0: 400 Years Of The Telescope

Name: Laura Meng
SID: 22430663
GSI: Johnathan Wright
Section #112
Laboratory 0: “400 Years of the Telescope”

The PBS documentary outlines our progressive journey in the field of astronomy and the resulted revolutionary discoveries from the continually improving technologies. The history of telescopes first began in the sixteen hundreds, when Hale’s invention of refracting telescopes drastically changed people’s view of the Universe at the time, for the view from the telescope revealed the Universe as dynamic, as opposed to static. Later on, Galileo Galilei improved on these telescopes and constructed several with increasing magnifying powers. With his own telescope, Galileo not only viewed our moon, but also observed those of Jupiter, triggering the development of modern science.
Furthermore, with the help of his telescope, Galileo also discovered that Venus goes through a whole cycle of phases, providing Nicholas Copernicus’ heliocentric theory with an instrumental proof, and challenging the traditional believes that Earth is the center of the Universe and that all other planets orbit around it. Although it led Galileo to great discoveries, his telescope experienced a defection in its lenses, called the chromatic aberration. Fortunately, Isaac Newton successfully solved this problem by reflecting the light onto a smaller and flatter mirror, which then brings the focus point outside the telescope, further improving the quality of the images being studied.

The ability to collect starlight is another useful feature of telescopes, for studying light from a star enhance astronomers’ understandings of our Universe.
By spreading starlight through a glass prism, astronomers are able to obtain the star’s spectrum, which provides them information about the star’s temperature, pressure, rotation speed and composition. However, a more advanced study of stars was limited by turbulence in the Earth’s atmosphere. This problem is later solved by the use of adaptive optics, which distort the shape many times per second to cancel out the atmosphere’s distortions. The invention of adaptive optics is critical in astronomical researches because it allows astronomers to study the rapid changes in sun’s turbulences, which will improve our understanding of our own climate. The most efficient way to completely remove the problems of our atmosphere, however, is to send a telescope into space, which is achieved by the Hubble Telescope. Although telescopes have advanced dramatically since the seventeenth century, astronomers are still striving for more improvements today with the hopes to learn more about the Universe, such as finding extraterrestrial
lives.

What I found interesting after watching this video is the fact that our Universe is not only expanding, but also doing so at an increasing speed. What I learned in term of this accelerating expansion is that all galaxies are moving away from each other. The farther ones are receding more rapidly, for every little bit of the Universe is stretching. Also, because of this expansion of space, there is no unique center of Universe, as each galaxy seems like the center of rapidly regressing neighboring galaxies. All in all, to think that the Universe has been expanding at an escalating speed for about 14 billion years is mind blowing. What I liked about the video is its inclusion of many photographs of our Universe. The photos served as a secondary base for the content of the video, backing up the information said in the video, and providing me with a visual knowledge of the space. Overall, I think the video offered a comprehensive evolution of astronomy, which enhances my understanding of the materials we learned in lectures.