We are too small and our statecraft is too feeble to be seen by a spacecraft between the Earth and the Moon. From this vantage point, our obsession w… - Carl Sagan

Briefly illuminated on the wall beside her desk was a quotation from the Parables of Franz Kafka: Now the Sirens have a still more fatal weapon than their song, namely their silence . . . Someone might possibly have escaped from their singing; but from their silence, certainly never.

The dangers that we face are part of the process, now well underway, of the unification of the planet — in language, culture, science, and commerce. They are both driven by the identical technological advances — this critical and delicate time coincides with the widespread availability of nuclear weapons. At the present rate of change, it seems likely that in the period between now and 2061, the turning point for the human species will have been reached.

If we survive until then, our passage to the next apparition of Halley's Comet should be comparatively easy. That perihelion passage will be in March 2134, when the comet will make an unusually close encounter with the Earth. It will come as close as 0.09AU or 14 million kilometers, less than half the distance of the 1910 encounter. It will then be brighter than the brightest star. If there are those to do the commemorating, the years 2061 and 2134 should be celebrated for the courage, intelligence, and common purpose of a species forced by urgent necessity to come to its senses.

Nearly every scientist has experienced, in a moment of discovery or sudden understanding, a reverential astonishment. Science - pure science, science not for any practical application but for its own sake - is a deeply emotional matter for those who practise it, as well as for those nonscientists who every now and then dip in to see what's been discovered lately.