Legend has it that Galileo Galilei dropped two weights from the Leaning Tower of Pisa to prove that objects of different weights fall at the same rate. Historians doubt this claim. They are also sceptical about Galileo’s description in his masterpiece Discourses Concerning Two New Sciences, of an experiment of rolling a 100-pound cannon ball and a 1-pound musket ball down an incline to study their acceleration using a water clock. “Too much accumulation of sources of error and inexactitude!” they exclaimed. Be that as it may, there is no denying that Galileo had dared debunk Aristotle’s theory which had been held sacrosanct for centuries. Aristotle, in the 4th Century BC, articulated that an object falls in proportion to its weight. A feather will take much longer to reach the ground than a rock. This erroneous assumption held ground for centuries because it tallies with our everyday experience. But Galileo had the wit to ask himself, “What if I tie the lighter object to the heavier object? Will the combined mass fall faster than the individual objects or will it fall at an average rate?” Thus the mind of the Father of modern science started working and he set out to deduce the law of falling objects mathematically as well as observe them experimentally. It was not just about who reaches the ground faster, it was also about the rate of fall – the acceleration. In 1604, Galileo did not have the advantage of time lapse photography or electronic sensors. So he had to slow down the fall using an inclined plane. Stillman Drake, a leading expert on Galilean science, accessed at the Biblioteca Nazionale Centrale in Florence, the manuscripts and scribbles left behind by Galileo and discovered some early papers that appeared to be some experiment conducted in 1604 in Padua. From the jottings, Drake recreated the following experiment: Galileo released a ball at the top of a wooden incline, noting, in the first few moments that it travelled a distance of 33 punti (points). After an equal amount of time had passed, the ball picked up speed and covered a distance of 130 punti and by the end of the third interval, 298 punti, then 526, 824, 1192, 1620. For the final distance, when the ball would have been moving at top speed, Galileo had actually written 2123 punti. Then he scratched it out and corrected it to 2104. Beside some of his figures he put a plus or minus sign, apparently indicating

Robert A Millikan

It is strange how one thing leads to another. Today, the electron is an accepted fact of life. Even though nobody can vouch that he has seen an electron, scientists have not only found out all its behavioural properties, they have rallied around beams of electrons in CRTs and TV sets and harnessed their behaviour to the benefit of mankind in gadget after gadget.

Michelson & Morley

In 1878, the New York Times announced, “It would seem that the scientific world of America is destined to be adorned with a new and brilliant name,” predicting that light would soon be measured “with almost as much accuracy as the velocity of an ordinary projectile.”

How was the Universe created? This is one question that has confronted the human mind over thousands of years. Various civilizations, cultures, religions and mythologies have sought to answer this differently. In modern times scientists too had to address this question and they could not arrive at a unique answer all at once.