Light & Optics Real World Connection

Light and Optics: Refraction!

When light passes from one material to another, the path of light must bend to the path of least time, or in other words, fastest route - this is what defines Refraction (bending). 

The Law of Refraction is: Sin0i = nSin0r

What the law of refraction simply mean: Sin(angle of incident) = n(index) * Sin(angle of refraction)

We get the coefficient of n(index) through a separate equation, but it symbolizes that the speed of light will ALWAYS slow down when moving from air through another material.

In the example below we get to see REAL LIFE INVISIBILITY!!

Inside the test tube is oil, and inside the beaker is oil, but the bottom of the test tube is invisible!! This is because light does not need to bend that much or refract due to the similar indexes (alike substances).  Because the beaker of oil has exactly the same index of refraction as the test tube of oil, the light will neither reflect nor refract  between the test tube and beaker. Therefore the bottom of the test tube will appear to be invisible.

Permanent vs. Temporary Magnets

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

Domain of object that is
SOMETIMES magnetic

Why are some materials more magnetic than others?

Different objects have different sets of domains, or group of atoms, that determine whether the object is magnetic all the time, sometimes, or never. If an object is always magnetic it means that its domain is lined up and that the electrons are all moving in a uniform motion. This then causes there to be a magnetic field because we know that moving charges = magnetic field. This uniform magnetic field is the strongest force and causes the object to be magnetic ALWAYS.

Objects like paperclips and paper on the other hand contain different domains. A paperclip is magnetic sometimes because it's domain is composed, but not lined up (in the visual above you can see that the sets of atoms are paired but are not in order). This causes their to magnetic fields rotating in different directions, and minimizes its magnetic force. Paper on the other hand is NEVER magnetic. Its domain is scattered completely and contains no magnetic-domain.