SETI bioastro: The Long-Term Future of Space Travel

From: LARRY KLAES (ljk4_at_msn.com)
Date: Tue Sep 13 2005 - 15:05:56 UTC

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    astro-ph/0509268 [abs, ps, pdf, other] :

    Title: The Long-Term Future of Space Travel

    Authors: Jeremy S. Heyl

    Comments: 4 pages, 3 figures

    The fact that we apparently live in an accelerating universe places
    limitations on where humans might visit. If the current energy density of
    the universe is dominated by a cosmological constant, a rocket could reach a
    galaxy observed today at a redshift of 1.7 on a one-way journey or merely
    0.65 on a round trip. Unfortunately these maximal trips are impractical as
    they require an infinite proper time to traverse. However, calculating the
    rocket trajectory in detail shows that a rocketeer could nearly reach such
    galaxies within a lifetime (a long lifetime admittedly -- about 100 years).
    For less negative values of $w$ the maximal redshift increases becoming
    infinite for $w\geq -1/3$.

    http://arxiv.org/abs/astro-ph/0509268


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