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Thread: Universe may not be expanding...

  1. #1 Universe may not be expanding... 
    Brassica oleracea Strange's Avatar
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    As I have occasionally been accused of only being interested in defending the status quo as well as having a blind faith in the big bang and other well-tested theories, I thought I would throw this idea out there:
    Cosmologist claims Universe may not be expanding : Nature News & Comment

    Christof Wetterich, a theoretical physicist at the University of Heidelberg in Germany, has devised a different cosmology in which the Universe is not expanding but the mass of everything has been increasing.
    An interesting idea, even if wrong...

    More here: [1303.6878] A Universe without expansion


    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
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    Looking at the paper it appears that, as with all the "no bang" cosmologies I have seen, this is yet another model based on a different coordinate choice. As he says in the paper:
    Our model should be interpreted as a new complementary
    picture of cosmology, not as opposing the more standard
    picture of an expanding universe. The different pictures
    are equivalent, describing the same physics.


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    If this model was true I would expect to see objects near the critical mass limit ( e.g. dense neutron stars, quark stars etc ) undergo spontaneous gravitational collapse due to the proposed mass increase, without all the accompanying signatures of supernovas; in other words - I don't agree that this model isn't testable. Needless to say that no such event has ever been observed to date; of course that does not rule out that such events exist, but still...I would be sceptical.
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    Quote Originally Posted by Strange View Post
    The different pictures
    are equivalent, describing the same physics.
    Again, I disagree. A mass increase such as the one required to make this model work would need a modified Higgs mechanism to be feasible. I don't think it is compatible with the current Standard Model.
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    I couldn't see how that cosmology produces an angular size distance that matches observation.
    Distance measures (cosmology) - Wikipedia, the free encyclopedia
    We see things at the size they were in the sky before space expanded, hence very distant objects look larger than you would expect.
    I believe in nothing, but trust gravity to hold me down and the electromagnetic force to stop me falling through
    Physics is the search for the best model not the truth, as only mythical beings know that.
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    Reading it again, I see that the papers odd coordinate system does produce an angular distance by effectively changing the size of the atom in the past.

    Now I don't understand how it maintains a sensible reference frame for the basic conservation of momentum, and therefor the speed of light.
    You can't just scale between commoving space, and space measured using atom widths, because the two reference frames are accelerating relative to the other. An object moving with constant vel in one reference frame is accelerating in the other.
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    Quote Originally Posted by Strange View Post
    As I have occasionally been accused of only being interested in defending the status quo as well as having a blind faith in the big bang and other well-tested theories, I thought I would throw this idea out there:
    Cosmologist claims Universe may not be expanding : Nature News & Comment

    Christof Wetterich, a theoretical physicist at the University of Heidelberg in Germany, has devised a different cosmology in which the Universe is not expanding but the mass of everything has been increasing.
    An interesting idea, even if wrong...

    More here: [1303.6878] A Universe without expansion
    Forrest Noble has been saying something similar to this for many years...
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  9. #8  
    Forum Bachelors Degree PetTastic's Avatar
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    I've been posting something similar for years, but never liked the idea of mass getting heavier.
    http://www.thescienceforum.com/new-h...ase-break.html
    Us shrinking or space expanding?
    These are out of date. The best match comes from assuming the laws of physics were identical in the past.

    Forrest Noble has been getting in trouble with the moderators on many forums for pushing his version
    Pan Theory - Alternative to the Big Bang Theory
    I believe in nothing, but trust gravity to hold me down and the electromagnetic force to stop me falling through
    Physics is the search for the best model not the truth, as only mythical beings know that.
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  10. #9  
    Brassica oleracea Strange's Avatar
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    Quote Originally Posted by Neverfly View Post
    Forrest Noble has been saying something similar to this for many years...
    But he was just making stuff up.

    His was more about things shrinking instead of the universe expanding. You can, of course, choose coordinates where that is the case (which means the speed of light varies over time and all sorts of slightly odd things). The thing is though, if you do that you haven't changed anything in the underlying model, just the representation of it. So, where the big bang model sees accelerating expansion, the alternative view must see accelerating shrinking. And so on.

    Forrest believes the "shrinking" model gives new insights (which it might) and that it gets rid of problems like dark energy or the original singularity. Of course, it doesn't because it is the same model.

    However, once you start making changes to the model, as Forrest does, then it is no longer the same thing. But in that case, it must be possible to convert the changes you make back to the standard big bang coordinates and analyse the effects there and compare them with observation. Forrest never accepted that and so never accepted that his ad-hoc manipulations don't correspond to observation.
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by Neverfly View Post
    Forrest Noble has been saying something similar to this for many years...
    But he was just making stuff up.

    His was more about things shrinking instead of the universe expanding. You can, of course, choose coordinates where that is the case (which means the speed of light varies over time and all sorts of slightly odd things). The thing is though, if you do that you haven't changed anything in the underlying model, just the representation of it. So, where the big bang model sees accelerating expansion, the alternative view must see accelerating shrinking. And so on.
    Most of these models best match observation with the rate of shrinking slowing over time.


    Quote Originally Posted by Strange View Post
    Forrest believes the "shrinking" model gives new insights (which it might) and that it gets rid of problems like dark energy or the original singularity. Of course, it doesn't because it is the same model.

    However, once you start making changes to the model, as Forrest does, then it is no longer the same thing. But in that case, it must be possible to convert the changes you make back to the standard big bang coordinates and analyse the effects there and compare them with observation. Forrest never accepted that and so never accepted that his ad-hoc manipulations don't correspond to observation.
    I think he considered it a process of progressive refinement, every time we pointed out an issue, he would fix it.
    I believe in nothing, but trust gravity to hold me down and the electromagnetic force to stop me falling through
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    Quote Originally Posted by pettastic View Post
    Quote Originally Posted by strange View Post
    Quote Originally Posted by neverfly View Post
    forrest noble has been saying something similar to this for many years...
    but he was just making stuff up.

    His was more about things shrinking instead of the universe expanding. You can, of course, choose coordinates where that is the case (which means the speed of light varies over time and all sorts of slightly odd things). The thing is though, if you do that you haven't changed anything in the underlying model, just the representation of it. So, where the big bang model sees accelerating expansion, the alternative view must see accelerating shrinking. And so on.
    most of these models best match observation with the rate of shrinking slowing over time.


    Quote Originally Posted by strange View Post
    forrest believes the "shrinking" model gives new insights (which it might) and that it gets rid of problems like dark energy or the original singularity. Of course, it doesn't because it is the same model.

    However, once you start making changes to the model, as forrest does, then it is no longer the same thing. But in that case, it must be possible to convert the changes you make back to the standard big bang coordinates and analyse the effects there and compare them with observation. Forrest never accepted that and so never accepted that his ad-hoc manipulations don't correspond to observation.
    i think he considered it a process of progressive refinement, every time we pointed out an issue, he would ignore it.
    fify.
    Last edited by tk421; September 23rd, 2013 at 08:55 PM.
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    Quote Originally Posted by tk421 View Post
    fify.
    Le Fem?

    What?
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    Quote Originally Posted by Neverfly View Post
    Quote Originally Posted by tk421 View Post
    fify.
    Le Fem?

    What?
    Hmm...very odd. I typed all caps (FIFY, for "fixed it for you") but the forum software converted it to lower case. I have no idea why.
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    Quote Originally Posted by tk421 View Post
    Quote Originally Posted by Neverfly View Post
    Quote Originally Posted by tk421 View Post
    fify.
    Le Fem?

    What?
    Hmm...very odd. I typed all caps (FIFY, for "fixed it for you") but the forum software converted it to lower case. I have no idea why.
    Ah, ok. It does that- I learned long ago not to start a post with an acronym, e.g. "PETA opposes alligator circumcision."

    I think the software automatically assumes you're yelling at someone if more than the first letter of the post is capitalized.
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    Quote Originally Posted by Neverfly View Post
    Quote Originally Posted by tk421 View Post
    Quote Originally Posted by Neverfly View Post
    Quote Originally Posted by tk421 View Post
    fify.
    Le Fem?

    What?
    Hmm...very odd. I typed all caps (FIFY, for "fixed it for you") but the forum software converted it to lower case. I have no idea why.
    Ah, ok. It does that- I learned long ago not to start a post with an acronym, e.g. "PETA opposes alligator circumcision."

    I think the software automatically assumes you're yelling at someone if more than the first letter of the post is capitalized.
    Thanks for the explanation -- that makes a great deal of sense! For a few moments, I thought I had a brain tumour. Now I can cancel that MRI...
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    I don't see how it's different to propose continually increasing distances, or continually speeding up time, or continually decreasing mass. They're all the same basic idea.



    Why don't we try another possibility? Why don't we propose that the universe is curved, just like Einstein predicted? If you are standing at any point on a spherically curved surface, then that surface appears to curve outward in all directions. Does it not?

    We just need to choose the right meaning for the concept of "curvature".
    Some clocks are only right twice a day, but they are still right when they are right.
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    Quote Originally Posted by tk421 View Post
    Now I can cancel that MRI...
    Nah, get it anyway. You still might have a tumor.
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    Quote Originally Posted by Neverfly View Post
    Quote Originally Posted by tk421 View Post
    Now I can cancel that MRI...
    Nah, get it anyway. You still might have a tumor.
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  20. #19  
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    Quote Originally Posted by PetTastic View Post
    I think he considered it a process of progressive refinement, every time we pointed out an issue, he would fix it.
    You are very obviously wrong. But I don't want to discuss Forrest "behind his back".
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by PetTastic View Post
    I think he considered it a process of progressive refinement, every time we pointed out an issue, he would fix it.
    You are very obviously wrong. But I don't want to discuss Forrest "behind his back".
    I was refering to his point of view (as is see it), not mine

    And I got the
    fify.
    First time
    Last edited by PetTastic; September 24th, 2013 at 05:01 AM. Reason: added (as is see it) due to me not being a mind reader
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    Quote Originally Posted by kojax View Post
    I don't see how it's different to propose continually increasing distances, or continually speeding up time, or continually decreasing mass. They're all the same basic idea.



    Why don't we try another possibility? Why don't we propose that the universe is curved, just like Einstein predicted? If you are standing at any point on a spherically curved surface, then that surface appears to curve outward in all directions. Does it not?

    We just need to choose the right meaning for the concept of "curvature".
    The cosmology discussed in the first post breaks one of the primary unspoken assumptions of standard cosmology.
    The size of the atom is fixed.

    There are two unspoken assumptions in standard cosmology.
    The first is the size of the atom is unchanging over time.
    BBT could be phrased as: If we are not shrinking, then space must be expanding.

    The second is that Newton's first law works in a coordinate system experienced by atoms.
    This only makes sense if atoms are a fixed size over time.
    BBT assumes that when viewed from a coordinate system where the universe if fixed size, moving objects slow down as atoms shrink.
    (Constant velocity can be measured in atom widths per second)
    If you change it so that the universe is an inertial reference frame, you get an object will continue to cross the universe at a fixed rate until acted on by a force.

    Once you start to doubt the size of the atom, you don't need curved space, darks energy or cosmological constants.
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    Quote Originally Posted by PetTastic View Post
    Once you start to doubt the size of the atom, you don't need curved space, darks energy or cosmological constants.
    You also end up with awful problems trying to scale the strong and weak interactions, without effecting any other laws of nature.
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    Quote Originally Posted by Markus Hanke View Post
    You also end up with awful problems trying to scale the strong and weak interactions, without effecting any other laws of nature.
    It may be possible to manipulate various other physical constants to make things work. But this is why we use the coordinate system we do (expanding space, constant speed of light, finite age for the universe, etc.): it is just the simplest way of representing the model. You can choose another one but it just gets more complicated and (for most people) counter-intuitive.
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  25. #24  
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    Quote Originally Posted by PetTastic View Post
    Once you start to doubt the size of the atom, you don't need curved space, darks energy or cosmological constants.
    That isn't true. It is still the same model: you still need to explain the accelerating expansion of space shrinking of atoms. You may label this "dark shrinkage" but it doesn't go away just because you have changed the coordinate system.
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    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by PetTastic View Post
    Once you start to doubt the size of the atom, you don't need curved space, darks energy or cosmological constants.
    You also end up with awful problems trying to scale the strong and weak interactions, without effecting any other laws of nature.
    Yes, agreed.
    In my view the cosmology discussed in the original post does not have a good answer for this.

    But saying that, the best way to get the required time dilation is to assume the laws of physics in the past (as experienced by an observer in the past) were identical to the laws of physics now.
    Double the size of the atom and the clocks must be running twice as slow, or everything breaks.
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by PetTastic View Post
    Once you start to doubt the size of the atom, you don't need curved space, darks energy or cosmological constants.
    That isn't true. It is still the same model: you still need to explain the accelerating expansion of space shrinking of atoms. You may label this "dark shrinkage" but it doesn't go away just because you have changed the coordinate system.
    If I started talking Higgs bossons explanations for something I do not have a clue about. I would be as bad as ...
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    Quote Originally Posted by PetTastic View Post
    Double the size of the atom and the clocks must be running twice as slow, or everything breaks.
    I don't see the connection between the size of an atom ( as measured by which observer ? ), and the rate of clocks ( as measured by whom ? ). Remember, there is no universal frame of reference.
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    Quote Originally Posted by Strange View Post
    It may be possible to manipulate various other physical constants to make things work. But this is why we use the coordinate system we do (expanding space, constant speed of light, finite age for the universe, etc.): it is just the simplest way of representing the model. You can choose another one but it just gets more complicated and (for most people) counter-intuitive.
    I don't think changing fundamental values will solve this issue - particularly the strong interaction works in highly non-linear ways, and would be extremely difficult to scale without effecting anything else.
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    The local observer would see no changes as he is made of matter.
    If a clock was double the size in the past, so was the observer, and his metre ruler, his diffraction grating, and all his other instruments.

    The clock in the past would only be twice the size when measured from commoving space.
    (Newtonian physics in comoving space) It's pendulum or balance wheel would be twice as large so it would run slower.

    The basic idea is that absolutly every experiment in the past to measure fundimental constants, conducted and observed from the past gives the same result as now.

    The laws of physics can be thought of as circular.
    We observe the physics of matter using instruments made of matter.
    The instruments change in exactly the same way as the matter they are observing, therefor you can never see a change unless you observe ancient matter using modern instruments. (powerful telescopes)
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    Quote Originally Posted by PetTastic View Post
    The basic idea is that absolutly every experiment in the past to measure fundimental constants, conducted and observed from the past gives the same result as now
    It is important to look at this in a 4-dimensional way - fundamental constants are only half the problem; the main issue here is that some of the fundamental interactions scale linearily ( e.g. electromagnetism ), whereas others work in non-linear ways, such as the field equations of GR, and the strong interaction. Demanding that everyone at all times measures the same constants during matter shrinkage over time will thus preserve only some laws of physics, while at the same time breaking others. Currently everything is very finely balanced, and it would be very difficult to apply any type of transformation to this without breaking something.

    The situation is further complicated by the fact that a continuous scaling of all matter will break time-like translation invariance, so the stress-energy tensor as used in GR will no longer be the conserved Noether current of translations in space-time. That means that GR in its current form couldn't be valid.

    Also, it needs to be remembered that we don't yet have a model of quantum gravity, so really we don't know yet which symmetry group underlies a unification of all forces. I very much doubt that this symmetry group scales in a linear way, leading to issues in all those situations where gravity and the other forces interplay.
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    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by PetTastic View Post
    The basic idea is that absolutly every experiment in the past to measure fundimental constants, conducted and observed from the past gives the same result as now
    It is important to look at this in a 4-dimensional way - fundamental constants are only half the problem; the main issue here is that some of the fundamental interactions scale linearily ( e.g. electromagnetism ), whereas others work in non-linear ways, such as the field equations of GR, and the strong interaction. Demanding that everyone at all times measures the same constants during matter shrinkage over time will thus preserve only some laws of physics, while at the same time breaking others. Currently everything is very finely balanced, and it would be very difficult to apply any type of transformation to this without breaking something.

    The situation is further complicated by the fact that a continuous scaling of all matter will break time-like translation invariance, so the stress-energy tensor as used in GR will no longer be the conserved Noether current of translations in space-time. That means that GR in its current form couldn't be valid.

    Also, it needs to be remembered that we don't yet have a model of quantum gravity, so really we don't know yet which symmetry group underlies a unification of all forces. I very much doubt that this symmetry group scales in a linear way, leading to issues in all those situations where gravity and the other forces interplay.
    I agree with every point above.

    This is purely a theoretical model that I use for science fiction purposes.
    However, I find it very interesting that if you match it to luminosity distance curves and angular distance curves by making matter shrink at 6% every billion years, then the luminosity distance curve has the correct shape for dark energy.
    http://www.thescienceforum.com/new-h...ase-break.html (post #17)

    You also get a universe a thousand billion years old that should be full of interstellar iron, so no need for dark matter.
    There is also no obvious epochs, just continuous behavior.

    There are some areas of it I do not like, particularly the way mass has to increase with time.
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    Quote Originally Posted by PetTastic View Post
    This is purely a theoretical model that I use for science fiction purposes.
    Fair enough
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    What if we took the position that the 4th axis, the time axis, can be tilted? Space time throughout the universe is curved according to some constant curvature.

    Suppose the 4th axis is treated as a line drawn perpendicular to the surface of curved space. If we treat 3d space like it were the surface of a sphere, and the 4th axis as perpendicular to this surface, then no matter where you stand on the sphere, the 4th axis is always tilting away from you. (It tilts more steeply away the further out you look.) Or...it might tilt toward us (if it should turn out we are standing on the inside of the spherical surface.)

    If velocity itself is just a vector where the "time" component is the rise, and the distance traversed in that time is the run, and a 90 degree angle is the (local) speed of light. Then tilting the time axis would cause apparent motion to be slower or faster, depending on what direction something is traveling.


    So if all light that reaches us is traveling in the same direction relative to the tilt, and the tilt increases with distance, then it might actually make sense from a General Relativity perspective for there to be a Hubble Shift. Even without expansion.
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    On the other hand............... I have to admit that, in the context of Big Bang Theory, the sphere and time axis analogy would equally serve to explain why there is an expansion also (if we are standing on the outside of the sphere.) Because it would mean that, as time advances, there is more and more surface area the higher you go.

    But.... something tells me this might come down to geometry. A non-scientific "gut" feeling. Validated only by the fact that so many other dilemas of the past ended up finding their explanation in geometry.

    What if Hubble shift is a "coordinate effect", like how "gravitational time dilation is a "coordinate effect"?
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    Time becomes an odd concept in this model.
    There is no suggestion of any change in the underlying flow of time.
    The fourth dimension remains unchanged.

    The time dilation seen in this model is predicted by the laws of physics and engineering, when applied in comoving space.
    Newton's laws do not simply scale, if you make a machine bigger, it runs slower.
    In this model matter or atoms is behaving like little machines that have been scaled.

    Double the size of the atom and it takes a photon twice as long to cross its width, but the observer in the past see no change because him and all his clocks are also scaled machines that have slowed down.

    The clocks run slower purely because their balance wheels, pendulums or quartz crystals are bigger, and the springs are softer.
    Chemical reactions slow down for the same reasons.

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

    In order to cross check the predicted behaviour of scaled matter with the local observers experience of it, you need to understand how his units of measurement compare to those of now. (Now always moving)

    If we start with the redshift z.

    Wavelength of light emitted by atoms in the past. (1+z) times longer.
    Observer in the past sees no measured change therefor is metre is (1+z) times longer.
    His law of physics are the same as ours so the size of his atoms is the same measured in metres as ours, but his metres. So, atoms are (1+z) times bigger.

    Photons coming from the past has (1+z) times less energy, but past observer see no change, so his joule is a factor of (1+z) smaller than modern.
    No change in the speed of light, so an Einstein in the past would see no change in the energy coming from matter, therefor mass is a factor (1+z) lighter.

    No change in the experience in the experienced EM forces generated by matter, gives us forces (1+z)^2 softer. Springs scale as predicted.

    Si units in past
    Time: s' = (1+z)s
    Length: m' = (1+z)m
    Energy: J' = J/(1+z)
    Mass: Kg' = Kg/(1+z)
    Force N' = N/(1+z)^2

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    [QUOTE=Strange;462396]
    Christof Wetterich, a theoretical physicist at the University of Heidelberg in Germany, has devised a different cosmology in which the Universe is not expanding but the mass of everything has been increasing.
    From what i understand the universe is expanding, because as mass expands it shows that information is increasing. You can't have the universe increase in information without an increase in mass. If you go backwards in time, there is less information per plank-time of the universe the further you go. Leading to the logical conclusion that at some point there was no mass and no information. As soon as you have the first second of plank-time you have a unit of information to measure how much space there is.
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    [QUOTE=AndreLeCoz;464848]
    Quote Originally Posted by Strange View Post
    Christof Wetterich, a theoretical physicist at the University of Heidelberg in Germany, has devised a different cosmology in which the Universe is not expanding but the mass of everything has been increasing.
    From what i understand the universe is expanding, because as mass expands it shows that information is increasing. You can't have the universe increase in information without an increase in mass. If you go backwards in time, there is less information per plank-time of the universe the further you go. Leading to the logical conclusion that at some point there was no mass and no information. As soon as you have the first second of plank-time you have a unit of information to measure how much space there is.
    I can see the link between information and mass.
    Information required to describe a system is entropy.
    Entropy is energy in a closed system no longer available for doing useful work.
    Energy is equivalent to mass.

    But I don't understand the
    because as mass expands
    bit.

    In cosmology terms increasing mass and expanding space are mutually exclusive, because they are both ways of explaining why we see less energy from the past.
    You only need one of them to describe the observed redshift.
    The cosmology does seem to be using a mixture of the two.

    I am going to have another look at that paper, because only changing mass breaks the Planck constant, it is the relationship between distance mass and time.
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    If it wasn't expanding and never has been, then it would always remain stagnant correct? If space never expanded from a beginning then how could there be any space to begin with? Unless of course space has always existed without a beginning. But that flies in the face of modern science like a big hot apple pie in Georges Lemaître's face.
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    Quote Originally Posted by AndreLeCoz View Post
    If it wasn't expanding and never has been, then it would always remain stagnant correct? If space never expanded from a beginning then how could there be any space to begin with? Unless of course space has always existed without a beginning. But that flies in the face of modern science like a big hot apple pie in Georges Lemaître's face.
    The cosmology refered to in the original post has mass increasing, but matter shrinking
    Quote from paper: [1303.6878] A Universe without expansion
    Then the cosmological increase of this ratio can also be attributed to shrinking atoms.
    So I don't understand your "stagnant" coment.

    You either need to explain where enough energy came from to create a universe or explain where space came from.
    Personally, I just perfer to keep an open mind.

    I am still curious about this "because as mass expands" It looks very familiar. Have you been reading some of Forrest Noble's posts
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    [QUOTE=AndreLeCoz;464848]
    Quote Originally Posted by Strange View Post
    Christof Wetterich, a theoretical physicist at the University of Heidelberg in Germany, has devised a different cosmology in which the Universe is not expanding but the mass of everything has been increasing.
    From what i understand the universe is expanding, because as mass expands it shows that information is increasing. You can't have the universe increase in information without an increase in mass. If you go backwards in time, there is less information per plank-time of the universe the further you go. Leading to the logical conclusion that at some point there was no mass and no information. As soon as you have the first second of plank-time you have a unit of information to measure how much space there is.
    Interesting point. Suppose empty space were increasing, while mass remained constant. Would that mean more information was appearing?
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    Quote Originally Posted by kojax View Post
    Interesting point. Suppose empty space were increasing, while mass remained constant. Would that mean more information was appearing?
    That is the standard interpretation. I don't know about more information, but one suggestion is that more energy is created (the energy "cost" of empty space) and this could be the explanation of dark energy.
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    Obvoiusly, I don't understand the details of this model, but I can't find any reference to time dilation in it.
    Once you take away the expansion of space as the explanation for the redshift, you also remove the explanation for time dialtion.
    I believe in nothing, but trust gravity to hold me down and the electromagnetic force to stop me falling through
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    Quote Originally Posted by kojax View Post
    Interesting point. Suppose empty space were increasing, while mass remained constant. Would that mean more information was appearing?
    It all seems illogical to me, but then again i don't study this stuff enough to come off as someone that truly knows what they're talking about, like some physics professor. However, imagine a bucket being filled with water. The bucket is measurement of volume, water is the universe expanding/filling up. The reason the space in increasing is because the universe is continuously expanding so there's more mass to increasing just like the water filling up the bucket.

    It simply doesn't make sense in my mind how you can have water filling up a bucket if the water isn't increasing, no?
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    Quote Originally Posted by Blueyedlion View Post
    It simply doesn't make sense in my mind how you can have more water filling up a bucket if the water isn't increasing, no?
    The current view is that the bucket (the universe) is expanding, making more room for the water (matter) which therefore spreads out (i.e. we see galaxies receding from one another).
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    Quote Originally Posted by Strange View Post
    The current view is that the bucket (the universe) is expanding, making more room for the water (matter) which therefore spreads out (i.e. we see galaxies receding from one another).
    Pretty sure the universe consists of the empty space as much as physical space. There's no 'extra stuff'. Just one large mass of universe in deferent fields and vibrations. I've heard you're position before but i'm pretty sure the 'container' and the ingredients' are the exact same thing. It's just that the ingredients is more active the rest/empty space isn' as much.
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    As far as information, certainly there are more possible combinations of interactions when matter is closer than there are when matter is further apart. Especially if we consider the problem of matter receding past the Hubble Sphere, and becoming unable to interact at all. Even falling short of falling off the hubble sphere, more empty space means a lower probability of any one photon randomly choosing a path that leads it to contact with an object.

    If we consider a photon in transit to not (yet) exist in any definite sense, then more photons in transit would mean less energy, kind of. Like a fractional reserve bank loaning out money it doesn't have, except the opposite.
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    Quote Originally Posted by Blueyedlion View Post
    Pretty sure the universe consists of the empty space as much as physical space.
    I'm not sure what you mean by "empty space" or "physical space". In this context, space simply means the way we measure distance between things. It is this metric that is changing over time, leading to the appearance of "expanding space" (which is a potentially misleading analogy).
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by kojax View Post
    Interesting point. Suppose empty space were increasing, while mass remained constant. Would that mean more information was appearing?
    That is the standard interpretation. I don't know about more information, but one suggestion is that more energy is created (the energy "cost" of empty space) and this could be the explanation of dark energy.
    Is there supposed to be more dark energy appearing all the time?

    If so, then what prevents this dark energy from forming into matter?
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    Quote Originally Posted by kojax View Post
    Is there supposed to be more dark energy appearing all the time?
    That is my understanding: proportional to the volume of space. That is one explanation for the accelerating expansion.

    If so, then what prevents this dark energy from forming into matter?
    Because it is very low energy density (which isn't changing). And there is nothing that requires energy to become matter.
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by kojax View Post
    Is there supposed to be more dark energy appearing all the time?
    That is my understanding: proportional to the volume of space. That is one explanation for the accelerating expansion.
    So BBT and SST aren't really all that different? The main difference is just the level of structure of the new matter/energy that is appearing. One expects baryonic matter, while the other only expects non-luminous energy to appear.

    But if we're going to allow new energy to emerge out of nowhere, then why not allow the CMBR to be appearing out of nowhere? Maybe the structured randomness that governs its appearance happens to be identical to the structured randomness of black body just because that is one of nature's recurring patterns? Nature does, after all, have some recurring patterns in it.



    If so, then what prevents this dark energy from forming into matter?
    Because it is very low energy density (which isn't changing). And there is nothing that requires energy to become matter.
    True, but it's still affected by gravity, so no reason why it shouldn't occasionally accumulate and form matter.
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    Quote Originally Posted by kojax View Post
    So BBT and SST aren't really all that different?
    Apart from the fact that one describes the evolution of the universe over time and the other describes an infinitely old, unchnanging universe.

    The main difference is just the level of structure of the new matter/energy that is appearing. One expects baryonic matter, while the other only expects non-luminous energy to appear.
    Well, we know that the vacuum has non-zero energy so it seems plausible that as you increase the amount of vacuum you would increase the amount of energy. Whereas we have no evidence of baryonic matter spontaneously appearing.

    But I really don't know much about dark energy and the hypotheses about what might explain it.

    True, but it's still affected by gravity, so no reason why it shouldn't occasionally accumulate and form matter.
    I am not aware of any instances of that happening with any form of energy. Also, that would imply you can remove energy from the vacuum, which you can't because it is already at its lowest energy level (which is non-zero).
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    Quote Originally Posted by kojax View Post
    One expects baryonic matter, while the other only expects non-luminous energy to appear.
    Not really. Let's assume ( for simplicities sake ) that dark energy is just the cosmological constant, i.e. a vacuum energy density ( there are many other possibilities though ). There are two key points to this :

    1. The vacuum has a form of dark energy density associated with it ( positive density ), which is constant over time
    2. That dark energy does negative work on its surroundings ( pressure ), thereby driving expansion of the universe

    Because the density is constant, and space expands, the total amount of energy must increase locally; however, because that energy does negative work on its surroundings, the amount of which is directly proportional to the amount of dark energy itself, total energy is globally conserved, at least in a classical sense ( energy is a difficult to define concept in GR ). The easiest way to see this is to look at it in terms of thermodynamics, where one finds that its laws are exactly obeyed in this process. See also this article for a layman's explanation :

    http://scienceblogs.com/startswithab...erated-expans/

    Not so in SST - that model requires the actual creation of matter ( which is not what we observe ), thereby globally violating the law of energy conservation.
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    Most people consider Big bang is to be just one big blast. One blast (as they call it ) went on to make a way for series of blast in each and every possible position ( not linear ).
    Blast of sun also happened to create our solar system. but this kind of blast happened where space had already existed . But with distribution of objects with mass into different position , did this lead to effect on time that existed in that particular position which had no presence of any object with mass.

    example position of some asteroid far from sun not affected by it's GRAVITY(?). Or according to conservation of mass theory - If those chunks of sun had not got blasted , then would the range of gravity field would have affected the time at that position different range than it has effected the time in that position after blast (by having or not having any chunk near or far in that position).

    series of blast is said to been happening now too. But not all blasts create space , but surely affect on distribution of mass in that region.
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    Quote Originally Posted by sciencestudy View Post
    Most people consider Big bang is to be just one big blast
    No, the Big Bang is not modelled as an explosion at all - not sure where you got that idea.
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    Quote Originally Posted by Markus Hanke View Post

    No, the Big Bang is not modelled as an explosion at all - not sure where you got that idea.
    Do you know what it is modelled as? I'm curious (hehe)
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    Quote Originally Posted by Curiosity View Post
    Do you know what it is modelled as? I'm curious (hehe)
    Sure...the Big Bang event is simply the "starting point" of an expanding universe. Picture it like a balloon which starts of completely deflated, and concentrated in just one point. Now you start blowing air into it, and the balloon inflates, with its surface expanding in the process. As it inflates, every point on the surface recedes from every other point as the balloon gets bigger and bigger. This is called metric expansion. It is space-time itself which expands, and not some explosion hurling matter into an already existing space.

    Please bear in mind that this is only a rough analogy, not an exact model; the universe corresponds to the surface of the balloon only, not its interior. The Big Bang just corresponds to the initial state of complete deflation.
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    Awesome, thanks. Is there any information on the exact model that you know of? I'm interested in learning more about it.
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    Quote Originally Posted by Curiosity View Post
    Awesome, thanks. Is there any information on the exact model that you know of? I'm interested in learning more about it.
    Yes, it's called the Lambda-CDM model, and is based on a particular solution to the Einstein field equations called Friedman-Lemaitre-Robertson-Walker metric. See here :

    Lambda-CDM model - Wikipedia, the free encyclopedia
    Friedmann
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by Neverfly View Post
    Forrest Noble has been saying something similar to this for many years...
    But he was just making stuff up.

    His was more about things shrinking instead of the universe expanding. You can, of course, choose coordinates where that is the case (which means the speed of light varies over time and all sorts of slightly odd things). The thing is though, if you do that you haven't changed anything in the underlying model, just the representation of it. So, where the big bang model sees accelerating expansion, the alternative view must see accelerating shrinking. And so on.

    Forrest believes the "shrinking" model gives new insights (which it might) and that it gets rid of problems like dark energy or the original singularity. Of course, it doesn't because it is the same model.

    However, once you start making changes to the model, as Forrest does, then it is no longer the same thing. But in that case, it must be possible to convert the changes you make back to the standard big bang coordinates and analyse the effects there and compare them with observation. Forrest never accepted that and so never accepted that his ad-hoc manipulations don't correspond to observation.
    Are you thinking about creating a new modell of the universe?
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    Quote Originally Posted by Strange View Post
    As I have occasionally been accused of only being interested in defending the status quo as well as having a blind faith in the big bang and other well-tested theories, I thought I would throw this idea out there:Cosmologist claims Universe may not be expanding : Nature News & Comment
    Christof Wetterich, a theoretical physicist at the University of Heidelberg in Germany, has devised a different cosmology in which the Universe is not expanding but the mass of everything has been increasing.
    An interesting idea, even if wrong...More here: [1303.6878] A Universe without expansion
    I missed this thread, interesting article. This idea is close to what I have been claiming. With push gravity everything is constantly growing. Gravity wouldn't even work without PG particles accumilating. Also the universe would be condensing or contracting as the particles constantly accumilated. I also believe it should be testable that mass on the average is always accumilating. Along with Accumilation would be different levels of radiation depending on how much matter was being pushed in at one time.
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    Not here Bill, please!
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    Quote Originally Posted by KALSTER View Post
    Not here Bill, please!
    I was just comenting on an article that someone else posted. When I read it I assumed it was OK for anyone to give their opinion. Sorry
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