The Time Ships — Stephen Baxter

THERE IS A SECRET PASSAGE TROUGH TIME
...and it leads all the way to the end of Eternity. But the journey has a terrible cost. It alters not only the future but the "present" in which we live.

A century after the publication of H. G. Wells' immortal The Time Machine, Stephen Baxter, today's most acclaimed new "hard SF author, and the acknowledged heir to the visionary legacy of Wells, Heinlein, and Clarke, returns to the distant conflict between the Eloi and the Morlocks in a story that is at once an exciting expansion, and a radical departure based on the astonishing new understandings of quantum physics.