The shuttle, a manned, multipurpose, orbital-launch space plane, was designed to carry payloads of up to about 30,000 kg (65,000 lb) and up to seven crew members and passengers. The upper part of the spacecraft, the orbiter stage, had a theoretical lifetime of perhaps 100 missions, and the winged orbiter could make unpowered landings on…
A gun is a weapon that uses the force of an explosive propellant to project a missile. Guns or firearms are classified by the diameter of the barrel opening. This is known as the calibre of the gun. Anything with a calibre up to and including .60 calibre(0.6 inches) is known as a firearm. The…
In the Geiger-Muller tube, particles ionize gas atoms. The tube contains a gas at low pressure. At one end of the tube is a very thin “window” through which charged particles or gamma rays pass. Inside the tube is a copper cylinder with a negative charge. A rigid wire with a positive charge runs down…
In modern society, radio is the most widely used medium of broadcasting and electronic communication: it plays a major role in many areas such as public safety, industrial manufacturing, processing, agriculture, transportation, entertainment, national defense, space travel, overseas communication, news reporting, and weather forecasting. In radio broadcasts, they use radio waves which can be both…
Chromium is a very hard, brittle, gray metal, which is sometimes referred to as Siberian red lead. It does not rust easily and becomes shiny and bright when it is polished. The shiny trim on our automobile bumpers and door handles is usually electroplated chromium. Most chromium comes from something called chromite which is a…
How Wind Tunnels Work A wind tunnel is a machine used to fly aircraft, missiles, engines, and rockets on the ground under pre-set conditions. With a wind tunnel, you can choose the airspeed, pressure, altitude, and temperature to name a few things. A wind tunnel is usually has a tube-like appearance with which wind is…
Marshland is covered with grasses, reeds, sedges, and cattails. These plants all have their roots in soil covered or saturated with water and its leaves held above water. Marshes may be freshwater or salt. Freshwater marshes develop along the shallow edges of lakes and slow-moving rivers, forming when ponds and lakes become filled with sediment.…
Many people today, including scientists and doctors, are questioning the suffering and killing of animals for the sake of human beings. Is it morally correct to dissect a frog or a worm for the purpose of educating a high school student? On the other hand, must “We study life to protect life” (1:131) The issue…
There is currently much debate on the desirability of landfilling particular wastes, the practicability of alternatives such as waste minimisation or pre-treatment, the extent of waste pre-treatment required, and of the most appropriate landfilling strategies for the final residues. This debate is likely to stimulate significant developments in landfilling methods during the next decade. Current…
The scene is breathtakingly beautiful; a thick brush of purple flowers blankets Canada’s wetlands. This blanket silences the expected sounds of the wetland environment, birds chirping, ducks splashing, insects buzzing and animals thriving. This unnatural silence is disturbing, the favourite flowers that used to litter this landscape are no longer visible, the water that used…
John Muir was a man of great importance in the history of the United States and in the preservation of it’s beauty. His tireless efforts to protect natural wonders such as Yosemite Valley demonstrated his undying love for the outdoors. Muir took a stand against the destructive side of civilization in a dauntless battle to…
Hurricanes get their start over the warm tropical waters of the North Atlantic Ocean near the equator. Most hurricanes appear in late summer or early fall, when sea temperatures are at their highest. The warm waters heats the air above it, and the updrafts of warm, moist air begin to rise. Day after day the…
The ban on elephant ivory trading has slowed down the poaching of elephants, but now poachers are getting their ivory from another creature, the hippopotamus. For the poacher, the hippo is an easy target. They stay together for long hours in muddy water pools, as many as eighty-one can be found in a single square…
A plant exists that is so strong that it can be grown without requiring chemicals in almost every part of the world. Many have touted this plant as a possible way in which to wean society from its dependence on fossil fuels for energy and the need to log forests for pulp, paper and wood. …
The Branta sandvicensis, or Hawaiian goose looks similar to the Canada Goose except only the face, cap, and hindneck are black; and Nene have buff-colored cheeks. The males and female have the same plumage. The feet of this goose are not completely webbed like the other geese. Lots of calls have been described but the…
Fluoride is a mineral that occurs naturally in almost all foods and water supplies. The fluoride ion comes from the element fluorine. Fluorine, the 13th most abundant element in the earth’s crust, is never encountered in its free state in nature. It exists only in combination with other elements as a fluoride compound. Fluoride is…
An estuary is a coastal area where fresh water from rivers and streams mixes with saltwater from the ocean. Many bays, sounds, and lagoons along coasts are estuaries. Portions of rivers and streams connected to estuaries are also considered part of the estuary. The land area from which fresh water drains into the estuary is…
Typically, the level of ocean water around the world is higher in the western Pacific and lower in the eastern, near the Western coast of South and North America. This is due primarily to the presence of easterly winds in the Pacific, which drag the surface water westward and raise the thermocline relatively all the…
The subject of deforestation and the effects that it has on the environment have been heavily debated for a long time; particularly over the last few years. Governments and large lumber companies see large profits in the mass deforestation of forests and state that their actions are having few, if any, harmful effects on the…
A deciduous forest, simply described is a forest that is leafless during the winter. Strong species make up this type of forest, meaning that the species can tolerate a wide range of conditions. In the extreme northern latitudes, the growing season is short causing the trees to be leafless the majority of the year. The…