Consider the universe as a sphere of approximate uniform density, i.e. a ball of gas. The elements (stars, galaxies) are small in comparison to distances.
Using the shell theorem (refer nearest wikipedia), the gravitational effect on a test object inside the sphere is proportional to the distance from the center. Therefore the g-field is zero at the center and increases in a linear mode to its maximum at the surface. The gravitational red shift would be proportional to the distance from the center, just as the Hubble constant. The contraction due to the gravitational effect would only require a compensating expanding force (source unknown) to maintain a sphere of constant radius, i.e. no need for an expanding universe.
Are there any reasons why this could not be the basis for an alternate theory to explain the Hubble constant?
QUOTE
The contraction due to the gravitational effect would only require a compensating expanding force (source unknown) to maintain a sphere of constant radius
That was Einstein's cosmological constant, which he later called the 'biggest mistake of my life'. And even with the cosmolgical constant, a steady state universe was not stable.
Hello phyti
The odds of us being at the center of the universe are very very small. So the observed symmetrical red shift in all visible directions is not likely due to your alternate theory.
The odds of us being at the center of the universe are very very small. So the observed symmetrical red shift in all visible directions is not likely due to your alternate theory.
What Montec said.
If gravity could account for some of the redshift, and reduce the effect of an expansion, wouldn't that reduce the size of the universe?
Opinions?
Opinions?
Hello phyti;
Just for the fun of it, let's pursue an alternate theory to the expanding universe.
First of all I have to deal with the part " Therefore the g field is zero at the center and increases in a linear mode to it's maximum at the surface". My reading of inside the shell shows that " the shell exerts no net force on particles anywhere within the volume ". Is this only for a hollow shell, or for your case also? I can understand a point outside the shell, but may be getting confused about a point inside the shell.
http://en.wikipedia.org/wiki/Shell_theorem
I have some ideas on getting around this if need be. Montec is right of course, but maybe we could consider a closed universe. Consider a closed universe with a radius of ten units. Pretend we would have to be within a radius of one unit or so.
My idea would be of a contracting universe with a thick contracting shell of matter falling inward after the big bang expansion, then hesitation.
Care to continue?
Just for the fun of it, let's pursue an alternate theory to the expanding universe.
First of all I have to deal with the part " Therefore the g field is zero at the center and increases in a linear mode to it's maximum at the surface". My reading of inside the shell shows that " the shell exerts no net force on particles anywhere within the volume ". Is this only for a hollow shell, or for your case also? I can understand a point outside the shell, but may be getting confused about a point inside the shell.
http://en.wikipedia.org/wiki/Shell_theorem
I have some ideas on getting around this if need be. Montec is right of course, but maybe we could consider a closed universe. Consider a closed universe with a radius of ten units. Pretend we would have to be within a radius of one unit or so.
My idea would be of a contracting universe with a thick contracting shell of matter falling inward after the big bang expansion, then hesitation.
Care to continue?
I guess my idea is too different. You are dealing with gravitational redshift. I was having stellar objects accelerating toward the collapsing shell giving a doppler shift. Excuse the intrusion.
QUOTE (Lasand+Jan 20 2009, 09:18 PM)
Hello phyti;
Just for the fun of it, let's pursue an alternate theory to the expanding universe.
First of all I have to deal with the part " Therefore the g field is zero at the center and increases in a linear mode to it's maximum at the surface". My reading of inside the shell shows that " the shell exerts no net force on particles anywhere within the volume ". Is this only for a hollow shell, or for your case also? I can understand a point outside the shell, but may be getting confused about a point inside the shell.
http://en.wikipedia.org/wiki/Shell_theorem
I have some ideas on getting around this if need be. Montec is right of course, but maybe we could consider a closed universe. Consider a closed universe with a radius of ten units. Pretend we would have to be within a radius of one unit or so.
My idea would be of a contracting universe with a thick contracting shell of matter falling inward after the big bang expansion, then hesitation.
Care to continue?
For a test object, the net force is:
zero inside the hollow shell, (also for electrically charged sphere)
linearly proportional to distance from center within sphere,
inversely proportional to sq of distance outside of sphere.
The idea could be modified to shell universe. The initial condition with weak gravity would allow the elements to expand away from the center.
Also consider a core of 1/2 the radius would only contain 1/8 of the total mass (with approx. uniform density). The interesting part is the natural consequence of redshift increasing outwardly. The earth could be off center with some variations in intensity, i.e. not 'ideal'.
Just for the fun of it, let's pursue an alternate theory to the expanding universe.
First of all I have to deal with the part " Therefore the g field is zero at the center and increases in a linear mode to it's maximum at the surface". My reading of inside the shell shows that " the shell exerts no net force on particles anywhere within the volume ". Is this only for a hollow shell, or for your case also? I can understand a point outside the shell, but may be getting confused about a point inside the shell.
http://en.wikipedia.org/wiki/Shell_theorem
I have some ideas on getting around this if need be. Montec is right of course, but maybe we could consider a closed universe. Consider a closed universe with a radius of ten units. Pretend we would have to be within a radius of one unit or so.
My idea would be of a contracting universe with a thick contracting shell of matter falling inward after the big bang expansion, then hesitation.
Care to continue?
For a test object, the net force is:
zero inside the hollow shell, (also for electrically charged sphere)
linearly proportional to distance from center within sphere,
inversely proportional to sq of distance outside of sphere.
The idea could be modified to shell universe. The initial condition with weak gravity would allow the elements to expand away from the center.
Also consider a core of 1/2 the radius would only contain 1/8 of the total mass (with approx. uniform density). The interesting part is the natural consequence of redshift increasing outwardly. The earth could be off center with some variations in intensity, i.e. not 'ideal'.
The galaxies are not moving away through preexisting space. Space is expanding throughout the universe carrying the galaxies with it.
Mitch Raemsch
Mitch Raemsch
QUOTE (AlexG+Jan 20 2009, 07:23 PM)
That was Einstein's cosmological constant, which he later called the 'biggest mistake of my life'. And even with the cosmolgical constant, a steady state universe was not stable.
I think it's possible to work around the problem of the need of an expanding force if you include some relativity into this. When you concider you are always at the center of the 'observable' or 'interacting' universe, it would take force to move from the center, a little bit outwards. But after you've done so, you're still at the center of the 'observable' universe.
All relative movement has a small acceleration in the opposite way of movement. This will prevent mass moving away AND towards eachother, creating a steady universe.
now the possible effects of this, I already worked out some of them:
- explaining the pioneer 10 / 11 anomaly
- changing the view of the Hubble constant (also effects light, redshift in all directions linear to distance)
- explaining galactic rotation problem. The loss of momentum will be compansated by loss of 'altitude' from the center. The loss of energy is VERY small, so it takes a LONG time before a galaxy 'shrinks'. This will have the same force as described in 'Modified Newtonian Dynamics', except the force is not towards the center, but deceleration of the circular orbit.
above solutions will cancel the need:
- MOND, circular deceleration has the same effect
- dark matter, no need to explain galactic orbits
- dark energy, no need to counter dark matter / causing expanding universe
QUOTE (ZeroTolerance+Jul 20 2009, 04:55 PM)
I think it's possible to work around the problem of the need of an expanding force if you include some relativity into this. When you concider you are always at the center of the 'observable' or 'interacting' universe, it would take force to move from the center, a little bit outwards. But after you've done so, you're still at the center of the 'observable' universe.
All relative movement has a small acceleration in the opposite way of movement. This will prevent mass moving away AND towards eachother, creating a steady universe.
now the possible effects of this, I already worked out some of them:
- explaining the pioneer 10 / 11 anomaly
- changing the view of the Hubble constant (also effects light, redshift in all directions linear to distance)
- explaining galactic rotation problem. The loss of momentum will be compansated by loss of 'altitude' from the center. The loss of energy is VERY small, so it takes a LONG time before a galaxy 'shrinks'. This will have the same force as described in 'Modified Newtonian Dynamics', except the force is not towards the center, but deceleration of the circular orbit.
above solutions will cancel the need:
- MOND, circular deceleration has the same effect
- dark matter, no need to explain galactic orbits
- dark energy, no need to counter dark matter / causing expanding universe
I tried. I really did. But this makes no physical sense at all.
All relative movement has a small acceleration in the opposite way of movement. This will prevent mass moving away AND towards eachother, creating a steady universe.
now the possible effects of this, I already worked out some of them:
- explaining the pioneer 10 / 11 anomaly
- changing the view of the Hubble constant (also effects light, redshift in all directions linear to distance)
- explaining galactic rotation problem. The loss of momentum will be compansated by loss of 'altitude' from the center. The loss of energy is VERY small, so it takes a LONG time before a galaxy 'shrinks'. This will have the same force as described in 'Modified Newtonian Dynamics', except the force is not towards the center, but deceleration of the circular orbit.
above solutions will cancel the need:
- MOND, circular deceleration has the same effect
- dark matter, no need to explain galactic orbits
- dark energy, no need to counter dark matter / causing expanding universe
I tried. I really did. But this makes no physical sense at all.
QUOTE (AlexG+Jul 20 2009, 10:31 PM)
I tried. I really did. But this makes no physical sense at all.
sorry, is it a specific part? or should I give it up altogether
sorry, is it a specific part? or should I give it up altogether
Give it up. Nothing there makes any sense.
QUOTE (AlexG+Jul 20 2009, 10:41 PM)
Give it up. Nothing there makes any sense.
it's my bad side: explaining what I'm tinking...
But I find lots of snippets on the internet which go the same way as I'm trying.
for example:
http://en.wikipedia.org/wiki/Pioneer_anomaly
"Extending the Hubble law (which relates the increase (redshift) of the wavelength of a photon from another galaxy to the expansion of the universe) to the realm of unbounded massive particles, the particle's associated de Broglie wavelength will be redshifted due to the expansion. This redshift corresponds to a decrease in the particle's momentum over time. Thus, the Pioneer spacecrafts' anomalous accelerations may be a counter example to the hypothesis of dark matter in the Milkyway galaxy.[14]"
14 - http://arxiv.org/abs/gr-qc/0610029v5
it's my bad side: explaining what I'm tinking...
But I find lots of snippets on the internet which go the same way as I'm trying.
for example:
http://en.wikipedia.org/wiki/Pioneer_anomaly
"Extending the Hubble law (which relates the increase (redshift) of the wavelength of a photon from another galaxy to the expansion of the universe) to the realm of unbounded massive particles, the particle's associated de Broglie wavelength will be redshifted due to the expansion. This redshift corresponds to a decrease in the particle's momentum over time. Thus, the Pioneer spacecrafts' anomalous accelerations may be a counter example to the hypothesis of dark matter in the Milkyway galaxy.[14]"
14 - http://arxiv.org/abs/gr-qc/0610029v5
QUOTE (ZeroTolerance+Jul 20 2009, 05:52 PM)
it's my bad side: explaining what I'm tinking...
But I find lots of snippets on the internet which go the same way as I'm trying.
for example:
http://en.wikipedia.org/wiki/Pioneer_anomaly
"Extending the Hubble law (which relates the increase (redshift) of the wavelength of a photon from another galaxy to the expansion of the universe) to the realm of unbounded massive particles, the particle's associated de Broglie wavelength will be redshifted due to the expansion. This redshift corresponds to a decrease in the particle's momentum over time. Thus, the Pioneer spacecrafts' anomalous accelerations may be a counter example to the hypothesis of dark matter in the Milkyway galaxy.[14]"
14 - http://arxiv.org/abs/gr-qc/0610029v5
The redshift of a photon happens because the speed of the photon is always c in every frame. This means that even if the emitter is moving away from the observer, the speed of the approaching photon is constant. The speed of the photon does not change to reflect the motion of the emitter, but the frequency does. In the case of massive particles, the speed is not constant and will change when measured from different frames. Since the particle's speed can change, there is no comparable frequency shift.
But I find lots of snippets on the internet which go the same way as I'm trying.
for example:
http://en.wikipedia.org/wiki/Pioneer_anomaly
"Extending the Hubble law (which relates the increase (redshift) of the wavelength of a photon from another galaxy to the expansion of the universe) to the realm of unbounded massive particles, the particle's associated de Broglie wavelength will be redshifted due to the expansion. This redshift corresponds to a decrease in the particle's momentum over time. Thus, the Pioneer spacecrafts' anomalous accelerations may be a counter example to the hypothesis of dark matter in the Milkyway galaxy.[14]"
14 - http://arxiv.org/abs/gr-qc/0610029v5
The redshift of a photon happens because the speed of the photon is always c in every frame. This means that even if the emitter is moving away from the observer, the speed of the approaching photon is constant. The speed of the photon does not change to reflect the motion of the emitter, but the frequency does. In the case of massive particles, the speed is not constant and will change when measured from different frames. Since the particle's speed can change, there is no comparable frequency shift.
The Standard Model describes a universe we could live in. But we don't live in it. We live in a substantially smaller and massively older universe than the one the Standard Model details. Hubble's redshift data has been misused (imho). I'm becoming more and more sure that we really don't have a solid method to measure galactic distances.
Halton Arp (one of Hubble's assistants) did a survey of QSO's associated with "parent" galaxies and showed dramatically different redshifts. The main argument against Arp is that the surveyed QSO's were/are not local to the galaxies. Yet in a number of cases there are clear filamentary associations.
Google "Intrinsic Redshift" or "Noncosmological Redshift" for better info than I can present here.
The BBT crowd dismisses these argument almost out of hand.
Halton Arp (one of Hubble's assistants) did a survey of QSO's associated with "parent" galaxies and showed dramatically different redshifts. The main argument against Arp is that the surveyed QSO's were/are not local to the galaxies. Yet in a number of cases there are clear filamentary associations.
Google "Intrinsic Redshift" or "Noncosmological Redshift" for better info than I can present here.
The BBT crowd dismisses these argument almost out of hand.
uaafanblog
Arp made a mistake in his associations. This is a long settled issue.
Grumpy
Arp made a mistake in his associations. This is a long settled issue.
Grumpy
QUOTE (Grumpy+Jul 22 2009, 10:06 PM)
uaafanblog
Arp made a mistake in his associations. This is a long settled issue.
Grumpy
Grumps,
I know there are interpretations (the majority) of the SDSS data that discount noncosmological redshift. However, there are (iirc) some interpretations of that data that support the concept.
I guess I look at the issue as a door. Arp opened it. Others pushed it open. Then a big wind came along and knocked the door against it's jamb. It didn't however latch it!
What about the Seyfert Galaxies study by Lopez-Corredoira and Guiterrez? Am I wrong to think their conclusions support Arp?
Just questions ... I'll happily stipulate that 99% of physicists accept that noncosmological redshift doesn't exist.
Arp made a mistake in his associations. This is a long settled issue.
Grumpy
Grumps,
I know there are interpretations (the majority) of the SDSS data that discount noncosmological redshift. However, there are (iirc) some interpretations of that data that support the concept.
I guess I look at the issue as a door. Arp opened it. Others pushed it open. Then a big wind came along and knocked the door against it's jamb. It didn't however latch it!
What about the Seyfert Galaxies study by Lopez-Corredoira and Guiterrez? Am I wrong to think their conclusions support Arp?
Just questions ... I'll happily stipulate that 99% of physicists accept that noncosmological redshift doesn't exist.
QUOTE
The redshift of a photon happens because the speed of the photon is always c in every frame. This means that even if the emitter is moving away from the observer, the speed of the approaching photon is constant. The speed of the photon does not change to reflect the motion of the emitter, but the frequency does. In the case of massive particles, the speed is not constant and will change when measured from different frames. Since the particle's speed can change, there is no comparable frequency shift.
I know c has a constant speed, which does not vary (in vacuum), so the frequency has to vary. That's a very funny thing about light. But what if light 'lost' energy on its travel, in all directions? What if everything lost 'momentum' on it's travel?
look at this link: http://www.math.ucla.edu/~jimc/documents/mond.html
Here is a proposal for expaining the pioneer anomaly with the MOND-theory. But I think some people missed a part:
QUOTE (->
| QUOTE |
| The redshift of a photon happens because the speed of the photon is always c in every frame. This means that even if the emitter is moving away from the observer, the speed of the approaching photon is constant. The speed of the photon does not change to reflect the motion of the emitter, but the frequency does. In the case of massive particles, the speed is not constant and will change when measured from different frames. Since the particle's speed can change, there is no comparable frequency shift. |
I know c has a constant speed, which does not vary (in vacuum), so the frequency has to vary. That's a very funny thing about light. But what if light 'lost' energy on its travel, in all directions? What if everything lost 'momentum' on it's travel?
look at this link: http://www.math.ucla.edu/~jimc/documents/mond.html
Here is a proposal for expaining the pioneer anomaly with the MOND-theory. But I think some people missed a part:
The Pioneer 10 spacecraft, at a distance from the Sun of about 67 astronomical units (AU) or 1.0×1013 m, experiences a measured acceleration toward the Sun of 1.32×10-6 m/s2, which is 8.74±1.33×10-10 m/s2 less than the Newtonian model[1, 5].
Because the universe is expanding, the spacecraft has an unmodelled velocity of 2.33×10&^-5 m/s. It takes light and gravitation 3.34×104 sec (0.4 day) to travel from the Sun to the spacecraft. In that time the spacecraft moves away by 0.78 m.
expanding universe: 2.33x10-5 m/s / 3.34x10^4 sec = 6,97^-10 m/s^2
pioneer anomaly 8.74±1.33×10^-10 m/s^2
what if both numbers are the same, within each margin of error? What if the pioneer looses energy the same way light does, while it travels? What if the loss of energy is actually the same:
sqrt(8.74±1.33×10^-10 * 6,97^-10) = 7,80x10^-10 m/s^2
hubble constant becoming: 80,34 km/s / parsec.
QUOTE
What if the pioneer looses energy the same way light does, while it travels
There is no known mechanism for either light or spacecraft loosing energy while it travels.
QUOTE (AlexG+Jul 23 2009, 12:25 AM)
There is no known mechanism for either light or spacecraft loosing energy while it travels.
there is, 'tired light'. An other expanation for redshift of light from far away.
QUOTE (ZeroTolerance+Jul 22 2009, 07:37 PM)
there is, 'tired light'. An other expanation for redshift of light from far away.
"Tired light" is the description given to an alternative to expansion to explain red-shift. However, there is no mechanism given for why light gets 'tired'. Tired light is mainly of historical interest.
Here, read up on it.
http://en.wikipedia.org/wiki/Tired_light
"Tired light" is the description given to an alternative to expansion to explain red-shift. However, there is no mechanism given for why light gets 'tired'. Tired light is mainly of historical interest.
Here, read up on it.
http://en.wikipedia.org/wiki/Tired_light
G'day from the land of ozzzz
Do we really understand the universe?
This paper is quite interesting
Misconceptions about the Hubble recession law
Jul-09
http://adsabs.harvard.edu/doi/10.1007/s10509-009-0057-z
Do we really understand the universe?
This paper is quite interesting
Misconceptions about the Hubble recession law
Jul-09
http://adsabs.harvard.edu/doi/10.1007/s10509-009-0057-z
QUOTE
Almost all astronomers now believe that the Hubble recession law was directly inferred from astronomical observations. It turns out that this common belief is completely false. Those models advocating the idea of an expanding universe are ill-founded on observational grounds. This means that the Hubble recession law is really a working hypothesis. One alternative to the Hubble recession law is the tired-light hypothesis originally proposed by Zwicky (Proc. Nat. Acad. Sci. 15:773, <CitationRef CitationID="CR28">1929</CitationRef>). This hypothesis leads to a universe that is an eternal cosmos continually evolving without beginning or end. Such a universe exists in a dynamical state of virial equilibrium. Observational studies of the redshift-magnitude relation for Type Ia supernovae in distant galaxies might provide the best observational test for a tired-light cosmology. The present study shows that the model Hubble diagram for a tired-light cosmology gives good agreement with the supernovae data for redshifts in the range 0<z<2. This observational test of a static cosmology shows that the real universe is not necessarily undergoing expansion nor acceleration.
Harry Costas
It is also quite wrong, as you would know if you had bothered to read the cites by rpenner and AlexG.
Grumpy
QUOTE
This paper is quite interesting
It is also quite wrong, as you would know if you had bothered to read the cites by rpenner and AlexG.
Grumpy
G'day from the land of ozzzz
Science is always questioning and testing. This is how we learn and correct our paths.
The cosmic age crisis and the Hubble constant in a non-expanding universe
Sep-08
http://adsabs.harvard.edu/abs/2008Ap%26SS.317...45S
Science is always questioning and testing. This is how we learn and correct our paths.
The cosmic age crisis and the Hubble constant in a non-expanding universe
Sep-08
http://adsabs.harvard.edu/abs/2008Ap%26SS.317...45S
QUOTE
The present paper outlines a cosmological paradigm based upon Dirac’s large number hypothesis and continual creation of matter in a closed static (nonexpanding) universe. The cosmological redshift is caused by the tired-light phenomenon originally proposed by Zwicky. It is shown that the tired-light cosmology together with continual matter creation has a universal Hubble constant H 0=(512 π 2/3)1/6( GC 0)1/3 fixed by the universal rate C 0 of matter creation, where G is Newton’s gravitational constant. It is also shown that a closed static universe has a finite age τ 0=(243 π 5/8 GC 0)1/3 also fixed by the universal rate of matter creation. The invariant relationship H 0 τ 0=3 π 261/2 shows that a closed static universe is much older (≈one trillion years) than any expanding universe model based upon Big-Bang cosmology. It is this property of a static universe that resolves any cosmic age crisis provided that galaxy formation in the universe is a continual recurring process. Application of Dirac’s large number hypothesis gives a matter creation rate C 0=4.6×10‑48 gm cm‑3 s‑1 depending only on the fundamental constants of nature. Hence, the model shows that a closed static universe has a Hubble constant H 0=70 km s‑1 Mpc‑1 in good agreement with recent astronomical determinations of H 0. By using the above numerical value for H 0 together with observational data for elongated cellular-wall structures containing superclusters of galaxies, it is shown that the elongated cellular-wall configurations observed in the real universe are at least one hundred billion years old. Application of the microscopic laws of physics to the large-scale macroscopic universe leads to a static eternal cosmos endowed with a matter-antimatter symmetry. It is proposed that the matter-antimatter asymmetry is continuously created by particle-antiparticle pair annihilation occurring in episodic cosmological gamma-ray bursts observed in the real universe.
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