It's not entirely true that objects of different masses fall at the same time.

While the difference in their falling times is *extremely* small in everyday situations, there are subtle factors at play:

* Air Resistance: The main reason objects of different masses *appear* to fall at the same time is because of air resistance. Air resistance is the force that opposes the motion of an object moving through the air. It depends on factors like the object's shape, size, and speed.

* A feather, for example, experiences significant air resistance, slowing its descent. A heavier object, like a bowling ball, experiences less air resistance relative to its mass.

* In a vacuum (no air), objects of different masses *will* fall at the same rate.

* Gravity's Uniformity: The Earth's gravitational pull acts on all objects equally, regardless of their mass. This means that a feather and a bowling ball are pulled toward the Earth with the same force *per unit of mass*.

* This is described by Newton's Law of Universal Gravitation: the force of gravity between two objects is proportional to the product of their masses and inversely proportional to the square of the distance between them.

The Experiment That Proved It

The famous experiment by Galileo Galilei demonstrated this principle. He dropped objects of different masses from the Leaning Tower of Pisa (though this story is debated by historians). While the objects didn't fall at *exactly* the same time due to air resistance, the difference was negligible.

Key Point: In a vacuum, where air resistance is eliminated, objects of different masses will accelerate towards the Earth at the same rate, meaning they will fall at the same time. This is because gravity acts on all objects equally, regardless of their mass.