Presentation is loading. Please wait.

Presentation is loading. Please wait.

Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum.

Similar presentations


Presentation on theme: "Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum."— Presentation transcript:

1 Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum

2 Electromagnetic Light Show Copyright © Houghton Mifflin Harcourt Publishing Company What is the nature of light? Light waves are different from other kinds of waves. When an electrically charged particle vibrates, its fields also vibrate, producing an electromagnetic (EM) wave. Light waves are vibrating electric and magnetic fields that transfer energy through space. Unit 3 Lesson 1 The Electromagnetic Spectrum

3 What is the nature of light? EM waves travel perpendicular to both electric and magnetic fields. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum

4 What is the nature of light? Radiation is energy that has been transmitted by waves or particles. This transfer of energy is called EM radiation. All EM waves move at the same speed in a vacuum: the speed of light. EM waves can travel through many materials. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum

5 What determines the color of light? Different wavelengths of light are perceived by our eyes as different colors. White light is what we perceive when we see all the wavelengths of light at once, in equal proportions. Our eyes only register three colors of light: red, green, and blue. All other colors we see are a mixture of these three colors. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum

6 Invisible Colors Copyright © Houghton Mifflin Harcourt Publishing Company What are the parts of the EM spectrum? The range of frequencies that EM waves can have is called the electromagnetic (EM) spectrum. Unit 3 Lesson 1 The Electromagnetic Spectrum

7 What are the parts of the EM spectrum? Infrared light has slightly longer wavelengths than red light has. Ultraviolet (UV) light has slightly shorter wavelengths than violet light has. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum

8 Star Light, Star Bright Copyright © Houghton Mifflin Harcourt Publishing Company How much of the sun’s energy reaches us? Most of the sun’s energy is in the narrow visible light range, but the sun gives off some radiation in every part of the spectrum. Unit 3 Lesson 1 The Electromagnetic Spectrum

9 How much of the sun’s energy reaches us? Not all wavelengths of light penetrate the atmosphere equally. Radio waves penetrate the atmosphere easily. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum

10 How much of the sun’s energy reaches us? Some EM radiation can be dangerous to humans, so we take extra steps to protect ourselves. UV light can be harmful. It can penetrate clouds. In space, the dangers from EM radiation are very high because there is no atmosphere to filter the radiation. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum

11 Frequency Asked Questions Copyright © Houghton Mifflin Harcourt Publishing Company How much energy does EM radiation have? Different frequencies of EM waves carry different amounts of energy. High-frequency EM waves have more energy than low-frequency EM waves have. Unit 3 Lesson 1 The Electromagnetic Spectrum

12 How much energy does EM radiation have? Because low-frequency waves, such as radio waves, carry less energy, they are safer. Walkie- talkies and baby monitors use radio waves. High-frequency waves, such as UV light, carry more energy and can be harmful. UV light causes sunburns, and X-rays require precautions. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum

13 Fire in the Sky Copyright © Houghton Mifflin Harcourt Publishing Company The stream of electrically charged particles from the sun is called the solar wind. When solar wind encounters Earth’s magnetic field, the particles are accelerated. When the accelerated particles collide with the atmosphere, they give off EM radiation in the form of light.

14 Unit 3 Lesson 1 The Electromagnetic Spectrum Fire in the Sky Copyright © Houghton Mifflin Harcourt Publishing Company Near the poles, the accelerated particles form an aurora that can light up the sky. The aurora at the North Pole is called the aurora borealis. At the South Pole, it is called the aurora australis. The color of the aurora depends on the type of atoms in the atmosphere that react with the solar wind.


Download ppt "Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 The Electromagnetic Spectrum."

Similar presentations


Ads by Google