How do you LIGHT Up your world ? Part I-Virginia SOL 5.3

1. How do you LIGHT Up your world ?Part I-Virginia SOL 5.3 ExaminingLight2004 with Hands-On Activities Compiled by, Marjorie Anne Wallace Elementary Science Resource Teacher 2002-2005 / NNPS & NSF Coop Agreement

2. Welcome to a power point presentation on LIGHT. • We will investigate the following: • 1. What is light? • 2.What are some sources of light around us? • 3. What are opaque, transparent, & translucent objects? • 4. What is a light wave? • 5.Are there any hands-on/minds-on activities I can do to learn more?

3. LIGHT Standards • Virginia Standards of Learning 5.3 a-e: • The student will investigate and understand basic characteristics of visible light and how it behaves. (*Key concepts, 5.3a-e, are listed in your teacher curriculum guide) • National Science Education Standards • Physical Science: Content Standard B • As a result of the activities in grades K-4, all students should develop an understanding of light, heat, electricity, and magnetism.

4. Light • Our primary source of light is the sun. • Light travels in straight lines at a speed of 186,000miles per second. • *Light waves travel fasterthan sound waves! • Light energy from the sun travels through space , reaches earth, and some of it turns to heat energy and warms the earth’s air. • Light from the sun also travels to the cells of green plants (producers) and is stored as energy. • When light reaches an object, it is absorbed, reflected, or passes through it.

5. Sensing Light • Humans have two light detectors. • Do you know what they are called?

6. How many sources of Light can you list and explain? • SUN=warms air, water, and land. • Fire=provides heat, light, and cooking fuel. • Lightning= • Firefly= • Flashlight= • Light bulb= • Laser beams= • Optical telephone fibers= *Trafficlights= *AIMS: Primarily Physics: Light Sources Activity

7. Can you answer these 5th grade 2003-SOL queries? • 1. A person will see a flash of lightning before they hear the thunder that goes with it because? *SOL 2003 querie #14/CORE 1 Exam (5.3e) • 2.Can you draw a long wavelength and a short wavelength next to it? *SOL2003 queire #9/CORE 1 Exam(5.3a) • 3.What scientific tools are used to study light? *SOL2003/CORE 2 Exam(5.3b) • 4. Can you contrast objects that are transparent, translucent, and opaque? *SOL2003/CORE 2 Exam(5.3d)

8. “Just Passing Through:” What happens when light strikes glass? Or waxed paper? Or a book? • If light travels through an object it is =transparent • If light is blocked by an object and a dark shadow is cast it is= opaque. • If some light passes through but not all and a light shadow is present it is=translucent. *AIMS:Primarily Physics: Just Passing Through Activity

9. What happens when light hits these objects? • Glass of water • School bus window • Notebook paper • Waxed paper • Plastic wrap • Tissue paper • Cardboard • Textbook • Hand lens…

10. Transparent objects: • The windows on a school bus, • A clear empty glass, • A clear window pane, • The lenses of some eyeglasses, • Clear plastic wrap, • The glass on a clock, • A hand lens, • Colored glass… • ALL of these are transparent. Yes, we can see through them because light passes through each of them.

11. Translucent objects • Thin tissue paper, • Waxed paper, • Tinted car windows, • Frosted glass, • Clouds, • All of these materials are translucent and allow some light to pass but the light cannot be clearly seen through.

12. Opaque objects: • Heavy weight paper, • Cardboard • Aluminum foil, • Mirror, bricks, buildings, • Your eyelids and hands, • Solid wood door, • All of these objects are opaque because light cannot pass through them at all. • They cast a dark shadow.

13. Let’s find out how light travels? • Simple Activity: 1 working flashlight • 1. Shine a flashlight on a wall. • 2. Does light from the flashlight reach the wall? How do you know? • 3. What evidence do you have showing light travels in a straight line? • 4.Record answers in your science journal • 5.Move closer with the flashlight. • Any changes? *Write a story about light.

14. Understanding Waves • The traditional hands-on/minds-on activities: • 1. “slinky lab: A Wave Simulation!” as well as • 2. “Waves in Action” (visual learner), and • 3. “Act It Out!Waves Tall and Small” (kinesthetic learner) activities will help children understand waves better. *Science Museum of Virginia: Light & Sound www.smv.mus.va.us • *Unitedstreaming movies:”Out of Darkness: An Introduction to Light: Facts About Light.”(auditory & visual learners). *Check with your building technology dept for your schools password.

15. What is light really?Electromagneticradiationwaves • Light waves are three dimensional. • Light waves vibrate in all planes around a center line. • The waves have high points called “crests.” • Waves also have low points called “troughs.” • *The distance from one crest to the next crest is called a “wavelength.” • *The number of waves passing a given point in one second is called the “frequency.” wavelength *A Science Museum of VA: Light Science Activity

16. Notice the wavelength is long(Radio waves) and gets shorter (Gamma Rays)

17. *Science Museum of VA A Wave Simulation Activity/Demo OR GEMS:”Invisible Universe” Comparing Wave Makers A wave simulation: • Materials: 1 long spring or rope • 1. Teacher and a strong student will hold either end of the coiled spring tightly braced against their body. • 2.Teacher will walk away from the student until the spring is loosely stretched between them. • 3.Gently snap the spring up and down once to send a wave of energy to the student’s hand. It will bounce back, or reflect, from the stationary end. • 4. Point out each wave has a crest (high half) and a trough (low half). Check for understanding

18. *Electromagnetic Radiation • Electromagnetic radiation can be described as a stream of photons. Each photon traveling in a wave-like pattern, moving at the speed of light and carrying some amount of energy. • The only difference amongst radio waves, visible light, and gamma-rays is the amount of energy of the photons. Radio waves have photons with low energies. Microwaves have a little more energy than radio waves. Gamma-rays and cosmic rays have highest energy waves and are the deadliest. *Page info from NSTA Conference 2004

19. Don’t’ forget…longest waves (radio) ..to shortest waves (cosmic) *Page info from NSAT Conference 2004

20. 1.Acting It Out! Waves Tall & Small Activity(The electromagnetic family) +2.Scaling the Spectrum Activity • Materials: • 1. 9 volunteers • 2. paper & pencil. • These 2 activities help to explain the electromagnetic spectrum and dispel some of the common misconceptions. *Science Museum of Virginia Acting It Out! Activity + Scaling the Spectrum Activity OR GEMS: Invisible Universe Comparing Wave Makers I.

21. Properties of Light summary • Light travels in straight lines • Light travels much faster than sound • We see things because they reflect light into our eyes • Shadows are formed when light is blocked by an object

22. Part 2 - Reflection • Reflection from a mirror: Normal Reflected ray Incident ray Angle of reflection Angle of incidence Mirror

23. The Law of Reflection Angle of incidence = Angle of reflection In other words, light gets reflected from a surface at ____ _____ angle it hits it. The same !!!

24. Clear vs. Diffuse Reflection • Smooth, shiny surfaces have a clear reflection: Rough, dull surfaces have a diffuse reflection. Diffuse reflection is when light is scattered in different directions

25. Using mirrors • Two examples: 2) A car headlight 1) A periscope

26. Refraction Refraction is when waves ____ __ or slow down due to travelling in a different _________. A medium is something that waves will travel through. When a pen is placed in water it looks like this: In this case the light rays are slowed down by the water and are _____, causing the pen to look odd. The two mediums in this example are ______ and _______. Words – speed up, water, air, bent