Poul Anderson · 1970 · Novel
During an epic voyage to a planet 30 light years away, the engines of the starship the 'Leonora Christine' are damaged. Unable to slow down, it attains light speed (the tau zero of the title). The disparity between time for those on board and external time becomes impossibly great. Eons and galaxies hurtle by, as the crew speed helplessly into the great unknown.
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