Major contribution/discovery

Archimedes - Principle of buoyancy; Principle of the lever- Greece 

Galileo Galilei - Law of inertia - Italy 

Christiaan Huygens - Wave theory of light - Holland 

Isaac Newton  - Universal law of gravitation; Laws of motion; Reflecting telescope - U.K. 

Michael Faraday -Laws of electromagnetic induction - U.K. 

James Clerk Maxwell - Electromagnetic theory; Light-an electromagnetic wave - U.K. 

Heinrich Rudolf Hertz -  Generation of electromagnetic waves - Germany 

J.C. Bose - Ultra short radio waves - India 

W.K. Roentgen - X-rays - Germany 

J.J. Thomson - Electron - U.K. 

Marie Sklodowska Curie -Discovery of radium and polonium; Studies on natural radioactivity -Poland 

Albert Einstein  Explanation of photoelectric effect; - Theory of relativity - Germany

Victor Francis Hess- Cosmic radiation- Austria

R.A. Millikan -Measurement of electronic charge- U.S.A.

Ernest Rutherford - Nuclear model of atom- New Zealand

Niels Bohr- Quantum model of hydrogen atom- Denmark

C.V. Raman- Inelastic scattering of light by molecules -India

Louis Victor de Borglie -  Wave nature of matter -  France

M.N. Saha - Thermal ionisation-  India

S.N. Bose- Quantum statistics- India

Wolfgang Pauli- Exclusion principle - Austria

Enrico Fermi- Controlled nuclear fission-Italy

Werner Heisenberg - Quantum mechanics; Uncertainty principle - Germany

Paul Dirac -Relativistic theory of electron; Quantum statistics - U.K.

Edwin Hubble - Expanding universe  U.S.A.

Ernest Orlando Lawrence-  Cyclotron-  U.S.A.

James Chadwick - Neutron- U.K.

Hideki Yukawa -Theory of nuclear forces -Japan

Homi Jehangir Bhabha - Cascade process of cosmic radiation- India

Lev Davidovich Landau -Theory of condensed matter; Liquid helium- Russia

S. Chandrasekhar- Chandrasekhar limit, structure and evolution of stars - India

John Bardeen -Transistors; Theory of super conductivity- U.S.A.

C.H. Townes - Maser; Laser- U.S.A.

Abdus Salam- Unification of weak and electromagnetic interactions - Pakistan