Unlike a sound waves, light waves do not need a medium to pass ... The partial shadow or penumbra is the lighter outer part of the shadow. Image caption, This is what the Sun looks like during ...

In learning about the parts of a wave, students will learn about wavelength and use their understanding to observe how visible light can be measured. This standard emphasizes student understanding of ...

Refraction close refractionProcess by which a wave changes speed and sometimes direction upon entering a denser or less dense medium, eg a light ray changes direction when refracted by a lens.