Narwhals can be called whales of the ice: in icy channels, ponds, and ice-shielded bays they seek sanctuary from killer whales, their chief predator, and their annual migrations following the seasonal rhythm of advancing and retreating ice.

Sculpted boulders found at Lepenski Vir, an example of the earliest monumental art known from central and western Europe, includes 15 figures with human features similar to Upper Paleolithic forms and to Middle Eastern Nantufian stone figurines.

A recording system was so secretly installed and operated in the Kennedy Oval Office that even Theodore C. Sorensen, the White House counsel, did not know it existed.

On the surface of Jupiter's moon Europa, water remains frozen, but the gravitational force of Jupiter and its other moons cause contractions that may generate so much heat that it would melt ice below Europa's surface.

The Scandinavian assault on Western Europe culminated in the early eleventh century with the Danish conquest of the English kingdom, which other Scandinavian kings attempted to repeat, unsuccessfully later in the same century.

Since digital recording offers essentially perfect reproduction—on compact discs, digital audiotapes, or digital videodiscs—audiophiles can accumulate vast collections of music, transferring them from one format to another, copying it, and digitally altering it with little effort and not damaging the sound quality.

Like humans and other warm-blooded animals, researchers report that the lotus has the remarkable ability of keeping its temperature in a narrow range.

Though widely used for decades to fuel home heating systems, utility boilers, and industrial furnaces, natural gas has still accounted for far less of the energy consumed in the United States than has oil.

Antipoverty initiatives have had to contend with two decades of economic shifts that have depressed wages of workers with little or no technical skills.

A recent survey showed that while many banks have service charges on interest-bearing and non-interest-bearing accounts with balances that are falling below a set minimum, some banks provide virtually free checking regardless of the account balance.