Dark Matter, Dark Energy And Dark Flow Explained, Maybe.

[A-wal]

I don't believe for a second that galaxies are moving away from each other faster than the speed of light. The explanation that it's because the space in between is increasing holds no weight because the space in between any two objects that are moving away from each other is increasing, and that can never happen faster than the speed of light. The reason galaxies are red shifted is because the space we're looking over is a curved surface. The universe is a four dimensional sphere. When we look at objects over a curved surface they don't just disappear at a certain distance, they appear red shifted. The universe is curved by the mass it contains and the further away we look the more space we're looking over between use and the observed object so the more red shifted it will appear.

 

The universe can be thought of as a three dimensional sphere to help visualise it. The surface of the sphere is the present moment, the interior is the past and the exterior is the future. From this perspective it appears that the universe started out as a single point and then expanded to the size it is now and will continue to expand forever into the future, but this is because we're visualising a four dimensional sphere in three dimensions. In reality the sphere never changes size and any given moment will be on the surface of the same sphere with the past towards the centre. The past looks like it has an ever decreasing surface area with a singularity at the centre but this is the case from any other frame of reference as well. It's a purely relative frame of reference.

 

As we look towards the other side of the sphere, from our perspective the universe is funnelled into a singularity at the exact opposite side of the sphere creating the illusion of a point in the universe that everything is attracted to. In an eternal universe the galaxies would have to recycle themselves and the number of dead stars would far outweigh the number of lit stars. In the standard model there hasn't been anywhere near enough time for black dwarf stars to exist, but in this model there could be loads of them. The dark matter observed tends to be around the edge of galaxies so that suggests stars are generally born at the centres of galaxies and steadily move outwards until they fizzle out. There would have to be a mechanism that converts the matter to energy that's then recycled back into the centre of the galaxies.

 

Edit:

This is a four dimensional sphere with one of the dimensions being time. This would mean that not only would an object approach in one direction as it recedes in the opposite direction like on a three dimensional sphere but also as an event recedes into the past it also approaches in the future. There's no paradox because it's impossible to get information through a singularity. Pretty trippy. Very beautiful though.

Edited July 18, 2015 by A-wal

[sanctus]

Just about the premise:

I don't believe for a second that galaxies are moving away from each other faster than the speed of light. The explanation that it's because the space in between is increasing holds no weight because the space in between any two objects that are moving away from each other is increasing, and that can never happen faster than the speed of light. The reason galaxies are red shifted is because the space we're looking over is a curved surface. The universe is a four dimensional sphere. When we look at objects over a curved surface they don't just disappear at a certain distance, they appear red shifted. The universe is curved by the mass it contains and the further away we look the more space we're looking over between use and the observed object so the more red shifted it will appear.

 

 

You misunderstand something completely, the expansion of space-time is not the same as increase in distance due to objects moving a part from each other.

 

If any 2 objects move away from each other it is true that the distance increases. But when people say "the space between is increasing" (NB: usually they phrase it better) they mean due expansion of space-time there is a bigger distance now than before. Or a simple way to confute your argument is that if you take 2 points in space and they have no peculiar velocity (i.e. both in same frame of reference and no movement wrt each other) than the distance between them increases anyway...that's the meaning of space being increasing.

 

Btw, it is fun that here you say the universe is curved and in another thread you say how GR and gravity curving spacetime is wrong ;-)

[Pmb]

sanctus - His understanding of cosmology as demonstrated in that post is seriously lacking. You're quite correct that the distance between galaxies is increasing because its the space itself that is  increasing. This fact is manifest in the solutions to Einstein's equation, i.e. the various metrics for the spacetime. Otherwise light wouldn't be able to travel FTL. But in reality light isn't locally traveling FTL its the fact that the space is increasing that allows it, all as you said. His excuse for why galaxies are red shifted is horribly wrong. In fact space itself may not even be curved. Experiments to date show that space itself is flat (i.e. zero curvature) and as such his excuse is wrong. He doesn't even appear to understand that there are three possibilities of the shape of the universe. One is with positive curvature (3-space is analogous to a 3-sphere), zero curvature (space is Euclidean) and negative curvature (3-space has a saddle like geometry). Which is correct depends on the mass density and right now the curvature is extremely small and possibly zero. So his claim that the universe is a four-dimensional sphere is an ignorant statement. He's confusing the geometry of the space with the geometry of the spacetime.

 

Folks  - You'd all do well to ignore this thread, or at least the contribution made by A-wal. They're all based on a very poor understanding of cosmology and GR.

[A-wal]

You misunderstand something completely, the expansion of space-time is not the same as increase in distance due to objects moving a part from each other.

No I haven't misunderstood at all. The idea that it an increase in distance is anything other than objects moving away from each other is so far beyond absurd it should be a huge embarrassment and I have no doubt it will be in the future looking back. When it was discovered that the redshift associated with distant galaxies would mean that they're moving away from each other faster than the speed of light something very stupid happened. Instead of treating it as proof that recession isn't the only cause of redshift it was inferred that the galaxies are moving away from each other faster than the speed of light, but not really, because it's the distance between them that's changing. Unbelievable!

 

If any 2 objects move away from each other it is true that the distance increases. But when people say "the space between is increasing" (NB: usually they phrase it better) they mean due expansion of space-time there is a bigger distance now than before. Or a simple way to confute your argument is that if you take 2 points in space and they have no peculiar velocity (i.e. both in same frame of reference and no movement wrt each other) than the distance between them increases anyway...that's the meaning of space being increasing.

For a start a point in spacetime can't possibly have a relative velocity. How could that be measured? It's only particles/waves that can have a velocity. Secondly you say that two points in spacetime have no movement with respect to each other and then say that they do because they're moving apart. That makes no sense! Which is it?

 

Btw, it is fun that here you say the universe is curved and in another thread you say how GR and gravity curving spacetime is wrong ;-)

I said no such thing. I said that within a localised coordinate system there's no distinction between objects following straight paths through curved spacetime and objects following curved paths through flat spacetime because the only statement you can make that has any physical meaning is that an object's is following a curved path through spacetime. I would have thought this was obvious but apparently not because general relativity attempts to describe curved space-time a physically distinct and in doing so gives an inaccurate and self contradicting description in which objects both can and can't cross the event horizon of a black hole depending on their arbitrary choice of coordinate system.

 

This is from a localised frame of reference. If the curvature of space-time globally is responsible for the increased redshift at greater distances then curved spacetime would be a physically meaningful concept but it would have no effect on the fact that in a localised frame of reference were redshift is negligible it would be impossible to make that distinction, in the same way that special relativity describes the effect of different relative velocities using the Lorentz transformations when acceleration is negligible.

 

sanctus - His understanding of cosmology as demonstrated in that post is seriously lacking. You're quite correct that the distance between galaxies is increasing because its the space itself that is increasing. This fact is manifest in the solutions to Einstein's equation, i.e. the various metrics for the spacetime. Otherwise light wouldn't be able to travel FTL. But in reality light isn't locally traveling FTL its the fact that the space is increasing that allows it, all as you said. His excuse for why galaxies are red shifted is horribly wrong. In fact space itself may not even be curved. Experiments to date show that space itself is flat (i.e. zero curvature) and as such his excuse is wrong. He doesn't even appear to understand that there are three possibilities of the shape of the universe. One is with positive curvature (3-space is analogous to a 3-sphere), zero curvature (space is Euclidean) and negative curvature (3-space has a saddle like geometry). Which is correct depends on the mass density and right now the curvature is extremely small and possibly zero. So his claim that the universe is a four-dimensional sphere is an ignorant statement. He's confusing the geometry of the space with the geometry of the spacetime.

No I'm not confusing three dimensional geometry with four dimension geometry and I'm well aware of the concept of a positively curved, negatively curved or flat universal geometry thankyou. If you actually had any understanding of this you'd have realised that if the redshift isn't caused by recession then the universe would necessarily be positively curved and it would be curved the same way in time so that any direction in time or space in a straight line would eventually lead back to its starting point, making it a four dimensional hypersphere.

 

Folks - You'd all do well to ignore this thread, or at least the contribution made by A-wal. They're all based on a very poor understanding of cosmology and GR.

:) Yea okay. This from someone who claims to be a relativity expert and knows the top people in the field but was completely unaware that general relativity describes gravity as objects moving along straight paths in curved spacetime. Folks - You'd do well to assume everything that this dude says is either wrong or a lie because he demonstrates time and again that he has no clue about the field he claims to be an expert in.

Edited August 20, 2015 by A-wal

[HydrogenBond]

Space-time is a dependent variable and therefore cannot lead the process of universal expansion. Currently the dependency of the expansion of space-time, is attributed to dark energy.  However, dark energy has never be proven to exist in the lab. Dark energy is only inferred through circular arguments based on need. In other words, we know space-time can't lead, but we can't see anything tangible and traditional dong this, therefore something unknown, we can;t see in the lab, has to be doing this.

 

In terms of lab proof, the only proven way we can alter space-time in the lab is to change mass geometry. This is not a hard experiment, using basic matter we can prove to exist. Yet we prefer the unprovable to do this. This may be needed for funding frontier pitch. 

 

As far as using something we can do in the lab, which we can show can impact space-time, all stars undergoing fusion are also burning mass into energy, with energy leaving the star, so we can see the star. The net loss of mass/energy, driven by the exothermic nature of fusion, will cause the space-time around stars to expand over time. 

 

Data has shown that galaxies and stars formed very early in the universe; less than a billion years. This implies billions of years of mass burn has occurred. 

 

The question becomes say we place a beam of light on one side of the universe that shines to the other side. This light has to go through billions of small incremental changes in local space-time due to the mass of stars decreasing with time.