MODERN ASTRONOMY

Ptolemy's theory continued to be accepted for about 1500 years. Throughout this period, Europeans paid little attention to astronomy, though most of the scholars questioned the views of Ptolemy when the Latin translation of his book Almagest-reached Europe. But no one could muster up courage to challenge it openly.

NICOLAUS COPERNICUS

Finally Nicolaus Copernicus, a Polish scientist, made a breakthrough in 1543 A.D. through his book-Concerning the Revolutions of the Celestial Spheres. The ideas of Copernicus caused a revolution in the field of astronomy. He held that the sun is the center of the heavenly-system and all the planets (including our earth) revolve round it. His theory is known as heliocentric theory.

GALILEO

Galileo was an Italian astronomer who developed a telescope to watch and study the sky and the bodies in it. His observations confirmed the views of Copernicus. Also, he discovered that several moons revolve round Jupiter. Galileo died in 1641 A.D.

SIR ISAAC NEWTON

Isaac Newton was born in 1642 A.D. in England. He rose to be the greatest scientist of his time. He discovered the Law of Gravitation. It explained the motion of the planets along fixed paths. Also, it explained why the heavenly bodies do not fall off their positions. Newton died in 1727 A.D. till then only six planets Mercury, Venus, Earth, Mars, Jupiter and Saturn - were known.

Soon two new planets came to be discovered-Uranus in 1781 A.D. and Neptune in 1846 A.D. Thus emerged a new view of the universe during the late 1800's. Pluto the ninth planet came to be discovered in 1930 A.D. after the death of Percival Lowell (1855-1916) A.D. who had predicted its existence in his lifetime.

The acceptance of the sun-centered theory confirmed the views of Aristarchus who had suggested it during 200's B.C. As a result, Ptolemy’s theory came to be rejected once for all.