The Big Bang Theory http://quest.nasa.gov/hst/QA/Universe_Origins/Reason_for_the_Big_Bang.1
QUESTION: Why do scientists believe in the Big Bang theory? ANSWER from http://liftoff.msfc.nasa.gov/academy/universe/b_bang.htmlThe Big Bang Theory is the dominant scientific theory about the origin of the universe. According to the big bang, the universe was created sometime between 10 billion and 20 billion years ago from a cosmicexplosion that hurled matter and in all directions. In 1927, the German priest Georges Lemaitre was the first to propose that the universe began with the explosion of a primeval atom. His proposal came after observing the red shift in distant nebulas byastronomers to a model of the universe based on relativity. Yearslater, Edwin Hubble found experimental evidence to help justify Lemaitre’s theory. He found that distant galaxies in every directionare going away from us with speeds proportional to their distance. The big bang was initially suggested because it explains why distant galaxies are traveling away from us at great speeds. The theory also predicts the existence of cosmic background radiation (the glow leftover from the explosion itself). The Big Bang Theory received its strongest confirmation when this radiation was discovered in 1964 byArno Penzias and Robert Wilson, who later won the Nobel Prize for this discovery. Although the Big Bang Theory is widely accepted, it probably willnever be proved; consequentially, leaving a number of tough,unanswered questions. http://web.archive.org/web/20080209122240/http://www.umich.edu/~gs265/bigbang.htm
Chris LaRocco and Blair Rothstein present:
THE BIG BANG:
It sure was BIG!!
The Hubble Telescope’s deepest view of the universe teaches us about the beginning
INTRODUCTION
We certainly know that our universe exists, however, this knowledge alone has not satisfied mankind’s quest for further understanding. Our curiosity has led us to question our place in this universe and furthermore, the place of the universe itself. Throughout time we have asked ourselves these questions: How did our universe begin? How old is our universe? How did matter come to exist? Obviously, these are not simple questions and throughout our brief history on this planet much time and effort has been spent looking for some clue. Yet, after all this energy has been expended, much of what we know is still only speculation.
We have, however, come a long way from the mystical beginnings of the study of cosmology and the origins of the universe. Through the understandings of modern science we have been able to provide firm theories for some of the answers we once called hypotheses. True to the nature of science, a majority of these answers have only led to more intriguing and complex questions. It seems to be inherent in our search for knowledge that questions will always continue to exist.
Although in this short chapter it will be impossible to tackle all of the questions concerning the creation of everything we know as reality, an attempt will be made to address certain fundamental questions of our being. It will be important to keep in mind that all of this information is constantly being questioned and reevaluated in order to understand the universe more clearly. For our purposes, through an examination of what is known about the Big Bang itself, the age of the universe, and the synthesis of the first atoms, we believe that we can begin to answer several of these key questions.
One of the most persistently asked questions has been: How was the universe created? Many once believed that the universe had no beginning or end and was truly infinite. Through the inception of the Big Bang theory, however, no longer could the universe be considered infinite. The universe was forced to take on the properties of a finite phenomenon, possessing a history and a beginning.
About 15 billion years ago a tremendous explosion started the expansion of the universe. This explosion is known as the Big Bang. At the point of this event all of the matter and energy of space was contained at one point. What existed prior to this event is completely unknown and is a matter of pure speculation. This occurrence was not a conventional explosion but rather an event filling all of space with all of the particles of the embryonic universe rushing away from each other. The Big Bang actually consisted of an explosion of space within itself unlike an explosion of a bomb were fragments are thrown outward. The galaxies were not all clumped together, but rather the Big Bang lay the foundations for the universe.
