Term 2 Light

Although I have learnt the topic on light in P6, many of the things taught are very new. Many interesting facts and concepts.
Light is the form of energy that enters our eyes and enables us to see things. It moves very fast at a speed of 300 000 000 m/s. Light can be obtained from two ways: directly, through the form of luminous objects and indirectly. through the reflection of non-luminous objects. This brings me to an important concept of light, reflection. When a ray of light strikes any surface, it changes its direction of travel. We say that the light ray is reflected. The law is basically Angle of incidence is equals to the Angle of Reflection. Surprisingly, this law applies to every single surface, convex, concave or straight. Even on a rough plane, this law applies when the light is reflected of the small lumps. However, due to the irregularity, the light is sent into different directions, causing it to be diffused or irregular.
Light can also be refracted. This refers to the bending of light as it passes through different mediums. For example, light bends away from the normal when it travels from an optically denser medium to an optically less dense medium. Optical density is a measure of the extent to which a substance transmits visible light. However, there is an exception. When a light ray strikes perpendicularly to the surface of an optical medium, there is no refraction this is because when it travels from air into glass, its angle of incidence is zero, thus its angle of refraction is also zero. Even though light is not bent, its speed still decreases when it enters the optically denser medium, glass.
White light might look colourless but it is actually quite colourful. It consists of the colours of the rainbow, red, orange, yellow, green, blue, indigo, violet also called the spectrum of light. These colours combine together to get white light. Thereforfe, white light can also be split into the colours of the rainbow through refraction. This is usually done through a prism. Sometimes, we can see this in the sky before or after raining. This is because there are still some water droplets in the air which refract the sun's rays.
All in all, lenses was an extremely interesting topic and pretty easy to grasp.