The Saga of Cuckoo Author:Frederik Pohl, Jack Williamson This book includes two full books: — "Farthest Star" and "Wall Around a Star" — Farthest Star: — CUCKOO WAS COMING...No one knew what it was--but everyone knew it was trouble. Designated Object Lambda when it first appeared on the fringes of the galaxy, 20,000 light-years away, it was traveling at one-sixth the speed of light. T... more »he astrophysicists said that it was vast...light....and had the potential for utter destruction. So an existing space probe was reoriented to intercept; it was staffed with replicates of both humans and aliens. Then the probe began to leak radiation....
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Tachyon transmission was a marvelous invention. A man could send infinite replicates of himself anywhere in the galaxy---wherever duty called. If one of the copies got killed, so what? The original would still be alive and well back on his home planet, and he could always send replacements. Such a man Ben Pertin, who lived on Earth.
Wall Around a Star:
Because nothing can go faster than light, except a tachyon, which cannot go slower than light, it is contrived that transmitters that send by tachyon beam information, such as body chemistry or radio messages, make the visiting of far off stars possible. The impossibility of having a person transmitted to another star and remember all he knew up to the point of transmission, is beyond belief. But this is science fiction, there has to some notions we cannot believe will happen.
Dr. Babylon has his working vacation in Polynesia interrupted by some message to return home, but the message is garbled or has missing information, so he does not know what is going on for some time after he gets home, and even then he finds he can only 'go with the flow.' He becomes two: one here on Earth and one around this place that is coming into our galaxy. The magic of the tachyon transmission is that one is not erased in the transmission, but copied, so there are two of each, or more, if one, somewhere, does not die. The place out in space is some sort of orbiter around this odd thing that is traveling through intergalactic space. It turns out to be a Dyson sphere from another galaxy. The other galaxy has turned itself into a black hole through natural attrition or evolution. It is quite a good story. The long spans of time involved are touched on, but never really dealt with. For instance, how long would it take to build a Dyson sphere? Would the sun even last that long? Review by David Brockert« less