Sir
Isaac Newton
Also known as the father of Physics , this
was the man who created a new subject (Physics) out
of the basic sciences. He was very engrossed in his
studies. He used to study for 24 hours continuously.
He had high observation powers which helped him discover
few of the most importan concepts in Science (such
as gravity).Newton discovered how the universe is
held together through his theory of gravitation. He
discovered the secrets of light and colour. He invented
a branch of mathematics, calculus, also invented independently
by Gottfried Leibniz, a German mathematician . Newton
made these three discoveries within 18 months from
1665 to 1667. 

The theories of motion and gravitation.
Newton said the concept of a universal force came to him
while he was alone in the country. He had been forced to
flee there because of the outbreak of bubonic plague in
the city of Cambridge. During this time, Newton suddenly
realized that one and the same force pulls an object to
earth and keeps the moon in its orbit. He found that the
force of universal gravitation makes every pair of bodies
in the universe attract each other. The force depends on
(1) the amount of matter in the bodies being attracted and
(2) the distance between the bodies. The force by which
the earth attracts or pulls a large rock is greater than
the pull on a small pebble because the rock contains more
matter. The earth's pull is called the weight of the body.
With this theory, Newton explained why a rock weighs more
than a pebble.
He also proved that many types of motion are due to one
kind of force. He showed that the gravitational force of
the sun keeps the planets in their orbits, just as the gravitational
force of the earth attracts the moon. The falling of objects
on earth seems different from the motion of the moon because
the objects fall straight down to the earth, while the moon
moves approximately in a circle around the earth. Newton
showed that the moon falls just like an object on earth.
If the moon did not fall constantly toward the earth, it
would move in a straight line and fly off at a tangent to
its orbit. Newton calculated how much the moon falls in
each second and found the distance is 1/3600 of the distance
an object on earth falls in a second. The moon is 60 times
as far from the earth's centre as such an object. Consequently,
the force of the earth on an object 60 times as far away
as another object is 1/3600.
