Who expressed the idea that heavy things fall faster than light things?

Answer 1

It was Aristotle, however he was wrong.It's maybe the most famous scientific experiment, Galileo Galilei's dropping objects from the leaning tower of Pisa in order to prove that all objects fall at the same rate, whatever their mass.In his Two New Sciences (1634) Galileo discusses the mathematics (first to apply mathematics for physics analysis) of a simple type of motion what we call today uniform acceleration or constant acceleration. Then he proposes that heavy bodies actually fall in just that way and that if it was possible to create a vacuum, any two falling bodies would travel the same distance in the same time. On the basis of this proposal, he predicts about balls rolling down an inclined plane, Finally, he describes some inclined plane experiments corroborating his theory.Galileo used inclined planes for his experiment to slow the acceleration enough so that the elapsed time could be measured. The ball was allowed to roll a known distance down the ramp, and the time taken for the ball to move the known distance was measured. The time was measured using a water clock.Galileo showed that the motion on an inclined plane had constant acceleration, dependent only on the angle of the plane and not the mass of the rolling body. Galileo then argued that free-fall motion behaved in an analogous fashion because it was possible to describe a free-fall motion as an inclined plane motion with an angle of 90°. Using Newton's laws, we can prove Galileo's theory by decomposing the gravitational force, acting on the rolling balls, into two vectors, one perpendicular to the inclined plane and one parallel to it. http://www.physics.smu.edu/~ryszard/1313fa98/1313-Incline_.PDFFollowing his experiments, Galileo formulated the equation for a falling body or an object moving in uniform acceleration: d=1/2gt2.The is some evidence shows that such experiments were performed by various scientists and experimenters preceding Galileo's work about falling bodies and by this disproving Aristotle's assertion that heavier bodies fall faster than light ones.As early as 1544, the historian Benedetto Varchi referred to actual tests which refuted Aristotle's assertion.In 1576, Giuseppe Moletti, Galileo's predecessor in the chair of mathematics at the university of Padua, reported that bodies of the same material but different weight, as well as bodies of the same volume but different material, dropped from a height arrived at the Earth at the same time.In 1597 Jacopo Mazzoni, of the University of Pisa, reported that he had observed objects falling at the same speed regardless of weight and pieces of an object descending at the same rate as the whole.The most notorious of those is Simon Stevin that in 1586 (3 years before Galileo) reported that different weights fell a given distance in the same time. His experiments, with the help of his friend Jan Cornetts de Groot, were conducted using two lead balls, one being ten times the weight of the other, which he dropped thirty feet from the church tower in Delft. from the sound of the impacts they concluded that the spheres fell with the same speed, not as stated by Aristotle. Stevin is regarded by many as the first one to perform falling bodies experiments.Experiments to demonstrate the phenomenon.1. Hold on the tip of the fingers of different hands a coin and a paper disc about one meter or more above the floor. Drop both of them simultaneously. The coin will reach the floor before the paper disc. From this experiment is possible to conclude mistakenly that heavier objects fall faster.2. Mount the paper disc on the coin and drop them together. Both objects will reach the ground at the same time. The meaning of this experiment is that not the amount of mass causes falling bodies to fall faster or slower but the resistance/friction of air because air resistance is applied here only to the coin and not to the paper disc and by that we can infer that air resistance and not the amount of mass prevented the paper disc from falling faster - the same as the coin.To exclude the possibility that the coin and the disc of paper attract each other you can show that they do not stick together in any position.Experiments are from:Weiss Moshe, Physics by Experimental Demonstrations, vol II, Jerusalem: Rubin Mass, 1968, pp. 208-209

Answer 2

Aristotle was the philosopher who proposed the idea that heavy things fall faster than light things. This concept was later proven false by Galileo through his experiments on falling bodies.