Property 4: Refraction
Snell’s Law: n1 sin(?1) = n2 sin(?2)
If n1 sin(?1) / n2 > 1 THEN there is NO value of ?2 that can satisfy Snell’s law (unless you count imaginary angles!).
The math is trying to tell us that there is NO transmitted ray. This is called
TOTAL INTERNAL REFLECTION.