By regarding the expanding universe as a motion picture, you can easily imagine "running the film backward. " If you do so, you find the universe getting smaller and smaller, and eventually you come to the moment when its whole mass is crammed into an infinitely dense point. Before that time it didn't exist, or at least it didn't exist in its present form.
Though there is some controversy about its exact age, most cosmologists would be inclined to agree that the universe has existed for about ten to twenty billion years. For scale, this can be compared to the four—and—a—half—billion—year age of the solar system, the time since the disappearance of the dinosaurs (sixty—five million years), and the age of the human race (about three million years).
The event that marked the beginning of the universe was christened the Big Bang; the term has now entered the vernacular of our culture. Originally the name referred only to the single initiating event; now, however, astronomers have come to use it to mean the entire developmental process of the birth and expansion of the cosmos.
The simple statement that the universe had a beginning in time is by now so obvious to astrophysicists that few give it a second thought. Yet it is a statement that has profound implications. Most civilizations embrace one of two opposite concepts of time. Linear time has a beginning, a duration, and an end; cyclical time, as its name suggests, continues around and around forever. In a universe that functions through cyclical time, the question of creation never arises; the universe always was and always will be. The minute you switch to linear time you immediately confront the vexing question not only of creation, but also of the Creator. Although there is no logical reason for the assumption, many people believe that if something comes into existence, it must do so in response to the actions of some rational being. Because of that belief, astronomers, even though they resist becoming involved in theological discussion, find themselves in one when they posit the Big Bang universe. It puts them squarely in the middle of an age—old debate.
One common misconception about the Big Bang that should be disposed of immediately is the notion that the universal expansion is analogous to the explosion of an artillery shell. The galaxies are not like bits of shrapnel speeding away from a central explosion . The raisin—in—dough analogy is a more satisfactory way to think about the whole process.
A newly discovered society that is based on cyclical time has a myth about the origin of the universe. What effect would this finding have on the author's opinion about societies that are based on cyclical time?[A] It is not relevant to the author's opinion.
[B] It would support the author's opinion.
[C] It would contradict the author's opinion.
[D] It would support the author's opinion only if it was shown that this society had no understanding of linear tim
The author's comparison of the universe to a motion picture serves to:[A] illustrate that the universe has operated according to linear time.
[B] demonstrate that the universe is actually older than most astronomers believe.
[C] show that galaxies were formed about five billion years ago.
[D] prove that the universe was created by a rational being.
According to the passage, which of the following statements is NOT true?[A] Many people believe that a rational impetus created the universe.
[B] The solar system was created immediately after the Big Bang.
[C] The universe is larger today than it was in the past.
[D] Different societies measure time differently.
Suppose that the solar system was actually found to be about twenty—five billion years old. What impact would this information have on current thinking about the universe's age?[A] It would support that thinking.
[B] It would undermine that thinking.
[C] It would neither support nor undermine that thinking.
[D] It would support that thinking only if the universe has expanded over time.
There are many debates implicit in the author's statements. In the context of the passage, the phrase "age—old debate " (last sentence of second last paragraph) refers to:[A] the question of whether "the Creator " created the universe.
[B] the controversy over linear versus cyclical time.
[C] the debate over the disappearance of the dinosaurs.
[D] the disagreement over the movement of galaxies
Which of the following would most strengthen opponents' arguments against the passage's claim about the movement of galaxies?[A] The discovery that galaxies are made up of different materials than the rest of the universe
[B] The discovery that the universe is growing faster in some directions than in others
[C] The discovery that galaxies frequently collide with each other, even though the universe is constantly growing larger
[D] The discovery that galaxies have continued to move, even though the universe has not increased in size for the past 5 billion years
Consider the author's main point in the passage. For which of the following statements does the passage provide some evidence or explanation?[A] The Big Bang proves that God exists.
[B] The universe will eventually be destroyed.
[C] The universe continues to expand in size.
[D] Linear time is more accurate than cyclical time.