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Fraser
2007-Mar-19, 03:00 PM
Come on, admit it, you've had this question. If the Universe is expanding from the Big Bang, what is it expanding into? What's outside the Universe? Ask any astronomer and you'll get an unsatisfying answer. ...

Read the full blog entry (http://www.astronomycast.com/cosmology/episode-28-what-is-the-universe-expanding-into/)

frednilert
2007-Mar-19, 10:21 PM
Thanks for providing a great pod cast generally and this episode in particular.

As I know you are aware this topic is hard to understand and I still “don’t get it”. I wonder if there is any other way of explaining “what is the universe expanding into?”

Steve Limpus
2007-Mar-19, 11:11 PM
Thanks for providing a great pod cast generally and this episode in particular.

As I know you are aware this topic is hard to understand and I still “don’t get it”. I wonder if there is any other way of explaining “what is the universe expanding into?”

Great show! :clap: I found it helped a lot. Here's how I see it now:

To science - there's "nothing" outside our universe, not even dimensions or time. Even if there is "something" we don't have any scientific terms of reference to describe it or any way of observing it.

There are various philosphical ideas out there to discuss different cool possiblities, but none of them are testable so are not relevant scientifically.

Just my view! :think:

Fraser
2007-Mar-19, 11:26 PM
When you write an email to your friend, how many points will that give you in Scrabble? The question doesn't make sense. Scrabble points are only awarded inside the game. Time, size, gravity, etc are concepts only relevant inside the Universe.

EvilEye
2007-Mar-20, 12:06 AM
I kept waiting for one of you to use the analogy of "distance" for time and space.

In other threads I tried to explain it this way.

Imagine you are alone in the empty nothing outside of the universe (if there could be).

And you want to "go ever there". You walk and walk and walk and walk....

Where are you now? You're in the same place you started. You have no reference point from which to determine anything.

There can't be anything outside of our doughnut (universe) - unless there is another doughnut nearby with which to measure ours against.

Most people like to think of the Universe like a galaxy. Where we are in this one, and can (in theory) go to another one. Unfortunatly the universe by the very definition of the word ...is EVERYTHING.

Your friend Phil Plait said it best.

"It's like asking 'What's north of the north pole?'"

SingleDad
2007-Mar-20, 12:42 AM
OMG my head hurts!!!

I love the show..... still trying to figure out... well everything after the open =/

KimB
2007-Mar-20, 10:42 AM
Never mind space, what is time expanding into?

Just a silly thought. As we look across the universe we see back in time, hey maybe the universe is expanding into time.

Another thought. When a 4 dimensional sphere passes through a three dimensional space you would see a small sphere growing from nothing reaching maximum dia then shrinking back to nothing. What would it look like to a three dimensional being inside the four dimensional sphere? Would it give the impression that the sphere (universe) was growing? when in reality it was just passing through.

EvilEye
2007-Mar-21, 03:36 PM
the 3 dimentions we can experience are all at 90 degrees from each other.

the 4th dimention is time.

another physical dimention would be 90 degrees from the other 3 first ones, so you would never be able to detect it except to detect it's effects on the other 3.

blueshift
2007-Mar-21, 08:34 PM
Never mind space, what is time expanding into?

J. Richard Gott and one of his students at Princeton wrote a paper several years ago proposing the possibility that a time loop existed where each event is preceded and followed by the same event. Like an episode in the Twilight Zone where the main character would wake up to the previous morning, there may have been such a rut that the dimension of time was curled up into. Entropy may have existed before the time loop broke its symmetry and may have been the cause of an asymmetry developing in the loop, allowing an expansion of the time loop into a future of never-before-events to occur.

Time, like space, may have expanded into today.

To ask what all 4 dimensions are expanding into has a relativistic underlying. Something else must not be expanding relative to it and that something else must further have an Aristotelian characteristic of being a special reference frame, violating the Copernican principle.

purdomj
2007-Mar-22, 01:55 AM
Very nice episode, I'm going to be thinking about this one for quite some time.

On a side note, Fraser mentioned at the beginning of the episode that the enhanced version of the show was being dropped due to feed confusion. While I understand this, would it be possible to still make the enhanced version available, but only as an optional download? I do not have an iPod or similar device, but quite enjoyed the enhanced version of the show by downloading the .mp4 file and playing it with Windows Media Player.

Thanks for a wonderful show!

Jesse

Fraser
2007-Mar-22, 03:25 AM
Very nice episode, I'm going to be thinking about this one for quite some time.

On a side note, Fraser mentioned at the beginning of the episode that the enhanced version of the show was being dropped due to feed confusion. While I understand this, would it be possible to still make the enhanced version available, but only as an optional download? I do not have an iPod or similar device, but quite enjoyed the enhanced version of the show by downloading the .mp4 file and playing it with Windows Media Player.

Thanks for a wonderful show!

Jesse

The enhanced versions took a lot of time to create, so we're going to focus our time on this improvements that more people can enjoy.

AliCDKey
2007-Mar-22, 04:49 AM
I have to say that episode blew my mind pretty much out of the water. Funny thing you should be talking about this because I decided to do a little research on how many theories there are on this finite or infinite universe theory and found this on Space.com:

http://www.space.com/scienceastronomy/top_10_weird_list-2.html

I personally believe that perhaps there is a bubble universe out there with parellel universes right next to ours. I do have question though about how the Universe is expanding...

Q: The pictures I've seen on how our Universe is expanding made me wonder about the two polar regions (I couldn't think of a better word to use to describe it) you see on the top and bottom of the expanding universe. Are we expanding all around (horizontally and vertically) or are we simply expanding just horizontally?

Sorry if that was a "noob-ish" question! :doh:

purdomj
2007-Mar-22, 11:46 PM
The enhanced versions took a lot of time to create, so we're going to focus our time on this improvements that more people can enjoy.

Fair enough.

Thanks again!

Jesse

wavey63
2007-Mar-23, 12:37 PM
Awesome show and awesome Podcast. I really have been getting into this lately and this is just what my brain needed, a good frying.Keep up the great shows and content!

traintaz
2007-Mar-25, 12:30 PM
i'm a former air traffic controller. the radio beacons that we used were omni directional. i'm wondering if, when the big bang occured, did it explode omni directionally as well? i picture in my mind a universe shaped like a peach, with the location of the big bang, in the center like the pit of the peach. this brings up my real question, if we could look far enough, would we see more of our universe as we look past where the big bang occured?

EvilEye
2007-Mar-25, 10:07 PM
i'm a former air traffic controller. the radio beacons that we used were omni directional. i'm wondering if, when the big bang occured, did it explode omni directionally as well? i picture in my mind a universe shaped like a peach, with the location of the big bang, in the center like the pit of the peach. this brings up my real question, if we could look far enough, would we see more of our universe as we look past where the big bang occured?

The main problem with the question is "where".

Before the Big Bang, there was no "Where" Where and when didn't have any reference point.

If you existed to see the universe begin, you would have been in it.

The other question I cannot explain. Many scientists believe that the universe is shaped sort of like a doughnut. No matter where you travel, you will eventually end up where you started.

I personally like to think of it this way....

Like time and space are all one... a bubble... like the earth.... But you can only move in one direction. Forward.

And if you continue in that direction, you will eventually reach a point where you began.

Even if the Earth expanded to the size of the Sun, you still could never traverse the surface without ending up at your starting point again. (provided you were going in a linear path)

Unfortunatly, we cannot deviate (at this date) from the linear path of time.

You can hold a DVD in your hand, and all points of time exist at once in that movie, right there in your hand... yet you can't experience it without watching it in a linear fashion and have it make any coherent sense.

SingleDad
2007-Mar-26, 02:28 AM
ok.... my daughter and I have listened to this pod-cast an uncountable number of times over the course of this week and we have come to one conclusion..... we want to eat the sprinkles off the dough nut

curry
2007-Mar-26, 06:27 PM
KimB, I think you are exactly right. The universe is expanding into time. We want to think that the edge of the universe is out there and expanding into space. The edge is right here in every point and it is expanding into the future. The universe is larger today than it was in the past and will be larger still in the future. Every point in the universe has a direct line of time back to the beginning an also into the future. Every point is the center and the edge. The universe is expanding into time right here, not into some space out there. The simple answer to, what is the universe expanding into, is that the universe is expanding into time.
Curry

Dulouz
2007-Mar-27, 08:38 PM
Come on, admit it, you've had this question. If the Universe is expanding from the Big Bang, what is it expanding into? What's outside the Universe? Ask any astronomer and you'll get an unsatisfying answer. ...

Read the full blog entry (http://www.astronomycast.com/cosmology/episode-28-what-is-the-universe-expanding-into/)

I love the show, and enjoyed this one.

I actually don't think it is a nonsense question to ask what is outside the Universe. In fact, it seems lazy not to ask the question.

The real answer is no-one knows. It helps science to make people excited and interested in the questioning, even if there is no answer, rather than being dismissive and snobbish about it. (I mean in general not you or Pamela)

It may be (almost certainly is) the case that Time and Space does not exist outside a finite Universe but there may be something else we had never thought about.

EvilEye
2007-Mar-27, 11:24 PM
Big or small we will ask questions like this forever.


(inverse)
If strings prove to be real... what are they made of? And then what makes them vibrate? And what are those things made of?

Roon
2007-Mar-29, 12:08 PM
"Homer, your theory of a donut-shaped universe is intriguing." -- Stephen Hawking on The Simpsons

JaceNicklien
2007-Apr-01, 01:30 AM
I do not believe asking "What is the universe expanding into?" is a "Nonsense Question".

If the universe is to be visualized as a "doughnut" (used loosely), and if this doughnut is surrounded by nonexistence, then the doughnut itself would not exist. If the universe exists, then where-ever the universe exists, must exist as well.

EvilEye
2007-Apr-01, 09:10 PM
I do not believe asking "What is the universe expanding into?" is a "Nonsense Question".

If the universe is to be visualized as a "doughnut" (used loosely), and if this doughnut is surrounded by nonexistence, then the doughnut itself would not exist. If the universe exists, then where-ever the universe exists, must exist as well.

Not exactly.

You could figure out that the Earth was a sphere without ever knowing what was beyond the sky above your head.

The universe includes time. Outide of that there is not even nothing. There is no outside.

In the curved nature of space, no matter how far you traveled in (what you believe to be) a straight line, you will eventually come back to your starting point. You can't go "away" from the center or a point beyond to the "outside" of the universe, because it doesn't have a center like a galaxy. The universe itself IS all of it. No more... no less.

curry
2007-Apr-06, 04:58 PM
As we look out, we see distant galxies all moving away from us. It looks like we are the center of the universe. We are, but we are not unique. Every place you could go in the universe would also look like it was the center. It would be the center.
There is no single point that is the only center or any edge away from that point. That concept requires an existing space that the universe expanded into. When you try to see the universe from the outside, you get a point center and an edge away from that center. We are not outside. All of the universe is inside of the universe. Every point is the center point. There is no edge to find out there. Everything out there is also the center.
When every point is the center, then there is no edge out there. Every point in a way is the edge that expands into the future.

Dulouz
2007-Apr-06, 08:52 PM
As we look out, we see distant galxies all moving away from us. It looks like we are the center of the universe. We are, but we are not unique. Every place you could go in the universe would also look like it was the center. It would be the center.
There is no single point that is the only center or any edge away from that point. That concept requires an existing space that the universe expanded into. When you try to see the universe from the outside, you get a point center and an edge away from that center. We are not outside. All of the universe is inside of the universe. Every point is the center point. There is no edge to find out there. Everything out there is also the center.
When every point is the center, then there is no edge out there. Every point in a way is the edge that expands into the future.

I enjoyed reading that - almost like Buddhist philosophy. Everyone and everything is both the centre of the universe to which all things metaphorically revolve and also the edge. Neither and both being true.

epitide
2007-Apr-12, 12:07 PM
Come on, admit it, you've had this question. If the Universe is expanding from the Big Bang, what is it expanding into? What's outside the Universe? Ask any astronomer and you'll get an unsatisfying answer. ...

Read the full blog entry (http://www.astronomycast.com/cosmology/episode-28-what-is-the-universe-expanding-into/)


If we were to say that the universe is CONTRACTING, we would say that it is shrinking and contracting into itself. We wouldn't be asking "into what!" The answer is straight forward: Into Itself!

So when we say that the universe is EXPANDING, we can say that it is just expanding out from it self. It's just expanding.

clint
2007-Apr-13, 01:10 PM
If we were to say that the universe is CONTRACTING, we would say that it is shrinking and contracting into itself. We wouldn't be asking "into what!" The answer is straight forward: Into Itself!

So when we say that the universe is EXPANDING, we can say that it is just expanding out from it self. It's just expanding.

Here's a different question:
What would happen to civilization (our earthly one or any other potential one) in those to scenarios.

Obviously, the contraction would be quite impossible to survive (unless you assume a multiverse which you could kind of 'hop' into for rescue)

What about expansion?
Would there be any theoretical obstacles to survival in an endlessly expanding (or even accelerating) universe?

I've heard about the universe eventually running out of energy in an ever-expanding scenario - could the assumption of dark energy affect or change this?

EvilEye
2007-Apr-16, 03:07 AM
If you believe in evolution, then the question is moot.

We will disolve like all the other species, either into something else, or die off long before it happens anyway. Being human doesn't give a free pass to the pool on the roof.

SSRedOctober
2007-Apr-18, 02:22 AM
The reason this question bothers me and so many other people (I hope I am not the only one that thinks of it this way) is because EVERYTHING including our universe should by our current understanding follow the same laws regardless of size or location. It is impossible for us to try to understand everything about the universe but we can make progress in our understanding by observing our near surroundings and making the logical assumption that everything else in the universe must follow the same laws. The way the rest of this universe must operate is the exact same way the universe operates in our known surroundings.
The only thing that makes sense is that the universe is indeed expanding. It is not a "cube of paper" and it is not a pastry. It is a mystery that we can not possibly comprehend. Even if the universe is indeed a particular named shape, it certainly must have a physical location, just as everything else does. However that location can not be described with an actual address such as 344,845,49 simply because we have no point to make a measurement from, everything is in constant motion throughout space. It is impossible to try to understand what shape the universe is and where it ends. Because at ones end there is anothers beginning. Even nothingness is something, and if that nothingness were to end, what would be beyond that? We just do not have the tools or the intelligence to understand. It is time to admit that we just do not know. We do not know what shape or how large the universe is, it could be exactly the size of our own solar system and everything beyond that is an illusion or a mind trick as God points and laughs at us trying to make up equations to understand where the end of the universe is.
To assume that the universe is shaped like a taurus or that the universe is only one among many is really just our attempt to stay sane and comfortable with our domination of our surroundings. We must have an answer or we feel inferior or scared which is unacceptable for many if not most people. Sorry everyone, but nobody knows, all we are is dust in the wind, never meant to understand EVERYTHING. We are indeed inferior in comparison to the one or the thing that created us. We are not the top of the food chain, the cosmos is the top of the food chain, and when the cosmos feel it is time for us to leave this planet we will be gone faster than a mild case of fleas on a short haired dog.

-Dustin Schroeder
feel free to email me to argue =D
starcraft834@yahoo.com

KiwiPhil
2007-Apr-20, 01:27 AM
Hi everybody,
Just wondering if anyone can give me any evidence for there not being anything outside of the universe or before it.

EvilEye
2007-Apr-20, 08:12 AM
Hi everybody,
Just wondering if anyone can give me any evidence for there not being anything outside of the universe or before it.

I can try to answer the first part.

You have a void. Put a point in that void and call it the universe. If you can see the point, then you are also part of that universe.

If you back up, then you are still part of that universe.

Regardless of how far away from that point you are, there is nothing beyond you. The universe is everything, everywhere and everywhen. And if you can observe it, then you are part of it.

You can't put a dot in a void and ask where it is. Where it is in relation to what?

SSRedOctober
2007-Apr-21, 07:21 AM
well said EvilEye. I like : "if you can observe it, then you are part of it." But the one argument I would make to that is this: We can not observe or understand dark matter, but it is most certainly. We give something we know nothing about a name and pretend we understand its effects and its properties. We observe its power, but we can not observe it or prove it is there. But we know it is there, right? Maybe so, maybe not. I like how you sum it up as everything, everywhere and everywhen though, that means that if there is/are "parallel universe/universes" that they are too part of one universe. Interesting.

EvilEye
2007-Apr-21, 12:49 PM
It can be further simplified by taking it down to 2 dimentions.

Imagine an endless sheet of paper.

Then put that dot on that sheet anywhere. Ask the dot, as you in the third dimention (up) look down on it) where it is, and the answer can only be "I am here". You ask "Where is here?" And the answer comes back "I am here. Where are you? I can hear you but I cant see you."

The dot has no concept of "up", so you cannot explain to him that you are in his presence. So to prove it, you move down through that sheet of paper. Dot senses your presence, and can still hear you, but you are only a veil of your whole as you pass through his 2 dimentional plane.

You disappear as you pass under the infinite sheet of paper, and Dot goes to work trying to explain this notion.

Dot is alone on this infinite sheet of paper and starts to ask where he is to himself. So he wanders around the sheet of paper and asks again, "Where am I but here?"

Then you put another dot on the paper. Now Dot and Dot 2 can see each other. Now you have time. Dot has distance & Time! He knows that it will take x amount of time to get to Dot 2. Now his question of "Where am I?" has meaning. "I am over here!" he can say to Dot 2. And Dot 2 has some location.

And Dot can ask Dot 2 meaningful questions now.

Now imagine that this infinite sheet of paper is one in an infinite stack of sheets with other "dots". They can never see each other, but they are all there amongst each other. (Multiple universes all occupying the same space in another dimention - the third in this case)

This isn't my idea... it's just a really simple way to explain how easy it is to see how hard it can be to contemplate something you can't see, but obviously exists.

KiwiPhil
2007-Apr-22, 10:14 PM
I think you've misinterpreted my question. You've given a good description of what it would be like if there is nothing outside the universe, but I'm ask what evidence there is for assuming there is nothing outside.

EvilEye
2007-Apr-23, 01:39 AM
That is a revolving question.

What evidence is there that there is anything at all outside of your own experience?

You are trying to place the universe in a "place". But the universe IS the place. Without the universe, there is no place. It isn't like a galaxy sitting in space. It is space and "stuff" all accounted for. You can't have five dollars in your pocket and ask where the other dollar is.

EvilEye
2007-Apr-23, 01:42 AM
Sorry.. my last attempt to explain it on my own. Asking what is beyond the universe is like asking how short something is.

KiwiPhil
2007-Apr-23, 02:12 AM
Okay try it this way. How so we know that there is nothing outside the area created in the Big Bang.

Anton
2007-Apr-24, 08:51 AM
How do we know that there is nothing outside the area created in the Big Bang.

We know that we don't know anything in this world for sure.

Therefore we also know that we know even less about what is out of this world.

So the answer is: We don't know.

What then do we know?
We know that if anything is OUTSIDE, it cannot be measured because measurement requires space and space is a consequence of the Big Bang.
We also know we cannot say it exists because that very word requires time to exist in and time is also a consequence of the Big Bang.

But don't despair! What we know and what we don't know reflect only one aspect of life. You just have to take a look at the discussions on episode 24 in this forum to see how willingly even the most fact-loving people dismiss those facts in order to let their minds free to roam the endless world of possibilities. And why not? We all need it and creativeness requires the ability to liberate the mind from the limitations of facts and knowledge.

And - even more importantly - in this OUTSIDE world where facts and knowledge are of no avail, your word is as good as another and your wildest speculation as valid as that of the most respected cosmologist.

Cougar
2007-Apr-26, 11:42 PM
We know that we don't know anything in this world for sure.
Actually, we know quite a bit about this world and even about the universe.


Therefore we also know that we know even less about what is out of this world.... We don't know.
I'd go along with that. We don't know anything about what is outside of our light horizon. No light or signals of any kind can reach us from "there," so... we don't know.

However, there are observations supporting inflation theory, and this would indicate:



"...the entire universe is expected to be at least 1023 times larger than the observed universe! ...if the inflationary theory is correct, then the observed universe is only a minute speck in a universe that is many orders of magnitude larger." -- Alan Guth


But don't despair! What we know and what we don't know reflect only one aspect of life. You just have to take a look at the discussions on episode 24 in this forum to see how willingly even the most fact-loving people dismiss those facts in order to let their minds free to roam the endless world of possibilities. And why not? We all need it and creativeness requires the ability to liberate the mind from the limitations of facts and knowledge.
Are you promoting the idea of living in a fantasy world? I think it's rather important to spend most of the time in the real world.


And - even more importantly - in this OUTSIDE world where facts and knowledge are of no avail, your word is as good as another and your wildest speculation as valid as that of the most respected cosmologist.
That's why most scientists are not even interested in such speculations. Why bother?

Anton
2007-Apr-27, 10:30 PM
Actually, we know quite a bit about this world and even about the universe.

Oh, I think there’s room for some humbleness here. Humanity is still in the “shock phase” of discovering the size and nature of the universe. My simple point is, we do not know all that much “for sure”.


”...if the inflationary theory is correct, then the observed universe is only a minute speck in a universe that is many orders of magnitude larger."

Yes and however large it may be it still is part of the spacetime created in the Big Bang. It’s still “inside” whereas KiwiPhil was asking about the “outside”. The common answer might be that as long as we can think of SOMETHING being outside or inside we can be sure it is part of the “Big Bang area” (to quote KiwiPhil) because that is the only place where these concepts have a meaning. But I wanted to give him a little more credit. It is quite common even for respected scientists to leave the realm of established facts every once in a while and allow themselves to speculate freely, or as you say, to live in a fantasy world for a while. It doesn’t hurt and it can be creative. And – it’s a world where KiwiPhil and you and I and Einstein can meet on an equal basis. We might not want to build a house there but it sure is worth visiting. I can recommend it ;)

JaceNicklien
2007-Apr-28, 07:27 PM
You have a void. Put a point in that void and call it the universe. If you can see the point, then you are also part of that universe.


Assuming by void we're talking about non-existence, I would like to see how you would place a point in it.
Hence what I said earlier, you can not exist in non-existence. Therefore if the universe exists, and it's expanding, then it must be expanding into something.

eric_marsh
2007-Apr-29, 04:29 PM
I have always enjoyed listening to Pamela, all the way back to the Slacker's Astronomy days. This episode has to be as much fun as any.

So if our universe is eaten by another universe with different parameters, what would we see? Would the two sets of parameters average out?

Seems that the question of what the universe is expanding into comes back to the root question of what started everything. For the Big Bang to have occured there had to be the potential for it to occur. So "where" did that potential exist? Certainly the "where" can not be viewed in terms of the dimensions of our universe because they did not exist.

KiwiPhil
2007-Apr-29, 08:23 PM
Hi, just wondering why everyone thinks that 'everything' came from the Big Bang?

EvilEye
2007-Apr-29, 11:07 PM
Yes. By saying void.. I meant absolutly nothing.

Putting a point in "it" was hypothetical.

If there is nothing, then where do you put the point? Anywhere you wish, because it's all the same. And that is MY point.

KiwiPhil
2007-Apr-30, 09:23 PM
I'm afraid this explanation is a little too unsatisfying for me. Correct me if I'm wrong, but the reason I've heard most often for there being nothing outside the universe is that everything that we can see is from the Big Bang so we can not know what occured before, therefore we should assume that there is nothing outside. I've just never recieved a good reason to make that assumption.

Anton
2007-May-01, 11:01 AM
… the reason I've heard most often for there being nothing outside the universe is that everything that we can see is from the Big Bang so we can not know what occured before, therefore we should assume that there is nothing outside. I've just never recieved a good reason to make that assumption.

That assumption is not forced upon you. The big answer is: We don’t know! Nobody knows!

Science deals with facts. Facts are established by discovering and measuring that which can be discovered and measured which automatically limits it to the spacetime created by the Big Bang. Outside that, science is completely and utterly useless.

Are you with me, KiwiPhil?

EvilEye
2007-May-01, 07:09 PM
How about this then. The Universe started inside itself. Its creation didn't happen in a where. It CREATED the where.

The universe isn't like the Earth where there is a clear outer edge (the surface) that you can go away from and go somewhere else in "space".

The universe incorporates time, and time is bent just like gravity can bend light. The universe folds back onto itself. There is no way to escape it. (short of maybe falling into a supermassive black hole)

If the universe were like the Earth only larger, then the question would make sense, but it is not, so the question really is moot.

eric_marsh
2007-May-02, 12:31 AM
I agree that the "where" in terms of what we understand "where" (x,y,x,t) started when the universe started. But as I said in a previous post, there has to have been the potential to create the universe and so where (in an entirely difference sense) did the potential exist. I guess I'm saying that there must have been some sort of potentials space, if you want to call it that.

EvilEye
2007-May-02, 01:21 AM
I agree that the "where" in terms of what we understand "where" (x,y,x,t) started when the universe started. But as I said in a previous post, there has to have been the potential to create the universe and so where (in an entirely difference sense) did the potential exist. I guess I'm saying that there must have been some sort of potentials space, if you want to call it that.


We don't know is the best answer but as a goofy guy on a farm I will try my best to explain it in my mind.

Imagine what it was like before you were born. Not the world and the people that made you. You yourself. There just simply was no you. And then there was.

There was always the potential for a "you", even from the point of the Big Bang. You are part of it. Every part of you is just as old as the Universe.

But you didn't exist. And then you did.

As Frasier and Pamela have said over and over, potential energy doesn't have to have a place. It just extists. Where? Nowhere.

When that rubber band releases that energy, it is released and all kinds of things (the Universe) can happen.

You just can't ever ask where that rubber band was. Because it wasn't... it was just potential energy waiting to be released.

Another way of trying to visualize it in just 3 dimentions is a box that represents everything. Fill it with nothing. Dig a hole in that nothing, climb into the hole, and pull the hole in after you. Then play that backward, and you have the big bang.

KiwiPhil
2007-May-02, 04:06 AM
Ok, let me state this a different way. I definitely believe in the Big Bang. However, I do not believe that the universe started in the Big Bang.

What reasons are there to believe that 'Time' and 'Space' began at the Big Bang. So far none of your posts have stated the reasons this must be.

Anton
2007-May-02, 12:15 PM
Ok, let me state this a different way. I definitely believe in the Big Bang. However, I do not believe that the universe started in the Big Bang.

What reasons are there to believe that 'Time' and 'Space' began at the Big Bang. So far none of your posts have stated the reasons this must be.

If time and space did NOT originate in the Big Bang there simply was no Big Bang. Einstein gave us all the reasons for that. Why would you believe in an idea that took a hundred or more years to develop and not believe in the results?

But when we talk about the Big Bang, we talk about our universe, our space and our time. As far as I know no one can prove you wrong (or right) if you claim that the Big Bang occurred inside another spacetime or on a turtles back.

KiwiPhil
2007-May-02, 08:28 PM
The reasons for believing in the Big Bang are that everything that we can see, has been calculated to have come from a single area. There is still no reason to assume that 'Time' and 'Space' did not exist before then.
All events in our universe should, theoretically, have there ultimate cause in the Big Bang. However I also believe there must be a cause to the Big Bang itself. The fact that everything obeys the idea of cause and effect should still include the Big Bang, as this definitely seems to be an effect.

EvilEye
2007-May-03, 01:16 AM
Kiwi... You are looking for evidence before the evidence existed.

KiwiPhil
2007-May-03, 01:29 AM
The assumption that nothing existed also needs evidence.

EvilEye
2007-May-03, 04:06 AM
The assumption that nothing existed also needs evidence.

And if you had evidence of nothing, what would it be?

Rororoyourboat
2007-May-03, 04:55 AM
Wouldn't the fact that one had evidence of nothing be evidence of something?
or
Would the evidence of nothing negate the evidence of anything... ahh

EvilEye
2007-May-03, 03:17 PM
Space is not nothing. Nothing is nothing.

If you and I are in a void, the only space there is, is between the two of us.

That space can expand if we move away from one another. If there is only one of us, then there is no space to expand.

clint
2007-May-03, 03:40 PM
Space is not nothing. Nothing is nothing...
Actually, there is no such thing as 'empty' space in our universe, right?
As I understand after show 32, everything is full of neutrinos, for a start ;)

Anyway, I think the core of the problem is that most laymen (and I include myself)
are still struggling with many of the phenomena of spacetime as we know it

However, the idea of 'there must be something outside' comes much more natural - even if it does not make any sense scientifically :think:

EvilEye
2007-May-03, 07:49 PM
Actually, there is no such thing as 'empty' space in our universe, right?
As I understand after show 32, everything is full of neutrinos, for a start ;)

Anyway, I think the core of the problem is that most laymen (and I include myself)
are still struggling with many of the phenomena of spacetime as we know it

However, the idea of 'there must be something outside' comes much more natural - even if it does not make any sense scientifically :think:

The answer is the same even though I suspect you are approaching it from a "something" point of view, and I am approaching it from a distance perspective.

Just like you can't have an inside if there is no outside, and you can't have an empty box without a box, you can't have space without distance.

In a hypothetically perfect void. No mass, no matter, ...perfect nothingness... there would be no measurement. There would be no time, no-'where'.

We keep trying to picture in our minds a perfect blackness that you could somehow move through.

But your own existence in that void would...well... void the void.

Now you have distance, which creates time. And since you are made of atoms, you have space (between the atoms) and time. In physics, you would try to fill that void, so you would be sucked apart and spread infinitely (and equally) throughout the void. And since it is endless, all of your atoms would cause the space between them to expand infinitely, going faster and faster forever and ever.

clint
2007-May-03, 10:19 PM
Ok, I get the ... point :lol:

No, seriously, between this last post of yours and the image of the endless paper sheet with a dot on it,
I think I'm starting to get the idea. Great explanation!


It can be further simplified by taking it down to 2 dimentions. Imagine an endless sheet of paper...


Last question, using that same image:
How did the point get onto the paper?
Doesn't that require some outside event to start it all?

Even if it's outside our spacetime, maybe from an additional dimension?
(in the image you use, that would be from the 3rd dimension,
outside the two dimensions of the endless 2D-paper sheet universe)

Isn't this - very roughly - how string theory tries to explain the Big Bang, by the way?

KiwiPhil
2007-May-03, 10:59 PM
I guess what I'm trying to say is, why does there have to be a 'hypothetically perfect void' at all. What reasons are there for believing that there is no matter outside the area created in the Big Bang?

EvilEye
2007-May-05, 12:15 AM
I guess what I'm trying to say is, why does there have to be a 'hypothetically perfect void' at all. What reasons are there for believing that there is no matter outside the area created in the Big Bang?

As no one in 3 pages have been able to adequately answer your question, my next suggestion is that you postulate a new theory, test it and write your own thesis explaining the answer you want.

Who knows? You may be the next Einstein.

Your question: "Where is nothing?"

My answer is nowhere.

If matter, time or space exists... it is within OUR universe.... or it is unattainable.

Unacceptable to you? OK.... You figure it out and tell US.

Much Love,
EE

Anton
2007-May-05, 11:54 AM
What reasons are there for believing that there is no matter outside the area created in the Big Bang?

KiwiPhil, your question may very well represent a lot of people so could you please help me understand what you are actually asking about? I am starting to believe that we are all trying to answer a question that you never meant to ask! As I see it, there are two alternatives here:

1. You are one out of millions of otherwise well-informed people who have never understood the Big Bang theory (or relativity) well enough to realize what it claims. Your post #52 might imply that you think of the Big Bang as an explosion and that you believe in it only because you find it logical that we can calculate backwards to a point in time when that explosion occurred. Well, most of the answers that you have received on this forum try to convey that the Big Bang is not that at all and if this misconception of the Big Bang theory is the reason for your question (and you have my full respect because you are certainly not alone) then I believe you should not turn to this forum for the answer. You should read a few good books on the subject!

On the other hand you might be putting an entirely different question. In that case you have just not done a good job explaining that to us:

2. You fully understand and accept that the very foundation of the Big Bang theory is that the universe that we observe and the space that surrounds us and the time that we live in – the interwoven concept of space-time – all originates in a singularity with no dimensions at all. If that is your position, your question is rather whether the Big Bang that caused OUR universe could take place INSIDE another universe, another space-time. Then I suggest you read a little more till you realize that you have just asked: “What is south of the south pole?”. If that question still makes sense to you, I offer the answer “Nobody knows and nobody CAN know because our concepts of space and time are as confined to our own universe (read my post #46) as the concepts of north and south are confined to the surface of the Earth”.

So in the first case, you are putting a question that can be answered by the Big Bang theory if you take the time to study it. In the second case your question can never be answered. It would be most clarifying if you could tell which category is yours or if you can find yourself a third one.

clint
2007-May-07, 09:37 PM
If you believe in evolution, then the question is moot.
We will disolve like all the other species, either into something else, or die off long before it happens anyway. Being human doesn't give a free pass to the pool on the roof.

I agree on that one,
but what about the survival chances of ANY species, ANY life?
(I mean, independent from the question if we humans can make it or not)

I was wondering wether an ever-expanding universe would pose any theoretical obstacles to the survival of ANY form of life?
(e.g. by going dark and running out of usable energy at a certain point in time)

AmroB
2007-May-08, 07:55 PM
Hi KiwiPhil,

You might like to have a look at two articles at Space.com (Links are at the bottom). I think that you’ll like these two hypotheses.

You can assess how deep your understanding to the Big Bang theory is, and why it is the most accepted model up to date. However, I think Anton is making a lot of sense in his post number 63.

While I’m at it, in my first post on this forum, I’d like to say hello to all forum subscribers. I hope to benefit from this forum and contribute where I can. And of course, very well done to Fraser and Pamela on Astronomy Cast. I love it, and love your approach guys. Thanks!

Article one Ekpyrotic Universe at

http://www.space.com/scienceastronomy/astronomy/bigbang_alternative_010413-1.html

Or this tiny URL

http://tinyurl.com/6ugu

Article two Cyclic Universe at

http://www.space.com/scienceastronomy/060508_mm_cyclic_universe.html

Or this tiny URL

http://tinyurl.com/qxuzg

KiwiPhil
2007-May-08, 08:25 PM
Anton, I couldn't help grinning when I read your post. mostly because I do fall into your first category. That is I do think of the Big Bang as an explosion. However, I have read quite a few good books on this subject and consider myself reasonably well informed. That said, if you would recommend some reading to sway me to your way of thinking, it would be well recieved.

EvilEye, As you may have guessed from my particularly leading questions, I do indeed have a theory about all this but really have no idea who to talk to about developing it further.

EvilEye
2007-May-08, 11:05 PM
Kiwi... You need to write a thesis. You don't need to be in college. Einstein wasn't. Your ideas are just as valid as established beliefs until they can be discounted.

I never meant to sound short with you.

Until I learned what I know now I too thought of the Big Bang as an "explosion".

Anton
2007-May-09, 10:24 PM
I do think of the Big Bang as an explosion. However, I have read quite a few good books on this subject and consider myself reasonably well informed. That said, if you would recommend some reading to sway me to your way of thinking, it would be well recieved.

Good to hear from you, KiwiPhil! I don't intend to persuade you over more than perhaps in modifying you statement in your post #50: "I definitely believe in the Big Bang."

Ever since Sir Frederick Hoyle, who definitely did not believe in the Big Bang, was unfortunate enough to accidentally name the theory almost 60 years ago, the term has stuck in everyone’s mind. Therefore it’s a very good idea to not use the Big Bang label to represent anything else. It should for ever be reserved for the theory independently conceived by Fridman and Lemaître, based on Einsteins general theory of relativity, developed by Gamow, Alpher and others, postulating that our universe originates from a singularity – a point with no dimensions in space or time – where Edwin Hubbles observations of receding galaxies is explained by the expansion of the space-time fabric.

If you believe in a big explosion, maybe you should call it the Big Blast or something similar. After all, the most common misinterpretation of the Big Bang also deserves a name :razz: and I agree with EvilEye, yours might be the embryo to a new grand theory. In any case, you are of course most entitled to hold that view. I can think of a few things to consider, though.

You would have to explain why galaxies pick up speed the further away they are from us. That would hardly be the case if they were flying away due to an explosion inside an existing space, whereas it follows by necessity if space itself is expanding.

As I see it we would also have to accept that our Milky Way galaxy is the very center of that primordial explosion since in a “pre-existing” space there must be such a center and the vast majority of galaxies can clearly be seen to rush away from us. In the Big Bang on the other hand, every point in the universe is part of the original center and every point, unless gravitationally bound, is naturally receding from every other point.

Simon Singh has written a good overview called, eh, Big Bang!

EvilEye
2007-May-10, 02:54 AM
You would have to explain why galaxies pick up speed the further away they are from us.

That one is easy. The universe is over 1/4 old.

Imagine streching a rubber-band beyond its limit. (Remember that a PERFECT vaccum would pull our universe against the force of gravity.)

At some point, the rubber band will BREAK. And when that happens what happens? The ends along with the whole thing, expannd faster in opposite directions exactly.

Expansion faster than gravity is not unnaceptable if we didn't know the first part of the equation - meaning the 1/4 of the timeline of the complete Universe.)

What I mean is that we have no way of knowing where half-way is.

Regardless of the theory, our Universe will cease to exist someday.

We know how old the universe is NOW, but we don't know how old it WILL be when it dies, so we can't know why we are expanding faster. We could still be in the first half of an explosion, or we could be at the end of a rubber band that snapped long after it passed the half-way mark.

Anton
2007-May-10, 03:15 PM
...we can't know why we are expanding faster.

I am not sure I’m smart enough to follow your argument here but I get the impression that you are talking about the increasing expansion rate of the universe (for instance due to dark energy) whereas I am talking about Hubble’s law (showing that the velocity at which distant galaxies appear to move away from us is proportional to their distance). Again:

If the velocity at which distant galaxies appear to move away from us is gradually increasing the further away they are, that would be a proof for the Big Bang statement that space itself is expanding: the further away to start with, the more space there is in between that can expand.

If instead we had a Big Blast INSIDE an existing space (ordinary explosion), at least I would not expect any such effect.

The fact that the whole universe is also increasing its expansion rate is a subject for another show, to quote Pamela and Fraser.

KiwiPhil
2007-May-10, 08:11 PM
If the velocity at which distant galaxies appear to move away from us is gradually increasing the further away they are, that would be a proof for the Big Bang statement that space itself is expanding: the further away to start with, the more space there is in between that can expand.

If instead we had a Big Blast INSIDE an existing space (ordinary explosion), at least I would not expect any such effect.



As far as I'm aware the velocity of singular galaxies are not increasing, (except for the effect of dark energy) unless you mean that the further they are from us the faster they appear to be travelling. This is just the standard definition of expansion, which I agree with.

Now correct me if I'm wrong, but if an explosion happened in a frictionless environment wouldn't it have the same sort of expansion if there was nothing to slow it down? (apart from gravity)

Anton
2007-May-10, 09:58 PM
As far as I'm aware the velocity of singular galaxies are not increasing, (except for the effect of dark energy) unless you mean that the further they are from us the faster they appear to be travelling. This is just the standard definition of expansion, which I agree with.

Yes I am referring to recessional velocity, that is the velocity at which distant galaxies APPEAR to move away from us. This means, as you say, that the galaxies themselves are not moving (which by the way they would be if we were talking explosion) but the space between them is expanding. If we call that “the standard definition of expansion” it is only because the Big Bang theory has become the standard theory. The theory explains why galaxies SEEM to move faster the further away they are, namely because of the expansion of space-time itself and that makes it a very unique kind of expansion.


Now correct me if I'm wrong, but if an explosion happened in a frictionless environment wouldn't it have the same sort of expansion if there was nothing to slow it down? (apart from gravity)

If you had a standard explosion inside an existing space you would NOT get that increasing effect because here it would be the galaxies that were moving (and let’s forget about gravity, dark matter and dark energy since these factors for now are not relevant and will only serve to confuse). The explosion would occur in a specific place inside that space and pieces of matter would fly away from that point in all directions at approximately the same speed. Each piece would maintain its speed. No force would act to increase it. What would you see if you could sit on one of these pieces? Well, you would certainly not find that all the other pieces were flying away from you. Those pieces behind you (in the direction of the original explosion point) and the pieces in front of you would maintain their distance to you since you were headed the same way and even if some of them were much farther away than others, that would not make them move faster. The ones that would recede at the highest speed would be the ones flying in the opposite direction. There would be no increase in speed whatsoever due to distance.

If you could remain at the original center of the explosion (and that’s where we appear to be) you would see all the other pieces of matter fly away from you at the same speed regardless of distance.

I think that if you agree with the standard definition of expansion as you say you do, then you have thereby already accepted that space itself is expanding and if you follow that backwards you will get to a point that contains not only all matter (like in an explosion) but all of space and all of time.

Sorry, I must keep it shorter next time...

EvilEye
2007-May-11, 12:09 AM
If we are but one of endless universes, like the foam of bubbles...

Expansion occurs within each of these bubbles for a time, and then one tiny bubble expanding next to a neighbor doing the same....with all neighbors around THEM doing the same, 2 of the bubbles suddenly open to each other, and become one larger bubble. Near the point of the time they are coming together, they begin to speed up radically, and then snap and then slow as the larger single bubble wobbles a tiny fraction of time and settles.

We may be at the point shortly before the universe snaps together with another.

Our neighbor is knocking, and we haven't let them in ....yet.

Fisherman
2007-May-12, 07:05 PM
Scientists also confirmed that in the first 8 billion years in the existence of the universe gravitational center collapse in the universe started to decay. Dark matter began losing its gravitational pull against the dark energy, began to pull apart the universe causing the galaxies to collide with each other (an example thousands galaxies collided in Abell 754.) A similar event of an explosion was accrued in the universe a side of the ball was ripped apart and allowing the galaxies to escape from the universe. Milky Way and many galaxies that were outside of the universe science believe that all these galaxies are part of the universe and appear to them more flat in shape. Galaxies will drift further and further apart and expend forever in endless dark space. Science also has similar theory hypotheses the universe will continue to expand.

As we compare evolution of the universe with a computer.
The first computer was build 1946 weight 28 tons, size 80’wx8’h, performance 5000 addition problems/sec. and inside 17840 vacuum tubes.
Computer build in 2006 weight negligible, size 90.3 sq.mm, performance 21.6 billion ops./sec. and inside 151.6 m transistors.
We can call evolution of a computer but who was behind of this marvel?

Also we should look at the universe in the same way there must be very intelligent Beings who has knowledge and purpose of their creation.

KiwiPhil
2007-May-14, 08:48 PM
The explosion would occur in a specific place inside that space and pieces of matter would fly away from that point in all directions at approximately the same speed. Each piece would maintain its speed. No force would act to increase it.

I'm afraid I must disagree. If you took a sphere of 'perfect' explosive, one in which every particle of it's mass repelled every other particle with the same force, then the particles on the outer edge would move the fastest due to having the combined forces of everything else pushing against them. This force would get steadily less as you look deeper because there would be less particles to supply the force. Each piece would maintatin its speed. No force would be needed to increase it. Each piece would already be moving in the appropriate way.

Anton
2007-May-15, 10:32 AM
If you took a sphere of 'perfect' explosive, one in which every particle of it's mass repelled every other particle with the same force, then the particles on the outer edge would move the fastest due to having the combined forces of everything else pushing against them. This force would get steadily less as you look deeper because there would be less particles to supply the force. Each piece would maintatin its speed. No force would be needed to increase it. Each piece would already be moving in the appropriate way.

OK, that’s intresting…

The Big Bang Theory has been developed during an 80-year period (90 or even 100 if you include the Einstein foundations). Over those years it has been refined and proved over and over again. Naturally, that does not exclude the possibility that another theory might one day replace it but, to say the least, the theory has had a good start.
The Big Bang Theory claims that the universe originates in a singularity and therefore is not an explosion of matter inside an existing space but an expansion of space itself.

I have two questions for you:


Why, in your opinion, is Hubble’s expansion law (that the speed of recession is proportional to distance) considered to be a key evidence in support of the Big Bang Theory?

If the expansion that we observe (that is expressed in Hubble’s law) can be explained by an explosion of matter in space as described by you, is there any other place our own galaxy can be located than in the dead center of that original explosion?

KiwiPhil
2007-May-15, 07:40 PM
Why, in your opinion, is Hubble’s expansion law (that the speed of recession is proportional to distance) considered to be a key evidence in support of the Big Bang Theory?

For the same reason as everybody else. Because all the Galaxies are moving apart, at some time they must have been much closer together.




If the expansion that we observe (that is expressed in Hubble’s law) can be explained by an explosion of matter in space as described by you, is there any other place our own galaxy can be located than in the dead center of that original explosion?


Absolutely. It can be anywhere out of the viewable range of the edge. All Galaxies are still going to be moving away from each other in a uniform way. It can't be within a viewable range of the edge otherwise we would notice a lack of stars from the area outside.

EvilEye
2007-May-15, 09:20 PM
But the big bang (bad name) didn't happen "over there".

We are a product of it still existing.

Fisherman
2007-May-16, 07:52 PM
A different way to expain "Big Bang"

At the beginning of time there was a huge Single Light where the Light Beings (or ET’s) lived as an undivided Light. The Light decided to have purpose for their existence. Up to now the Light had drifted aimlessly through endless dark space. The Light Beings decided to create the universe and chose the size and the shape of the universe a very simple design -a ball with patches--to hold all of the galaxies. It appeared to me as a huge ball with patches stitched together (similar to a soccer ball). The Light Beings constructed the first universe and this huge ball was one billion light-years in diameter (also science confirmed that the 1st universe was much smaller and was galaxies primitive design) The Light decide to separated themselves into 12 billion individual Light Beings. Every Light Being had chosen the way he likes to be different in his appearance and understanding, in other words every Light Being wanted to be unique. The ball (universe) was ready for the creation of the galaxies.
Before construction started each Light Being had to calculate his own galaxy, such as how the galaxy would look like, how big it would be, and how many arms it would have. The size of the galactic center needed to hold all stars, planets and moons and the rest of the parts of the galaxy. In the first created universe, the galaxies exploded more or less at the same time, as the galaxies were created at the same time (science have own similar explanation of Big Bang.)

Anton
2007-May-16, 08:44 PM
For the same reason as everybody else.

I doubt that!

In your version, Hubble's law is NOT a key evidence for the Big Bang but rather for a Big Blast. So to clarify my question:

Why, in your opinion, is Hubble’s expansion law considered by the general scientific community to be a key evidence in support of the Big Bang Theory INSTEAD of the "Big Blast"?

Let me quote Wikipedia which sums it up quite nicely:


"The metric expansion of space is a key part of science's current understanding of the universe, whereby spacetime itself is described by a metric which changes over time in such a way that the spatial dimensions appear to grow or stretch as the universe gets older. It explains how the universe expands in the Big Bang model, a feature of our universe supported by all cosmological experiments, astrophysics calculations, and measurements to date.

The expansion of space is conceptually different from other kinds of expansions and explosions that are seen in nature. Our understanding of the "fabric of the universe" (spacetime) requires that what we see normally as "space", "time", and "distance" are not absolutes, but are determined by a metric that can change. In the metric expansion of space, rather than objects in a fixed "space" moving apart into "emptiness", it is the space that contains the objects which is itself changing. It is as if without objects themselves moving, space is somehow "growing" in between them."

For all I know, your idea might lead the way to a new standard creation theory, but it seems to be decades behind when it comes to "cosmological experiments and astrophysics calculations" to prove it. And it definitely stands in opposition to the Big Bang Theory which you have claimed to believe in ;)

KiwiPhil
2007-May-17, 07:56 PM
Sorry anton but I disagree.

It seems to me that your quote from wiki:

It explains how the universe expands in the Big Bang model, a feature of our universe supported by all cosmological experiments, astrophysics calculations, and measurements to date.

So It's not really saying that the Big Bang model is supported by all cosmological experiments, astrophysics calculations, and measurements to date, but just that the expansion of it is. After that it is speculation.

These cosmological experiments, astrophysics calculations, and measurements to date can also support alternative theories, as long as they don't directly disprove them.

Anton
2007-May-17, 09:31 PM
These cosmological experiments, astrophysics calculations, and measurements to date can also support alternative theories, as long as they don't directly disprove them.

Your last post indicates that I might finally have persuaded you into realizing that you do NOT believe in the Big Bang Theory but in a contending idea that challenges the very core of the Big Bang. And as long as you stand by that, it’s fine with me. The Big Bang has not been proved beyond ALL reasonable doubt and probably never will. But after all these decades it certainly has a massive support and for very good theoretical and experimental reasons.

So maybe your answer to my question is something like this:

“The reason why the general scientific community finds Hubble’s expansion law to be a key evidence for the Big Bang is that the truth has not yet dawned on them, namely that the most widespread misconception of the Big Bang is actually the place to look for answers.”

This time I will quote an appeal from NASA:s WMAP-site:


Please avoid the following common misconceptions about the Big Bang and expansion:


The Big Bang did not occur at a single point in space as an "explosion." It is better thought of as the simultaneous appearance of space everywhere in the universe. That region of space that is within our present horizon was indeed no bigger than a point in the past.

By definition, the universe encompasses all of space and time as we know it, so it is beyond the realm of the Big Bang model to postulate what the universe is expanding into.

EvilEye
2007-May-18, 01:32 AM
This thread is going in circles...or should I say a parabola.

I recommend it be locked. All ideas, theories, and pure facts have been established, and it is not progressing.

I'm guilty of doing it before....I have learned.

Fisherman
2007-May-19, 11:57 PM
In space the same law is applied; as we look an airplane must be pressurized if is exterior shell damaged anything inside will rush out with tremendous speed. The same was happens to galaxies in the universe. Milky Way galaxy was a part of the universe but the last 6 billion years drifting in endless dark space and how today the universe appears flat to astronomers (160 billion light years wide.)

EvilEye
2007-May-20, 03:09 PM
O.K. My last try.

Imagine a perfect void.

Now put something with mass (which includes energy) in it.

Physics likes order within its chaos. So it wants everything to be equal as far as pressure goes.

The "something" will be shredded apart and try to equally fill that void. And if the void is endless, then it is a losing battle. Everything will continue to rush away from everything else like an expanding balloon forver.

Since gravity is a property of mass, then sometimes, those laws will come into effect and draw one thing speeding away close to another and cause them to spiral inward toward each other...creating stars & planets, galaxies, and clusters.... but even THEY are still rushing out into that void trying to fill it.

The space inside the universe is EXPANDING. There is a void beyond it into which the universe is trying to fill.

EvilEye
2007-May-20, 03:21 PM
As soon as I typed the previous one, and old experiment came to mind.

Put an empty balloon with no hole (representing the universe) into a box (representing the void).

Remove all the air from the box.

What happens to the balloon? What is inside the balloon? Nothing. What is outside the balloon? Nothing.

clint
2007-May-20, 04:11 PM
... today the universe appears flat to astronomers (160 billion light years wide.)

Where did you get that number from?

Here's what Wikipedia says about the size of the universe:
http://en.wikipedia.org/wiki/Observable_universe#Size



O.K. My last try...

Don't give up, your posts are very instructive!!!

KiwiPhil
2007-May-20, 07:59 PM
Your last post indicates that I might finally have persuaded you into realizing that you do NOT believe in the Big Bang Theory but in a contending idea that challenges the very core of the Big Bang. And as long as you stand by that, it’s fine with me. The Big Bang has not been proved beyond ALL reasonable doubt and probably never will. But after all these decades it certainly has a massive support and for very good theoretical and experimental reasons.

Okay I'll admit it. I guess you have covinced me that I do not believe in the big bang model. Though I think the term explosion may be misleading. I don't think of it as a typical explosion, but more of an extreme repulsion.


This time I will quote an appeal from NASA:s WMAP-site:


Please avoid the following common misconceptions about the Big Bang and expansion:


The Big Bang did not occur at a single point in space as an "explosion." It is better thought of as the simultaneous appearance of space everywhere in the universe. That region of space that is within our present horizon was indeed no bigger than a point in the past.

By definition, the universe encompasses all of space and time as we know it, so it is beyond the realm of the Big Bang model to postulate what the universe is expanding into.


I'm afraid these quotes are again basically just assumptions. They don't give any information as to why they made their assumptions, so I still find it unconvincing.

Fraser
2007-May-21, 02:12 AM
Have you listened to our two-part episode where we describe all the different lines of evidence for the Big Bang? If you don't like the theory, you have to come up with evidence that the Big Bang can't explain, or an alternative theory that explains all the evidence better than the Big Bang.

If it intuitively doesn't feel right to you, that's not a good enough reason.

KiwiPhil
2007-May-21, 03:03 AM
Hi Fraser.

Yeah I have listened to those two episodes, but it was quite a while ago so I think I'll listen to them again.

One question I'd like to ask. Why was it necessary for the universe to have come from a single point and not from a mass with a measurable size?

Anton
2007-May-21, 02:29 PM
There is something called The Friedmann-Lemaître-Robertson-Walker (FLRW) metric. It’s one out of many solutions of the Einstein field equations of general relativity, but it is the one that has been singled out over the years because it does the best job in explaining the observational evidence for the kind of expansion we see in the universe. This is one of the mathematical substructures you will have to wrestle with if you are to challenge the Big Bang theory.

As for the original singularity, Lemaître had this idea in 1931 of a primeval atom which was “a mass with a measurable size”. It kinda collapsed during the years to come though due to a combination of the gargantuan pressure of gravity and Einsteins theory of general relativity. :lol:

JPLogical
2010-Mar-21, 10:33 AM
Hi I know I'm a little late on this thread but I've just started listening to the Astronomy cast. I find it very interesting but I think sometimes the Scientist contradict themselves.

1st Problem I have is that they say they can actually calculate how old the Universe is. Or said in a different way, how long the big bang has been expanding.
Then, when they get ask "so what is it expanding into", They say it is a no-sense questions.

But we are asking because you said it is a certain age, 13.7 something Billion LYears?

baskerbosse
2010-Jul-21, 06:31 AM
When you look outwards (in all directions) you look back in time.
13.7 billion light years away you hit the cosmic background radiation emanating from the big bang itself.
Since there is no center of the universe, it doesn't matter which direction you look, you are looking at the Big Bang.
(In that sense, in the observable universe, we are the furthest from the Big Bang, everything you can see is closer to the big bang than you are)

;-)

Peter