By: Lanting Zhuang Shuzhou Chen Zhengzhou Wang Boyu Chen Shijia Gong

1. Telescopes By: Lanting Zhuang Shuzhou Chen Zhengzhou Wang Boyu Chen Shijia Gong

2. History of telescope The earliest recorded working telescopes were the refracting telescopes that appeared in the Netherlands in 1608. Their development is credited to three individuals: Hans Lippershey and Zacharias Janssen, who were spectacle makers in Middelburg, and Jacob Metius of Alkmaar. Galileo greatly improved upon these designs the following year. The idea that the objective, or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope.The potential advantages of using parabolic mirrors—reduction of spherical aberration and no chromatic aberration—led to many proposed designs and several attempts to build reflecting telescopes. In 1668, Isaac Newton built the first practical reflecting telescope, of a design which now bears his name, the Newtonian reflector.

3. How telescope works A telescope is an instrument that aids in the observation of remote objects by collecting lights

4. How telescope works

5. How telescope works • It’s an extension to vision. The extension is achieved through the use of two lens • The objective lens collects lots of light from a distant object and brings that light to focus. • An eyepiece lens takes the bright light from the focus of the objective lens "spreads it out" to take up a large portion of the retina.

6. TWO PROPERTIES OF A TELESCOPE • how well it can collect the light • how much it can enlarge an image

7. Types of telescopes • Optical telescopes • Radio telescopes • X-ray telescopes • Gamma-ray telescopes • High-energy particle telescopes • Other types of telescopes

8. Optical telescopes • The refracting telescope which uses lenses to form an image. • The reflecting telescope which uses an arrangement of mirrors to form an image. • The catadioptric telescope which uses mirrors combined with lenses to form an image.

9. Radio telescopes • Radio telescopes are directional radio antennas used for radio astronomy. The dishes are sometimes constructed of a conductive wire mesh whose openings are smaller than the wavelength being observed. Multi-element Radio telescopes are constructed from pairs or larger groups of these dishes to synthesize large 'virtual' apertures that are similar in size to the separation between the telescopes; this process is known as aperture synthesis.

10. X-ray telescopes • X-ray telescopes can use X-ray optics, such as a Wolter telescopes composed of ring-shaped 'glancing' mirrors made of heavy metals that are able to reflect the rays just a few degrees. The mirrors are usually a section of a rotated parabola and a hyperbola, or ellipse. In 1952, Hans Wolter outlined 3 ways a telescope could be built using only this kind of mirror. Examples of an observatory using this type of telescope are the Einstein Observatory, ROSAT, and the Chandra X-Ray Observatory. By 2010, Wolter focusing X-ray telescopes are possible up to 79 keV.

11. Gamma-ray telescopes • Higher energy X-ray and Gamma-ray telescopes refrain from focusing completely and use coded aperture masks: the patterns of the shadow the mask creates can be reconstructed to form an image. X-ray and Gamma-ray telescopes are usually on Earth-orbiting satellites or high-flying balloons since the Earth's atmosphere is opaque to this part of the electromagnetic spectrum. However, high energy x-rays and gamma-rays do not form an image in the same way as telescopes at visible wavelengths. An example of this type of telescope is the Fermi Gamma-ray Space Telescope.

12. High-energy Particle Telescopes • High-energy astronomy requires specialized telescopes to make observations since most of these particles go through most metals and glasses. In other types of high energy particle telescopes there is no image-forming optical system. Cosmic-ray telescopes usually consist of an array of different detector types spread out over a large area. A Neutrino telescope consists of a large mass of water or ice, surrounded by an array of sensitive light detectors known as photomultiplier tubes. Energetic neutral atom observatories like Interstellar Boundary Explorer detect particles traveling at certain energies.

13. Other types of telescopes • Gravitational wave detector, aka gravitational wave telescope • Neutrino detector, aka neutrino telescope

14. How Telescope Changed Science • By using telescope, people can finally observe the mysterious outer space clearly. We put the Hubble Space Telescope in outer space and this allow the telescope get purer images. The Hubble Space Telescope is powered by solar energy, so it can work continuously. People in old time can only dream it but now it all become reality. • Some other kind of space telescope are also used to take pictures of earth and use those images in applications such as Google earth; thus, we can use those information in our daily life.

15. How Telescope Changed Science • Marine Telescope were widely used in maritime explore in old time. They don’t have GPS to guide them and the Marine Telescope one of the rare tools allow seaman know where they are on the ocean. It greatly changed people’s geographical knowledge and find new land. • Magellan completed the first circumnavigation of the Earth and his great adventure provided the earth is basically round. (in his time, people don’t believe the earth is round, if someone says earth is round, people will think that is not scientific.

16. SELF INSIGHT • Benefit from telescope: • Telescope has been broadly used in military, which can help soldiers to observe the circumstance from long distance. • For astronomy, Telescope is a necessary instrument for astronaut, which provide a clear view for astronaut to observe planets in the universe. • For general life, the telescope can help us to view the further scenery.

17. Self insight • Disadvantages of telescope: • The telescope provides a good condition for criminal to do illegal action, such as shooting with sniper rifle. • It convenient people to peep from long distance.

18. Works cited • Hubble Space Telescope. Page 4. HuDong.Nov.14.2010. <http://tupian.hudong.com/s/%22%E5%93%88%E5%8B%83%E2%80%9D%E5%A4%A9%E6%96%87%E6%9C%9B%E8%BF%9C%E9%95%9C/xgtupian/1/4>. • Hubble Space Telescope. Page 6. HuDong.Nov.14.2010. <http://tupian.hudong.com/s/%22%E5%93%88%E5%8B%83%E2%80%9D%E5%A4%A9%E6%96%87%E6%9C%9B%E8%BF%9C%E9%95%9C/xgtupian/1/4>. • Navigation Map with Marine Telescope. Bigkampung.April 6, 2011. <http://bigkampung.com/royal-caribbean-deal/navigation-map-with-marine-telescope-absolutvision>. • Pirates of the Caribbean2. Pcgames.Jan 25, 2008. <http://photos.pcgames.com.cn/source/460899.html>. • http://www.howstuffworks.com/telescope1.htm • Courtesy of NASA and Space Telescope Science Institute. Credit: NASA, C.R. O'Dell and S.K. Wong (Rice University)