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Telescopes

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Telescopes

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Presentation Transcript

  1. Telescopes

  2. Telescopes Key Concepts • What are the regions of the electromagnetic spectrum? • What are telescopes and how do they work? • Where are most large telescopes located?

  3. Telescopes - Key Terms • Telescope • Electromagnetic radiation • Visible light • Wavelength • Spectrum • Optical telescope • Refracting telescope • Convex lens • Reflecting telescope • Radio telescope • Observatory

  4. Telescope • A device that makes distant objects appear to be closer. • Galileo made the telescope famous. He was the first to see sunspots, Saturn’s Rings, and the four large moons of Jupiter

  5. Electromagnetic Radiation • Energy that can travel through space in the form of waves Examples of Forms of Radiation • visible light – radiation you can see • infrared – feel as heat • radio waves

  6. Ranges from long wavelength radio waves to short wavelength gamma rays

  7. Types of Telescopes • Instruments that collect and focus light and other forms of electromagnetic radiation. • Optical telescope – uses lenses or mirrors to collect and focus visible light • Two types – refracting and reflecting • Non-optical – Use other forms of electromagnetic radiation such as radio waves, x-rays and gamma rays

  8. Refracting Telescopes • Uses convex lenses to gather and focus light • Convex lens is a curved piece of glass that is thicker in the middle than the edges • The larger the lens the more light the telescope can collect • Simple refracting telescope has 2 lenses – the objective lens and the eyepiece lens • Yerkes Telescope in Wisconsin is the largest refracting telescope

  9. Reflecting Telescopes • Isaac Newton built the first in 1668 • Uses a curved mirror to collect and focus light • The larger the mirror, the more light that can be collected • Largest optical telescopes today are reflecting

  10. Radio Telescopes • Devices used to detect radio waves from objects in space • Most have curved reflecting surfaces that focus radio waves the way the mirror does in reflecting telescopes • Concentrate the faint radio signals onto small antennas like those on radios Ex. The Very large Array, Arecibo

  11. Other Telescopes Detect: • Infrared – Spitzer Space Telescope • Ultraviolet • X-rays – Chandra X-Ray Observatory • Gamma rays Hubble Space Telescope detects visible, ultraviolet, and infrared

  12. Observatories • A building that contains one or more telescopes. (some in space) • Many large observatories located on mountaintops or in space – atmosphere makes images blurry. • Radio telescopes are not affected by atmosphere