Do you remember learning about Galileo, the father of physics, who was born in Pisa, Italy, in 1564 and discovered the Rings of Saturn, among other things? Galileo lived until 1642 and in the 15th century discovered that any object falling to earth, falls at the same rate.

He mentioned that a cannonball and a feather, if dropped from the same height, will touch the ground at the same time provided there is no air resistance. I always found this hard to believe.

Even Galileo had difficulty explaining it for quite a long time. Four centuries later, with the current technology, it has been experimentally demonstrated. Open the attachment, watch full screen to view / listen to the verification experiment. 

Galileo Galilei
(15 February 1564 – 8 January 1642) was an Italian polymath. Galileo is a central figure in the transition from natural philosophy to modern science and in the transformation of the scientific Renaissance into a scientific revolution.

  <-- click here for the experiment