THE TELESCOPE FROM GEOCENTRIC TO HELIOCENTRIC AND BEYOND

THE TELESCOPE FROM GEOCENTRIC TO HELIOCENTRIC AND BEYOND Earth-centered universe Sun-centered universe BY BRAIN CANNON, 1 S T PERIOD PLTW

FORWARD THINKING “By taking our sense of sight far beyond the realm of our forebears' imagination, these wonderful instruments, the telescopes, open the way to a deeper and more perfect understanding of nature. ” —René Descartes, 1637

THE ORIGINAL INVENTION • Lenses were introduced to Europe around the 13 th century • By 1300, the first eyeglasses were available in cities such as Venice and Florence (Mason, 2010) • Advances in lens making and polishing soon followed • The tools for making a telescope were available but, for reasons that are not clear, the invention of the telescope had to wait • The telescope first appeared in the Netherlands in 1608 The earliest known illustration of a telescope: Giovanbattista della Porta included this sketch in a letter written in August 1609

BASIC DESIGN

TELESCOPE TIMELINE Hans Lippershey applies for a patent for a refractor telescope 1609 1608 Sir Isaac Newton builds the first workable reflector telescope William Herschel builds a telescope with a giant reflector mirror that was 49 inches wide 1721 Galileo Galilei makes a refractor telescope and turns it to the skies 1908 1789 1668 John Hadley produces the first workable Gregorian telescope Edwin Hubble used the 100" Hooker telescope to determine that the size of the universe was much larger than previously known 1924 The 60 Inch Mount Wilson reflector is completed

SIGNIFICANT CHANGES • Refracting telescopes telescope constructed of two convex lenses • Long focal length refractors telescopes with focal lengths as long as 150 ft. • Aerial telescopes objective was mounted on a swiveling ball-joint on top of a tall structure Newton's first compact reflecting telescope had a mirror diameter of 1. 3 inches lens that would focus all colors to a single point • Reflecting telescopes • Achromatic refracting telescopes • Large reflecting telescopes process of depositing a layer of silver on glass telescope mirrors • Radio telescopes detect and collect data on radio waves from deep space uses infrared light to detect celestial bodies • Infrared telescopes (O'Rourke, 2009)

IMPACT ON CIVILIZATION Humans use to believe that the earth was the center of the universe Using the telescope, Galileo proved that the earth was revolving around the sun

IMPACT ON CIVILIZATION Throughout its 400 -year history, the telescope has changed our view of the universe and our view of ourselves • Telescopes showed that the universe was far larger than had been imagined — and our place in it far smaller than had been imagined • Telescopes allowed humans to view differences between planets and form the basis of our understanding of the solar system • The invention of the telescope marked the beginning of the scientific revolution of the 18 th century • These instruments helped us make the first valid measurement of the speed of light • Telescopes have also helped us understand gravity and other fundamental laws of the physical world (NASA, n. d. )

REFERENCES Mason, B. (2010, October 2). How the Telescope Changed Our Minds | WIRED. Retrieved from http: //www. wired. com/2008/10/how-the-telesco/ NASA. (n. d. ). NASA - Have Telescopes Changed Our View of the Universe? Retrieved from http: //www. nasa. gov/centers/jpl/education/telescopes 20100405. html O'Rourke, B. (2009, August 25). Four Hundred Years Ago, Galileo's Telescope Changed The World. Retrieved from http: //www. rferl. org/content/Four_Hundred_Years_Ago_ alileos_Telescope_Changed_The_World/1807134. html