50, 100 and 150 Years Ago; March 2003; Scientific American Magazine; by Staff Editor; 1 Page(s)

NITROGEN SCARCITY-"Nitrogen tantalizes mankind with the paradox of poverty in the midst of plenty. All living things on this planet-animal and vegetable-must have nitrogen in their food. Yet the free nitrogen in the air is so difficult to incorporate into foodstuffs that man must engage in back-breaking toil to conserve the comparatively small amount that nature captures and fixes in the soil. However, since 1949 a flurry of discovery has turned up undreamed numbers of microorganisms that fix nitrogen. We can look forward to the possibility that we may some day be able to exploit the power of these organisms, and so help nature's nitrogen cycle to enrich our earth."

MILKY WAY NOT FREAKISH!-"The universe may be twice as large, and twice as old, as astronomers have supposed, according to Harlow Shapley of the Harvard College Observatory. If every galaxy is twice as far away as we had thought, it must also be twice as big. As a consequence, the Milky Way, which was supposed to be an exceptionally large galaxy, would be about the same size as the Andromeda nebula and many other galaxies. This is a relief to astronomers, who have been unable to see any reason for the local galaxy's being a giant freak. The new estimate would clear up another discrepancy. The universe was previously estimated to be about two billion years old, whereas geological evidence indicates that the earth is over three billion years old. The revised estimate of the universe's size also doubles its age to four billion years."