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Digital music was a $1.3 billion business in 2007, but it still only comprised 10 percent of consumer music spending

compete with Apple and the future of music CD sales.

“The challenge remains for the industry to find new ways to compete with Apple, who remains the dominant player for portable media devices,”

According to the American College Dictionary, pollution is defined as:  �to make foul or unclean; dirty.

When it is unfit for its intended use, water is considered polluted.

Point sources of pollution occur when harmful substances are emitted directly into a body of water.

Japan entered into its second major prehistoric period, a civilized era known as the Yayoi period.

he name Yayoi is derived from an area Tokyo known as Yayoi, where the first documented pottery from this period was discovered in an archaeological excavation in 1884.

ron and bronze materials are believed to have been exchanged with Japanese envoys either for token tributes or prisoners of war.

The suit is made out of either Proban or the same Nomex material that lines the inside of the driver's helmet.

More has been published about the extinction of dinosaurs at the K-T boundary than any other group of organisms. Excluding a few controversial claims, it is agreed that all non-avian dinosaurs went extinct at the K-T boundary. The dinosaur fossil record has been interpreted to show both a decline in diversity and no decline in diversity during the last few million years of the Cretaceous, and it may be that the quality of the dinosaur fossil record is simply not good enough to permit researchers to distinguish between the choices.[54] Since there is no evidence that late Maastrichtian nonavian dinosaurs could burrow, swim or dive, they were unable to shelter themselves from the worst parts of any environmental stress that occurred at the K-T boundary. It is possible that small dinosaurs (other than birds) did survive, but they would have been deprived of food as both herbivorous dinosaurs would have found plant material scarce, and carnivores would have quickly found prey to be in short supply.[35] The growing consensus about the endothermy of dinosaurs (see dinosaur physiology) helps to understand their full extinction in contrast with their close relatives, the crocodilians. Cold-blooded crocodiles have very limited needs of food (they can survive several months without eating) while warm-blooded animals of similar size need much more food in order to sustain their faster metabolism. Thus, under the circumstancies of food chain disruption above mentioned, non-avian dinosaurs died [55] while some crocodiles survived. In this context, the survival of other endothermic animals, such as some birds and mammals, could be due, among other

An aircraft is a vehicle which is able to fly through the Earth's atmosphere or through any other atmosphere. Rocket vehicles are not aircraft if they are not supported by the surrounding air. All the human activity which surrounds aircraft is called aviation.

Heavier-than-air aircraft must find some way to push air or gas downwards, so that a reaction occurs (by Newton's laws of motion) to push the aircraft upwards. This dynamic movement through the air is the origin of the term aerodyne. There are two ways to produce dynamic upthrust: aerodynamic lift, and powered lift in the form of engine thrust. Aerodynamic lift is the most common, with aeroplanes being kept in the air by the forward movement of wings, and rotorcraft by spinning wing-shaped rotors sometimes called rotary wings. A wing is a flat, horizontal surface, usually shaped in cross-section as an aerofoil. To fly, the wing must move forwards through the air; this movement of air over the aerofoil shape deflects air downward to create an equal and opposite upward force, called lift, according to Newton's third law of motion. A flexible wing is a wing made of fabric or thin sheet material, often stretched over a rigid frame. A kite is tethered to the ground and relies on the speed of the wind over its wings, which may be flexible or rigid, fixed or rotary. With powered lift, the aircraft directs its engine thrust vertically downwards. The initialism VTOL (vertical take off and landing) is applied to aircraft that can take off and land vertically. Most are rotorcraft. Others, such as the Hawker Siddeley Harrier, take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight. Similarly, STOL stands for short take off and landing. Some VTOL aircraft often operate in a short take off/vertical landing regime known as STOVL. A pure rocket is not usually regarded as an aerodyne, because it does not depend on the air for its lift (and can even fly into space), however many aerodynamic lift vehicles have been powered or assisted by rocket motors. Rocket-powered missiles which obtain aerodynamic lift at very high speed due to airflow over their bodies, are a marginal case.

The forerunner of the aeroplane is the kite

1. Tokyo, Japan Metropolitan area: 34 million people City: 12.5 million people Tokyo is by far the largest urban region in the world. Despite its size and complexity, Tokyo has a very efficient public transportation, which accounts for almost 80 percent of all daily journeys in Tokyo.

1. Tokyo, Japan Metropolitan area: 34 million people City: 12.5 million people Tokyo is by far the largest urban region in the world. Despite its size and complexity, Tokyo has a very efficient public transportation, which accounts for almost 80 percent of all daily journeys in Tokyo. Urban Detail: Tokyo Bay has been gradually filled up to create more space for housing and offices. Odaiba, an island entirely created out of waste material, became one of Tokyo’s most interesting tourist spots with futuristic architecture, shopping, and entertainment centers. (Photo: Miki Yokoyama)

Eventhough parachutes seem to have been used in China since the 1100s and that Leonardo da Vinci of Italy had invented devices similar to parachutes nowadays, worldwide skydivers state that the French inventor André-Jacques Garnerin is the one to make the first parachute. In 1797 he jumped from a balloon over Paris using a parachute and kept on making other jumps in France and also in England.

In World War I , that is between 1914 and 1918, the military began using parachutes in their missions

end of the spectrum are the reds and oranges. These gradually shade into yellow, green, blue, indigo and violet. The colors have different wavelengths, frequencies, and energies. Violet has the shortest wavelength in the visible spectrum. That means it has the highest frequency and energy. Red has the longest wavelength, and lowest frequency and energy. LIGHT IN THE AIR Light travels through space in a straight line as long as nothing disturbs it. As light moves through the atmosphere, it continues to go straight until it bumps into a bit of dust or a gas molecule. Then what happens to the light depends on its wave length and the size of the thing it hits. Dust particles and water droplets are much larger than the wavelength of visible light. When light hits these large particles, it gets reflected, or bounced off, in different directions. The different colors of light are all reflected by the particle in the same way. The reflected light appears white because it still contains all of the same colors. Gas molecules are smaller than the wavelength of visible light. If light bumps into them, it acts differently. When light hits a gas molecule, some of it may get absorbed. After awhile, the molecule radiates (releases, or gives off) the light in a different direction. The color that is radiated is the same color that was absorbed. The different colors of light are affected differently. All of the co

d after Lord John Rayleigh, an English physicist, who first described it in the 1870's.) WHY IS THE SKY BLUE? The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by t

As you look closer to the horizon, the sky appears much paler in color. To reach you, the scattered blue light must pass through more air. Some of it gets scattered away again in other directions. Less blue light reaches your eyes. The color of the sky near the horizon appears paler or white.