The "Dark Energy" Problem.

[Crazyhorse]

Isn't the Nexus great...
I don't have a single person in my life who I can discuss Red Shift with...

I'm the smartest person I know (in my reality tunnel) but I'm a retarded toddler compared to some of the minds that frequent this forum.

Word I totally feel the same way. It's still early I'm sure someone will come along who knows a lot more about all this than I do and can help with my questions just like I'm trying to help others understand where I'm able.

But right now my brainmeats are sleepy I think I'll go rest them awhile and let my consciousness go play in the Zero dimension. :thumb_up:

 

[Guyomech]

If I've got my facts straight, the observation made in the 1990s had to do with looking at a certain class of supernovae, a type that is almost always of a very particular light spectrum signature due to the size and type of star causing them. And the more distant they got, the faster away they were moving, above and beyond what was expected from the average redshift. Because this supernova type is usually very predictable in its behavior, these unexpected differences are considered to be very significant; after counting and averaging a large number of them, the additional acceleration factor was derived. The Dark Energy theory is only there as a way to account for this difference. Physicists are not thrilled about having to include it, but are still in broad disagreement about what it all means.

 

[Vodsel]

Cool thread.

Crazyhorse - I'm no physicist either, but I've sniffed around too. After reading your first post, my only doubt following your reasoning has to do with the relation you imply between space and time, within relativity. Einstein defined time as "the reading on a suitably-synchronized clock located at the same position as the event" and as you know he demolished the concept of an absolute time. But that relativity of time does not imply it shrinks or expands along with space in a literal sense. It simply means that every observer has its own measure of time.

But you are definitely on to something with your post. I believe the problem with the concept of dark energy has to do with the previous assumptions. It's like Einstein with his "cosmological constant". He introduced it because his calculations pointed at an expanding universe, and that didn't agree with his concept of a static universe. After Hubble's red shift evidence he dismissed the cosmological constant and eventually called it the most embarrassing screwup in his career. I believe like you do that "dark energy" is a misstep, and the problem lies within the interpretation of the observations. Mostly, because that interpretation implies an homogeneous relative speed of the different areas of the universe.

Among the alternative theories to dark matter, there's this idea by Christos Tsagas, a greek cosmologist, that you might like.

It starts with others' recent findings showing that, relative the rest of the universe, our region of spacetime is moving fast. Also, recent evidence suggests that the universe appears to be expanding more towards a preferred axis. Tsagas proposes that

the acceleration of the universe in our immediate vicinity is caused by its motion alone. The universe beyond our region isn't accelerating outward; rather, it is safely rolling to a stop.

Once you consider that different regions of the universe might have different momentums, and keep in mind that the measurement of these momentums is essentially determined by the momentum of the observer's system, things might start to clear up.

I have the feeling this is the right direction, and I think it agrees with some of your hunches.

 

[rjb]

Wow, this gave me some food for thought.

Vodsel pointed out better than I could have the fact that time is just a relative notion (ie: absolute time doesn't exist). So, in Einstein's equation, time is just like some kind of graph to map changes. It doesn't mean anything in the relativity theory, other than provide a point of reference. So, in that sense, there really isn't a "space-time fabric", but rather just space. Which isn't entirely accurate anyway, since space itself contains electrical and magnetical forces, as well as microscopic and quantum particles.

I never really understood how the "red shift" thing worked. I mean, I'm sure there isn't a team at NASA spending each day calculating if the space expanded or not, let alone the fact that we don't know where the border of the universe is, if there is one. So how do they know that the space is expanding? To me, it just seems a silly opinion based on some local facts that we have (ie: we extrapolate information about the whole universe based on what's happening in our observable surroundings).

However, what I'm inclined to believe, is this: the universe is not expanding, is not contracting, but rather "breathing". All planets, stars, solar systems and what have you are just a part of this intergalactic soup, and the universe itself is the bowl. Everything inside it is just shifting position, like when you swirl soup in a bowl. The vegetables are not expanding (so you could say space is expanding/contracting, but matter is not), but the "rotational" force applied to the whole thing creates the illusion that objects are moving farther away from the point of observation (if this were to be anywhere inside the bowl). In fact, the matter is just travelling to another position.

 

[Guyomech]

Vodsel: had not heard of Tsagas, thanks for posting that! It's one of those really sensible considerations that sometimes our physics seems to lack.

Now, back to the interwoven space/time thing. Crazyhorse, you have already touched on it two different ways: one being that matter is woven into a spacetime matrix of some sort, the other is that matter is actually moving "through space", as in my rocket analogy. I don't think you can have it both ways. My problem with the idea of it all being woven together is that how would you see any expansion? If all of it were expanding together, this expansion would be visible only to an observer outside the system. Because we are able to observe the expansion, that classifies us as moving "through space" rather than being an embedded part of a spatial matrix. As such, my rocket analogy still stands.

I think it's interesting how we humans (myself included) are so opposed to the notion of eventual total darkness in the universe, and wish to see proof of it recycling itself, of some kind of "afterlife" or continuity, despite the fact that we are talking about timescales of billions or even trillions of years. This may simply be the same "where do I go when I die?" narrative, writ large. It's entirely possible that the exquisite balance of the universe that allows matter to exist and form into self introspective aggregations like ourselves... This balance may be attainable only by including this (ultimately fatal) acceleration factor.

 

[Crazyhorse]

If I've got my facts straight, the observation made in the 1990s had to do with looking at a certain class of supernovae, a type that is almost always of a very particular light spectrum signature due to the size and type of star causing them. And the more distant they got, the faster away they were moving, above and beyond what was expected from the average redshift. Because this supernova type is usually very predictable in its behavior, these unexpected differences are considered to be very significant; after counting and averaging a large number of them, the additional acceleration factor was derived. The Dark Energy theory is only there as a way to account for this difference. Physicists are not thrilled about having to include it, but are still in broad disagreement about what it all means.

This pretty much fits my understanding of it as well, I think you're right on target here. Except that I haven't personally seen much disagreement about it. Whenever I run across the idea in the media or in documentaries or whatever I usually get the impression it's being stated with a lot more certainty than it seems to deserve, and up to now I haven't been aware of anyone offering any significant alternatives. However:

Among the alternative theories to dark matter, there's this idea by Christos Tsagas, a greek cosmologist, that you might like.

It starts with others' recent findings showing that, relative the rest of the universe, our region of spacetime is moving fast. Also, recent evidence suggests that the universe appears to be expanding more towards a preferred axis. Tsagas proposes that

Quote:
the acceleration of the universe in our immediate vicinity is caused by its motion alone. The universe beyond our region isn't accelerating outward; rather, it is safely rolling to a stop.

Once you consider that different regions of the universe might have different momentums, and keep in mind that the measurement of these momentums is essentially determined by the momentum of the observer's system, things might start to clear up.

I have the feeling this is the right direction, and I think it agrees with some of your hunches.

Aha! Now we're getting somewhere! Thanks very much for this.

I've heard of Dark Flow before, but never really made the connection to what I'm talking about here, or looked specifically into Tsagas' ideas. Wikipedia mentions him very briefly as one alternative in their page on dark energy, but doesn't seem to take it very seriously or go into his ideas at all. It just mentions our part of the universe possibly moving faster relative to others. But after reading THIS summary, I'm excited to learn more about it as it does indeed seem like what he's saying is at least in the same book as what I'm proposing, if not exactly on the same page. Although I'd have to disagree with his idea that when the expansion comes to a stop, that's the end of the story and the end of time. I'd like to know more about what he's basing that conclusion on. The suggestions of a disk-shaped universe on that Wiki page are really interesting to me too, and I'll definitely have to look more into that as well. :thumb_up:

So right now it appears to me that if there's a major problem with my idea, it seems to lie in whether or not Relativity ties the speed of the expansion of space together to the local perception of time the way I perceive it to. I still don't see any reason why it shouldn't work this way, based on my understanding of it so far. But of course getting a really good grip on the concept of relativity is probably one of the most difficult things in modern physics, right up there with REALLY understanding string theory and other far-out quantum interpretations (I'm a fan of M-Theory, myself, but it's definitely not always easy to get my head around.)

Anyway this at least gives me a direction to look for further understanding, thanks very much for feeding the fires of my curiosity!

 

[Crazyhorse]

However, what I'm inclined to believe, is this: the universe is not expanding, is not contracting, but rather "breathing". All planets, stars, solar systems and what have you are just a part of this intergalactic soup, and the universe itself is the bowl. Everything inside it is just shifting position, like when you swirl soup in a bowl. The vegetables are not expanding (so you could say space is expanding/contracting, but matter is not), but the "rotational" force applied to the whole thing creates the illusion that objects are moving farther away from the point of observation (if this were to be anywhere inside the bowl). In fact, the matter is just travelling to another position.

I think I understand where you're coming from, thanks for contributing. As I see it, the problem with what you're saying here, is that if things were really just sort of moving in and out, or swirling around rotationally, measuring the spectrum of the light from distant areas would show some things moving towards us (light wavelengths compressing towards blue), and other things moving away (wavelengths stretching into red). But like Guy described, after looking in all directions and at different stages of the universe's history, the overall large-scale picture we've had since Hubble in the 30's is very strongly that of everything moving away from everything else. The evidence for this really seems pretty solid and consistent, although I agree it COULD all just be a misinterpretation. But it would take some very solid new evidence to shake up that particular idea in the science community.

Vodsel: had not heard of Tsagas, thanks for posting that! It's one of those really sensible considerations that sometimes our physics seems to lack.

Agreed for sure! This guy and his team deserve a lot more recognition, and serious consideration.

Now, back to the interwoven space/time thing. Crazyhorse, you have already touched on it two different ways: one being that matter is woven into a spacetime matrix of some sort, the other is that matter is actually moving "through space", as in my rocket analogy. I don't think you can have it both ways. My problem with the idea of it all being woven together is that how would you see any expansion? If all of it were expanding together, this expansion would be visible only to an observer outside the system. Because we are able to observe the expansion, that classifies us as moving "through space" rather than being an embedded part of a spatial matrix. As such, my rocket analogy still stands.

I don't think I'm actually trying to have it both ways, maybe I'm just not describing my perception of it clearly enough. I'm not trying to say that matter is woven into space-time in such a way that they could expand together and would only be seen from outside. In fact that's exactly what I'm trying to say is NOT the case. :d See my earlier description of a boat on a lake, or more accurately in regards to expansion I think, a surfboard riding a wave.

Rather than saying we are moving "through space", I'd describe it as moving "with space", At least as far as the expansion is concerned. Although I'd say we also move THROUGH space at the same time as far as our galactic rotation and other more local motions are concerned. Sort of like how I can move THROUGH an airplane by walking from the front to the back, counter to the direction of it's motion, but still be moving much faster WITH the airplane in the opposite direction.

If space-time is the fabric, or like a rubber sheet as Einstein would have it, then matter is simply an object sitting on top of that sheet, affecting it and being affected by it, but not actually an integral part of it. If the sheet itself is moved (or stretched), matter gets moved along with it, but at the same time it can move around independently on the surface in other directions. I hope that makes a little more sense.

I think it's interesting how we humans (myself included) are so opposed to the notion of eventual total darkness in the universe, and wish to see proof of it recycling itself, of some kind of "afterlife" or continuity, despite the fact that we are talking about timescales of billions or even trillions of years. This may simply be the same "where do I go when I die?" narrative, writ large. It's entirely possible that the exquisite balance of the universe that allows matter to exist and form into self introspective aggregations like ourselves... This balance may be attainable only by including this (ultimately fatal) acceleration factor.

This is a very good point, and I don't really disagree. It may ultimately be unknowable, and I'm only certain that I'm not certain. :d Like I said at the beginning, my problem with the idea of a "one shot" universe is mainly esthetic. It just doesn't fit with the way everything else seems to work in cycles within cycles, and nothing ever goes to waste. A self-recycling universe also neatly answers the very big question of what initiated the big bang.

Thanks to everyone for an interesting discussion!

 

[Eliyahu]

Anarchy wrote:

Ok, so I believe that if we observe what nature is doing in the micro, you can apply that to the macro. Just like the brain cell, universe thing.

Nice observation ^^^

 

[Crazyhorse]

Just Because.

[youtube]

From the big bang to black holes,
From dark matter to a possible big crunch,
Our image of the universe today
Is full of strange sounding ideas.

- Stephen Hawking

 

[DeMenTed]

Just Because.

[youtube]

From the big bang to black holes,
From dark matter to a possible big crunch,
Our image of the universe today
Is full of strange sounding ideas.

- Stephen Hawking

Very nice

 

[DeMenTed]

Very nice CH

 

[Crazyhorse]

Yeah, that guy has made a bunch of those videos, and they're all really cool. But I think that one is my favorite. :d

Here's a bit more Youtubery, these should hopefully help explain some of the stuff I've been talking about for anyone still scratching their heads.

[youtube]

[youtube]

[youtube]

 

[Mr.Peabody]

I kept reading and reading this thread, with many things to say, and then everyone said exactly the things I was!

Crazyhorse:
It seems to me, from what I've read here your idea deserves looking in to. With the advent of the local acceleration(which is new to me and got me excited) it could explain this shift in local time, causing the illusion of an accelerating universe.
I never considered the idea that one of the parameters of measurement could be flawed.
It's very elegant!

I had another idea about if the universe is indeed accelerating apart which may be satisfactory, as well. I do recognize my bias for a cyclical universe, as it seems more appealing.

My idea is this:

We perceive the universe in three dimensions, but according to many theories (string, quantum, others) there do exist higher dimensions. If a two dimensional person is living on the surface of a ball, he would still only see his two dimensions, even though his universe is warped into a third dimension.
This could be true of our own universe; it could be warped in to a fourth dimensional sphere. The causes for this shape could be gravity, or maybe it just felt like it.

So, if the universe is warped in such a way maybe the big bang happened on the very edge of this sphere and has been expanding outward. There would come a point where the matter would reach the half way point, and start accelerating back in due to gravity. So in this way the universe would explode on one end, expand, contract on the other, and explode again, making a new cycle. It would be really interesting to view from a fourth dimensional, super sped-up perspective!

I know a sphere isn't the exact way it would be, but at the moment I am not very good at imagining the fourth dimension. I think a toroid (donut) would work, too. The big thing is, we would be unaware of the warped space which would make it hard to test/prove such an idea.

I hope I didn't jack a post that has run its course, but I just really wanted to see what others thought. Thanks for a great thread, I have really enjoyed reading it!

 

[Crazyhorse]

My idea is this:

We perceive the universe in three dimensions, but according to many theories (string, quantum, others) there do exist higher dimensions. If a two dimensional person is living on the surface of a ball, he would still only see his two dimensions, even though his universe is warped into a third dimension.
This could be true of our own universe; it could be warped in to a fourth dimensional sphere. The causes for this shape could be gravity, or maybe it just felt like it.

So, if the universe is warped in such a way maybe the big bang happened on the very edge of this sphere and has been expanding outward. There would come a point where the matter would reach the half way point, and start accelerating back in due to gravity. So in this way the universe would explode on one end, expand, contract on the other, and explode again, making a new cycle. It would be really interesting to view from a fourth dimensional, super sped-up perspective!

I know a sphere isn't the exact way it would be, but at the moment I am not very good at imagining the fourth dimension. I think a toroid (donut) would work, too. The big thing is, we would be unaware of the warped space which would make it hard to test/prove such an idea.

Hello Mr. Peabody! I hope you're treating your human well! He always seemed like a nice kid on your show, but I suppose he must be all grown up by now.

I think four (or more) spatial dimensions are a definite possibility, in fact I can't really see how the "rubber sheet" warping of space-time to create gravity could work WITHOUT it! These animations that are used to demonstrate the idea always show the "sheet" as a flat, 2D grid or plane being pushed downwards by the mass of an object. But that's got to be a gross oversimplification just to make it easier to understand. Since space is actually 3 dimensional (plus time), and goes all around the object not just on a flat plane through the middle, it seems to me there's no known direction for that dip or depression caused by the mass to GO unless it is pushing into a 4th spatial dimension. :surprised Am I wrong?

Anyway your idea is interesting, and I want to give it some real thought before jumping to a conclusion. I know that spherical and donut shaped universes have been proposed before and rejected, but I'm not entirely sure why. Maybe they were only being considered in 3 dimensions, but that would seem very narrow minded. THIS video explains why it's currently believed to be mostly flat, but since I THINK we wouldn't be able to percieve the 4th dimensional curve anyway, I'm not sure it actually disproves the idea. For the same reason, I'm not sure whether objects actually would appear to accelerate in such a universe, since it appears to us to be flat(ish). So would moving around a 4th dimensional curve make a difference to an objects apparent speed? I don't know, but it seems like something pretty juicy to chew on for a bit.

The other thing that occurs to me, is that since it's actually space-time expanding around this theoretical shape, not just matter, how does that affect what happens when it reaches the other end? I suppose all the matter gets compressed back to a singularity just like in the big crunch, but unless the "other end" of SPACE is actually moving across the sphere (or torus) along with all the matter, the next cycle would be big-banging into a pre-existing space, not inflating space-time itself, which is a whole different scenario than the big bang we're familiar with. Hmmm...

Ok then, all ponder circuits set to maximum. Begin countdown to overload!

I hope I didn't jack a post that has run its course, but I just really wanted to see what others thought. Thanks for a great thread, I have really enjoyed reading it!

Not at all! Thanks for joining in. I'd say we're not done here until all the mysteries of the cosmos have been unraveled, so we might as well get comfortable this could take a while! :d

 

[Guyomech]

One important point to make here is that time, which is often billed as a fourth dimension but not necessarily perceived by us as one, really is one. It's a physical axis the same as the familiar XYZ axes. The difference is that we can't move back and forth through this dimension at will, the way we can with the other three. But try imagining yourself as being a flesh colored 4 dimensional tube, starting out tiny at your moment of conception but being a continuous 4D tubular form reaching up till the present and then potentially into the future. The 3D self that you see in the mirror is actually a 3D cross section of this 4D tube.

There is a fourth dimension all around us; we move through it every day and are intimately familiar with its workings. We just aren't accustomed to thinking of time as a physical dimension, even though it truly is one.

 

[Crazyhorse]

This is true. I like the "human snake" image you get picturing a person throughout their whole lifetime. It just gets confusing because while it IS a dimension, it's not a spatial dimension, like X,Y,Z. it's temporal. It's only physical when combined with the other 3. So calling it the 4th dimension can be kind of confusing, especially when you start considering the idea of higher spatial dimensions. It's not zero dimensional, because it does have length. But length is already the first spatial dimension.. so what the hell do we call it? :?

 

[cyb]

so what the hell do we call it? :?

T Dimensional...??

 

[Crazyhorse]

so what the hell do we call it? :?

T Dimensional...??

Actually yeah you're right. That's how it's notated in calculations and stuff. You watched the videos didn't you.

 

[cyb]

so what the hell do we call it? :?

T Dimensional...??

Actually yeah you're right. That's how it's notated in calculations and stuff. You watched the videos didn't you.

Just popped into my head....

Spacetime=XYZ+T...:d

 

[Crazyhorse]

Right on well done, I'd actually forgotten about that but that's what Einstein called it. The 4th D thing was coined by someone later I think. But I've always thought it was confusing/misleading. It's like a built-in assumption there can't possibly be more than 3 spatial dimensions, and that's just not very smart IME.

Anyone for T?