Unit 10: Refraction.

   Today was just learn, learn, learn. First we learned about flat mirrors, we learned there were things called real images and virtual images. A real image is when the light converges at one point, therefore it can be focused. A virtual image is when there is no converging, like when you look at your self in a mirror. There are also upright images and inverted images, these are somewhat self explanatory, upright is when it looks the same and inverted is when it is upside down.
  Next we learned about what happens when we have curved mirrors, well the light will bend. We learned that the index of refraction is equal to the speed of light in a vacuum (3x10^8 m/s) divided my the speed of light in the medium. Oh by the way, refraction is the change of direction of a wave due to changes in wave speed because of changes to the medium. We also had to know some indexes of refractions, such as vacuum=1, air=1, water=1.33, glass=1.5 and diamonds=2.42. We also learned that the larger the index of refraction the slower the speed of light in that medium. If the light is going from a fast medium to a slow one the ray will move towards the normal, if it going from slow to fast it will move away from the normal. (The normal is a perpendicular line to the surface). Oh I almost forgot, there are these things called converging lenses and diverging lenses. A converging lens makes the light go together, while a diverging one makes it spread out. Basically this is what we learned today...OH WAIT! Most important thing, called Snell's Law. The index of refraction of the first ray times the sin of the first angle will equal index of refraction of second ray time sin of second angle.

This is when Mr. Blake was playing with a curved mirror and lasers.