It has been rightly said that need is the mother of inventions. Most of the inventions and discoveries owe their successful operation to necessity. Unless there is want we cannot struggle to attain the goal. The history of human progress in all walks of life is the history of man's endeavour to reach new goals.
When man felt hungry, he started hunting and till land. The need for shelter lead the man to built huts and houses. The need for quick travel resulted in the invention of the fastest means of transport, making the world short. At the time of need , the human mind, which is creative and imaginative, thinks in a very quick manner.