Why Can’t an Object Reach the Speed of Light?

According to Einstein’s special relativity, a massive object cannot reach the speed of light (c).

As its velocity approaches (c), its relativistic energy increases enormously:

E = γmc², where γ = 1/√(1 − v²/c²)

When (v tends to c), γ → ∞, so an infinite amount of energy would be required to reach (c).

Light can travel at (c) because photons have zero rest mass.

Key idea: A massive object can approach the speed of light, but can never reach it.