YemKay

We all are aware that bodies fall at same rate irrespective of their weights. Well, let’s see how our geniuses have arrived at this in the days where there was no definition for velocity or acceleration. While reading Stephen Hawking’s A Briefer History of Time, I stumbled upon the explanation given for bodies falling at same rate. This snippet taken from Google Book Search shows,

(continuing…) forces cancel out and a body will always fall at the same rate irrespective of its weight.

How a layman would understand this? There comes the giant Galileo, who gave a simpler explanation long back in 16th Century. Here is the excerpt taken from the book “On Giants’ shoulders“. Here is the excerpt,

He (Galileo) imagined a light and a heavy body tied together and asked the question ‘Does the presence of the light body help or hinder the fall of the heavy body?’. Now if, as Aristotle had maintained and, as intuition may tell us, light body would impede the fall of the heavy body, because it would lag behind and restrain it. But Galileo reasoned that if we consider the entire assemblage of heavy plus light body together, well, that is heavier than the heavy body on its own, so the assemblage should fall faster, and so we arrive at the contradiction that the presence of the light body should both speed up and slow down the fall of the heavy body. That is obviously nonsense, and so the only way we can reconcile it is to suppose that both heavy and the light body fall at the same speed.

What a wonderful example of Galileo’s reasoning? The former explanation using Newton’s laws can be commonly found in our text books. But Galileo’s reasoning makes more sense and our education system doesn’t induce such a reasoning power into us.

This video below shows the Hammer-Feather drop experiment performed by the astronaut David Scott on moon during Apollo 15 mission. Since there was no atmosphere, a feather and a hammer fell at the same rate and the entire world witnessed this historic proof for Galileo’s findings.