World without end?
MIT’s Technology Review blog today reports on a new paper by Wun-Yi Shu at the National Tsing Hua University in Taiwan, which disposes of the Big Bang model of cosmology and replaces it with a model that makes space-time and mass related to each other in a new way. A pdf file of the paper entitled “Cosmological Models with No Big Bang” can be downloaded here.
The empirical problem it principally addresses is the observation of the unexpectedly large red-shift in electro-magnetic waves from Type I supernovas, an observation first made in the 1990s. The conclusion drawn from the observation is that the supernovas are receding at an unexpectedly fast rate and accelerating. To account for this, standard cosmological models posit the existence of “dark energy,” which would account for the apparently observed increased acceleration. The amount of such “dark energy” needed is astonishingly large — 75% of the energy-mass of the universe. This seems (to someone with no connection to the field) to be a very large fudge factor.
Shu’s model does away with dark energy. According to the review in Techonology Review:
“Shu’s idea is that time and space are not independent entities but can be converted back and forth between each other. In his formulation of the geometry of spacetime, the speed of light is simply the conversion factor between the two. Similarly, mass and length are interchangeable in a relationship in which the conversion factor depends on both the gravitational constant G and the speed of light, neither of which need be constant.
“So as the Universe expands, mass and time are converted to length and space and vice versa as it contracts.
“This universe has no beginning or end, just alternating periods of expansion and contraction. In fact, Shu shows that singularities cannot exist in this cosmos.”
Shu explains in the abstract that begins the paper that his model:
“can explain the cosmic acceleration without introducing a cosmological constant into the standard Einstein field equation, negating the necessity for the existence of dark energy. There are four distinguishing features of these models: 1) the speed of light and the gravitational ‘constant’ are not constant, but vary with the evolution of the universe, 2) time has no beginning and no end, 3) the spatial section of the universe is a 3-sphere, and 4) the universe experiences phases of both acceleration and deceleration. One of these models is selected and tested against current cosmological observations of Type Ia supernovae, and is found to fit the redshift-luminosity distance data quite well.” (p2)
It of course remains to be seen whether accounting for the redshift in certain supernovas is enough to overthrow the current penchant for the Big Bang, but at this point it’s possible to ruminate on the metaphysical impact of one view or the other. Years ago I heard a geologist tell the following story.
An astronomer has delivered a lecture on the fate of Everything in which he estimated that the universe would go dark in about 500 trillion years. During the question period an anxious woman in the audience hesitatingly got up and asked him to repeat how long he thought was left for the universe. He repeated: “500 trillion years.” She said down, visibly relieved, and said: “Thank God. I thought you said 500 billion.”
The person who told me this was illustrating an ordinary person’s lack of understanding of large numbers, especially relating to “deep time” so the cosmological predictions are undoubtedly not accurate. But the story bears a different interpretation. Humans are profoundly disturbed at the thought of the end of everything. The Greeks, for instance, believed the universe was eternal in both directions. It was the Judeo-Christian influence that interjected the disturbing notion of a directional time arrow with a beginning and end (presided over by the creator who had neither a beginning nor an end). The latter view is probably less compatible with our naturally-selected self-preservational consciousness, but it’s philosophical hold on the Western mind is pervasive — perhaps even among cosmologists.
There is a problem, however, with both the Big Bang and the Shu version. In either case history is obliterated. In one for good; in the other just to be repeated. These different views (themselves different from the Greek / Judeo-Christian duality), lead Milan Kundera to suggest a different metaphysical duality in The Unbearable Lightness of Being: If the universe repeats, then everything is heavy and fixed — It must be (as in the phrase from the Beethoven symphony). If the universe ends, then everything has an unbearable lightness.
William James would probably consider excessive concern (or perhaps any concern) over cosmology theory to be unhealthy. It is, however, probably hard-wired in the species.