You will now create an outline for your final assignment.
In this lesson you learned about light waves: the electromagnetic spectrum where light waves range from very small (gamma) to very large (radio), visible light that we can see with the light detectors we call eyes, and how light waves interact with matter. You took notes on almost every page of the lesson, and now it's time to use them, as well as any other evidence presented, to compose your own multimedia project, or write a final essay, in which you describe and summarize all of that light-wave knowledge you've collected..
As you compose your project, try to think of ways to connect, either graphically or in writing, the ways in which different types of light waves are used and how they interact with matter. One idea is to create a story or comic strip that follows the made-up adventures of a light wave as it travels from its source, interacts with different types of matter and encounters other types of light waves.
If you create a multimedia project that requires a social-media, video or audio platform that is not directly offered by this lesson, you will need to post it to a file-sharing site (Dropbox, Google Drive and Microsoft Teams are examples) and then upload the link to the Write It plug-in. Here are some ideas for what you might want to do:
Use Organize It to outline your ideas. You can review your notes in “My Work” as well as any of the following videos and glossary terms.
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
Electromagnetic waves transfer energy in a transverse fashion, so just like a mechanical transverse wave, electromagnetic waves can have long or short wavelengths and high or low frequencies, depending on how much energy the wave is carrying.
And all of this light energy, called radiation, has been arranged by scientists into a nice little chart called the electromagnetic spectrum.
Arranged by frequency, the radiation ranges from low energy radio waves, to microwaves, to infrared radiation, to visible light, followed by ultraviolet light, x-rays, and finally to gamma rays, which have the highest frequency, and therefore the highest energy.
The electromagnetic spectrum is the entire range of wave frequencies and lengths that light energy can travel, and we humans can only see this tiny part with our eyes. But we can feel this part (infrared/heat, ultraviolet/sunburn) with our skin, and have created instruments to hear this part (radio) with our ears, and cook our food using this part (microwave). We use x-ray radiation to see inside our bodies, and create gamma radiation in our nuclear power. \
All in all, our lives are connected to the electromagnetic spectrum--whether we like it or not.
Electromagnetic Wave (or Light Wave)
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
Consider a rainbow. Although it may seem magical, what you are really seeing is an incredibly accurate visual representation of the electromagnetic spectrum. Each of those colors your eyes detect is an example of different wavelengths and different frequencies of energy being transferred from the sun, through the vacuum of space, refracting through the particles in the atmosphere, entering your eye and being processed by your brain.. And incredibly, the light we see is only a tiny fraction of the electromagnetic energy traveling all around us and even through us.
Humans can detect wavelengths between 700 nm (red) and 400 nm (violet) with our naked eyes. These wavelengths are what we call visible light. All other wavelengths of electromagnetic radiation are invisible to us--we can't see it, even though it is there.
So although a rainbow may seem magical, the two little energy detectors in your head (eyes) deserve some credit too.
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
Take a look. What you are seeing is not exactly that apple. What you are seeing is light energy interacting with the apple, being detected by your eye and interpreted by your brain. Different objects have different properties that absorb, reflect and even allow light energy to pass through.
And not all wavelengths of energy do the same thing in every object or medium.
This red apple absorbs all visible wavelengths of light energy except the red. The result? Red wavelengths are reflected to our eye and the apple looks red to us.
A green apple looks green because it reflects the green wavelengths.
Some matter allows light energy to go through it (a glass of water) and as it does, the energy interacts with the matter and its speed and trajectory change depending on the angle it hits. This is called refraction. The result? That cool broken-straw illusion, why you are no good at spearfishing, and best of all, the lens on your eyeball that allows you to see.