The light travels at a speed of 3×10⁸m/s. The light from the sun’s surface takes 8 minutes 17 seconds to reach the earth surface. As human beings, we can’t travel at the speed of light, because only no mass particles like photons can travel at light speed. We can’t accelerate any object to travel at light speed, because it takes infinite energy to accelerate the objects. No matter is required to carry a light hence it can travel in space where no air is present. Unlike sound energy, it can travel only through objects like solid, liquid. So only sound can’t be heard in space.