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Light Experiments


Index Adding Colors

4

Bending Light

6

Making a Color Viewing Box

7

Making a Rainbow

8

Seeing in Three Dimensions

9

What Makes a Sunset

12

Supply List

13

References

14

Children’s Literature

15

Notes

16

Games With Four Mirrors

6

Making a Kaliedoscope

7

Making a Periscope

8

Mirrors

9

Slinky Waves

12


Index Supply List

13

References

14

Children’s Literature

15

Notes

16


Adding Colors

Index

Red, blue, and green are the primary colors of light. All of the colors of the rainbow can be made by combining the primary colors. Let’s see what happens when these beams are combined.

Materials

Three flashlights Red, blue, and green cellophane Tape Scissors

What To Do

Cut the cellophane so that it covers the flashlight lens. Tape the cellophane to the flashlight. Aim the flashlights at a nearby white wall. Overlap the red and blue beams on the wall so that the red beam overlaps half of the blue beam. Aim the green beam so that all three colors hit the same spot on the wall.

Questions

1. What color is produced when the blue and red beams are overlapped? 2. What color is produced when the green overlaps with the red beam and when the green overlaps with the blue beam? 3. What color is produced when all three beams are combined in the same spot?

Summary

When the beams of light are projected onto each other the colors are added together. When red light is mixed with green light, yellow light is produced. When red light is mixed with blue, magenta is produced. When blue light is mixed with green light, cyan is produced. The combination of all three should produce white. Cyan, magenta, and yellow are secondary colors of light. Note to Volunteers: The primary colors of paints and pigments are different than that of light. Color in painting is not made by splitting white light. The primary colors of paint are magenta, cyan, and yellow (red, blue, and yellow). When they are mixed together you get black, not white like light.

Source

“Awesome Experiments in Light and Sound.” M. DiSpezio, published by Sterling, 1999, p. 20-21. © S. Olesik, WOW Project, Ohio State University, 2000.


Bending Light

Index

Light bends or refracts when it moves from one transparent material to the next. This is what causes prisms to separate light; the different colors of light are bent different amounts as they move into the prism.

Materials

Pencil Clear tall drinking glass Water

What To Do

Fill a drinking glass halfway with water. Place a pencil in the glass. Describe the appearance of the pencil. Continue to fill the glass with water, and compare the appearance of the pencil now.

Questions

1. What did you observe when the pencil was placed in the glass? 2. What happened when you continued to fill the glass?

Source

“Awesome Experiments in Light and Sound.” M. DiSpezio, published by Sterling, 1999, p. 20-21. © S. Olesik, WOW Project, Ohio State University, 2000.


Making A Color Viewing Box

Index

What causes the color of an object? When light hits an object, the object absorbs or subtracts certain colors and reflects the remaining colors. The reflected colors of light give the object its color.

Materials

3 shoeboxes with a large rectangular hole cut into the lid Bright flashlight Red, green, and blue cellophane White index cards Red, blue, and green crayons Scissors Tape

What To Do

Make three boxes with holes cut in each as described. One the index cards make three wide bands of color using the crayons. Each card, for each box, should have the red, blue and green bands arranged in the same order. Tape a card inside each box so that it will be directly below the hole in the lid. Place the green cellophane in the lid of one box and secure it with tape. Do the same with the red and blue cellophane on the remaining two boxes. Shine a flashlight through the colored cellophane lid of each box. Record changes in color of the three bands of color on the white cards when looking into the box with the green, red, and blue cellophane.

Question

1. If a tomato were placed in each of the boxes, what color would you predict the tomato would have? Why? Try it. Explain the differences in color that you observe.

Summary

The cellophane filters only let light of the same color pass through and stop other colors from getting through. For example, a red filter only lets red light through and stops all other colors. In the box containing the green cellophane, the green appears greener, and the red and the blue appear black because only green light is allowed through the filter. In the box containing the red cellophane, the green and the blue bands appear dark.The white card appears red since white reflects all colors and only red is allowed through the filter. This makes the red band difficult to see, since it blends in with the background.

Source

“How Science Works.” Judith Hann, Dorling Kindersley Limited, 1991, London, p. 96. “101 Great Science Experiments: A Step-By-Step Guide.” Neil Ardley, Dorling Kindesley, 1993, London, p. 53. “Over the Rainbow: The Science of Color and Light.” Barbara Taylor, Random House, 1991, New York, p. 30. © S. Olesik, WOW Project, Ohio State University, 2000.


Making A Rainbow

Index

When a beam of white light shines into water it bends. Each color in the white light is bent at a slightly different angle, which causes the colors to be spatially separated. Shining light through a prism has the same effect, because light bends as it travels through different transparent materials.

Materials

Prisms: quartz, acrylic Light ray box Transmission diffraction grating slides Spectroscope

What To Do

Position the prisms in front of the light ray box so that the light will shine through them. Adjust the position of the prisms, turning them slowly, moving them closer to or further from the light source, until a rainbow is visible in the light shining through the prism. Hold the white card near the prisms. The rainbow will be seen more easily on the white background. Another way to make a rainbow from white light is to use a diffraction grating to separate the colors. Hold the diffraction gratings up to your eye and look out the window or at a white light. The diffraction grating works a little differently than the prism, but the effect should be the same. Light shining through the diffraction grating will be separated into its color components. Compare the colors seen when using the diffraction grating to separate sunlight and the light from a computer screen. Spectroscopes are simple instruments that separate light into its color components. They can provide more information about the light than the prisms and diffraction gratings can because they separate the colors into distinct bands and arrange them according to the wavelength of each color of light. The spectroscopes are triangular in shape. The narrow end is the eyepiece to look through. Point the wide end of the spectroscope toward the light source to be separated into components. For example, point the spectroscope out the window. When looking into the spectroscope, on the right side at the back of the display there is a continuum displayed with numbers appearing below the continuum. Colored bands will appear vertically along the continuum to show what colors were combined in the light source. The numbers below the continuum are the wavelength of the observed light. Try pointing the spectroscope at a computer monitor screen. There red, blue, and green light will be observed. Dots of those three colors are used to make up all the colors on the computer screen. Try pointing the spectroscope at a fluorescent light. You will see the white light it produces does not have the same components as “natural light.”

Questions 1. Can you see all six colors of the rainbow on the white card (Red, Orange, Yellow, Green, Blue

and Violet)? 2. What happens to the separated colors if the white card is moved further away from the prism?

Source

“Science Workshop, Light Color and Lenses.” Pam Robson, Gloucester Press, 1993, New York, p. 22-23. “101 Great Science Experiments: A Step-By-Step Guide.” Neil Ardley, Dorling Kindesley, 1993, London, p. 49. “Science for Fun: Light and Color,” Gary Gibson, Copper Beach Books, Brookfield, p. 18-19. © S. Olesik, WOW Project, Ohio State University, 2000.


Seeing in Three Dimensions

Index

Most animals have two eyes. Each eye provides a different view of the world, but the brain automatically combines them when both eyes are open. By combining the images viewed with both eyes the brain creates a three dimensional view.

Materials

Cardstock Red and green cellophane Tape Scissors Three-dimensional red-green picture

What To Do

Make a pair of glasses from card stock. Cut out holes for the eyepieces. Tape red cellophane over one hole and green over the other. Look at the 3-D picture through the glasses. View various objects through these special boxes.

Questions

1. Does everything look different? 2. Did the 3-D picture really look three-dimensional?

Summary

Color filters only allow light of the same color to pass through them, so the red filter only allows red light to pass through it and the green filter only allows green light through. A red object is seen as red because it reflects red light and absorbs all other colors of light. If a red object is viewed through a green filter it will appear dark or black because the red light it reflects is not allowed to pass through the green filter. If a red object is viewed through a red filter it will be difficult to see. Since only red light is allowed through the red filter, the light from the red object will blend in with the other red light the filter allows through. Wearing the 3-D glasses thus results in a situation in which each eye sees a drastically different view of the same object. The eye covered with red cellophane only sees green images and the eye covered with green cellophane only sees red. Three-dimensional pictures are created by printing part of the image in red and superimposing another part of the image in green. Each eye sees a different part of the picture when the 3-D glasses are used because the filters allow different colors to reach each eye. The brain combines the two images, which provides the illusion of depth and allows three-dimensional viewing from a two-dimensional image.

Source

“Science for Fun: Light and Color,” Gary Gibson, Copper Beach Books, Brookfield, 1993, p. 18-19. “Science School,” M. Manning and B. Granstorm, Kingfisher, 1998, p. 34-35. © S. Olesik, WOW Project, Ohio State University, 2000.


What Makes a Sunset?

Index

At sunset the sky often looks orange or red. This experiment will help you understand why these color changes occur.

Materials

Beaker or clear, colorless drinking glass Water Milk or non-dairy powdered coffee creamer Spoon Flashlight

What To Do

Place water in the beaker, and shine the flashlight through the water onto a white wall or white card. Add a little milk to the water. Stir the milky water with the spoon. Only orange and red light rays pass through the milky water and reach the wall because the milky water stops some colors in the light from getting through.

Summary

Billions of tiny particles of dust are in the atmosphere and are too small to see. However when light hits these particles the light bounces off them and is scattered. Blue and violet light scatters the most and orange and red scatter the least. At sunset and sunrise when the sun is low in the sky, the sun’s rays travel through a thicker portion of the atmosphere than in midday, so they run into more particles in the atmosphere and the light is scattered.

Questions

1. What color(s) do you see when the light is placed directly above the glass? 2. What color(s) do you see when the light is shown through the side of the glass?

Source

“The Science Book of Color.” N. Ardley, Harcourt Brace Jovanovich, New York, 1991, p. 10-11. “Over the Rainbow: The Science of Color and Light.” Barbara Taylor, Random House, New York, 1992. © S. Olesik, WOW Project, Ohio State University, 2000.


Supply List Adding Colors

Three flashlights Red, blue, and green cellophane Tape Scissors

Bending Light

Pencil Clear tall drinking glass Water

Making A Color Viewing Box

3 shoeboxes with a large rectangular hole cut into the lid Bright flashlight Red, blue, and green cellophane White index cards Red, blue, and green crayons Scissors Tape

Making a Rainbow

Prisms: quartz, acrylic Light ray box Transmission diffraction grating slides Spectroscope

Seeing in Three Dimensions

Cardstock Red and green cellophane Tape Scissors Three-dimensional red-green picture

What Makes A Sunset?

Beaker or clear, colorless drinking glass Water Milk or non-dairy powdered coffee creamer Spoon Flashlight

Index


References

Index

“Awesome Experiments in Light and Sound.” M. DiSpezio. Sterling: 1999. “Over the Rainbow: The Science of Color and Light.” Barbara Taylor. Random House: New York, 1991. “How Science Works.” Judith Hann, Dorling Kindersley Limited: London, 1991. “Light.” Trevor Day. Steck-Vaughn Company: 1998. “Light and Sound.” Peter Lafferty. Benchmark Books: New York, 1996. “Light Fundamentals.” Robert Wood. McGraw Hill: 1997. “101 Great Science Experiments: A Step-By-Step Guide.” Neil Ardley. Dorling Kindesley: London, 1993. “The Science Book of Color.” Neil Ardley. Harcourt Brace Jovanovich: New York, 1991. “Science For Fun: Light and Color.” Gary Gibson. Copper Beach Books: Brookfield. “Science Workshop: Light, Color, and Lenses.” Pam Robson. Gloucester Press: New York, 1993. “Science School.” M. Manning and B. Granstorm. Kingfisher: 1998. “Teaching Physical Science Through Children’s Literature.” S. Gertz, D.J. Portman, and M. Sarquis. McGraw Hill: 1996.


Children’s Literature

Index

“Day Light, Night Light: Where Light Comes From.” By Franklyn Mansfield Branley. Illustrated by Stacey Schuett. HarperCollins Publishers: New York, 1998. ISBN 0-06-027295-3. “The Magic School Bus Makes a Rainbow: A Book About Color.” By George Bloom and Jocelyn Stevenson. Illustrated by Carolyn Bracken. Book adaptation of an episode of the animated TV series The Magic School Bus, based on the series by Joanna Cole and Bruce Degan. Scholastic, Inc.: New York, 1997. ISBN 0-590-92251-3. “Light.” By Trevor Day, photography by Chris Fairclough. Raintree Steck-Vaughn Company: Austin, 1998. ISBN 0-8172-4943-5. “Me and My Shadow.” By Arthur Dorros. Illustrated by the Author. Scholastic, Inc.: New York, 1990. ISBN 0-590-42772-5. “All the Colors of the Rainbow.” By Alan Fowler. Children’s Press: New York, 1998. ISBN 0-516-20801-2. “Light and Dark.” By Rebecca Hunter. Raintree Steck-Vaughn Publishers: Austin, 2001. ISBN 0-7398-2973-4. “The Rainbow and You.” By E.C. Krupp. Illustrated by Robin Rector Krupp. HarperCollins Publishers: Singapore, 2000. ISBN 0-688-15602-9. “Science Magic With Light.” By Chris Oxlade. Aladdin Books Ltd.: London, 1993. ISBN 0-8120- 1984-9. “The Usborne Internet-Linked Library of Science: Light, Sound & Electricity.” By Kirsteen Rogers, Phillip Clarke, Alastair Smith, and Corinne Henderson. Usborne Publishing Ltd.: London, 2001. “Sound and Light.” By Robert Snedden. Reed Educational & Professional Publishing: Hong Kong, 1999. ISBN 1-57572-870-2. “The Usborne Illustrated Encyclopedia: Science and Technology.” Usborne Publishing: London, 1996. “The Magic School Bus Gets a Bright Idea: A Book About Light.” By Nancy White. Illustrated by John Speirs. Book adaptation of an episode of the animated TV series The Magic School Bus, based on the series by Joanna Cole and Bruce Degan. Scholastic, Inc.: New York, 1999. ISBN 0-439-10274-X.


Notes

Index

There are currently no notes on this unit. If you have suggestions or changes to make on the experiments or units, please email us! Our address is wow@chemistry.ohio-state.edu. Š S. Olesik, WOW Project, Ohio State University, 2000.

Copyright Š 2002-2010 by S.Olesik, Wonders of Our World Project (WOW), the Ohio State University. Permission to make digital or hard copies of portions of this work for personal or classroom use is granted without fee provided that the copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page in print or the first screen in digital media. Abstracting with credit is permitted.


Games with Four Mirrors

Index

This experiment illustrates that light rays move in straight paths even after reflecting off of mirrors.

Materials

4 plane mirrors round stickers

What To Do

Hide and Seek Place four mirrors on a table. Make sure they are arranged in a zig-zag pattern with two approximately parallel to each other. This is an experiment that is done in teams. One person is the hider and the other the seeker. Both must keep their chins somewhere on the edge of the table. The seeker must move each mirror until he/she sees the hider. All four mirrors must be used by the seeker.

Making a Face

Place round stickers on four mirrors so that one mirror has two eyes, one mirror has two ears, one has a nose and one has a mouth. Line up all four mirrors so you can see a whole face in the mirror closest to you. Place the four mirrors in approximately the same position as “Hide and Seek”, above. Keep chin on table. You can change the position of your head or the mirrors.

Questions

1. Can you make silly faces by moving the mirrors differently?

Summary

These experiments illustrate that light moves in precise “rays.”

Source

“Mirrors: Finding Out About the Properties of Light.” Bernie Zubrowski. Morrow Publishers: New York, 1992. © S. Olesik, WOW Project, The Ohio State University, 2000.


Making a Kaleidoscope

Index

Kaleidoscopes use reflections to make beautiful patterns. This experiment involves making a basic kaleidoscope.

Materials

Mylar with reflective coating Cardboard Tracing paper Plastic film Cellophane tape Double-sided cellophane tape Sequins

What To Do

Cut 3 cardboard pieces and 3 pieces of Mylar (2” x 4”). Attach cardboard pieces to Mylar using double-sided tape. Tape these three pieces together with mirror surfaces facing inside. Cut an equilateral triangle piece of cardboard that will fit on the end of the kaleidoscope. Punch a hole in the center of this piece of cardboard before attaching. Make two other equilateral triangles of the same size from the tracing paper and the plastic film. Use cellophane tape to enclose two sides of triangle. Add sequins to the pouch made from the tracing paper and film. Attach this to the end of the Kaleidoscope with tracing paper on the exterior of the scope.

Questions

1. What happens to the pattern when you shake the Kaleidoscope? 2. Can you identify the number of reflections in the kaleidoscope? 3. What causes the multiple reflections in a kaleidoscope?

Source

© S. Olesik, WOW Project, The Ohio State University, 2000.


Making a Periscope

Index

A periscope uses light rays to see above objects.

Materials

Empty foil or plastic wrap container Two acrylic mirrors Ruler Exacto knife

What To Do

Remove the serrated cutting edge from the cardboard foil or plastic wrap container. Tape the container closed. Make a right angle with two sides of the mirrors having lengths of 2”. Place the triangles on the ends of the foil box that is opposite the side of the box from the taped side. Mark where the hypotenuse hits the box. Cut lines into the box where the marks were made. Cut two rectangular holes on the opposite sides of the box. Make these approximately 2” long. Try viewing an object on the table from below the table.

Question

1. Light rays travel in straight lines. Does the periscope use this attribute of light?

Summary

Light reflects at the same angle as it hits the object. The top mirror is placed so that it reflects light down to the other mirror. The bottom mirror is positioned at the same angle as the top mirror and reflects the light beam out of the periscope toward your eye.

Source

“Light.” Trevor Day. Steck-Vaughn Co., 1998. “101 Great Science Experiments” Neil Ardley. Dorling Kindersley, 1993. © S. Olesik, WOW Project, The Ohio State University, 2000.


Mirrors

Index

This is an experiment that will show what reflections are.

Materials

2 plane mirrors

What To Do and Questions

First carefully look at your image in one mirror. Hold up your left hand. Where does it appear? Close or wink your right eye. What do you see in the mirror? Tape two mirrors together. Adjust their position so that they are at a 90° angle relative to each other. Compare the image of a clock face in one mirror and in two mirrors. What difference do you see? In the two-mirror setup there is a double reflection. Can you change the position of the two mirrors so that you see 2, 4 and 6 images of your face when you look into both mirrors?

Extension for Upper Grades

Count the number of images in hinged mirrors at 90°, 60°, 45° and maybe 30°. Use a protractor to help measure angles.

Summary

1. A perfect image is observed for angles where 360 divided by the angle is a whole number. The number of images should be n = 360/angle - 1.

Source

“Experimenting with Light and Illusions.” Alan Ward. Chelsea House Publishers, 1991. © S. Olesik, WOW Project, The Ohio State University, 2000.


Slinky Waves

Index

Both sound and light travel as waves, but sound waves behave in a different way than light waves. Light waves can move either up and down or from side to side. They are called transverse waves and they are the same type of waves as those you see on water. Sound waves, which are longitudinal waves, move back and forth in the direction that the sound is traveling.

Materials

1 long length of thin rope (6-8 ft.) 1 Slinky

What To Do

Tie one end of the length of rope around a post or door handle and hold the other end fairly tight. Shake your hand up and down to make a wave in the rope. This is a transverse wave, like a water wave or a light wave. Shake your hand faster and observe what happens. Stretch out the Slinky on a smooth floor and ask a friend to hold one end. Holding the other end, give it a sharp push toward your friend. Notice the wave of tight coils move along the Slinky. This is a longitudinal wave, like a sound wave.

Questions

1. When shaking the rope, what happens to the number of waves when you shake your hand faster? 2. When shaking the rope, what happens to the number of waves when you shake your hand farther from side to side or up and down? 3. What should you do to make waves in the Slinky of higher frequency and greater amplitude?

Summary

Sound waves move through the air with a squeezing and stretching of molecules of air. When a vibration is produced the air around the source of the vibration is pushed together tightly, then stretched out as the squeezed air molecules push away from each other. This motion continues and the longitudinal sound wave propagates through the air. If you watch the thin cone on the front of a loudspeaker you can see that the sounds make it bounce in and out. When the cone vibrates, it pushes and pulls the air in front of it, first squeezing the air as it pushes it and then stretching the air as the cone pulls back. If you put your hand in front of a working loudspeaker you can feel the air vibrating. When something causes an object to vibrate, the sound waves spread out as ripples of squeezed air in the same way that ripples of water spread out. The number of these highpressure waves per second is the frequency of the sound. The amount that the air is squeezed in each ripple is the amplitude of the sound. The greater the squeeze, the louder the sound.

Source

“SOUND: Science Projects.” Simon de Pinna, Raintree Steck-Vaughn Publishers: Austin, 1998, p. 8-9. © S. Olesik, WOW Project, Ohio State University, 2000.


Supply List Games With Four Mirrors 4 plane mirrors Round stickers

Making a Kaleidoscope

Mylar with reflective coating Cardboard Tracing paper Plastic film Cellophane tape Double-sided cellophane tape Sequins

Making a Periscope

Empty foil or plastic wrap container Two acrylic mirrors Ruler Exacto knife

Mirrors

2 plane mirrors

Slinky Waves

1 long length of thin rope (6-8 feet) 1 Slinky

Index


Reference

Index

“Awesome Experiments in Light and Sound.” Michael DiSpezio. Sterling: 1999. “Experimenting with Light and Illusions.” Alan Ward. Chelsea House Publishers: 1991. “Experiments With Light and Mirrors.” Robert Gardner. Enslow Publishers: Springfield, 1995. “Light.” Trevor Day. Steck-Vaughn Company: 1998. “Light Fundamentals.” Robert Wood. McGraw Hill: 1997. “Mirrors: Finding Out About the Properties of Light.” Bernie Zubrowski. Morrow Publishers: New York, 1992. “101 Great Science Experiments” Neil Ardley. Dorling Kindersley: London, 1993. “Science for Fun: Light and Color.” Gary Gibson. Copper Beech Books: Brookfield, 1993. “Science Workshop: Light, Color and Lenses.” Pam Robson. Gloucester Press: New York, 1993. “SOUND: Science Projects.” Simon de Pinna. Raintree Steck-Vaughn Publishers: Austin, 1998.


Children’s Literature

Index

“Day Light, Night Light: Where Light Comes From.” By Franklyn Mansfield Branley. Illustrated by Stacey Schuett. HarperCollins Publishers: New York, 1998. ISBN 0-06-027295-3. “The Magic School Bus Makes a Rainbow: A Book About Color.” By George Bloom and Jocelyn Stevenson. Illustrated by Carolyn Bracken. Book adaptation of an episode of the animated TV series The Magic School Bus, based on the series by Joanna Cole and Bruce Degan. Scholastic, Inc.: New York, 1997. ISBN 0-590-92251-3. “Light.” By Trevor Day, photography by Chris Fairclough. Raintree Steck-Vaughn Company: Austin, 1998. ISBN 0-8172-4943-5. “Me and My Shadow.” By Arthur Dorros. Illustrated by the Author. Scholastic, Inc.: New York, 1990. ISBN 0-590-42772-5. “All the Colors of the Rainbow.” By Alan Fowler. Children’s Press: New York, 1998. ISBN 0-516-20801-2. “Light and Dark.” By Rebecca Hunter. Raintree Steck-Vaughn Publishers: Austin, 2001. ISBN 0-7398-2973-4. “The Rainbow and You.” By E.C. Krupp. Illustrated by Robin Rector Krupp. HarperCollins Publishers: Singapore, 2000. ISBN 0-688-15602-9. “Science Magic With Light.” By Chris Oxlade. Aladdin Books Ltd.: London, 1993. ISBN 0-8120-1984-9. View summary “The Usborne Internet-Linked Library of Science: Light, Sound & Electricity.” By Kirsteen Rogers, Phillip Clarke, Alastair Smith, and Corinne Henderson. Usborne Publishing Ltd.: London, 2001. “Sound and Light.” By Robert Snedden. Reed Educational & Professional Publishing: Hong Kong, 1999. ISBN 1-57572-870-2. “The Usborne Illustrated Encyclopedia: Science and Technology.” Usborne Publishing: London, 1996. “The Magic School Bus Gets a Bright Idea: A Book About Light.” By Nancy White. Illustrated by John Speirs. Book adaptation of an episode of the animated TV series The Magic School Bus, based on the series by Joanna Cole and Bruce Degan. Scholastic, Inc.: New York, 1999. ISBN 0-439-10274-X.


Notes

Index

There are currently no notes on this unit. If you have suggestions or changes to make on the experiments or units, please email us! Our address is wow@chemistry. ohio-state.edu. Š S. Olesik, WOW Project, Ohio State University, 2000.

Copyright Š 2002-2010 by S.Olesik, Wonders of Our World Project (WOW), the Ohio State University. Permission to make digital or hard copies of portions of this work for personal or classroom use is granted without fee provided that the copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page in print or the first screen in digital media. Abstracting with credit is permitted.


Light Book