Light and Optical Systems

The Decolonizing Light project explores ways and approaches to decolonize science, such as revitalizing and restoring Indigenous knowledges, and capacity building. 

Offical website of Wilfred Buck, Indigenous star lore expert.

Light is what enables you to see around you. To put it in the words of science, light is made up of waves. And where do these waves come from? These waves travel from light sources, the bounce of different objects and enter our eyes, which then allows us to see things. 

This is a short video displaying examples of natural and artificial light sources. 

Watch this video to find out what light is and how it helps us see. Learn words like energy, emit, light sources and reflection. 

In this video we learn all about Light.  We learn where it comes from and identify a number of sources of light. We also learn how we can change light through reflection, refraction, or by blocking light all together.  It is a great video that introduces the concept of light.

Beyond what we can touch, taste, smell, and hear, we experience the universe through light. But how did we come to discover light, and how did we learn light’s true nature, as the fastest thing in the universe, an electromagnetic spectrum, a wave and particle capable of the most amazing things? 

In order to understand how we study the universe, we need to talk a little bit about light. Light is a form of energy. Its wavelength tells us its energy and color. Spectroscopy allows us to analyze those colors and determine an object’s temperature, density, spin, motion, and chemical composition. 

You actually know more about it than you may think! The electromagnetic (EM) spectrum is just a name that scientists give a bunch of types of radiation when they want to talk about them as a group. Radiation is energy that travels and spreads out as it goes-- visible light that comes from a lamp in your house and radio waves that come from a radio station are two types of electromagnetic radiation. 

In this video Paul Andersen explains how light can be absorbed, reflected, or transmitted as it moves from one medium to another.  The reflection of different wavelengths creates the perceived color of an object.  Absorbed light is converted to energy and transmitted light moves through the material.  

Why does a pencil look bent in water?

In this video Paul Andersen explains how light can be refracted, or bent, as it moves from one medium to another. 

Follow along during an exploration of different materials to determine if they are translucent, transparent or opaque.

What is Light? This video describes the difference between luminous and non-luminous objects.

What is it that helps us see things around us? Your answer might be 'eyes'. And that's probably correct! But then why don't the same eyes help us see those things in the dark? Watch the video to know more! 

How does reflection work? Learn more about how light bounces off a surface, the angle of incidence, the angle of reflection and more.  

***EXCELLENT VIDEO*** How does refraction work? Why does an an object appear to change shape in water?

Follow along with this experiment to see refraction in action.

Have you ever wondered why the far away objects appear closer when viewed through binoculars? What are the two transparent materials in front of the binoculars that make those objects appear nearer? Watch this video to know more! 

How light can be controlled through lenses, including eyeglasses, telescopes, magnifying glass, binoculars and cameras. 

The microscope is an optical device that is used to see very small objects ( Unicellular organisms), While telescopes is an optical instrument that is used to see very large objects in space. So, let's get started. 

A magnifying glass consits of a convex lens. This lens collects the light rays, that are reflected form the object. When it enters the lens, they become refracted and change their direction. Therefore, they enter the eye in a larger angle which makes the object appear larger. 

You may have to wear glasses. How do they work? When you are farsighted ( hyperopia) objects far away are clear but object close appear blurry. This type of problem can be fixed with a convex lens. A concave lens is used to fix the opposite problem created when you are nearsighted. 

Concave and Convex Mirrors are Spherical Mirrors. These Curved Mirrors are discussed in the video. Difference between Concave and Convex Mirrors is discussed and compared with a Plane Mirror. Uses of Concave and Convex Mirrors are shown. Which type of mirrors are you using in your everyday life? 

***WATCH the first 9 minutes***

This video answers the questions:

How does light reflect off mirrors?

How does light reflect off concave and convex mirrors?

What is the difference between a concave and convex mirror?

What are the reflection rules for concave and convex mirrors?

What are the properties of light?

How is light reflected off concave mirrors?

How is light reflected off convex mirrors?

Phil explains how telescopes work and offers up some astronomical shopping advice.

***WATCH first 6 minutes and 30 seconds.

Explore how to use a light microscope with the Amoeba Sisters! Includes microscope parts, how to use, and some helpful tips! Additionally, this video  introduces a few types of light microscopes as well as electron microscopes. 

Use this presentation to help you review for the Unit Exam.