STM-D-0596Paper2007Published and peer-reviewed

The Return of a Static Universe and the End of Cosmology

Lawrence M. Krauss · Robert J. Scherrer

Abstract and summary · read the original at the source

In one page

Lawrence Krauss and Robert Scherrer run the standard cosmology forward and ask what a physicist a hundred billion years from now could still measure. Their answer is: almost nothing we measure today. Everything beyond the Local Group is carried past the horizon that dark energy sets, and its light is redshifted away, so the future sky holds one merged galaxy in an otherwise empty space. The microwave background stretches until its peak falls below the plasma frequency of interstellar gas, which screens it from anyone inside that galaxy — and that happens before the universe is fifty times its present age. Stellar processing raises the helium abundance until the primordial share is lost inside it, and destroys the deuterium that anchors the light-element story. Relativity offers no rescue, because the argument that forces a universe to expand or contract assumes homogeneity, and theirs will not be homogeneous. Vacuum energy will then outweigh matter by a factor of a trillion inside the horizon, and be undetectable.

Why it matters hereChapter 2 treats the vacuum’s energy as the dominant physical quantity in the universe, and this paper makes the sharpest possible point about it: that dominance is invisible to observers who cannot see across the scale on which it acts, so what we can measure is a function of when we look. Chapter 13 takes the corollary — we happen to live in the narrow epoch when both the expansion and the vacuum energy driving it can be read off the sky, which makes measuring them now, and understanding what the vacuum is, a matter of timing as much as of instruments.

What it claims

01Extrapolating the current ΛCDM universe forward, every structure beyond the Local Group is driven outside the de Sitter event horizon on a timescale of order 100 billion years, and light from those objects is exponentially redshifted, so within a time comparable to the lifetime of the longest-lived main sequence stars everything outside the local cluster becomes invisible.Sect. A, The disappearance of the Hubble Expansion
Published and peer-reviewed
02The vacuum energy will then dominate the horizon volume with a matter-to-vacuum density ratio of about one part in a trillion, and precisely because of that dominance the inhabitants will have no probe of the length scales on which it acts — dark energy is undetectable not only when its density is far below that of matter but also when it is far above.Sect. A, paragraph beginning ‘This will be true in spite of the fact’
Published and peer-reviewed
03The cosmic microwave background disappears as well: by about 100 billion years its peak is redshifted to roughly one metre, near 300 megahertz, with the intensity down by about twelve orders of magnitude; and well before that it redshifts below the interstellar plasma frequency of about 1 kilohertz, set by an electron density near 0.03 per cubic centimetre, at which point it is screened from any observer inside the galaxy — an expansion factor of about 100 million, reached when the universe is less than fifty times its present age.Sect. B, Vanishing CMB
Published and peer-reviewed
04General relativity by itself will not lead those observers back to an expanding universe, because the inference that a universe must expand or contract rests on the hypothesis that it is homogeneous and isotropic, which will manifestly fail for them: a non-singular, isolated, self-gravitating island surrounded by empty static space is entirely consistent with the theory.Sect. C, General Relativity Gives No Assistance
Published and peer-reviewed
05The nucleosynthesis evidence is erased too. Stellar processing drives the helium mass fraction toward about 0.6, dwarfing the primordial 0.25, and destroys the relic deuterium, while the quasar-backlit Lyman-alpha systems that give today’s deuterium measurement will have redshifted beyond the horizon. Observers will be able to bound the age of their island from stellar evolution, but not to infer that it began in a hot Big Bang.Sect. D, Polluted Elemental Abundances
Published and peer-reviewed
06The authors’ conclusion is that observational cosmology has a window rather than a permanent view: observers ten times earlier could not have detected the effect of dark energy on the expansion, observers ten times later will not be able to tell that the universe expands at all, and we live at the one epoch that can verify both.Sect. E, Conclusion
What to watch

Read it · abstract

Abstract

We demonstrate that as we extrapolate the current ΛCDM universe forward in time, all evidence of the Hubble expansion will disappear, so that observers in our "island universe" will be fundamentally incapable of determining the true nature of the universe, including the existence of the highly dominant vacuum energy, the existence of the CMB, and the primordial origin of light elements. With these pillars of the modern Big Bang gone, this epoch will mark the end of cosmology and the return of a static universe. In this sense, the coordinate system appropriate for future observers will perhaps fittingly resemble the static coordinate system in which the de Sitter universe was first presented.

The way in

https://arxiv.org/abs/0704.0221Published as General Relativity and Gravitation 39, 1545-1550 (2007), doi 10.1007/s10714-007-0472-9, and again as International Journal of Modern Physics D 17, 685-690 (2008), doi 10.1142/S0218271808012449, by Lawrence M. Krauss of Case Western Reserve University and Vanderbilt University and Robert J. Scherrer of Vanderbilt University; the work was supported in part by the Department of Energy. The author version is free to read on arXiv as 0704.0221, posted 2 April 2007 with a third version on 27 June 2007, and that record carries arXiv’s assumed licence for legacy submissions rather than a Creative Commons licence — checked on the arXiv abstract page on 2026-09-08, and no Creative Commons statement appears in the text either. So this sheet carries the summary, the claims and the authors’ own abstract and sends the reader to the source. The claims are located against the arXiv version’s lettered sections. A companion sheet in this library carries the live question of what dark energy is actually doing, and how the observations are read: /library/stm-2d66d437f4.

How to cite it

Lawrence M. Krauss, Robert J. Scherrer (2007) The Return of a Static Universe and the End of Cosmology. doi:10.1007/s10714-007-0472-9

Where it sits in the curriculum

What the vacuum is The unified picture