Through which of the following will a light wave travel the fastest?

A.

glass wall

B.

water

C.

outer space

D.

air

It would be D. air because The fastest thing in the whole universe is the speed of light in a vacuum (like outer space!), clocking in at a great 2.99 x 10 8 m/s. Light travels in waves, and we call thistraveling propagation. Propagation of waves has both a speed and a direction, called the velocity.