Stethoscope='='='='='='

Who invented the stethoscope?

In 1816, the French physician Rene Theoplhie Hyacinthe Laennec (1781-1826) introduced a performated wooden cylinder which concentrated the sounds of air flowing in and out of the lungs, and described the sound which it revealed. The modern form of stethoscope, with flexible tubes connection the earpieces to a circular piece placed against the chest, was developed later in the nineteenth century.

Birth details of ____TAOISM

Who was the founder of Taoism and what were the principles Taoism was based upon?

Two great philosophers who influenced the Chinese thought were confucius and Lao-tzu, the latter founding Taoism. Lao-tzu, said to have lived between 604 and 531 practice of thrift, humility and compassion. Form and ceremony held no place in his religion. Some of the other principles preached by Taoism are simplicity, patience, contentment and harmony. Taoism began its decline about AD 906, especially after the T'ang Dynasty, and today its followers number fewer than 52 million, many abandoning it and embracing Buddhism. In 2005, altogether, there were said to be 27,34,000 Taoists worldwide.

According to Taoism, the universe is believed to be kept in balance by the opposing forces of Yin and Yang that operate in dynamic tension between themselves. Yin is female and watery; the force in the moon and rain which reach its peak in the winter; Yang is masculine and solid; the force in the sun and earth which reaches its peak in the summer. The interaction of Yin and Yand is believed to shape all life.

From the fourth century, rivalry between Taoists and Mahayana Buddhists was strong in China, leading to persecution of one religion by the other. This was resolved by mutual assimilation, and Taoism developed monastic communities similar to those of the Buddhists.

Sand /////// Glasssssssss

How is sand turned into glass?

The raw material from which glass is made is silica, the most abundant of all the earth's minerals. Milky white in colour, it is found in beach in the world has been formed by water pounding rocks into tiny particles, sand is the major source of silica. Sand also contains other minerals, but silica is the main component because it is hard, insoluble and does not decompose, as it outlasts the others.

Pure silica has such a higher melting point that no ordinary fire would convert it into glass. It is said that the first glass-makers had lit their fire on sand which was impregnated with soda(compounds of sodium) left behind by evaporated water from a lake of sea. The soda reduces silica's melting point. Today, lime and soda are combined bottles, window panes and cheap drinking glasses. When glass cools, its structure does not return to the crystalline structure of silica, which is opaque. Instead, it forms a disordered structure rather than a frozen liquid, which is transparent. Other metas may be added to provide colour or to improve the quality of finished glass.

Ice Ice __ baby

How can ice float on water?

Ice floats on water because a piece of ice is lighter than the same amount of water. The ice is not very much lighter than the water, so it floats low in the water.

When water freezes to ice, the water molecules line up in rows. But as they do so, the molecules move apart slightly. The ice increases in size as it forms and this gives ice a lower density than water, making it float in water.

The force between the molecules is very strong, and nothing can resist the expansion that occurs as the ice forms. This is why water pipes sometimes bursts when the weather gets warmer, the ice melts and water pours from the cracked pipe. It is unusual for a liquid to expand on freezing, but it is a good thing that water does so. The layer of ice that may form over lakes and the sea in winter prevents the water beneath from freezing.

Feel of Metal

Why does metal feel cold?

When you touch something made of metal, it feels cold. The reason for this is that some heat flows from your fingers into the surface of the metal. Because the skin on your fingers loses heat, it gets cold and the metal feels cold.

Metal objects feel cold in a cool climate because metal is a good conductor of heat. This means that heat flows through metal easily. Heat, therefore, leaves the skin of your fingers and flows into the metal. It does this because your fingers are warmed than the metal. The heat moves on through the metal, so that the surface of the metal does not get as warm as the skin on your fingers. Heat continues to flow from your fingers into the metal, and it feels cold.

Wood or cloth are poor conductors of heat. The surface of an object made of wood or cloth quickly warms up as you touch it, and it does not feel cold.