13 OCT 2013 by ideonexus
The Hourglass
Not the flowing waters of time but the falling sands of time have given
modern poets their favorite metaphor for the passing hours. In England,
sandglasses were frequently placed in coffins as a symbol that life's time had
run out. "The sands of time are sinking," went the hymn. "The dawn of
heaven breaks."
But the hourglass, measuring time by dripping sand, comes late in our
story. Sand was, of course, less fluid than water, and hence less adapted to
the subtle calibration required by the v...Folksonomies: engineering invention
Folksonomies: engineering invention
Sand vs water, the evolving art and ingenuity involved in crafting this timepiece.
08 JUN 2011 by ideonexus
Spring Recapitulates Evolution
Spring provides a kind of annual recapitulation of the evolution of life on Earth, an opportunity to celebrate anew the greening of the planet three and a half billion years ago by the first photosynthesizing bacteria. All life—the whole glorious parade along the path—depends upon the photosynthesizers. As spring dresses the deciduous woodlands in its Easter best, the nonphotosynthesizers get moving too. Suddenly the woods are skittering, fluttering, munching. singing. From rock-hard seed...First the leaves come back, photosynthesizing to produce the energy the animals will consume for life as well.