Read the following passage and mark the letter A, B, C, D on your answer sheet to indicate the correct answer to each of the questions
According to some accounts, the first optical telescope was accidentally invented in the 1600s by children who put two glass lenses together while playing with them in a Dutch optical shop. The owner of the shop, Hans Lippershey, looked through the lenses and was amazed by the way they made the nearby church look so much larger. Soon after that, he invented a device that he called a “looker”, a long thin tube where light passed in a straight line from the front lens to the viewing lens at the other end of the tube. In 1608 he tried to sell his invention unsuccessfully. In the same year, someone described the “looker” to the Italian scientists Galileo, who made his own version of the device. In 1610 Galileo used his version to make observations of the Moon, the planet Jupiter, and the Milky Way. In April of 1611, Galileo showed his device to guests at a banquet in his honor. One of guests suggested a name for the device: telescope
When Isaac Newton began using Galileo’s telescope more than a century later, he noticed a problem. The type of telescope that Galileo designed is called a refractor because the front lens bends, or refracts, the light. However, the curved front lens also caused the light to the separated into colors. This meant that when Newton looked through the refracting telescope, the images of bright objects appeared with a ring of colors around them. This sometimes interfered with viewing. He solved this problem by designing a new type of telescope that used a curved mirror. This mirror concentrated the light and reflected a beam of light to the eyepiece at the other end of the telescope. Because Newton used a mirror, his telescope was called a reflector
Very much larger optical telescopes can now be found in many parts of the world, built on hills and mountains far from city lights. The world’s largest refracting telescope is located at the Yerkes Observatory in Williams Bay, Wisconsin. Another telescope stands on Mount Palomar in California. This huge reflecting telescope was for many years the largest reflecting telescope in the world until an even larger reflecting telescope was built in the Caucasus Mountains. A fourth famous reflector telescope, the Keck Telescope situated on a mountain in Hawaii, does not use a single large mirror to collect the light. Instead, the Keck uses the combined light that falls on thirty-six mirrors
Radio telescopes, like optical telescopes allow astronomers to collect data from outer space, but they are different in important ways. First of all, they look very different because instead of light waves, they collect radio waves. Thus, in the place of lenses or mirror, radio telescopes employ bowl-shaped disks that resemble huge TV satellite dished. Also, apart from their distinctive appearance, radio telescope and optical telescopes use different methods to record the information they collect. Optical telescopes use cameras to take photographs of visible objects, while radio telescopes use radio receivers to record radio waves from distant object in space
Question 37: What did Newton notice about Galileo’s telescope when he used it?