28 Feb - National Science Day - Remembering Sir Raman

February 28 is celebrated as National Science Day. On February 28 we remember a great scientist Sir C.V. Raman. His discovery placed India on the world Science map. He was the first person from Asia to be awarded a Nobel Prize in any field of science.

It was on this day years ago (February 28, 1928) that Sir C.V. Raman made a discovery that later came to be known as the Raman Effect. He was awarded a Nobel Prize in 1930.

In 1986, the National Council for Science and Technology Communication (NCSTC) asked the Government of India to designate February 28 as National Science Day to commemorate the legacy and discovery of the Raman Effect. The theme for 2012 is Clean Energy Options and Nuclear Safety.

Raman Effect

While working as professor at the University of Calcutta Raman started experiments to study how light behaved when it passed through various substances. On February 28, 1928, he found that light of only one colour was passed through a liquid emerged out with small traces of another colour. This meant that the molecules in the liquid were changing the colour of some of the light passing through it. The discovery created a sensation around the world and was named the Raman Effect. In 1930, C.V. Raman became the first person from Asia to be awarded a Nobel Prize in any field of science. The date of the discovery, February 28, is now celebrated as National Science Day in India.

The Raman Effect has been very useful in many areas of science. It was found that when light was passed through a substance, a series of colours were seen that could be specific for a substance and thought of as a fingerprint of the substance. This idea has been used in chemistry, medicine, biology and many other areas of science to find out what a substance’s material composition.

Raman spectroscopy employs the Raman effect for materials analysis. It is used to analyze a wide range of materials, including gases, liquids, and solids. Highly complex materials such as biological organisms and human tissue can also be analyzed by Raman spectroscopy.

New legless amphibian family found in India

A new family of legless amphibians, caecilians, has been discovered in northeastern India by a team of scientists led by a Delhi University professor, S D Biju. These animals could be mistaken as huge earthworms; but they are actually vertebrates with backbones and more like salamanders or frogs. Prof. Biju and team named the new family as Chikilidae and the new genus as Chikila, deriving the name from the Northeast Indian tribal language of Garo.

DNA evidence suggests the family split from its closest African relatives more than 140 million years ago, when the ancient super-continent of Gondwana fragmented, separating present-day India and Africa. Until this discovery, there were only nine known families of legless amphibians or caecilians, found across the wet tropical regions of Southeast Asia, India, Sri Lanka, parts of East and West Africa, the Seychelles and northern and eastern parts of South America.

Caecilians are very hard to spot as they live either underground or under leaf litter that lies on the soil. The females incubate their young for several months without eating. Their eggs hatch into adult caecilians, with no larval stage in between. Their eyesight is very limited and their skulls adapted for burrowing.

Professor Biju, also known as Frogman, found them in the forest area and close to human settlement, so conservation of this group may be extremely challenging. Some of the animals have reportedly been killed by villagers who mistook them for poisonous snakes. In fact, they carry no venom. Slash and burn agro-practices can also pose challenge for this newly found animal in the north-eastern state of India. One positive point for the new discoveries is that the region seems to be free of the fungal disease chytridiomycosis, which has devastated amphibian populations in many parts of the world.

Globally, amphibians are the most threatened group of animals, with about 40% of species on the Red List. But new discoveries are regularly made, though most come from rarely-visited regions of rainforest rather than quite densely-populated areas.

These findings have been published in a paper titled 'Discovery of a new family of amphibians from Northeast India with ancient links to Africa' in the current issue of Proceedings of Royal Society of London B.