1. Light and Sound Waves
Part 1

2. Energy Light and Sound are forms of energy. They travel in waves!
Energy gives us power to move, for electricity, and much more! It is very important to all living things.
In order for students to understand both light and sound, they must understand that light and sound are different forms of energy.
This powerpoint focuses mainly on light and sound, however.

3. Light Light lets you see the world around you!
All things give off their own light!
The length of light waves lets us see color.
The light we can visibly perceive is located on the electromagnetic spectrum under the term “visible light”.
The spectrum also includes radio waves, microwaves, infared, UV, x-rays, and gamma. Each category has different wavelengths, radio waves having the longest wavelength and gamma waves having the shortest. A wavelength is measured by the distance between each “peak” of the waves. Refer to the diagram and notice how the wavelength continually gets shorter as you go down the electromagnetic spectrum. Some wavelengths can be seen or detected by certain animals, but we are limited to the light we perceive in the “visible light” spectrum.
All objects reflect light. The light reflected is the color of the object at that given time. For instance, in the dark, objects give off no light, and therefore no color, so we cannot visibly see them. When objects are illuminated, they give off light.

4. Light Light can go through clear objects, but not opaque ones.
Opaque means that something is not able to be seen through.
Light has the ability to penetrate clear objects, but not opaque ones. Light bounces off opaque objects, leaving in turn an area known as a “shadow”. Shadows are created when light is not able to fully penetrate an object, leaving behind a 2D area where there is little/no light.
Using a prism to demonstrate how light can penetrate objects and make a multitude of colors is a good example of this concept.

5. Sources of Light
When light illuminates objects, you can see them. Objects give off color when they light up.
sunlight
candles
fire
light bulbs
Illumination - to be lit up, hit by light. As explained in previous notes, objects only give off color when they are illuminated by a certain source of light.
Common, everyday sources of light today include light from electrical sources and from daylight.

6. Fun Facts! Light travels from the Sun to the Earth as sunlight.
It bounces off all objects that it hits.
For example, you can use a mirror to change the direction of light!
Light has the ability to travel very great distances, and that is seen through its ability to transverse space and penetrate to the Earth’s surface. This sunlight brings warmth and energy to plants and other animal life on earth, making it a vital “ingredient” in the recipe of life.
When light comes into contact with another object, it is often reflected. This can be demonstrated by shining a beam of light at a mirror. Take note that the beam will change direction based on the position of the mirror.

7. Sound
Sound waves cause vibrations in the air and can even go through water!
Little hairs in your ear pick up movement in order to hear sound.
Sound waves create vibrations through matter to create sound. We perceive sound by receiving and interpreting these vibrations using our ears.

8. Fun Facts about Sound Waves!
Sound is measured by frequencies
Ears vibrate similarly to the source of the vibration
Dogs can hear more sounds than people can!
Sound is measured in frequencies. Different organisms perceive different ranges of frequencies. Parts of the inner ear vibrate in accordance to receiving frequencies from the environment, allowing for the perception of sound itself.
For example, domestic animals often sense earthquakes before we are able to detect it through noise.

9. Animals use sound to find food and to travel.
Some animals use sound to locate their food or to scope out their environments. An example would be the process of echolocation, in which organisms make use of sound by detecting returning sound waves that have bounced off prey or other objects.

10. Vibrations Vibrating objects make sound too!
Vibrations create their own sound waves that we can hear.
Vice versa, vibrating objects also create their own sound. In order to create sound, there must be vibrations. An example would be using a tuning fork. Hitting the tuning fork causes it to vibrate, which in turn creates a nice ringing sound. As the prongs become still again, the sound fades away.

11. Devices
People use different devices to communicate over long distances
Telephones!
Radio!
Cellphone!
Internet!

12. Vocab Energy-usable power
Light-a form of energy that makes it possible to see things
Sound-a type of energy made by vibrations
Opaque-something that is not able to be seen through
Sound waves-waves that are formed when sounds are made; they move through the air and carry sound into your ear
Vibration-a continuous slight shaking movement; a series of small, fast movements from side to side
Frequencies-number of waves that pass a fixed point per unit time
Illuminate-lights up