What Is The Universe Expanding Into?

[Ravenstar]

Here's a question. During the beginnings of our universe (Planck time - very small amount of time) the 4 main forces split from an earlier state where scientists believe they were one unified force… but… matter was 'born' then without mass… until it interacted with the Higgs field.. and/or the Higgs Boson.. would that not make the Higgs field one of the main forces?  So 5 instead of 4?  Was just wondering… since without the Higgs Field matter can not have mass and our universe as we know it would not exist…. there is also the mystery of why there was slightly more matter than anti-matter.. also making our universe, as it is, possible.

 

addressing the above topic - space-time being flat is the reason (or effect) for the universe having zero net energy, correct? ( I believe I'm starting to get this stuff!) Would this in any way be an expression of expansion? It would have to be because it's an expression of neutral energy (neither positive nor negative).

 

It seems to me that all of these variables are intrinsically inter-related.

[RogueScholar]

The answer is both exceptionally complex and beyond my ability to explain in great detail unfortunately. With the four fundamental forces, force carrying particles (photons with electromagnetism, W & Z bosons with the weak force, gluons with the strong force and I presume the proposed graviton with gravity) have to "behave" in a certain way. We say that these are gauge invariant. Unfortunately, diving into what that way really means is exceptionally complex. However, the Higgs mechanism is not gauge invariant as I understand said mechanism.

 

As I stated, this is probably not a satisfying answer and to really understand it you have to understand things like symmetry and symmetry breaking and gauge theory. Unfortunately I am not qualified to talk about such things with any authority but hopefully you can at least see that the Higgs mechanism differs from the fundamental forces.

 

You are correct in that these concepts are fundamentally interrelated. I hope that helps somewhat.

[Fweethawt]

I just want one of those cool lookin' balloons...

[ExCBooster]

Thank you, Bhim! Although I do know that matter isn't relevant to space-time, I probably took on more than I should have in too short a space, trying to deal with both at once. The thing is, colloquially, the way most people use the word "universe" includes everything in it. But I'd argue that matter and QM is important to teaching yourself science. Mostly, duderonomy, because intuition and "common sense" are both big fat liars.

 

Step 1) when trying to teach yourself science, especially the "big ticket" items like cosmology, you absolutely have to discard everything you think you know about how the universe and everything in it works. Follow the data only. If you assume that matter is made of real, solid, things that are like that all the way through, then you have a very tough time dealing with even the most basic ideas in quantum mechanics. If you assume that, naturally, there's always a "something" out there, if a thing is expanding, it's very hard to deal with the most basic ideas in cosmology. (Hilariously, by far the easiest major scientific Theory to make sense of is Natural Selection, because it does operate on scales we're used to dealing with, and therefore in a very intuitive way.)

 

Step 2) the reason for the above is that we exist on a very small and specific slice of the universe, scale-wise. We can deal somewhat intuitively with things in our range of direct observation, but things that are REALLY small, or REALLY large, we struggle to comprehend how things operate on such scales. The classic Charles and Ray Eames film Powers of Ten should be required watching in every science class, for this exact reason. We're comfortable dealing with things on the scale of picnics in Chicago, not galaxy superclusters, or quarks. So, if you can spare nine minutes, it's an extremely worthwhile link to click, just to get an idea of scale.

[Ravenstar]

Thank you, both!

[RogueScholar]

ExC, I think much of the problem regarding understanding is that people need to spend a significant amount of time building foundational knowledge. We talk about these topics in a very superficial way but there is an exceptionally rich tapestry of foundational concepts that underpin these things that we often casually discuss. Ultimately, it will not really be possible to talk about things such as gauge invariances if we lack the fundamental appreciation of core concepts. This is why you learn about Maxwells equations and such in a calculus based undergrad physics class well before diving into quantum mechanics and quantum field theory. You need to learn to wrap your head around what a field theory is and Maxwells equations are probably a good start. Unfortunately, a significant amount of foundational knowledge underpins this concept as you have to really have a feel for working with calculus, diff equations and integration. This is where undergrad classical mechanics and electromagnetism and waves come into play. It's a highly stratified process and we often jump over these basic concepts and right into these exceptionally complex frameworks. This means a bunch of stuff gets lost in the translation and it is easy to think we understand more than we actually do.

 

While intuition breaks down, we often have to use more intuitive and not entirely correct pictures to explain these concepts to people like us because we simply lack all the foundational knowledge and experience. Unfortunately, because these explanations are easier to understand and are often qualitative, it's easy to develop a false sense of understanding.

 

Even worse is somebody like me who knows just enough to thrown down a few big words that impress but not enough to grasp even a basic understanding of things like quantum field theory. I guess my main point is that sometimes it's best to slow down, focus on basics and always admit ignorance. It sucks because people have so many good questions and real answers are exceptionally complex and often not well described.

 

The powers of ten is a great video, I perfer the 1970's version as it gives you a constant scale of things. This was one of the first videos I would show my students when we covered measurements, fundamental units of measurement, vectors, scalers and so on back when I taught a (non-calculus) allied health physics class.

[Ravenstar]

I agree… however, I think one of the greatest gifts a scientist (at least a science educator) can have is the ability to convey these very complex subjects to the layperson - to make it somewhat accessible - which is why I believe NDT's and Michio Kaku's video's are so popular. My math, frankly, sucks… no.. sucks is a severe understatement  LOL   it isn't even close to my forte - yet I still want to explore some of these things, at least at some level - it fascinates me to no end. One of the problems I see in our society is the disparate understanding of science between the scientists and the regular people. It makes science sound like magic and I almost understand why some think that trust in science takes faith. (almost)

 

I believe the ability to transpose these concepts in simple terms is a gift though… the vast majority of scientists, being steeped in the basics and more complex theories and calculations will think in those terms - that laypeople can not possibly comprehend. Understandable. Jargon, in any field, excludes the uninitiated.

[duderonomy]

Thank you, Bhim! Although I do know that matter isn't relevant to space-time, I probably took on more than I should have in too short a space, trying to deal with both at once. The thing is, colloquially, the way most people use the word "universe" includes everything in it. But I'd argue that matter and QM is important to teaching yourself science. Mostly, duderonomy, because intuition and "common sense" are both big fat liars.

 

Step 1) when trying to teach yourself science, especially the "big ticket" items like cosmology, you absolutely have to discard everything you think you know about how the universe and everything in it works. Follow the data only. If you assume that matter is made of real, solid, things that are like that all the way through, then you have a very tough time dealing with even the most basic ideas in quantum mechanics. If you assume that, naturally, there's always a "something" out there, if a thing is expanding, it's very hard to deal with the most basic ideas in cosmology. (Hilariously, by far the easiest major scientific Theory to make sense of is Natural Selection, because it does operate on scales we're used to dealing with, and therefore in a very intuitive way.)

 

Step 2) the reason for the above is that we exist on a very small and specific slice of the universe, scale-wise. We can deal somewhat intuitively with things in our range of direct observation, but things that are REALLY small, or REALLY large, we struggle to comprehend how things operate on such scales. The classic Charles and Ray Eames film Powers of Ten should be required watching in every science class, for this exact reason. We're comfortable dealing with things on the scale of picnics in Chicago, not galaxy superclusters, or quarks. So, if you can spare nine minutes, it's an extremely worthwhile link to click, just to get an idea of scale.

 

Wow, that Powers of Ten video was amazing!

It also occurred to me while I was watching it that the year it was made, 1977, I was in full Pentecostal mode, Word-Faith and all of that. Damn that I wasn't into this stuff instead. I might be a wee bit smarter and a little richer too today. I find it interesting that you say that intuition and "common sense" are big fat liars. Of course I don't think they are, but in the case of learning about what makes the Universe tick, I have to agree. Especially since my knowledge and judgement were tainted and skewed by religion for so long. Goddidit covered a whole lot of territory, so I didn't need science to explain it to me. Someday, Biblegod was going to just open my head and stuff all of that knowledge into me, I guess. Even the Bible said that "In the ages to come..." he would show us yada yada, and now we see through a glass darkly, and blah blah blah.

 

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Thanks again to everyone. I read all of the new posts since I was here last, and I will again. I don't understand a couple of things though that I just can't seem to get past...

 

1) I may not be able to find the edge of BAA's 3D cat, but I can as a flea stand on it's nose and wave my itchy appendages into the air. If the 3D cat is the Universe, what am I waving into?

 

2) If "the Universe" isn't all there is, as I've always understood it, what is it then? That brings me right back to asking what else is out there beyond it (not in a God sense, but in a what's it made of sense).

 

I'm still working on my books. Two from the juvenile section of my library, and one by Stephen Hawking, "The Universe in a Nutshell". Last night I watched an hour or so of videos online at the Khan Academy (sorry no link) about Cosmology and the expanding Universe.

 

All that you folks have said and all that I've read and watched seem to be saying the same thing. One of these days, I'm hopeful, it will penetrate this brick I call a skull and make sense to me.

[bornagainathiest]

Ravenstar,

 

I'll give some thought as to how answer your questions (from post # 26) and get back to you soon.  As RS says, these are incredibly complex issues and I need to find a down-to-earth analogy to illustrate how I think these processes work.

 

Thanks,

 

BAA.

[bornagainathiest]

Ok Dude, some answers.
 .

.

.

1. What are you waving your appendages into?
 
When you (as a human, not a flea ) see a tree it doesn't appear as a 2D circle to you (it's cross-section) it appears as a fully-3D object, right?  That's because you and the tree are 3D objects.  You both occupy a common dimension and so there's no dimensional 'edge' you can see or be aware of.

 

But if you draw a circle on a piece of paper you are looking down on a 2D surface from our 'higher' 3rd dimension. 

So beings in higher dimensions can see lower dimensions, but not the other way round.  We can see 1D lines and 2D surfaces (lower than us) and 3D volumes (same level as us) but we can't see anything 4D or higher. 

 

That's why we don't see any edges of these higher dimensions. 

We're simply not naturally equipped to do so.  However, mega-brains like Einstein and Hawking aren't naturally equipped either - they just use their smarts to build mathematical descriptions of higher dimensions.  And as RogueScholar has just pointed out to Ravenstar, this is stupendously complex stuff.

 

Anyway, back to Dude the flea.

As a bug you occupy the same dimensional space as the cat's fur, it's internal organs, the air around it, the planet Earth and the entire universe - so you're not waving your appendages into another dimension.  Everything around you is 3D.  There's no edge for you to push your appendages past.

 

But...if you were a 2D flea, crawling across the 2D cut out cat, then you would come to an edge...!

For you, reality would seem to come to an end.  You'd have no more success trying to cross this edge than you (as a human) would have trying to walk thru a solid 3D object like a wall. 

 

So the analogy holds good for flat cats, but not solid ones.  Ok?

.

.

.

2.  If the universe isn't all there is.

 

Ok Dude, you're coming unstuck over the terminology and how it's used.

When I use the word, 'universe' I'm usually very careful to distinguish between the observable universe (all that we can see) and the greater or wider universe that lies beyond, which we... cannot see but which infer exists.

 

(Please go back to post # 25 and re-read about the observational horizon of the lone yachtsman.  That should help explain the difference between a visual edge and a real, physical edge.)

 

So when I say that the observable universe isn't all that there is, I'm using inference to make that statement.

Inference is a tool we all use to make judgements about what we cannot see -  based on what we can see.  Just as the yachtsman can infer the existence of islands and continents beyond his visual horizon, so we can infer the existence of galaxies and galactic clusters beyond our visual horizon.

 

Therefore, here's an ever-widening description of how we infer things to be.

 

A.  The observable universe is calculated to be about 93 billion year lights across.

 

B.  We infer that it doesn't physically end there, but goes on outwards, extending a much greater distance than this.

 

C.  Inflationary theory indicates that the wider universe is at least a thousand times larger than the observable portion.

 

D.  Inflation also indicates that what we call the wider universe is a 'pocket' universe and that other, equally vast pocket universes exist at very much greater distances. 

 

E.  Inflation is also considered to be an on-going and accelerating process and not a one-off event. 

This means that we cannot know if our pocket universe was the first one to come into existence.  But, if it was, then Inflation has been on-going and accelerating for at least 13.72 billion years - which is the age of our pocket universe.  This means that the Inflationary process has been generating pocket universes for at least 13.72 billion years.

 

Since our pocket universe was 'generated' in an incredibly small fraction of a second we have no reason to think that Inflation will take any longer to generate these other pocket universes.  Which means multiplying this ultra-fast rate of universe generation by 13.72 billion years and then factoring the exponential acceleration of the Inflationary process, while remembering that this THE most conservative estimate the math will allow.  Please read the 'Rice on a Chessboard' story to get an idea of what we're dealing with here, Dude. http://en.wikipedia.org/wiki/Exponential_growth

 

More pocket universes than grains of sand on the planet Earth simply doesn't do the math any kind of justice!

 

But that's not all there is to this equation.

Cosmological science has rules that must be adhered to. One of the most basic and foundational of these is the Copernican Principle.  http://en.wikipedia.org/wiki/Copernican_principle. Taking this principle into account, we cannot assume that our pocket universe was the very first one, where the Inflationary process first began.  We must assume that our pocket universe is typical and average - not first and special. 

 

Doing this gives us no fixed time frame to use in calculating how long Inflation has been going.

The figure of 13.72 billion years cannot be used, because that figure is tied to our pocket universe and the Copernican principle prevents us from declaring that we were the first.  So the twin questions of how long inflation has been going and how long it has been exponentially accelerating CANNOT be answered.

 

This explains why Andrei Linde's model of Eternal Inflation is considered to be persuasive.

http://en.wikipedia.org/wiki/Eternal_inflation In this model of inflationary cosmology our pocket universe is part of an infinite fractal multiverse.  Just as a fractal has no specific end or beginning and can be 'zoomed' into or out of without reaching a specific point of origin, so the inflationary fractal multiverse is considered to be (at least) eternal into an endless future or eternal into an endless past AND an endless future.

 

More pocket universes than atoms in our observable universe simply doesn't do this math any justice!

.

.

.

So you see Dude, by rigorously sticking to the evidence, to logical inference and to the established principles of cosmological science - the math goes off the scale!  There simply is no need for a Creator in an eternally-existing Inflationary multiverse. Those Christian apologists who do try and tackle these BIG questions either don't play by the rules and/or simply deny the evidence.

.

.

.

But that's no big news, is it?

.

.

.

Anyway, I hope this overlong post is of help. 

 

Thanks,

 

BAA.

 

 

 

 

 

 

 

[Justus]

The universe is expanding. I get that...it's still on the move after the Big Bang. But what is the universe expanding into?

 

  c²

[duderonomy]

 

The universe is expanding. I get that...it's still on the move after the Big Bang. But what is the universe expanding into?

 

  c²

 

???  Can you be a bit more specific Justus?

[duderonomy]

Ok Dude, some answers.

 .

.

.

1. What are you waving your appendages into?

 

When you (as a human, not a flea ) see a tree it doesn't appear as a 2D circle to you (it's cross-section) it appears as a fully-3D object, right?  That's because you and the tree are 3D objects.  You both occupy a common dimension and so there's no dimensional 'edge' you can see or be aware of.

 

But if you draw a circle on a piece of paper you are looking down on a 2D surface from our 'higher' 3rd dimension. 

So beings in higher dimensions can see lower dimensions, but not the other way round.  We can see 1D lines and 2D surfaces (lower than us) and 3D volumes (same level as us) but we can't see anything 4D or higher. 

 

That's why we don't see any edges of these higher dimensions. 

We're simply not naturally equipped to do so.  However, mega-brains like Einstein and Hawking aren't naturally equipped either - they just use their smarts to build mathematical descriptions of higher dimensions.  And as RogueScholar has just pointed out to Ravenstar, this is stupendously complex stuff.

 

Anyway, back to Dude the flea.

As a bug you occupy the same dimensional space as the cat's fur, it's internal organs, the air around it, the planet Earth and the entire universe - so you're not waving your appendages into another dimension.  Everything around you is 3D.  There's no edge for you to push your appendages past.

 

But...if you were a 2D flea, crawling across the 2D cut out cat, then you would come to an edge...!

For you, reality would seem to come to an end.  You'd have no more success trying to cross this edge than you (as a human) would have trying to walk thru a solid 3D object like a wall. 

 

So the analogy holds good for flat cats, but not solid ones.  Ok?

.

.

.

2.  If the universe isn't all there is.

 

Ok Dude, you're coming unstuck over the terminology and how it's used.

When I use the word, 'universe' I'm usually very careful to distinguish between the observable universe (all that we can see) and the greater or wider universe that lies beyond, which we... cannot see but which infer exists.

 

(Please go back to post # 25 and re-read about the observational horizon of the lone yachtsman.  That should help explain the difference between a visual edge and a real, physical edge.)

 

So when I say that the observable universe isn't all that there is, I'm using inference to make that statement.

Inference is a tool we all use to make judgements about what we cannot see -  based on what we can see.  Just as the yachtsman can infer the existence of islands and continents beyond his visual horizon, so we can infer the existence of galaxies and galactic clusters beyond our visual horizon.

 

Therefore, here's an ever-widening description of how we infer things to be.

 

A.  The observable universe is calculated to be about 93 billion year lights across.

 

B.  We infer that it doesn't physically end there, but goes on outwards, extending a much greater distance than this.

 

C.  Inflationary theory indicates that the wider universe is at least a thousand times larger than the observable portion.

 

D.  Inflation also indicates that what we call the wider universe is a 'pocket' universe and that other, equally vast pocket universes exist at very much greater distances. 

 

E.  Inflation is also considered to be an on-going and accelerating process and not a one-off event. 

This means that we cannot know if our pocket universe was the first one to come into existence.  But, if it was, then Inflation has been on-going and accelerating for at least 13.72 billion years - which is the age of our pocket universe.  This means that the Inflationary process has been generating pocket universes for at least 13.72 billion years.

 

Since our pocket universe was 'generated' in an incredibly small fraction of a second we have no reason to think that Inflation will take any longer to generate these other pocket universes.  Which means multiplying this ultra-fast rate of universe generation by 13.72 billion years and then factoring the exponential acceleration of the Inflationary process, while remembering that this THE most conservative estimate the math will allow.  Please read the 'Rice on a Chessboard' story to get an idea of what we're dealing with here, Dude. http://en.wikipedia.org/wiki/Exponential_growth

 

More pocket universes than grains of sand on the planet Earth simply doesn't do the math any kind of justice!

 

But that's not all there is to this equation.

Cosmological science has rules that must be adhered to. One of the most basic and foundational of these is the Copernican Principle.  http://en.wikipedia.org/wiki/Copernican_principle. Taking this principle into account, we cannot assume that our pocket universe was the very first one, where the Inflationary process first began.  We must assume that our pocket universe is typical and average - not first and special. 

 

Doing this gives us no fixed time frame to use in calculating how long Inflation has been going.

The figure of 13.72 billion years cannot be used, because that figure is tied to our pocket universe and the Copernican principle prevents us from declaring that we were the first.  So the twin questions of how long inflation has been going and how long it has been exponentially accelerating CANNOT be answered.

 

This explains why Andrei Linde's model of Eternal Inflation is considered to be persuasive.

http://en.wikipedia.org/wiki/Eternal_inflation In this model of inflationary cosmology our pocket universe is part of an infinite fractal multiverse.  Just as a fractal has no specific end or beginning and can be 'zoomed' into or out of without reaching a specific point of origin, so the inflationary fractal multiverse is considered to be (at least) eternal into an endless future or eternal into an endless past AND an endless future.

 

More pocket universes than atoms in our observable universe simply doesn't do this math any justice!

.

.

.

So you see Dude, by rigorously sticking to the evidence, to logical inference and to the established principles of cosmological science - the math goes off the scale!  There simply is no need for a Creator in an eternally-existing Inflationary multiverse. Those Christian apologists who do try and tackle these BIG questions either don't play by the rules and/or simply deny the evidence.

.

.

.

But that's no big news, is it?

.

.

.

Anyway, I hope this overlong post is of help. 

 

Thanks,

 

BAA.

 

 

I really appreciate all the work you put into this, BAA.

I never heard of the Rice on a Chessboard description of exponential growth, but I remember my dad showing me when I was quite young what would happen if I were to put a penny down on the first day of a month, and then double it everyday for the next 30 days. It's the same principal and it was quite eye opening.

Again, I followed all of the links in your post and will again. Sometimes reading things a couple of times over helps to make it stick.

 

Let's get back to the 3D cat. I just can't get past this. I, Duder the flea, am still standing on the nose of the cat waving my itchy appendages into something that is non-cat. The actual cat might be in the same dimension I'm in, but if the cat is the Universe, what is the non-cat?

What is the fourth dimension?

What did the Big Bang expand into? What are pocket universes expanding into? Is the "nothing", or the void that Vigile spoke of possible? It seems to me that even nothing must be made of something. Nothing must be amenable to the Universe expanding into it, hence it has properties, and if it has properties, it must be something. 

[Bhim]

???  Can you be a bit more specific Justus?

In my experience, Christians often obfuscate and provide cursory responses to legitimate questions in order to create a false sense of profundity.

[RogueScholar]

Dude, unfortunately, simplistic analogies like cats and balloons break down quite quickly so they are really only good in a very limited sense. Where we stand right now, there's no real way than I'm aware of to see if anything is beyond our "universe." Perhaps looking at things a bit differently may be more helpful? Since the universe is everything we can possibly observe, it makes sense to say that the universe is "everything." If you can perhaps form that model in your mind, you might be able to look at the universe in a less worriesome way. Think of the universe as not expanding into some unknown something but rather the universe, everything that we could ever know anything about is stretching. In this sense it's not necessarily expanding into something but rather the universe, space its self is stretching. So you could say the universe is all that there is and it's simply stretching and not expanding into anything. I could be way off point but at this time we can in a certain sense say the universe is infinite and if some boundary exists, there's no way to reach it and it cannot interact with us or influence us.

 

Of course the best but probably the least appealing answer is we don't know.

 

As I've stated I'm no cosmologist nor am I an astronomer so take my comments with hesitation.

[bornagainathiest]

 

 

 

 

I really appreciate all the work you put into this, BAA.

I never heard of the Rice on a Chessboard description of exponential growth, but I remember my dad showing me when I was quite young what would happen if I were to put a penny down on the first day of a month, and then double it everyday for the next 30 days. It's the same principal and it was quite eye opening.

Again, I followed all of the links in your post and will again. Sometimes reading things a couple of times over helps to make it stick.

 

Let's get back to the 3D cat. I just can't get past this. I, Duder the flea, am still standing on the nose of the cat waving my itchy appendages into something that is non-cat. The actual cat might be in the same dimension I'm in, but if the cat is the Universe, what is the non-cat?

What is the fourth dimension?

What did the Big Bang expand into? What are pocket universes expanding into? Is the "nothing", or the void that Vigile spoke of possible? It seems to me that even nothing must be made of something. Nothing must be amenable to the Universe expanding into it, hence it has properties, and if it has properties, it must be something. 

 

 

Dude,

 

I've given this my best shot and I'm sorry if I failed.

 

As RS says, the analogies break down pretty quickly.

And as I've said, the theorists can map out and describe other dimensions using exotic math.  All I can do is use the analogies - the math is way beyond me.  I'll be going to back to an analogy when I respond to Ravenstar's questions and hopefully it'll work.  Again, I'm sorry that I can't get any further here with balloons and cats.  

 

 

If it's any consolation, theorists are (and have been) scratching their heads about what 3D SPACE actually is - for decades. There are several competing theories, but actually finding ways to test them seems just as difficult as doing the math on the blackboard.  Progress is painfully slow.  Perhaps the bona fide detection of gravitational waves will be just the breakthru that's needed?

 

In other areas of physics, knowing how a wave passes thru a transmitting medium can tell us something about that medium and news about gravitational waves (or their failure to be detected) should be forthcoming next month or early next year.

 

Here's hoping for a positive result !

 

Thanks,

 

BAA.

[ExCBooster]

duderonomy, if you like fiction, and want to understand mathematical dimensions, then I'd recommend the novel Flatland.

 

It's very much older, and weird, but very fun to read, and you'll come out of it with a great idea of the "3D cat." (Ignore the copious theological commentary, and the social commentary for now, we're talking mathematics, here, which is the metaphor the thing operates on.) The novel is set in Flatland, a 2D plane. All of the characters are 2D geometric shapes. If you were a citizen of Flatland, you would be in the 2D plane, so if you looked at another Flatlander next to you, you would "see" a 1D line: _____________________   because you're always seeing them from the edge on. Good so far? Okay.

 

You and me aren't from Flatland. We inhabit 3D space, so we see people and cats from the side on. We "see" a 2D projection of a person of a cat. Let's go back to Flatland, for a bit. Suppose (spoiler alert!) a sphere visits Flatland. The sphere is 3D, but as it passes through the 2D plane, Flatlanders can only "see" 1D projections of the 2D "slice" of the 3D object, as it passes through their observable 2D space. They'd see this:

 

. then _ then ____ then ___________ then ___ then _ then .

 

Similarly, although we can't directly "see" objects in higher dimensions than as 3D objects in 2D projections, we CAN "see" them as slices in 2D projections of what they'd look like from the side as they pass through 3D space. A square is a 2D figure of four 1D lines. A cube is six 2D squares, like a box, in 3D. A tesseract is a 4D object that has a cube for each of its eight 3D "sides." We can't see the tesseract as one whole thing, in one go, but we can see the tesseract as animated 2D projections of each 3D "slice" of the tesseract as it passes through 3D space. That's how dimensions work.

[duderonomy]

So far, I still don't get what the Universe is expanding into.  I guess the answer is, as most of you have said, that we just don't know.

 

Are the furthest galaxies we can see really moving away from us faster than the closer ones are? How could that be if they aren't bending space-time any more than they were at an earlier time, if the speed of light is a constant and that's how we know they are moving at all?  Wouldn't they all be moving away from us at the same uniform speed?

 

I have to say that the question of 'what is the Universe expanding into' itself and the other questions that follow from it are leading me into a lot of knowledge I didn't have before. I'm still following links and re-reading everything.

 

The idea of gravitational waves makes perfect sense to me, for instance, and the sooner they are detected, the better.  I'm also picking up a lot of terminology that I hope I can someday get through my brane (see what I did there?).

 

Again, I want to say thank you to everybody trying to help me understand this stuff. All the work you put into your posts isn't being wasted on me.

[bornagainathiest]

Ok Dude... I hear ya!

 

Please look at the two number lines below and I'll explain.

We are sitting in the Milky Way galaxy and all the other galaxies (1, 2,3, etc.) are seen to be moving away from us at greater and greater speeds ( 4, 8, 12, 16, etc.).  That's the key to this whole puzzle.  There's a difference between what we see to be happening and what is actually happening. 

 

WHAT WE SEE TO BE HAPPENING.

We see galaxy 1 moving away from us at a speed of 4, galaxy 2 at a speed of 8, galaxy 3 at 12 and so on.  The further away from us, the faster they appear to go.  

 

WHAT'S ACTUALLY HAPPENING.

Each galaxy is actually moving at a constant speed away from it's immediate neighbor.  You can check this out for yourself, simply by counting the number of spaces (dashes and arrows) between each number.  But these constant speeds add up, making more distant galaxies appear to be moving faster.

 

 

8 <----7 <----6 <----5 <----4 <----3 <----2 <----1 <---- Milky Way ----> 1----> 2----> 3----> 4----> 5-----> 6-----> 7----> 8

 

   32       28      24      20     16      12       8        4                 0                4------8------12---- 16-----20-----24------28-----32--

 

-------------------------------------------------------------------------------------------------------------------------------------------------------

 

Q.  Are the furthest galaxies we can see really moving away from us faster than the closer ones are? 

 

A.  No.  They simply appear to be.  

The space between galaxies is expanding no faster between 7 and 8, than it is between 1 and 2.  But to us (at zero) galaxy 8 appears to moving at 32, while galaxy 1 appears to be moving at 4.  Yet they are all moving apart at the same rate.  To any static observer, more distant galaxies will always appear to be moving faster than nearby ones.  So if we could instantly move a billion light years in any direction, we'd see exactly the same thing happening - nearby galaxies moving slowly away from us (at a speed of 4) and more distant galaxies moving much more rapidly (at 32).  It doesn't matter where you are, the increasing speed of more distant galaxies always appears to be the same.

 

Q.

How could that be if they aren't bending space-time any more than they were at an earlier time, if the speed of light is a constant and that's how we know they are moving at all?

 

A.  There's no need to get into fancy space-time bending to explain this, Dude.  That's just over complicating things.  The apparent increasing speed of more distant galaxies is easily explained by the addition of their constant speeds, relative to each other.  The apparent speed is a cumulative effect, not a real one.  This is why the constancy of the speed of light isn't violated here.  It's a purely optical effect and not a real one. 

 

We know the galaxies are moving because of the red shift in their light.  Here's a non-technical (British) explanation.  http://www.passmyexams.co.uk/GCSE/physics/the-expanding-universe-red-shift.html  Please look back at the number lines above and you'll see that I've shown the red shifts increasing, relative to the distance from the Milky Way.  From us to 1 or 2 it's like this ---- and from 7 to 8 it's like this ----, yet the speed of the universe's expansion is the same as it is between 7 and 8 as it is between 1 and 2.  

 

Q.   Wouldn't they all be moving away from us at the same uniform speed?

A.   They are.  But more distant galaxies appear to moving faster, because of their cumulative speed, relative to us.

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That help?

 

Thanks,

 

BAA.

[Fweethawt]

I'm also picking up a lot of terminology that I hope I can someday get through my brane (see what I did there?).

Yeah, I see what you did.

 

You just pissed off the crickets because for the first time in the history of ever, you just made them STFU and stare blankly into the camera.

 

 

 

 

Ha-ha!

[bornagainathiest]

Hello Ravenstar.  

 

You've set me three exacting questions, which I'll have to tackle one-by-one.

The first is about the Higgs boson and mass.  The second is about the relationship of matter to anti-matter in the universe. The third is about the flatness of space and the total energy value of the universe being summed to zero.

 

One at a time, ok?

 

Here's a question. During the beginnings of our universe (Planck time - very small amount of time) the 4 main forces split from an earlier state where scientists believe they were one unified force… but… matter was 'born' then without mass…

 

Apparently so.

General Relativity tells us that matter and energy are equivalent and (under certain conditions) one can become the other.  Thermonuclear fission (nuclear reactors) and fusion (in the cores of stars) release a small amount of matter's 'rest mass' in the form of energy.  The matter/anti-matter engines of the USS Enterprise release even more. Of those three examples the last two rely on putting certain types of matter under tremendous pressures and ultra-high temperatures to release the latent energy.

 

Now that's the reverse of what happened during and just after the Big Bang, isn't it, R...?

The universe went from an ultra-compressed, ultra-hot speck to become a vast, rapidly inflating domain in the blink of an eye.  As it expanded it cooled rapidly and the pressures plummeted.  That's what's being described here...   http://en.wikipedia.org/wiki/Chronology_of_the_universe ...where each successive epoch is colder and more rarefied than the last.  The Higgs mechanism is theorized to give mass to matter between 10 ^-12 and 10^-6 seconds after the Big Bang.  As described here... 

 

1. The weak force and electromagnetic force, and their respective bosons (the W and Z bosons and photon) manifest differently in the present universe, with different ranges;
2. Via the Higgs mechanism, all elementary particles interacting with the Higgs field become massive, having been massless at higher energy levels

 

So the splitting of the 4 main forces and the beginning of the Higgs mechanism only happened once the pressure and the temperature had fallen below certain critical thresholds.  

 

until it interacted with the Higgs field.. and/or the Higgs Boson.. would that not make the Higgs field one of the main forces?  So 5 instead of 4?  Was just wondering… since without the Higgs Field matter can not have mass and our universe as we know it would not exist…. 

 

The key point to grasp Ravenstar, is this.

Mass is only possible in a low-pressure, low temperature universe.  Compress and heat the universe up again and the temperature and the pressure goes up until the Higgs mechanism is no longer possible and then the four forces begin to re-unite with one another.   Carry on doing this and the universe will go back to it's original state.   That's what is hypothesized to happen if there's a Big Crunch at the end of time.  http://en.wikipedia.org/wiki/Big_Crunch

 

Perhaps the best analogy to use here is the H²O molecule.

In their most energetic state H²O molecules are steam, but if they are cooled and allowed to expand, they go thru two dramatic phase transitions, becoming liquid water and then solid ice.  In a not-dissimilar way, the early universe began as pure energy and then, as it expanded and cooled  it went thru a series of phase transitions that allowed new mechanisms to become viable and for new materials to form.  Ice can't form at high temperatures. It requires cooling to come into existence.   

 

So does the Higgs mechanism.

Therefore, you're both  right and wrong, R.  The universe TODAY couldn't exist without mass.  But between the Planck and Hadronic epochs - it could.  Everything that went to make up the universe we see today was there, albeit in the form of energy, not matter and not mass.

 

there is also the mystery of why there was slightly more matter than anti-matter.. also making our universe, as it is, possible.

 

addressing the above topic - space-time being flat is the reason (or effect) for the universe having zero net energy, correct? ( I believe I'm starting to get this stuff!) Would this in any way be an expression of expansion? It would have to be because it's an expression of neutral energy (neither positive nor negative).

 

It seems to me that all of these variables are intrinsically inter-related.

 

I hope that helps.

 

Thanks,

 

BAA.

[bornagainathiest]

Second response, Ravenstar.  

 

"Why was there slightly more matter than anti-matter in the early universe?"  

 

Well, it seems that this one is a bit of a mystery.   This Wiki page sums things up.  http://en.wikipedia.org/wiki/Baryon_asymmetry

"The Big Bang should have produced equal amounts of matter and antimatter. Since this does not seem to be the case, it is likely some physical laws must have acted differently for matter and antimatter. There are several competing hypotheses to explain the imbalance of matter and antimatter that resulted in baryogenesis, but there is as yet no one consensus theory to explain the phenomenon."

 

Fyi, Baryogenesis is the fancy name for what happened in the early universe, when matter and anti-matter (energetically!) cancelled each other out on contact.  Here's a massively-simplified summary of what Alan Guth has to say about this process in his book, 'The Inflationary Universe'.

 

1.  The smallest building blocks of matter that we know of are called quarks.

2.  Matter is made of atoms and the protons and neutrons in atoms are made up of trios of different 'flavors' of quark.

3.  These days quarks are never found by themselves but are always bound together with other quarks in various combinations.

4.  But in the very early universe the temperatures and pressures were so high that quarks could zip around freely on their own.  They were just too energetic to bind to anything else and form stable protons and neutrons and atoms. 

5.  The Big Bang produced almost equal quantities of quarks (matter) and anti-quarks (anti-matter).  Perhaps 300,000 quarks for every 299,999 anti-quarks.

6.  And, as we know, matter and anti-matter annihilate each other on contact, yielding only energy.  LOTS of energy!

7.  So after the epoch of quark / anti-quark annihilation, only the quarks were left standing.

8.  Once the temperature and pressure had dropped enough the remaining quarks could become protons, neutrons, atoms and molecules.

9.  Fast forward 13.72 billion years and these atoms and molecules have become... us.

10.  But if the Big Bang's balance of quarks to anti-quarks had been exactly equal, then we wouldn't be here and neither would the universe.

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One of the competing hypotheses that seeks to explain the imbalance of matter and anti-matter in the early universe is Inflationary theory.  As you know Ravenstar, Inflation isn't considered to be a one-off event but an on-going process which generates a multitude of pocket universes.  Therefore, this process gives ample opportunity for there to be many, many pocket universes where the matter / anti-matter imbalance favors an asymmetric period of annihilation (see # 7), leading to matter-dominated universes like ours.  

 

However, to be totally fair and impartial it's necessary for me to be quite clear that Inflation still hasn't been fully confirmed to the necessary standard of confidence for us to rule out other possibilities.  It remains a firm contender, but that is all.  As always, it is the evidence that will decide the matter.  (Pun intended! )

 

Thanks,

 

BAA. 

 

 

 

 

 

[RipVanWinkle]

Bhim: Do scientists have hypotheses on what lies  "above" the balloon shaped universe (using your description)? I don't mean other universes, but the "space" beyond our universe?  Rip

[duderonomy]

 

I'm also picking up a lot of terminology that I hope I can someday get through my brane (see what I did there?).

Yeah, I see what you did.

 

You just pissed off the crickets because for the first time in the history of ever, you just made them STFU and stare blankly into the camera.

 

 

 

 

Ha-ha!

 

 

I'm not sure what you mean, Fwee, but if I did something smart I assure you it was purely accidental!

[Joshpantera]

He's just asking about 11 dimensional hyper space, right? 

 

 

 

The string theory answer as explained in the video would be that each individual 3D universal sphere or bubble is expanding out into a greater region of space, wouldn't it?

 

I think that's how I've heard it described anywho.....