Dragon's Egg

One good idea carefully worked out has redeemed many an otherwise unremarkable sf novel, and this is an object lesson in the process. Forward's idea is to superimpose two time schemes on the same event: the discovery of intelligent life on Dragon's Egg, a neutron star approaching the solar system. The size, shape, motion, and time-perception of these beings ("cheela") are dictated by the intense heat, gravity, and magnetic activity of their world. They are something like modified Flatlanders a few millimeters long and can travel comfortably only along the lines of magnetic force ("the easy direction"), while their basic life processes take place at the speed of nuclear rather than molecular events - on their time scale a fifth of a second (the duration of the Egg's spin) is roughly equivalent to a day, and ten generations occupy about two of our hours. As the Egg approaches our sun the cheela are nomadic barbarians; a couple of Earth weeks later they are a civilization of sorts worshiping the new star; a few Earth days after that they are capable of signaling to the Terran expedition sent to observe the Egg. By the time the human crew has completed its mission, the cheela (now thousands of generations removed from their nomadic forebears) have far surpassed anything in 21st-century technology. This is a splendid scheme, and Forward (an astronomer in real life) has a wonderful time working out the details of cheela existence. He is less successful - indeed, embarrassingly amateurish - with his human characters. Never mind; the cheela episodes are good enough to carry the whole thing. (Kirkus Reviews)