Understanding Our Universe (1957)

[Music] how are we learning about our universe with the aid of great telescopes that peer millions and billions of light years into space past our solar system past our galaxy into the depths of space to solve questions on the very nature of our universe we are using spectroscopes and spectrographs to help us learn the composition of stars we are using light intensifying devices and specially designed cameras with these and many other wonderful instruments astronomers all over the world are helping us gain an understanding of our universe their findings are used to help navigate airplanes and ships to adjust the timing of great clocks to help in the forecasting of weather and especially weather cycles to help us understand the nature of the world in which we live and to use our understanding to transform matter into energy all this and more has come in part through our explorations of the universe these explorations began thousands of years ago on the pasture lands of the ancient world here where flocks were guarded by shepherds at night astronomy began these ancient shepherds knew the stars noted how they changed positions and how they seemed to be grouped in different ways that resembled things and people and animals the ancient people gave names to the groups of stars and composed stories about them in some ancient lands men spent their lives studying the sky they found that the movements of the sun and moon and stars and planets could be predicted and this rudimentary astronomy became a very valuable science ancient peoples whose civilizations were based on agriculture planted their crops according to the stars for the stars indicated the coming of the seasons ancient travelers depended on the sun by day and the positions of stars by night to guide them on long journeys across strange or uncharted lands these ancient astronomers had only their eyes in the skies at night they worked without accurate instruments yet they determined how long a year was and developed calendars and made fairly accurate star charts but with the development of the telescope about 350 years ago man's knowledge of the universe began increasing rapidly the first great discovery was that the sun is the center of our solar system and around the sun revolves a system of planets including the earth a few hundred years ago astronomers knew of seven planets as better telescopes have been made and more has been learned we have learned of nine planets this is a picture representing our solar system it would take 1200 years to fly across it at the speed of sound yet our entire solar system is only a tiny spot in our universe our sun is one star just one of millions of stars all part of the milky way this great system of stars is called a galaxy our galaxy of stars is shaped like a disc it is so thick it takes light more than ten thousand years to cross it and for a beam of light to travel across the length of this galaxy it would take 100 000 years in photographs taken through great telescopes more than a million galaxies have been noted and no one knows the limits of our universe spectrographs have also aided in our understanding of the universe they record special pictures taken through the great telescopes of the light from the sun and other stars in the universe by comparing these special pictures of starlight with similar pictures of the light given off by the different elements when they burn scientists can tell which elements are present in the stars and also learn about a star's size temperature and motion the new science of radio astronomy is helping astronomers learn about parts of our universe that cannot be seen radio telescopes detect certain radiations from outer space some of which are produced by galaxies in collision radio astronomy will help scientists learn much about the structure of our own and other galaxies equally important is knowledge of our sun and the solar system we are watching an eclipse of the sun with clouds in the immediate foreground through studying eclipses of the sun astronomers have learned much about this source of our light and heat at the moment the moon cuts off the light of the sun a corona a great halo of light bursting forth around the moon can be seen but the corona appears for a very short time during an eclipse and its nature could not be studied until astronomers engineered special devices to attach to telescopes they found ways to photograph the surface of the sun and see solar prominences which caused the corona great streams of mainly hydrogen gas rise up several thousand miles from the surface of the sun they jut out sometimes as much as a million miles and most are many times as large as our earth the study of these prominences tells us about the sun and about the forces in our universe in the camera the action has been speeded up about 300 to 700 times so the movement can be seen clearly observing the sun's surface carefully even without telescopes ancient astronomers noted spots these changing strange dark spots on the sun are probably caused by huge eruptions of gases within the sun when these eruptions are numerous they cause magnetic storms on earth and perhaps affect weather cycles as astronomers continue their studies we will learn more about these spots on the sun yes in the more than 300 years we have had telescopes we have peered vast distances into our universe and learned much about it but even greater horizons of knowledge lie ahead they are opened by rockets which can escape our earth's gravity as we go higher and higher above the earth the day of actually exploring our universe seems about to dawn here is an actual photograph of the earth made from miles above it we will know more of our earth through artificial satellites around it next can come travel away from the earth to other bodies in our solar system yes more and more in years to come we will be working and planning to gain a greater understanding of our universe