# Physics - Light & refraction

posted by on .

I go this question in a test just today, but I know I got it wrong because I didn't study this section.

It was something along the lines of this I'm pretty sure.

"Explain why there is no critical angle when light travels from air to water"

Can someone explain this to me?

• Physics - Light & refraction - ,

The critical angle is an angle in which light going from a optically dense substance to a lessor dense substance will undergo total internal reflection. If light is going from air, the optically less dense (lower index of refraction), there will be no total reflection at the boundry.

• Physics - Light & refraction - ,

Basically what bobpursely is saying is that you are going from a high index of refraction to a low index of refraction, so you'll have total reflection inside the object. if you are going from air to water, then you are going from a low index to high index, so you won't have total reflection inside the object. bobpursely, correct me if i'm wrong, but i think that's what you're saying.