Thomas Edison Lightbulb - Mrs. Jones's Classroom



Name _________________________________________________________5.3 a-e LightThe student will investigate and understand basic characteristics of visible light and how it behaves. Key concepts includea)transverse waves;b)the visible spectrum;c)opaque, transparent, and translucent;d)reflection of light from reflective surfaces; ande)refraction of light through water and prisms.You will have three quizzes:5.3 a & bYou must understand what light is and how it travelsYou must be able to draw and label a transverse waveYou must be able to explain the visible spectrum – What is it? How does it work? What makes the colors?You must also understand light that is not visible to us.How do light waves compare with sound waves?5.3 a, b, c, d, and eIn addition to what you need to know for the first quiz, you need to be able to explain what happens in a rainbow and a prism, you need to know all of your terms.5.3 a, b, c, d, and eIn addition to what you need to know of the first two quizzes, you need to know the accomplishments of Thomas Edison and Lewis Latimer Terms you need to know:DiffractionOpaqueReflectRefractTelescopeFilamentTransparentMicroscopeConcave lensSpectroscopeConvex lensTranslucentLight Electromagnetic spectrumLight is everywhere in our world. It is a type of energy that travels in transverse waves. Light has many different wavelengths, most of which we cannot see. Light is an electromagnetic wave caused by excited electrons.Transverse Waves-771525866775Most kinds of waves are transverse waves. In a transverse wave, as the wave is moving in one direction, it is creating a disturbance in a different direction.The electromagnetic spectrum is more familiar to you than you might think. The microwave you use to heat your food and the cell phones you use are part of the Electromagnetic Spectrum. The light that our eyes can see is also part of the electromagnetic spectrum. This visible part of the electromagnetic spectrum consists of the colors that we see in a rainbow - from reds and oranges, through blues and purples.-1457325126365Light FrequenciesLight waves also come in many frequencies. The frequency is the number of waves that pass a point in space during any time interval, usually one second. -8096252190115??Color is the thing we perhaps notice most about light in the world around us. But why we see colors the way we do all has to do with light. The reason something appears to be the color that does is that the object is absorbing all the other colors of light except the ones we see, which are reflected back to our eyes. If something absorbs all the colors, it appears black, if it reflects everything, it appears white. Color comes from what is called the visible spectrum of light. This spectrum goes from red to orange to yellow to green to blue to indigo to violet, all the major colors of the spectrum, and everything in between. An easy way to remember this order is to remember Roy G. Biv, much like the -895350-723900colors of the rainbow. Scientists measure the wavelengths of light in this spectrum in nanometers or billionths of a meter. Red has the longest wavelength, and violet has the shortest. So, what color we see depends on the wavelength of the light we absorb into our eyes. The primary colors are red, green, and blue, from these colors, every other color can be made.Visible light is a combination of several different wavelengths of light traveling together. These wavelengths are represented by the colors red, orange, yellow, green, blue, indigo, and violet (ROYGBIV).Light waves are characterized by their wavelengths. In the visible spectrum, red has the longest wavelength, and violet has the shortest. Wavelengths get progressively shorter from red to violet.Light travels in waves. Compared to sound, light travels extremely fast. It takes light from the sun less than 8? minutes to travel 150 million kilometers to reach the Earth.Color also varies on the amount of light present in the area, which is why things can appear different in different light, and with different reflectors around them. A prime example is people with blue eyes, depending on the clothes they are wearing, the shade of blue in their eyes can lighten or deepen, depending on which light waves are being reflected by the clothes they are wearing. Outside of the visible spectrum, there are many non-visible forms of light, infra-red which is used in remote controls, ultraviolet light, used in black lights, x-rays used in x-ray machines, and gamma rays and other various forms of radiation given off from the sun. Light will travel forever unless it hits an object. When it does hit something it will do one of three things:Reflection is when waves, whether physical or electromagnetic, bounce from a surface back toward the source. A mirror reflects the image of the observer.Refraction is when waves, whether physical or electromagnetic, are deflected when the waves go through a substance. The wave generally changes the angle of its general direction.? Absorption is when all the light energy is absorbedOne of the most important experiments on light was made by Isaac Newton. He was the greatest of all English men of science. He discovered that sunshine (white light) is made up of many colors. Over 300 years ago, Sir Isaac Newton passed a beam of white light through a prism. A prism is a triangular piece of glass, which allows light to spread out into a band of seven colors. These colors are red, orange, yellow, green, blue, indigo, and violet. Newton then sent this light through a second prism where the light became white once again. What did Sir Isaac Newton do? He first took the white light apart and then he put it back together again.-552450655320All a prism does is refract light. White light is composed of many different frequencies and wavelengths and a different frequency will correspond to a different color of light. When the light travels through the prism, it slows the light down and will refract it. Each frequency that makes up the white light slows down differently from each other, and thus refract at different angles. Which is why the rainbow is always in the order or red, orange, yellow, green, blue, indigo, and violet because red light travels slower than violet light when it travels through the prism, it will refract at a higher angle than violet lightThe most common example of a spectrum is the rainbow created in nature.The rainbow is caused by sunshine (white light) shining on water droplets that are in the air just after a summer shower. Thousands of these water droplets break up the light, just like Sir Isaac Newton's prism. Can you make a rainbow? Of course! Make your own rainbow by turning on the garden hose, which has a nozzle that will make a fine mist, or spray. Make sure the sunlight is coming over your shoulder. You have made a rainbow. How do lenses work?A lens works by refraction: it bends light rays as they pass through it so they change direction. (You can read a full explanation of why this happens in our article on light.) That means the rays seem to come from a point that's closer or further away from where they actually originate—and that's what makes objects seen through a lens seem either bigger or smaller than they really are.Types of lensesThere are two main types of lenses, known as convex (or converging) and concave (or diverging). Convex lensesIn a convex lens (sometimes called a positive lens), the glass (or plastic) surfaces bulge outwards in the center giving the classic lentil-like shape. A convex lens is also called a converging lens because it makes parallel light rays passing through it bend inward and meet (converge) at a spot just beyond the lens known as the focal point. Photo: A convex lens makes light rays converge (come together) at the focal point or focus. The distance from the center of the lens to the focal point is the focal length of the lens.Convex lenses are used in things like telescopes and binoculars to bring distant light rays to a focus in your eyes.-38100022923500Concave lensesA concave lens is exactly the opposite with the outer surfaces curving inward, so it makes parallel light rays curve outward or diverge. That's why concave lenses are sometimes called diverging lenses. (One easy way to remember the difference between concave and convex lenses is to think of concave lenses caving inwards.)A concave lens makes light rays diverge (spread out).Concave lenses are used in things like TV projectors to make light rays spread out into the distance. In a flashlight, it's easier to do this job with a mirror, which usually weighs much less than a lens and is cheaper to manufacture as well.If you are farsighted, meaning that you can see far but you can't see objects close up, that means your eye is too short in terms of the distance of your retina to your lens. The image focuses behind the retina, so it becomes blurry. When you add a convex lens, it will help bend the light more and converge the light rays onto the retina, so you will see the image clearly. If you are nearsighted, your retina is farther away from your lens, so the image is focusing in front of your retina, so you can't see distant objects. That's when you need a concave lens. Concave lens will diverge the light rays onto the retina.Transparent, Translucent, and OpaqueA transparent object is something that will allow all of the light rays to pass through it. Things like glass, some kids of plastic and food wrap are transparent because of the density of the molecules inside it. A translucent object is a material that will only allow some or a little bit oh the light rays to pass through it. Things like wax paper, cloth and paper are translucent because of the density of the molecules inside it. An opaque object is something that will allow no light to pass through it because the density of the object is too great. Things like wood folders and mirrors are opaque. The Inventions of Thomas Edison 0-444500Edison's phonograph was the first machine that could record a person’s voice and play it back. There is much to learn about Thomas Alva Edison, who was born February 11, 1847. He was a great inventor who loved to experiment and discover how things worked. The three inventions considered Edison's greatest are the electric light system, the phonograph, and a motion picture machine that was a forerunner of the movie camera. Today, his inventions have been updated by others to a variety of light bulbs, CD players for music, and the video camera. The PhonographThomas Edison invented the phonograph back in 1877. This is the very first machine that could record a person’s voice and play it back. Edison recited the nursery rhyme “Mary Had a Little Lamb” on a tin cylinder that captured the recording. With a needle running through the grooves as it turned, this early recording device played back Edison's voice. Before the phonograph was invented, people only had entertainment by live musicians and actors. This invention allowed people to have music anytime.The First Motion Picture Machine487680091186000Edison invented the “kinetoscope,” which was a box that contained strips of pictures. When the person looked through a hole, the pictures were pulled through, with the result that it looked as if the pictures were moving. People came to see his motion picture machine in New York City, where they paid a nickel to see the first short movie in 1894.Thomas Edison LightbulbLet there be Light!-88582583185000Historians agree that Thomas Edison was not the inventor of the electric light bulb, but he did produce the first commercially viable one. Earlier light bulbs were experimented with as far back as 1802; and there were 23 others who had invented light bulbs, some of whom were still working on them at the time of Edison’s work.Three factors in combination are generally recognized as contributing to Edison’s success:A durable incandescent materialElimination of air from the bulb-a better vacuumA filament material of high resistanceThis is an early sketch from Thomas Edison of his light bulb.3905885168846500Thomas Edison’s serious incandescent light bulb research began in 1878, filing his first patent later that year…”Improvement In Electric Lights” in October 1878. His experiments involved the fabrication and testing of many different metal filaments, including platinum. Platinum was very difficult to work with, and prone to being weakened by heating and oxygen attack.In addition, platinum was expensive, and too low in resistance; which would require heavy copper conductors in Edison’s electric distribution system he was designing to supply commercial installations of his bulbs. This system would later become the model for our modern electric utility power distribution system of today.Edison then resorted to a carbon-based, high-resistance, filament. One year later in October 1879 Edison successfully tested a filament that burned for 13.5 hours. Continuing to improve his design, by November 1879, he filed for a U.S. patent for an electric lamp using “a carbon filament or strip coiled and connected … to platina contact wires”. The filament was made from a piece of carbonized thread.By New Year’s he was demonstrating lamps using carbonized cardboard?filaments to large crowds at the Menlo Park laboratory. It was not until several months after the patent was granted that Edison and his team discovered that a carbonized bamboo filament could last over 1200 hours. A year later, Edison began manufacturing commercial lamps using carbonized Japanese bamboo as filaments.Throughout his career, Edison worked on many improvements to his signature invention, an invention that literally changed the way we live after dark. Prior to the light bulb, folks burned lamp oils or used manufactured natural gas for illumination, a rather dangerous way to provide illumination. Electric lights became cheap, safe, and convenient to use and the public and commercial concerns installed them in rapidly increasing numbers. The rest is history.-771525255270Lewis Latimer is considered one of the 10 most important Black inventors of all time, not only for the sheer number of inventions created and patents secured but also for the magnitude of importance for his most famous discovery. Latimer was born on September 4, 1848 in Chelsea, Massachusetts. His parents were George and Rebecca Latimer, both runaway slaves who migrated to Massachusetts in 1842 from Virginia. George Latimer was captured by his slave owner, who was determined to take him back to Virginia. His situation gained great notoriety, even reaching the Massachusetts Supreme Court. Eventually George was purchased by abolition supporters who set him free.In 1880, after moving to Bridgeport, Connecticut, Latimer was hired as the assistant manager and draftsman for U.S. Electric Lighting Company owned by Hiram Maxim. Maxim was the chief rival to Thomas Edison, the man who invented the electric light bulb. The light was composed of a glass bulb which surrounded a carbon wire filament, generally made of bamboo, paper or thread. When the filament was burned inside of the bulb (which contained almost no air), it became so hot that it actually glowed. Latimer was able to improve Edison’s light bulb when he devised a way of encasing the filament within a cardboard envelope which prevented the carbon from breaking and thereby provided a much longer life to the bulb and hence made the bulbs less expensive and more efficient. This enabled electric lighting to be installed within homes and throughout streets. ................
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