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Technology Devices to Overcome Limitation of Light and Hearing
Saw Aik Hongon 1 April 2013
Transcript of Technology Devices to Overcome Limitation of Light and Hearing
Class : 2S
School : Sekolah Menengah Kebangasaan St. Mark Technology Device to Overcome Limitation of Sight and Hearing Function of devices that can overcome the limitation of sight Microscope - To see object that are too small for the naked eye.
- Giovanni Faber coined the name microscope for Galileo Galilei's compound microscope in 1625.- Optical microscope ( the first invented ) , have one / more lenses that are refractive glass and occasionally of plastic to focus light into the eye or another light detector . Telescope - To see far - off objects such as stars and planets. - the first known practical telescopes were invented in Netherlands.
- An instruments that aids in the observation of remote objects by collecting electromagnetic radiation.-The history of the telescope dates back to the early 1600s. Galileo Galilei is commonly credited for inventing the telescope, but this is not accurate. Binocular -Binoculars using roof prisms may have appeared as early as the 1870s in a design by Achille Victor Emile .-Porro prism binoculars are named after Italian optician Ignazio Porro who patented this image erecting system in 1854 .-To see tiny distant objects such as birds in the sky. -a pair of identical or mirror .-Symmetrical telescopes mounted side by side and aligned to point accurately in the same dirrection allowing the viewer to use both eyes when viewing distant objects. Magnifying glass -The earliest evidence of "a magnifying device, a convex lens forming a magnified image" was Aristophanes's "lens", from 424 BC, a glass globe filled with water. Roger Bacon described the properties of a magnifying glass in 13th-centuryEngland. Eyeglasses were developed in 13th-century. -to make tiny objects appear larger than the original.
-convex lense that is used to produce a magnified image of an object.
-also called a hand lens in laboratory contexts. Ultrasound machine -The use of sound waves to detect masses has been used since the 1880’s when Pierre and Jacques Curie discovered the piezoelectric effect. In 1914, after the Titanic disaster, Paul Langevin investigated ways to detect icebergs. - to scan and see the foetus in a pregnant mother.
-a cyclic sound pressure wave with frequency greather than the upper limit of the human hearing range. Periscope - In 1854 Hippolyte Marié-Davy invented the first naval periscope, consisting of a vertical tube with two small mirrors fixed at each end at 45°. Simon Lake used periscopes in his submarines in 1902. -to see a view beyond and obstructing object.
-an instrument for observation from a concealed position.
-consisits of an outer case with mirrors at each end set parallel to each other at 45 degree angle. X-ray machine -In 1887, Nikola Tesla began to investigate X-rays and produced the bremsstrahlung process. In 1895, Wilhelm Röntgen began observing and further documenting X-rays while experimenting with vacuum tubes. On January 18, 1896 an X-ray machinewas formally displayed by H.L. Smith.-to see the internal organs or to inspect baggages at the airports. Introduction Humans have sight and hearing limitation . Without any devices , our sight and hearing was limited . Limitations of sight can be overcome by using appropiate optical devices such as Microscope , Telescope and others. The range of frequency of hearing in human is 20 Hz and 20 000 Hz . It was different according to the age of a person ( Children -larger range of hearing frequency than adults ) . Hearing limitations can be overcome by using appropriate hearing aids such as stethoscope , megaphone , microphone , earphone , headphone , PA System and others. All of these devices helps us to makes our live easier. Objective The objectives of learning about the limitation of sight and hearing :
-I have learnt that our hearing and sight has its limitation.
-I have learnt that we can overcome the limitation of our sight and hearing by using or wearing technology devices.
The technology devices have make our live easier :
i)Doctors use stethoscopes to hear our heartbeats .
ii)Teachers use microphone in the assembly . The function of device that can overlimit the limitation of hearing Stethoscope -The stethoscope was invented in France in 1816 by René Laennec at the Necker-Enfants Malades Hospital in Paris.
-helps doctors to detect the soft heartbeats of patients . -The initial inventor of the speaking trumpet is a subject of historical controversy, as both Samuel Morland and Athanasius Kircher lay claim to the device. Morland, in a work published in 1655, wrote about his experimentation with different horns and his most successful variant.-boosts weak sounds ( the function of Megaphone as same as Microphone ) Earphone Megaphone Public Address System -collects and amplifies sounds before sending them to the middle ear . -invented by Nathaniel Baldwin around 1919 were commonly used for early radio work. -amplifies voices so that they can be heared from far away. -invented by Edwin Jensen and Peter Pridham.-Edwin Jensen and Peter Pridham of Magnavox began experimenting with sound reproduction in the 1910s; working from a laboratory in Napa, California, they filed the first patent for a moving coil loudspeakerin 1911.