Reflection and refraction

• What is reflection and refraction

  • When something hits a different medium than it is currently in it reflects and refracts

• An example and Equations

  • 

  • the angle of reflection is the same as the incoming angle

    • ${\theta }_1={\theta }_r$

  • Unlike sound (in air) the speed of light in matter is slower

    • $v=\frac{c}{n}$ , Sn is the coefficient of the medium

  • the equation dictating the path that the light takes is

    • Snell’s Law: $n_1\sin {\theta }_1=n_2\sin {\theta }_2$

  • The critical angle is when there is total internal reflection

    • ${\theta }_c={\sin }^{-1}\left(\frac{n_2}{n_1}\right)$

  • Brewster’s angle

    • $\tan {\theta }_1=\frac{n_2}{n_1}$

• Total internal reflection

  • is as the name suggests when the light beam is trapped in the medium and cannot escape

    • 
    • when the angle of incidence equals the critical angle ${\theta }_c:$
      • $n_1\sin {\theta }_c=n_2\sin 90°$
      • ${\theta }_c={\sin }^{-1}\left(\frac{n_2}{n_1}\right)$

    • When the angle of incidence exceeds ${\theta }_c$ total internal reflection occurs.