Contribution of Scientists
His achievements include improvements to
the telescope, military compass and consequent astronomical
observations like confirmation of the phases of Venus, the discovery of the four
largest moons of Jupiter and analysis of sunspots. His famous works are heliocentrism,
kinematics,
dynamics and strength of materials.
Albert Einstein (1879 –1955) Germanian Theoretical Physicist
He received the 1921 Nobel Prize in Physics for his discovery of the law
of the photoelectric effect. He developed the general and special theory of relativity and theory
of Brownian Motion. His famous mass–energy equivalence formula E = mc2
formed the basis of nuclear energy. Einstein’s field equations explain particle theory and
the motion of molecules.
He made contributions to atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. His quantum theory
states that electrons move from a higher energy level to a lower one in
discrete steps, but not continuously, by emitting a photon (light quantum). He theorized that electrons revolve in stable
orbits and while in their stable orbits, they do not radiate energy.
He is best known for Bose–Einstein statistics and the theory of the Bose–Einstein condensate. Bose-Einstein statistics, assumed that
light is a gas of indistinguishable particles. Einstein’s adoption of this statistics to atoms, led to the existence of a
phenomena known as Bose-Einstein condensate, a dense collection of bosons (which are particles with integer spin,
named after Bose). Bose was awarded Padma Vibhushan in 1954.
Sir Chandrasekhara Venkata Rāman (1888 –1970) Indian, Tamilian Physicist
He was the first Asian and first non-White
to receive the Nobel Prize for Physics in 1930 for the discovery that when light
traverses a transparent material, some of the light that is deflected, changes
in wavelength. This phenomenon is called Raman scattering and
the result is Raman effect. In 1954 he was awarded the Bharat Ratna.
Subrahmanyan
Chandrasekhar
(1910–1995) Indian-American, Tamilian Astrophysicist
He won the 1983 Nobel Prize for Physics for his discovery of
Chandrasekhar Limit named after him. He showed that there is a maximum mass
which can be supported against gravity by pressure made up of electrons and
atomic nuclei. The value of this limit is about 1.44 times a solar mass. If the
mass of a star exceeded this limit, the star would collapse into a neutron star or black hole
and not become a white dwarf. He was the nephew of Sir C.V.Raman.
Newton described universal gravitation and the three laws of motion. He showed that the
motions of objects on Earth and of celestial bodies are governed by the same natural laws, by showing the
consistency between Kepler's laws of planetary motion and his
theory of gravitation. He built the first reflecting telescope. He showed that the
coloured light does not change its property by separating out a coloured beam. This is known as Newton's theory of colour.
Rutherford was awarded the Nobel Prize in Chemistry in 1908 for his
investigations into the disintegration of the elements, and the chemistry of
radioactive substances. The Rutherford model of
the atom
proved that atoms have their charge concentrated in nucleus.
He was credited as the first person to artificially disintegrate an element in
a nuclear reaction. He discovered the alpha,
beta, and gamma rays, proton
and radioactive half-life . He identified alpha particles as helium
nuclei. Element 104, Rutherfordium, is named in his honor.
Marie Curie’s achievements include using radioactivity
techniques for isolating radioactive isotopes,
and the discovery of two elements, polonium
and radium
and the treatment of neoplasms, using radioactive isotopes. She was the first woman
to win a Nobel Prize and the only woman to win in two different sciences. She
shared her 1903 Nobel Prize in Physics with her husband Pierre Curie
and with Henri Becquerel. She won the 1911 Nobel Prize in Chemistry.
Friedrich Wilhelm Ostwald (1853 –1932) Baltic German
Chemist
He received the Nobel Prize in Chemistry in 1909 for his work
on catalysis,
chemical equilibria and reaction velocities. He
is also known for the Ostwald process for the mass production of nitric acid
from ammonia. He discovered the law of dilution
which is named after him. Ostwald's rule
concerns the behaviour of polymorphs. The mole concept
was introduced by him. He linked it to the ideal gas.
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