Celestial bodies are spherical in shape because of gravity. Whenever enough mass gathers close together, the resultant gravity, which follows the inverse square law, pulls equally in all directions and results in a spherical shape. Irrespective of the material composition of the celestial body, a diameter of a few hundred kilometres is sufficient to create a spherical form.

Early in the 1800s, gold was discovered in Australia. Most of the ‘strikes’ were in the vicinity of the Blue Mountains near Bathurst. In 1851, a prospector named Hargraves – who had been in California during the gold-rush two years earlier – discovered rich traces of gold in Summer Hill Creek. The news spread rapidly and within two months the …

Astronauts are weightless in space because then they are continually falling between worlds, or they are falling around the earth and never reaching its center: hence they are like riders in a rapidly descending lift where everything is falling at the same speed and there is no relative motion between the lift and its occupants.

There are several forms of the sport of archery. They include bow hunting, target archery, field archery and flight shooting. In flight shooting the object is to shoot the arrow as far as possible. Special bows with a draw weight of up to 91 kg (200 lb) are used, and small lightweight arrows. In ordinary flight shooting, archers shoot while …

Acentric chromosomes are formed as a result of inversion of genes in one of the chromosomes in a homologous pair. This is a type of chromosomal aberration. Homologous loci are paired at meiosis. The meiotic anaphase will contain a chromatid connecting the two centromeres, called a chromatid bridge; a chromatid lacking a centromere altogether is called an acentric fragment. Neither …

When the British retreated from Washington during the war of 1812 they took prisoner a Dr William Beanes and held him aboard a warship in Chesapeake Bay. Francis Scott Key, an American lawyer, obtained permission to intercede for the release of his friend as the British fleet was preparing to bombard Fort McHenry, which protected Baltimore. The British agreed to …

The Incas were an Indian people who lived in the Andean region of South America. The first Inca ruler, Manco Capan (c. A.D. 1200) was believed to have been descended from the sun god. The Incas thirsted for power. They warred against and defeated their neighbours, and soon their empire extended from central Chile to the present Colombia-Ecuador border. Having …

The Green Mountain Boys had their origins in a dispute over land in America. In 1749 Governor Benning of New Hampshire began to grant lands west of the Connecticut River (which today is Vermont), even though New York put in a strong claim. In 1770 the New York Supreme Court held that all Hampshire west of the Green Mountains were …

The first real explorers of the Ancient World were the Phoenicians. They were a people who had settled on a costal strip of land at the eastern end of the Mediterranean, now known as the Lebanon, who had many colonies, the most important being Tyre and Sidon. Phoenician wealth originally came from a dye made from a small shellfish found …

During the twelfth or thirteenth centuries the third had greatest of the Mexican civilizations arose – the Aztecs. They were a warlike race which gradually grew in power, becoming the strongest nation in Mexico. Their capital, Tenochtitlan, was built on islands in a marshy area where Mexico City stands today. They worshiped a blood-thirsty pantheon of gods, led by Huitzilopochtli, …