Introduction
The term light waves can be used differently by different people. Physicists tend to casually use 'light waves' to mean exactly the same thing as electromagnetic waves, but most non-physicists do not. So, what is the difference?
Electromagnetic waves (or electromagnetic radiation) are waves made of oscillating magnetic and electric fields, and include radio waves, microwaves, infrared, visible light, ultraviolet, x-rays and gamma rays. Like all waves, they carry energy, and that energy can be very high-intensity (like the electromagnetic waves we receive from the sun). When looking at the visible light spectrum, the blue end of the electromagnetic spectrum is high frequency, high energy and short wavelength. The red end of the electromagnetic spectrum is low frequency, low energy and long wavelength.
Light is just one part of the electromagnetic spectrum, the part that our eyes can see. So when most people talk about light waves, this is what they mean. However, in physics, 'light waves' often refer to any and all waves in the electromagnetic spectrum.
In this lesson you will learn more about light, as well as complete a task about this topic to test your knowledge. Good luck!
Task
To test your knowledge and teach you new things about light, you will be given a simple test of 10 questions.
To answer these questions you will need to watch this video.
Process
1) Is light a particle or a wave?
- particle
- wave
- both
2) What is the principle of how light works called?
- Huygens principle
- Haygens principle
- Youngs principle
3) What happens when a light wave hits a flat object?
- part of it gets blocked
- all of it gets blocked
- it passes through the object
4) What is it called when waves are reshaped by obstacles?
- constructive interference
- diffraction
- destructive interference
5) Who conducted the double slit experiment?
- Thomas Young
- Thomas Huygens
- Christian Huygens
6) What kind of math can be used to calculate the path difference?
- trigonometry
- algebra
- statistics
7) What happens if you double the amplitude of a waves peak?
- it gets two times as bright
- it gets four times as bright
- it gets nine times as bright
8) What color will a light with a higher frequency and a shorter wavelength be?
- blue
- red
- white
9) When will diffraction happen?
- when light passes through a single slit
- when light passes through two slits
- in both cases
10) What do the places where waves interfere destructively become?
- brightest spot
- dimmest spot
- shadows
Evaluation
Congratulations, you have finished your task. Here are the correct answers to the questions, so you can check how many you got right and if you got something wrong, you can go back to the video, rewatch it and see what you missed.
1) Is light a particle or a wave?
- both
2) What is the principle of how light works called?
- Huygens principle
3) What happens when a light wave hits a flat object?
- part of it gets blocked
4) What is it called when waves are reshaped by obstacles?
- diffraction
5) Who conducted the double slit experiment?
- Thomas Young
6) What kind of math can be used to calculate the path difference?
- trigonometry
7) What happens if you double the amplitude of a waves peak?
- it gets four times as bright
8) What color will a light with a higher frequency and a shorter wavelength be?
- blue
9) When will diffraction happen?
- in both cases
10) What do the places where waves interfere destructively become?
- shadows
Conclusion
Now we have come to the end of this lesson, hope you were successful at completing the task, if you have any questions, be sure to ask them or rewatch the video and see what you missed!