Question

Question 2

PART B-Essay type Questions (5 Marks each) Answer one of the following questions in the exam booklets provided using essay style, i.e. paragraphs comprised of grammatically correct sentences If you answer more than one question, you may earn bonus marks (up to a maximum of 10 marks for good answers to all three questions) 1. Identify and explain the various methods used to determine distances to stars and galaxies. 2. Describe three major scientific observations which have cosmological significance (be sure to include the observation of the Cosmic Microwave Background.) How can these observations be explained within the context of the hot big bang model? To what extent does each observation support or refute the model?

Answer 1

In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from 10⁻³⁶ seconds after the conjectured Big Bang singularity to some time between 10⁻³³ and 10⁻³² seconds after the singularity. Following the inflationary period, the universe continues to expand, but at a less rapid rate.^[1]

Inflation theory was first developed in 1979 by theoretical physicist Alan Guth at Cornell University. It was developed further in the early 1980s. It explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the Universe (see galaxy formation and evolution and structure formation).^[2] Many physicists also believe that inflation explains why the universe appears to be the same in all directions (isotropic), why the cosmic microwave background radiation is distributed evenly, why the universe is flat, and why no magnetic monopoles have been observed.