Tile shells of crabs found around a particular coastal location in Japan seem mostly to resemble the legendary face of a Samurai. Given below are two explanations of this observed fact. Which of these strikes you as a scientific explanation?
(a) A tragic sea accident several centuries ago drowned a young Samurai. As a tribute to his bravery, nature through its inscrutable ways immortalized his face by imprinting it on the crab shells in that area.
(b) After the sea tragedy, fishermen in that area, in a gesture of honour to their dead hero, let free any crab shell caught by them which accidentally had a shape resembling the face of a Samurai. Consequently, the particular shape of the crab shell survived longer and therefore in course of time the shape was genetically propagated. This is an example of evolution by artificial selection.
[Note: This interesting illustration taken from Carl Sagan's 'The Cosmos' highlights the fact that often strange and inexplicable facts which on the first sight appear 'supernatural' actually turn out to have simple scientific explanations. Try to think out other examples of this kind].

Give the salient features of Einstein's theory.

Name four fundamental forces in nature.

Does imagination play any role in physics?

Physics has a very limited scope and only in practice of a few blessed ones. Do you agree?

Ravinder and Mohender were discussing the role of Physics in society. Ravinder said to Mahender that Physics does not have any impact on society. He had no knowledge of science as he was the student of Arts stream. Ravinder who is the science student of class XII explained him that the fate of society is intimately linked with Physics because whatever is discovered in Physics, it immediately effects the society. The advancement in the field of communication such as radios, computers, TVs and mobile phones connect the people with each other. Nuclear energy have brought a profound change in the thinking and living style of the human beings.
(i) What values are displayed here by Ravinder?
(ii) Give any five discoveries which has effected the society more.

Deepa's uncle was surprised to see the fast changes in the world. He is not so educated. He asked Deepa to tell him the names and qualities of some persons who have contributed for bringing the rapid changes in the world. Deepa who is science graduate explained about some discoveries and the names of scientist who have done a marvellous work in physics.
(i) Why Deepa's uncle was so curious to know things changed recently?
(ii) What values are displayed by Deepa?
(iii) Name at least three Indian scientists.

Science, like any knowledge, can be put to good or bad use, depending on the user. Given below are some of the application of science. Formulate your views on whether the particular application is good, bad or something that cannot be so clearly categorized.
(i) Mass vaccination against small pox to curb and finally eradicate this disease from the population.
(ii) Television for eradication of illiteracy and for mass communication for news and ideas.
(iii) Prenatal sex determination.
(iv) Computers for increase in work efficiency.
(v) Putting artificial satellites around the earth.
(vi) Development of nuclear weapons.
(vii) Development of new and powerful techniques of chemical and biological warfare.
(viii) Purification of water for drinking.
(ix) Plastic surgery.
(x) Cloning.