Because there is no longer any air, there is no more opposing force – this makes the feather and the bowling ball fall to the ground at exactly the same time (see our video below for a demonstration).

Why do the feather and the ball reach the ground at the same time in the vacuum chamber experiment?

In explaining Einstein's theory, Cox said, "The reason the bowling ball and the feather fall together is because they're not falling. They are standing still. There is no force acting on them at all."

Does a feather and ball dropped together?

If you drop a feather and a bowling ball from the same distance anywhere on Earth, they will fall at different rates. The feather will drift breezily to the ground while the bowling ball plunks downward immediately. But this explanation leaves an important factor out of the equation: air resistance.