Wall Around a Star

"Wall Around a Star" by Frederik Pohl & Jack Williamson, © 1983 This futuristic novel is wonderful. There is a good story and some wild imagined innovations. The oddest part is the hero is a linguist!! Who ever thought a linguist would save the world? The funniest part is his name: Jenson (Jens) Babylon. The science that is novel is the tachyon transmitters. 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?