Just in time for the millennium, elder statesman Dyson (Physics/Institute for Advanced Study, Princeton; From Eros to Gaia, 1992, etc.) sounds off on three technological revolutions that could radically transform human social arrangements—if we play our cards right. A big “if,” since some people may not like the cards, and Dyson’s ideas are still on the drawing boards. As the title suggests, one of his visions involves harnessing solar energy. Dyson’s proposal is to breed plants that will convert radiant energy into liquid fuel, which could feed directly into local pipelines. On the human genome, Dyson has no doubt that its data will be used, initially by the rich, for “reprogenetics”—tailoring the genes of the unborn to confer whatever traits parents deem advantageous. (Cloning is a minor issue by comparison, Dyson believes.) Eventually, such gene tinkering could lead to speciation, dividing not just rich and poor but social groups according to lifestyle or philosophical beliefs. To avoid the inevitable intergroup hostilities, we will seek what Dyson calls “the high road” to space (he believes that, by the end of the 21st century, space travel will have become far more practical). The Internet, not confined (as it is today) to the computer-literate, but as a universal source of knowledge and communication, reaching rural villager and city slicker alike, is another of Dyson’s dreams for the future. Dyson argues that the technologies can be used to advance social justice and lessen economic disparities (though he never explains how reprogenetics jibes with that ideal). Dyson admits he was wrong about (the latter) two of the three technologies he had hopes for back in the 1980s: genetic engineering, artificial intelligence, and space travel, so one may take his current scenarios not as prophecies but as one man’s hopes. Adding to the book’s value, however, are Dyson’s authoritative commentaries on how past technologies have changed society and, as always, his exemplary prose style.