The Naked Scientists

The Naked Scientists Forum

Author Topic: Can higher density of the Universe be responsible for increasing expansion rate?  (Read 1786 times)

Offline Pivz_

  • First timers
  • *
  • Posts: 3
    • View Profile
Because the Universe is expanding, its average density (on a really, really macroscopic scale) should be reducing. So let's look in any direction from the Milky Way, towards the cosmic microwave background. A galaxy 1 billion l.y. away would be X million years in the past (not 1 billion years, because of the expansion of the Universe). In the past, the Universe was denser than now. Another galaxy 2 billion l.y. away is Y million years in the past (Y>X, but not Y=2X,).
As I understand it, the current consensus explains the fact that the light from galaxy 2 is more (and not proportionately to the distance) redshifted than that of galaxy 1, by saying that the rate of the Universe's expansion is increasing - the further away a galaxy is from us, the faster it is speeding away and the more redshifted its light is.

Is it possible that this disproportionate (to the distance) increase in redshift is actually caused by higher Universe density in the past? Similarly to how the light from a source in a low orbit around a black hole would be redshifted, because the light has to expend energy to get higher gravitational potential or, to put it in another way, the light has to lose frequency when moving from more curved spacetime (closer to the black hole/further back in time when Universe density was higher) to less curved spacetime (further away from the black hole/closer to our time when Universe density is lower).



 

Offline JoeBrown

  • Sr. Member
  • ****
  • Posts: 150
  • Thanked: 4 times
  • Does everything simple always gotta be so complex?
    • View Profile
I posted a similar hypothesis in this forum but it was moved to "New Theories".

    The Naked Scientists Forum
    On the Lighter Side
    New Theories
    Dark Energy - is it a farce?

www.thenakedscientists.com/forum/index.php?topic=66046.0

I too have reasoned the change in distribution or topology of gravity field has and does cause Einstein Shift in light.  So when we look toward the past the gravity lens shifts light as it becomes diluted everywhere outside concentrated masses of galaxies.
 

Offline evan_au

  • Neilep Level Member
  • ******
  • Posts: 4126
  • Thanked: 247 times
    • View Profile
Quote
the current consensus explains the fact that the light from galaxy 2 is more (and not proportionately to the distance) redshifted than that of galaxy 1
Unfortunately, redshift is often the only measurable characteristic of a distant object.
In the absence of any other evidence, for a long time astronomers assumed that distance was proportional to red shift, via the Hubble Constant.

It was only by looking for an independent measure of distance (in this case, Type 1a supernovas) that a divergence was found from a linear Hubble relationship. A Nobel Prize was awarded for this work.
See: http://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe
(This same article has several alternative theories for this observation, beyond the current popularity champion, "Dark Energy").

There are concerns that there may be more than one version of Type 1a supernova, which might require tweaking of these findings.

However, if we manage to detect more black hole mergers via gravitational waves, that may provide an independent measure of the rate of expansion of the universe, since analysis of this initial discovery produced an estimate of its distance from luminosity, and also its red-shift.
 

Offline JoeBrown

  • Sr. Member
  • ****
  • Posts: 150
  • Thanked: 4 times
  • Does everything simple always gotta be so complex?
    • View Profile
Dark Energy is a flawed concept.

Its pretense is that there is one (and only one) cause of redshift, the doppler effect.

We know the Einstein shift is another form, completely ignored by the largely "accepted" thesis.  Einstein shift is a funny thing. 

We know it happens when light exits a star's gravitational field and we also know the reverse happens as light enters Sol's and the Earth's field.

Although the two always happen w/ respect to extra solar originating light, their effects are more or less consistent and  canceled (to a degree) by the reversal.

We don't have a simple lab experiments with which to experiment with Einstein shift, but the doppler effect is easily witnessed via sound emanating from passing vehicles, which makes it the norm, somewhat common place and logically its the only "accepted" form.

We have but one universe which we can observe.  If we ignore it's past with lambda-cdm or steady state or whatever theory floats your momentary boat.  Its evolution should be considered, the changes in distribution of the gravity field are part of the the whole observation.  We can't go back in the past, but every time we peer at the stars, we're looking back in time...  The further back you look, the more light is shifted.   A strange energy we have no explanation???  Or is it another effect that's been neglected?  I expect the latter, it's easy to understand why.
« Last Edit: 10/03/2016 11:34:47 by JoeBrown »
 

Offline puppypower

  • Hero Member
  • *****
  • Posts: 556
  • Thanked: 43 times
    • View Profile
If dark energy is causing the expansion of the universe, and the expansion of the universe is causing energy to red shift, and a red shift of energy means the potential of the photons are decreasing by going from shorter to longer wavelength, does that mean that dark energy acts like negative energy?

I tend to believe that dark energy is an addendum theory, that was added to resolve the energy balance problem, created by the assumption of no preferred reference in the universe. That premise violates energy conservation. Instead of getting rid of this bad premise, everyone is wanting to double down and use dark energy as the fudge factor. Energy conservation needs a zero state and a preferred reference hierarchy.

If you do the legal math, energy conservation is one of the few laws of science. While no preferred reference is not a law of science but more like a tradition. If law does not come first, this is called lawlessness. No assumption should come before a law, unless a magic trick is the goal; levitation. Magic, uses science and technology but is allowed to break the laws of physics, since the goal is to confuse and impress the audience. The ladies like the bad boys.

My theory for the universe is centered on the assumption that laws of physics, like energy conservation, have to come first. Physics needs to be lawful. This implies there needs to be ground state reference and a reference hierarchy, which is the same in all references. The best choice of ground state is the speed of light, since this is the same in all references.

I work under the assumption that the speed of light is the ground state reference of the universe. This can be inferred by there being a net conversion of matter to energy, instead of energy to matter in our current universe. When forces act they spontaneously lower the potential of matter with the release energy. The energy appears on the lower potential product side of the equation. 

The red shift of the universe is consistent with energy returning to the ground state of the speed of light. If we could move at the speed of light, the universe would appear like a point-instant. The only wavelength of energy that can be seen at that point-instant reference, would be infinite wavelength energy. The reason is, smaller than infinite wavelength energy would appear to be contracted to less than a point, in this point reference. Less than a point is a math contradiction, since point is as small as you can go. The net effect is to lower the potential with the speed of light, energy move toward infinite wavelength; red shift.

Gravity and GR is also consistent with the speed of light ground state. Matter, via gravity, by causing local space-time reference to contract, moves local reference in direction of the C reference. At the speed of light, reference contracts to the limit of a point-instant reference. This may occur in black holes. All roads lead to the same place; C ground state.

The original topic is could a higher density universe be responsible for a higher expansion rate.

We infer expansion from the red shift, which in my model is connected to energy and photons lowering potential with the ground state of C. Therefore the red shift should be higher, the higher the potential the energy is with the ground state. That means higher production rates of energy, from matter/gravity, that is hot off the press. This would be due to more stars and other energy emitting phenomena, setting a higher energy potential with C.

Higher mass density would be the cause. However, this would be in the context of more, less dense dusty and gaseous matter in the universe, and more matter in the form of massive integrated objects like stars, galaxies, etc; generating energy such as by fusion and mass burn.
« Last Edit: 10/03/2016 12:59:58 by puppypower »
 

Offline evan_au

  • Neilep Level Member
  • ******
  • Posts: 4126
  • Thanked: 247 times
    • View Profile
Quote from: JoeBrown
Dark Energy... Its pretense is that there is one (and only one) cause of redshift, the doppler effect.
A second cause of redshift is velocity-based time dilation.

Over cosmological distances (and relative velocities), relativistic effects require modification of the Doppler shift equations.

See: http://en.wikipedia.org/wiki/Relativistic_Doppler_effect
 

Offline JoeBrown

  • Sr. Member
  • ****
  • Posts: 150
  • Thanked: 4 times
  • Does everything simple always gotta be so complex?
    • View Profile
Don't relativistic doppler shift and gravity shift relate to the same underlying principle?

We can surmise the field of gravity has changed, through the evolution of the universe.

By neglecting that aspect, we surmise Dark Energy.  Coincidence?
 

Offline Colin2B

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 1921
  • Thanked: 124 times
    • View Profile
Don't relativistic doppler shift and gravity shift relate to the same underlying principle?
One is due to motion relative to us, the other a difference in gravitational field intensity. You can get gravitational redshift from a source that is not moving relative to us. They are related by the equivalence principle, but they are not the same.
« Last Edit: 11/03/2016 18:25:39 by Colin2B »
 

Offline JoeBrown

  • Sr. Member
  • ****
  • Posts: 150
  • Thanked: 4 times
  • Does everything simple always gotta be so complex?
    • View Profile
One is due to motion relative to us, the other a difference in gravitational field intensity. You can get gravitational redshift from a source that is not moving relative to us. They are related by the equivalence principle, but they are not the same.

The equivalence principle requires relative equivalence. 

*I* think it's reasonable to consider when a photon started its' journey, 14 billion years ago (about the furthest we can see), one *may be* correct in assuming mass was somewhat equivalently distributed here, there and everywhere, at that point time. 

However, during 14 billion years of it's journey, there are two nearly comprehensible states of change that would likely have occurred.

  • The Universe expands a an increasing rate, nothingness likes to expand
  • Field of gravity dissipates, because mass attracts

Curiously, these two sound a lot like the same thing.

We have a fair understanding of gravity and the mysterious force has no reasonable explanation. 

Ironically the mysterious one force attracts more funding.  LOL...  Wonder why...  One might conclude the "accepted" is more practical because it begets more funding.  Thought neither is likely to ever be proven.
« Last Edit: 11/03/2016 21:58:20 by JoeBrown »
 

Offline Colin2B

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 1921
  • Thanked: 124 times
    • View Profile
The equivalence principle requires relative equivalence. 
Can you expand on what you mean by that?
To me the equivalence principle is that the laws of physics are the same in an accelerating frame as they are in a uniform gravitational field.

*I* think it's reasonable to consider when a photon started its' journey, 14 billion years ago (about the furthest we can see), one *may be* correct in assuming mass was somewhat equivalently distributed here, there and everywhere, at that point time. 

However, during 14 billion years of it's journey, there are two nearly comprehensible states of change that would likely have occurred.
When those photons arrive here we can see exactly what the distribution of mass was at that point in time, we don't need to assume.
« Last Edit: 12/03/2016 08:43:53 by Colin2B »
 

Offline JoeBrown

  • Sr. Member
  • ****
  • Posts: 150
  • Thanked: 4 times
  • Does everything simple always gotta be so complex?
    • View Profile
The equivalence principle requires relative equivalence. 
Can you expand on what you mean by that?
To me the equivalence principle is that the laws of physics are the same in an accelerating frame as they are in a uniform gravitational field.
When one refers to a "uniform gravitational field" one tends to think the field of gravity is static.  We can understand this is not the case, changes in the field of gravity, among all is is difficult, if not impossible, to establish or verify.  We know the larger a mass, the stronger the gravity field for that mass.

When we look at the universe as a whole, we tend to think the galaxies and stars that we see have always existed. The steady state theories fails, because we understand gas collapses into stars, galaxies and black holes.  This process is slow compared to the speed of light.  But it's also somewhat tenacious.  One must accept that all mass is in a constant state of flux one way or another.  Black holes grow, stars form, burn, collapse or explode.

The field of gravity is in a constant state of flux.  Compared to the speed of light it may be perhaps minuscule change, but one cannot have one form of change not affect others.

If the Universe is 14 billion years old.  I'm confident the distribution of gravity changed in that period of time.  Otherwise you lend credence to steady state theories.

Quote
*I* think it's reasonable to consider when a photon started its' journey, 14 billion years ago (about the furthest we can see), one *may be* correct in assuming mass was somewhat equivalently distributed here, there and everywhere, at that point time. 

However, during 14 billion years of it's journey, there are two nearly comprehensible states of change that would likely have occurred.
When those photons arrive here we can see exactly what the distribution of mass was at that point in time, we don't need to assume.

Light traveling from the nearest galaxy has been in transit for 2.5 million years. I suppose if your going to use equivalency to determine shift, flux in gravity should also be accounted for during that period of time.  How one would determine flux, when we've only detected our first set of gravity waves, may prove challenging.
 

Offline evan_au

  • Neilep Level Member
  • ******
  • Posts: 4126
  • Thanked: 247 times
    • View Profile
Quote from: Pivz_
Can higher density of the Universe be responsible for increasing expansion rate?
I think not.

This is what post-Hubble Einstein's general relativity predicts (when you set Einstein's "cosmological constant" to zero): the increased density of the universe in the past means that the rate of expansion should be slowing; but because the universe is less dense now, the universe should still be slowing, but at a slower rate than when the universe was denser.

The open question was whether this rate was enough to stop the expansion, and have the universe reverse into a collapse, or would it continue to expand forever?

It was the work to confirm this "fate of the universe" that showed that the expansion of the universe did not fit with a zero cosmological constant.

So I suggest that the greater density in the past has been taken into account. And now the search is on for something that would act like a non-zero cosmological constant.
 

Offline jeffreyH

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 3927
  • Thanked: 55 times
  • The graviton sucks
    • View Profile
The question should be was the energy released at the big bang enough for any of the subsequent mass to achieve escape from the system. If not then there are two further scenarios. The first is re-collapse (big crunch) and the second requires input of energy from elsewhere. Where would the extra energy come from? Something in the system has to be changing. Even with the big bang escape energy scenario the extra energy has to be explained. Was cosmic inflation a result of this extra energy being present all along?
 

The Naked Scientists Forum


 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums
 
Login
Login with username, password and session length