Welcome to the Supercharged Science Light, Lasers, and Holograms Teleclass Webinar! You can fill out this worksheet as we go along to get the most out of time together, or you can use it as a review exercise at the end of the class to see where your strengths are. What we re going to cover today: Light Speed Diffraction Wavelength and Frequency Coherence Intensity, Polarization and Phase Fluorescence Electromagnetic Spectrum Photoelectric Effect Absorption Holograms Transmission Measurement techniques Reflection Lenses, Microscopes and Telescopes Refraction Fiber Optics & Communication Write down two things you really want to know about light, lasers and/or holograms: 1. 2. Do this NOW: Write down WHY you want to learn about the things you mentioned above. What will it give you, or provide you with, or make possible for you if you now understand these things that you wanted to learn? IMPORTANT: During class, you can either fill out the worksheet, OR if that s too stressful or a hassle, just set it aside and fill it out after class is over so you can enjoy watching the class. Answer key is on the last page, so put it in a place where you won t be tempted to peek at the answers until after you ve given it your best shot. 2017 Supercharged Science Page 1
Material List: Hair Tape Pencil Ruler Paper Clothespin Paperclip Calculator Rubber band Glass of water Red laser Flashlight Small mirror Pond water Old CD Scissors Pliers Clear Plastic Film (from the window part of a pasta, cookie, or other food box) 1 cm 3.5 cm 6 cm 2017 Supercharged Science Page 2
Templates: 2017 Supercharged Science Page 3
During the Lesson: You can look over the worksheet so you know what to listen for as you go through the class with me, or you can go through it along with me during class. OR flip it over and forget about it and just enjoy the class. When class is over, flip it back over and fill it out and be amazed at how much you ve picked up and learned! 1. Your eyes and skin are light. 2. Light is that can travel through. 3. White light has the wavelengths ( ) of visible light at the same intensity. 4. Light changes when it crosses a boundary. 5. Refraction is when light changes or direction when it crosses mediums. 6. light is monochromatic ( color). 7. Light sources create different combinations of and brightness. 8. Laser light is : the waves have the same wavelength, travel in the same direction, are in phase, and have the same polarization. 2017 Supercharged Science Page 4
9. LASER: ight mplification by timulated mission of adiation. 10. Light reflects at the same it comes in at, measured from the line. 11. Light can either get, converted to heat, reflected back, or through when it encounters something. 12. Light when it passes through narrow spaces or over edges. 13. When interact, they make patterns called. 14. When two light waves, it creates light and dark patterns called interference. 15. Lenses and distort images to the image. 16. A packet of light is called a. 17. Phosphorescence is light after being excited to a higher energy state. 2017 Supercharged Science Page 5
18. The Photoelectric Effect is when are emitted from an object when light hits the surface. 19. Light is a and a. 20. A diffracts light into an image. Hologram can be the 3D image or the system doing the imaging. 21. Holograms are 3D images from a light source. 22. What I didn t know about geology until class today was: 2017 Supercharged Science Page 6
Vocabulary Words: Concave lenses work to make objects smaller (door peep hole), and are curved inward like a cave. Convex lenses make them larger (magnifying lenses), and have a bump in the middle you can feel with your fingers. The amount of energy a photon has determines whether it s a particle or a wave. Photons with the lowest amounts of energy and longest wavelengths (some are the size of football fields) are radio waves. The next step up are microwaves, which have more energy than radio waves. IR has slightly more energy, and visible light (the rainbow you can see with your eyes) has more energy and shorter wavelengths. Ultraviolet (UV) light has more energy than visible, and x rays have even more energy than UV, and finally the deadly gamma rays have the most amount of energy. Filters can be used to block certain wavelengths. Intensity, or brightness, is the amount of photons (packets of light) you have in a certain amount of space. A flashlight has less intensity than a car headlight. LASER stands for Light Amplification by Stimulated Emission of Radiation. Most lasers are monochromatic (one color). Lasers are concentrated beams of light, and are illuminated by small particles (like smoke and dust). Lenses work to bend light in a certain direction (refraction). A lens is a curved piece of glass or plastic that changes the speed of the light. Lenses have the same effect on lasers as on light beams. Light can be defined by four things: intensity (how bright), frequency (or wavelength), polarization (the direction of the electric field), and phase (time shift). Objects can either be a light source (like the sun) or reflect light (like the moon). Light can change speeds, but the maximum light speed is through a vacuum (186,000 miles per second). Light changes speeds when it passes through a different material (like water, glass, or fog). Depending on the optical density of the material, light will bend by different amounts. Glass is optically denser than water. Water is more optically dense than air. When two beams of light are out of phase with each other, it s like playing a G and A on the piano. This is called phase shift. Blue and UV light eject electrons from metal plates, but red light does not (photoelectric effect). Polarization has to do with the direction of the electric field. Your sunglasses are polarizing filters, meaning that they only let light of a certain direction in.
When a beam of light hits a window, it bends and changes speed (refraction). Technically, the wavelength (color) changes but the frequency stays the same. In order for this to happen, the speed of light must also change. Razor edge slits create interference patterns. Slits are skinny holes that allow light to pass through. Scientists use slits to filter out all other light sources except the one they want to use in their experiment. When you change the wavelength, you change the color of the light. The wavelength () equals the speed of light (c) divided by the frequency (), or = c /. 2017 Supercharged Science Page 8
Answer Key: 1. Your eyes and skin are light detectors. 2. Light is energy that can travel through space. 3. White light has all the wavelengths (colors) of visible light at the same intensity. 4. Light changes speeds when it crosses a boundary. 5. Refraction is when light changes speed or direction when it crosses mediums. 6. Laser light is monochromatic (one color). 7. Light sources create different combinations of colors and brightness. 8. Laser light is coherent: the waves have the same wavelength, travel in the same direction, are in phase, and have the same polarization. 9. LASER: Light Amplification by Stimulated Emission of Radiation. 10. Light reflects at the same angle it comes in at, measured from the normal line. 11. Light can either get absorbed, converted to heat, reflected back, or transmitted through when it encounters something. 12. Light diffracts when it passes through narrow spaces or over sharp edges. 13. When waves interact, they make patterns called interference. 14. When two light waves interact, it creates light and dark patterns called interference. 15. Lenses bend and distort images to magnify the image. 16. A packet of light is called a photon. 17. Phosphorescence is light emitted after being excited to a higher energy state. 18. The Photoelectric Effect is when electrons are emitted from an object when light hits the surface. 19. Light is a particle and a wave. 20. A hologram diffracts light into an image. Hologram can be the 3D image or the system doing the imaging. 21. Holograms are 3D images from a coherent light source. 2017 Supercharged Science Page 9