In addition to the potential problems noted for the idea of using gravitationally slingshot asteroids to shift Earth’s orbit and thereby foster life in the face of the sun’s increasing luminosity (“Save the Earth,” June 2001), Kepler’s third law ensures that the length of Earth’s year will increase along with the distance from Earth to sun. Both the lengthening itself and the consequent distortions of the seasons will wreak havoc on the life cycles of countless living things — not to mention man-made calendar systems and annual schedules.
More importantly, though, our growth-oriented global civilization is unsustainable, degrading the ecosystems on which it depends, making it possible that the human species itself may become extinct along with this way of life. Whether civilization collapses during this century or a thousand years from now, it will be, to put it mildly, long before the sun makes life itself impossible. Given the present age of the genus Homo, to worry about our fate a billion years from now when we already face the possibility of our imminent (evolutionarily speaking) extinction is like a month-old baby so sick that it may not survive the day nevertheless worrying about death from a different disease at age 80.
The cosmos is a fascinating and worthwhile field of study, but sometimes people just need to get their heads down to Earth. Only by pursuing sustainable ways of living will we have even a remote chance of seeing a billion years pass. The eventual fate of the sun is among the lowest priorities for life on Earth today.