The Law of Refraction

This week, our job was to create an original image depicting what we have learned in class about Light Optics. Since I was interested in air to water refraction, I used a figurine to partially submerge in a glass of water. As you can see, the portion of the cat that is underwater looks larger than normal. It also seems displaced. How is this possible? Well, in this picture, light is moving from air to glass to water to glass and then back to air. Because air, glass, and water are different substances, the incident of refraction or the speed in which light moves through these different materials are different as well. For air, the incident of refraction (n) is 1 while n for glass is 1.52 and  n for water is 1.33 so when light passes from the air to glass to water it travels at different speeds. This is why the cat appears to look larger and displaced underwater. In order to determine how much the light refracted (the angle of refraction) we use the Snell's Law which states:

This image shows the angle of refraction from air to water

This is another image explaining refraction of light as it moves from air to water

                                              This image shows refraction of light to glass

Standard 6.3--Permanent and Temporary Magnets

Standard 6.3: Explain how objects like the earth and metals can be permanent or temporary magnets.

                                                                   MARS INTERIOR                                                           

                                                                  (solid)

One of the key concepts that we learned during this unit is that moving charges generate magnetic fields. We know that Earth generates a magnetic field because the outer core of Earth is molten, meaning that there are very hot metals such as iron and nickel moving around the outer core in liquid form . These metals have charges and these moving charges are what makes Earth one large magnet. In addition , Earth's rotation around the sun helps the current of the moving charges in the outer core to generate Earth's magnetic field that protects us from foreign space objects penetrating our atmosphere. Other planets aren't so lucky. Mars, for example, does not have a molten outer core and therefore no moving charges so it does not have a magnetic field. 


         EARTH INTERIOR

A magnetic domain is a region in which the magnetic fields of atoms are aligned (pointing in the same direction) and grouped together. Earth is a PERMANENT MAGNET, meaning that the domains are always aligned. As long as Earth has moving charges, it will always be magnetic. Paper clips are TEMPORARY MAGNETS,  meaning that they can be magnetic at times and not at others. When a paper clip comes in close contact with a permanent magnet, the domains of the paper clip line up and it becomes temporarily magnetic. When the paper clip is removed from the permanent magnet's magnetic field, the domains become askew and the paper clip is no longer magnetic. Items such as paper are never magnetic because their domains never align even when they come in contact with another magnet.