can a sphere has a critial angle

[no idea]

can a sphere has a critial angle

[chroot]

I'm afraid you'll have to be a little more specific.

- Warren

[no idea]

i mean why the water drop can total internal reflect and we can see a rainbow.I THINK CIRLCE DOES NOT HAS TOTAL REFLECT

[Moe]

The light is refracted twice. Once when it enters the drop of water, and a second time when it exits. The angle of refraction depends on the wavelenght of the light. So red will be refracted at a different angle than blue. The whole thing works like a prism, and you get your rainbow. Is that what you wanted to know?