At first, the bird lived in an egg. So its knowledge at that time was limited to the egg, and it thought that the world was small and round and made of pale blue she'll, like the egg in which it lived.
Next, the bird lived in a nest in its mother's breast. So it thought at the time that the world was like its nest made of straw.
The bird learned to flutter out of the nest, it saw the leaves of the tree and thought the world also was made of leaves.
When the bird learned to fly, it flew out of the tree into the wide world. It now realized that its previous opinions of the world were wrong, and that it was not possible for any bird to know what the world is made of.
The world we live in presents an endless variety of fascinating problems which excite our wonder and curiosity. The scientific worker attempts to formulate these problems in accurate terms and to solve them in the light of all the relevant facts that can be collected by observation and experiment. Such questions as 'what',' How', 'Where' and 'when' challenge him to find the clues that may suggest possible replies. Confronted by the many problems presented by, let us say, an active volcano, we may ask: what are the lava made of? How does the volcano work, and how is the heat generated? Where do the lava and gases come from? When did the volcano first being to erupt, and when is it likely to erupt again?
In terms of chemical compounds and elements, the question 'How' refers to processes—the way things are made or happen or change. The ancients regarded natural processes as the manifestation of energy acting on or through matter. Volcanic eruptions and earthquakes no longer reflect the erratic behavior of the Gods of the underworld; they arise from the action of the Earth's internal heat on and through the surrounding crust. The source of the energy lies in the material of inner earth. In many directions, of course, our knowledge is still incomplete, only the first of the question we have asked about volcanoes, for example, can as yet be satisfactory answered. The point is not that we know pretend to understand everything, but that we have faith in the orderliness of natural processes. As a result of two or three centuries of scientific investigation, we have come to believe that nature is understandable in the sense that when we ask questions by way of appropriate observation and experiment, she will answer truly and reward us with discoveries that endure. The author speaks about volcanoes as an example of natural phenomena that affect human lives, for which all the answers are not known yet. Scientist all over the world are trying to unravel the mystery surrounding volcanoes and their unpredictable eruptions that disrupt human lives. Why do eruptions happen, what is lava, where does it come from, when did eruptions start— the answers to these questions will give scientists the knowledge to predict suck events in the future and minimize losses to human life and property