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