What’s the deal?

REFRACTION- CHANGE IN DIRECTION DUE TO CHANGE IN SPEED OF A WAVE

Passing through one medium to another.

Wavelength increases or decreases, but frequency stays the same.

Light travels 300 million m/s, but slows down in solids and liquids.

Sound travels faster in solids and liquids because the particles are closer together allowing for the vibration of the particles to move quicker.

AB

C

Angle A is always larger than angle B and bends towards the normal

Angle B is smaller than angle C because the light speeds up and bends away from the normal

Why does it Bend?

Visible light is composed of a spectrum of colors, which can be separated using a prism.

A prism refracts rays of light and separates the colors because each one has a slightly different wavelength, and is bent at a different angle.

This is how rainbows are formed. Rain drops refract the sunlight.

So what is the deal?

Light bends as it’s refracted by the light(bending away from the normal), causing the image to appear bent.

Your brain assumes light travels in a straight line, so it tracks it back to the point (the virtual image)

http://www.youtube.com/watch?v=fhBZ40jIo4Q

CRITICAL ANGLE

As the angle of incidence increases the angle of refraction increases until it gets to 90 degrees, at this point the angle of incidence is at the critical angle.

TOTAL INTERNAL REFLECTION

If the angle of incidence increases beyond the critical angle waves will bounce of the internal surface and reflect into the block this is known as total internal reflection.

Fiber Optics Periscopes

Diamonds’ sparkle