Certain theorists believe that some time after the Big Bang, fluctuations in the flow of matter and energy constituted seeds for galaxy formation. All models for generating fluctuations on a cosmological scale require a phase transition--a change in the fabric of space to produce lumps and ripples in the distribution of matter. When water freezes to form an ice cube, for example, parts often freeze at slightly different rates to form regions of ice, seen as fractured lines and planes that do not quite mesh. The question is when the phase transition took place.
The idea of a late phase transition is appealing because such a change would have occurred after energy in the form of electromagnetic radiation, or of photons, stabilized. This means a late phase transition would have had practically no effect on the microwave background radiation, which pervades the universe and appears uniform in every direction.
Alternative theories in which phase transitions happened earlier have difficulty explaining how fluctuations can grow to become seeds for galaxy formation without distorting the microwave background radiation to a greater extent than has been observed. Measurements of distortions in the microwave background radiation would provide the best tests of the new model. The less distortion observers detect, the more promising a late phase transition model will look.
1) According to the passage, which of the following would be regarded as most helpful in assessing competing hypotheses concerning the formation of galaxies?
A) An accurate measurement of the fractured lines and planes present in the fabric of space
B) The reliable detection of lumps and ripples in the matter in the distant regions of space
C) Accurate information regarding the amount of distortion in microwave background radiation
D) Detailed astronomical maps of visible galaxies with an age estimation of their distribution
E) An accurate measurement of the rate of the flow of matter and energy necessary to distort microwave background radiation
2) Which of the following best describes the primary focus of the passage?
A) Considering the possibility of a late-phase transition in the formation of the galaxies
B) Analyzing the causes of the fluctuations in matter and energy in galaxy formation
C) Describing the way in which galaxies formed after the Big Bang, and proposing other hypotheses
D) Comparing various theories regarding late phase transition, and assessing ways of judging their validity
E) Examining the possibility of a late phase transition in the formation of microwave background radiation
3) The author brings up the information about uniformity of microwave background radiation in order to
A) show the ways in which fractured lines and planes do not mesh
B) propose that an early phase transition is less likely
C) explore why a late phase transition did not leave greater distortion in the fabric of microwave background radiation
D) analyze the likelihood of flaws and lumps in the plane of space
E) examine the idea that the Big Bang produced lumps and ripples in matter