the same as mine. I just hope that even just one little thing that I say and you guys argue over someone might just say "hell he might have something there!" That would make little ole me very happy. That is what all of this is all about, everyone putting their penny's worth in until someone comes up with something so crazy or simple but it fits the jigsaw perfectly. So lets go!
Theoreticly, is it possible for a star to leave a galaxy? And if so, what would possibly cause it?

antoniseb
2006-Apr-17, 06:31 PM
is it possible for a star to leave a galaxy? And if so, what would possibly cause it?

Yes we've observed one or more stars doing that. They seem to have been cases where a double star has passed close to the SMBH in the center of the galaxy. The pair gets ripped apart, and one star falls toward the SMBH, while the other star goes sailing off at greater than escape velocity. This is a rare event.

It is also possible for an Asymmetric supernova explosion to launch a neutron star with greater than escape velocity, but we don't really know the mechnism for this yet (we have some ideas).

On the broader matter of looking for alternatives, if you have a real idea you'd like to explore please bring it up in the Against The Mainstream section of the forum.

Kaptain K
2006-Apr-17, 06:48 PM
All the rest still is theory, the same as mine.
Sorry, but it is not the same as yours. Yours is at best a hypothesis. In science, theory does not mean "guess"!

farmerjumperdon
2006-Apr-17, 06:52 PM
In that case K I see it more as an Orange with its pips as the galaxies and dark matter as its flesh supporting the pips. As it grows the pips grow and move apart evenly with it. I look to nature itself for mimicing signs of larger more complex things. Such as huricanes on earth mimic spiral galaxies.

I personally like the raisins-in-a-baking-muffin analogy since it has 3 dimensions and is not "empty" in the middle, (but rather has "galaxies" spread throughout).

neilzero
2006-Apr-17, 10:23 PM
Perhaps I can sumarise: It appears that The big bang ocurred at Earth and that Earth is at the center of the Universe. Likely, persons in far distant galaxies also observe that the big bang occured at their location and that they are at the center. The galaxy we are in blocks our view, more in some directions than others. Adjusting for this difference; evidence of the big bang is in all directions. We can not find a center. This seems counter-intuitive until you study non-Eulidian geometry. Persons who have made an indepth study feel there is compelling evidence for the big bang model. Competing theories are not nearly so robust, but that could change. As more observations are made a radically new model may emerge as the mainstream theory. Neil

david_phil
2006-Apr-18, 09:32 PM
I'm afraid that until someone who has the interest and resources to help me make my hypothisis into a fully fledged theory I have to stick with what I'm doing now- getting what info. I can from you guys. I haven't got a main-frame to produce models etc. or a radio telescope in the back garden, but you are nearly as good though. My idea is if dark matter connects the stars and planets together with the SMBH that would be why they stay in fairly standard orbit around the BH. But what if you were just about far enough away from the BH for its effects via dark matter bacome so small that you start to move away from the centre. The interesting bit then would be what effect it would have on that stars' local space-time. Closer you get to a BH the slower time goes, the further would be the opposite. Perhaps thats why more people say " isn't time flying by!"

david_phil
2006-Apr-27, 09:08 PM
Well, it looks like the end of this thread then!