Maybe our universe is not expanding after all!! New theory

phys.org...

For nearly a century, the consensus among astrophysicists has been that the universe started with a Big Bang and has been expanding ever since. This hypothesis formed because researchers found that in analyzing the light emitted from stars, a redshift occurred—where its frequency changes as an object that emits light moves away from us. But Wetterich says the redshift might me due to something else—an increase in the total mass in the universe.

Wetterich's idea is that light emitted from an atom is governed by the mass of its particles—if that atom were to become larger in mass, the light that it emits would change in frequency as its electrons became more energetic. More energy would appear as light moving toward the blue spectrum, while less energy (an atom losing mass), would move toward the red spectrum. Thus, Wetterich reasons, if the mass of observable objects were once less, we would now see them with a redshift as they expand. If his line of reasoning is true, Wetterich says it's possible that the universe is actually contracting.

We discuss a cosmological model where the universe shrinks rather than expands during the radiation and matter dominated periods. Instead, the Planck mass and all particle masses grow exponentially, with the size of atoms shrinking correspondingly. Only dimensionless ratios as the distance between galaxies divided by the atom radius are observable. Then the cosmological increase of this ratio can also be attributed to shrinking atoms. We present a simple model where the masses of particles arise from a scalar "cosmon" field, similar to the Higgs scalar. The potential of the cosmon is responsible for inflation and the present dark energy. Our model is compatible with all present observations. While the value of the cosmon field increases, the curvature scalar is almost constant during all cosmological epochs. Cosmology has no big bang singularity. There exist other, equivalent choices of field variables for which the universe shows the usual expansion or is static during the radiation or matter dominated epochs. For those ``field coordinates`` the big bang is singular. Thus the big bang singularity turns out to be related to a singular choice of field coordinates.

The paper has not been peer reviewed but his line of reasoning as judged by comments from others in the field suggest a new openness to this new line of thinking. Unfortunately unless another break through in measurement is attained it will just remain a theory; but so is the big bang. Interesting none the less..

one exciting prospect of this new theory is that it would do away with the idea of a singularity existing just before the Big Bang—a point at which conventional physics breaks down. Instead it might suggest that the universe is simply in a constant state of flux with no real beginning and no real end.

very nice read sir..however we are a very young species among trillion galaxy around us..every theory that make sense we accept..but there is still mistery until we clearly see with our super technology see back billion years ago when this solar system was created..until now our mistery our space still a wonder..

Space (life) is expanding

Consciousness (focus) is contracting

In essence, we are evolving. Taking on more and more, while becoming more focused in order to achieve it. We see it in the cosmos as well as our own minds and bodies.

Edit: in the end its still a paradox that could go either way

reply to post by 727Sky

As Feynman said, a theory that can't be tested is a good theory because nobody can prove it wrong.
(He was being sarcastic).
This is such a theory.

reply to post by Arbitrageur

Can't the creator of the theory adjust it so that it can be tested?

I don't think whoever made the theory intentionally wanted it to be untestable?

reply to post by jonnywhite

To test some aspects of string theory would require much more powerful colliders, so hypothetically someday more powerful accelerators might be built and then those tests could be done.
However I'm not sure how this could ever be tested, as the OP article says:

Unfortunately, Wetterich's theory can't be tested because of the relative nature of mass. Everything we are able to see has a mass that is relative in size to everything else. Thus if it's all growing, we wouldn't have anything to measure it against to see that it's happening.

Besides that, I don't think his conclusion makes sense:

arxiv.org...

In conclusion, we have constructed a “variable gravity
universe” whose main characteristic is a time variation
of the Planck mass or associated gravitational constant.
The masses of atoms or electrons vary proportional to the
Planck mass. This can replace the expansion of the universe.
A simple model leads to a cosmology with a sequence
of inflation, radiation domination, matter domination, dark
energy domination which is consistent with present observations.

Can someone explain to me how his idea which replaces the expansion of the universe, is consistent with dark energy domination consistent with present observations, which tell us that the expansion of the universe is accelerating? It seems like a self-contradiction to me.

Tagged to return when I get a chance, after reading it in full.

reply to post by Arbitrageur


This could mean that the universe is not expanding and that there is no need for dark matter/energy. This seems to be an 'easy way out' of finding what the darks really are or are not, if they exist at all.
Another one of those theories which, if proveable at all, won't be for some time.
How this fits in with the multiverse theory is anybody's guess.
Physics and philosophy really are coming together.
I wonder how many angels could fit on the horse-head of a nebula.

reply to post by 727Sky

Instead it might suggest that the universe is simply in a constant state of flux with no real beginning and no real end.

Same line of thought as Hannes Alfven, contradicting Lemaitre's theory:

To Alfven, the Big Bang was a myth - a myth devised to explain creation. "I was there when Abbe Georges Lemaitre first proposed this theory," he recalled. Lemaitre was, at the time, both a member of the Catholic hierarchy and an accomplished scientist. He said in private that this theory was a way to reconcile science with St. Thomas Aquinas' theological dictum of creatio ex nihilo or creation out of nothing.

But if there was no Big Bang, how -and when- did the universe begin? "There is no rational reason to doubt that the universe has existed indefinitely, for an infinite time," Alfven explained.

tmgnow.com...

I don't think we'll really find out unless we have the technological advances to do so. Many hypothesis, very little factual answers. Highly interesting though !!

Good article, nice thread ! S&F !!

So (according to this hypothesis), if mass is increasing, does that mean that the mass of the universe was once (looking backwards a long time ago) approaching [color=lt blue]zero? AND does that mean that as time moves forward, the mass of the universe will approach [color=lt blue]infinity?

Also, was the total mass ever actually "zero", or looking backward in time, was it always just approaching zero? If it was always just approaching zero, then does that mean the universe had no beginning -- i.e., that it always existed? And if it there was a time that the mass of the universe was zero, then that means it had a beginning? If so, then how did that beginning come about?

I think the chance of humans understanding more than a fraction of a percent of the structure and workings of the universe is about nil. At least they still refer to them a 'theories'.

My word. This a mother of a gobbledygooky theory
and needless to say, wouldnt go very far if untestable.

Originally posted by Arbitrageur
Can someone explain to me how his idea which replaces the expansion of the universe, is consistent with dark energy domination consistent with present observations, which tell us that the expansion of the universe is accelerating? It seems like a self-contradiction to me.

It's because the theory isn't actually predicting new physics. It is a reformulation of conventional physics in a set of new coordinates and fields which, superficially appear different, but actually predict the same observables.

The money shot from the manuscript:

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. This can
be seen by a redefinition of the metric, which leads to the
“Einstein frame” with constant Planck mass and particle
masses and an expanding universe. In the Einstein frame
the big bang has a singularity, however. The possibility of
different choices of fields describing the same reality may
be called “field relativity”, in analogy to general relativity
for the choice of different coordinate systems. Field relativity underlies the finding that strikingly different pictures,
as an expanding or a shrinking universe, can describe the
same reality.

One key finding is that he unifies the inflation period and dark energy as aspects of the same physical mechanism, the new (hypothetical) scalar 'cosmon field'. (Which likely isn't a physical field in the sense of quantum field theory with particles and everything that goes along with it, but a mathematical 'trick').

Furthermore, an important feature is the simplicity of our model covering both inflation and present dark energy, dominated by the same simple quadratic potential for the scalar cosmon field. Finally, the identification of the big bang singularity as a matter of the choice of field coordinates sheds new light on this old problem.

If there are no mistakes in the paper, it is quite novel and interesting, solving, or really reparameterizing a number of less related phenomena as one.

The thing is that the big bang 'singularity' actually did seem to correspond to significant physical effects, it is not just a mathematical inconvenience.

What would be much more interesting is if this theoretical view lead to proposals for novel actual physics which could be experimentally validated and even better engineered.