Chapter-1 of Class 11 Introduction To Physics Short Notes for 2021-22 part- 2

Chapter-1 of Class 11 Introduction To Physics Short Notes for 2021-22

1.2 Ancient Indian Physics

Indian phyloshpers thought that universe is composed of four elements which are Prathvi(Earth),Jal(water),Samir(air),Pawak(fire). The jain Philoshphers then added Akaash(ether), fivth Element to it. Later on Buddhists Discarded Akaash and added Joy,Life and Sorrow.

Pakhudha Katyayana A contemporary Buddha was first to plead the theory of atoms.

The Jain Believed and consider that all atoms were identical. But at that time atoms were considered as eternal, being minutest particles, invisible to eyes and completely without magnitude.

In Ancient India

Brahma Gupta obsereves the theory of attractive force of the earth, but no law of gravitation was propounded.

Water or solids expands on heating but it was no experimentaly studied.

Important points of Rig Veda

Agni(energy) is conserved and everlasting.This statement agrees with modern law of conservation

Heat is produced on rubbing two pieces of stones.it agrees with modern law which is that heat is produced on friction.

Sun Rays are of Seven colours. In modern law it also states that sunlight has Seven colours.

Each substance attract other substance in universe. This statement agrees with modern law of gravitation

Celestial Objects revolve in stationary elliptical orbits.

Facts Related To Physics by ancient scientists

1. In Nyaya Kundali- Shridhanacharya states that when we deform the forces from the bodies of high density, Then they return back to original state. this is same as in modern physics law of elasticity.

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2. Nyaya Darshan of Maharishi Kanad states that objects which are not visible by our naked eye can be visible by the help of glass(lens),mica or crystals. This statement is same as in modern day use of lenses.
3. Maharishi Kanad in his Veg Sanskar States that increase in motion is the cause of force applied, more the force more will be motion and every force produces an equal and opposite force which is as same as Newtons law of Motion.
4. In Brahat sahita of barh mihir, it is stated that the multicoloured sun rays decompose by the air particles in a cloudy sky, they appear in the form of rainbow. this statement agrees the dispersion of light