Library.

“In a vacuum, a metal hammer and a feather dropped from the same height at the same time will land at the same time.”

The evidence shows that a hammer and a feather dropped together in a vacuum will fall with the same acceleration and reach the ground at the same time. This is a standard result of classical physics and has been demonstrated both on the Moon and in vacuum-chamber experiments on Earth. Apparent differences in ordinary air are caused by drag, not by gravity acting differently on heavy and light objects.

“At least one particle can travel faster than the speed of light in a vacuum.”

The claim is not supported by the evidence. The main experimental episode behind it, OPERA's faster-than-light neutrino result, was later explained by measurement errors and superseded by results consistent with the speed of light. The remaining support consists of theoretical speculation about tachyons or misunderstood superluminal effects, not a confirmed observation of any particle traveling faster than light in vacuum.