Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Extragalactic astronomy

Cosmic censorship

Nature volume 415, pages 374–375 (2002)Cite this article

Cosmologists believe the Universe will expand forever, but our powers to observe it will not accelerate at the same rate. What does this mean for the future of astronomy?

The night sky seen through a large telescope is adorned with billions of galaxies in a rich variety of shapes and sizes. Yet 100 billion years from now, the sky is likely to be dark and drab, with only a handful of galaxies still visible to us. The discovery in 1998 that the expansion of the Universe is accelerating1,2 (rather than slowing down or even reversing) has generally been heralded as good news for our long-term future, because it suggests that the Universe will expand forever, rather than end in a cataclysmic crunch. But it has long been known that such a future is fraught with problems that are likely to make it fairly lonely. Apart from the inevitable death of individual objects, such as our Sun running out of fuel, all but our closest neighbours will disappear forever across a 'cosmic event horizon' from beyond which no light or information will ever reach us. In a paper available as a preprint, and appearing soon in Physical Review D, Abraham Loeb3 has quantified this cosmic censorship to a new level of detail, and his results provide sobering news for extragalactic astronomers.

This is a preview of subscription content

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

Buy

All prices are NET prices.

Figure 1: Here today, gone tomorrow: galaxies visible to the Hubble Space Telescope.

ROBERT WILLIAMS/HUBBLE DEEP FIELD TEAM/NASA

References

  1. Perlmutter, S. et al. Nature 391, 51–54 (1998).

    ADS  CAS  Article  Google Scholar 

  2. Riess, A. G. et al. Astron. J. 116, 1009 (1998).

    ADS  Article  Google Scholar 

  3. Loeb, A. Phys. Rev. D (in the press); http://xxx.lanl.gov/abs/astro-ph/0107568

  4. Wang, X., Tegmark, M. & Zaldarriaga, M. http://xxx.lanl.gov/abs/astro-ph/0105091

  5. Efstathiou, G. et al. http://xxx.lanl.gov/abs/astro-ph/0109152

Download references

Author information

Affiliations

  1. Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, 19104-6396, Pennsylvania, USA

    Max Tegmark

Authors
  1. Max Tegmark
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Max Tegmark.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Tegmark, M. Cosmic censorship. Nature 415, 374–375 (2002). https://doi.org/10.1038/415374a

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1038/415374a

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing