changes in earth and sky

In the second century AD a Greek writer named Lucian wrote a story about a trip to the moon. He did not even know how far the moon was but his story revealed that the idea of space travel was certainly not new. Much later in 1865, the French novelist Jules Verne wrote a story in which his travelers..

Milky way is the galaxy that includes the sun, the earth and the rest of our solar system. It also includes huge clouds of dust particles and gases that lie throughout it and depths of interstellar space. The term Milky Way also refers to the portion of the Milky Way galaxy that can be se..

Air is an important natural resource providing the basis of life on earth. Entire biosphere depends on air. Air in the atmosphere provides oxygen to plants and animals, by virtue of which they are able to live. The composition of air (78% N, 21% O, 0.03% CO 2 ) is necessary to be maintain..

Calculating Kinetic energy using the formula E=(1/2)mv 2 Calculating changes in gravitational potential energy near the Earth Problems involving conservation of energy in simple systems Calculating momentum as the product mv Momentum as a separately conserved quantity, differ..

Calculating Kinetic energy using the formula E=(1/2)mv 2 Calculating changes in gravitational potential energy near the Earth Problems involving conservation of energy in simple systems Calculating momentum as the product mv Momentum as a separately conserved quantity, differ..

Air Pollution - Air is an important natural resource providing the basis of life on earth. Entire biosphere depends on air. Air in the atmosphere provides oxygen to plants and animals, by virtue of which they are able to live. The composition of air (78% N, 21% O, 0.03% CO 2 ) is necessar..

. Scientists in the early periods considered water to be an element. In 1784, Henry Cavendish burnt a mixture of hydrogen and oxygen and prepared water in his laboratory. By doing so, he proved that water is not an element, but a compound. Do you know how much water is there on the earth?..

If a non-magnetic piece of metal like copper is suspended at its center of gravity, the copper plate remains horizontally in equilibrium. If on the other hand, a magnetic needle is suspended at its center of gravity so that it is free to take up any position in the magnetic north-south plane, it m..

. These developments indicate a gradual change in the life style of mankind. Today metals are so vital to the modern man that it is unthinkable to live without them. They are essential for the construction of houses, transportation, communication, electricity, household articles, scientif..

. The fickle nature of the mob is also beautifully revealed. The setting is in Caesar's house. Caesar says that there is great turmoil in the sky and on earth. Calpurnia who is Caesar's wife had cried out in her sleep, asking for help, on seeing him murdered. She enters and asks..