This photo shows the concept of reflection. Reflection is the change in direction of a wavefront at the interface between two different media so that the wavefront returns into the medium from which it originated. The law of reflection says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected. This is specular reflection as it is a visual caused by the light of the sun. The mountains, greenery, & clouds are all reflected because the smoothness of the lake gives a fine image reflecting back.

This photo is a clear example of fiber optics and the attenuation of light. In optical fibers, attenuation is the rate at which the signal light decreases in intensity by absorption/scattering of photons. Fiber optics are long, thin strands of very pure glass or plastic about the diameter of a human hair. They are arranged in bundles called optical cables and used to transmit light signals over long distances. This cable in particular is a larger classroom version of one of the small fibers just to display the internal reflection of the light going through. Because the cable is much larger than the narrow industrial fibers, the fact that we see light coming out shows that the angle of the reflection of the light in the pipe is too great allowing the photons to scatter. Due to the fact that glass fiber has a low attenuation, it is used for long-distance fiber optic cables, while plastic fiber has a higher attenuation and, thus, a shorter range. A lot of internet connections are fiber optic; data is transferred by light signals through the cables. This is a photo of plastic fiber. You can clearly see the decrease in the intensity of the white flashlight as it turns yellow throughout the swirl, but you can also see that it has travelled through the fibers as it shines out the other side.

This photo displays the focal point of a converging lens in the shadow of a projector. In this type of lens the glass (or plastic) surfaces bulge outwards in the center giving a lentil-like shape. A converging lens has its name because it makes parallel light rays passing through it bend inward and meet (converge) at a spot just beyond the lens known as the focal point. The focal point is on the opposite side of the lens to that from which the light rays originate. The distance from the center of the lens to the focal point is the focal length of the lens. The light coming from the projector shines through the lens which was held up in front of it. The lens is positioned so that the focal point is shown in the center of the shadow. If you were to reposition the lens, the light that is the focal point is actually the part of the projected picture covered by the lens upside down due to the light as it continues to pass through the lens after the focal point.