Question 1: The Big Bang Theory explains the origin of the universe as an expansion from an extremely hot and dense initial state. Describe in your own words what the theory proposes about the beginning of the universe.

Answer: The theory proposes that the universe started from a very hot, dense state and has been expanding ever since.

Question 1: Define cosmic microwave background radiation and explain its significance as evidence for the Big Bang Theory.

Answer: Cosmic microwave background radiation is the thermal radiation left over from the early stages of the universe, and it provides evidence for the Big Bang as it is a uniform background radiation detected from all directions.

Question 2: What does the redshift of galaxies indicate about the expansion of the universe?

Answer: Redshift shows that galaxies are moving away from us, indicating that the universe is expanding.

Question 1: Explain the concept of cosmic inflation and its role in the early universe.

Answer: Cosmic inflation is a rapid exponential expansion of the universe immediately after the Big Bang, which explains the large-scale uniformity and structure of the universe.

Question 1: The current age of the universe is estimated to be approximately 13.8 billion years. If the universe has been expanding at a constant rate, estimate its current radius, given that the speed of light is 3.0 × 10^8 m/s. (Hint: radius = speed × time).

Answer: Radius ≈ 4.2 × 10^26 metres

Question 1: Design a simple thought experiment to demonstrate how the redshift of light from distant galaxies supports the expansion of the universe. Describe the key variables involved and safety precautions if applicable.

Answer: A thought experiment involves observing the light from a galaxy and measuring its wavelength. If the wavelength is longer (redshifted) compared to a stationary source, it indicates the galaxy is moving away, supporting expansion. Key variables include wavelength, galaxy velocity, and distance. As it is a thought experiment, physical safety precautions are not applicable.

Question 1: A set of distant galaxies shows a consistent redshift indicating they are moving away from us. The velocity of these galaxies ranges from 10,000 km/s to 30,000 km/s. What does this data suggest about the rate of expansion of the universe?

Answer: The data suggests that the universe is expanding at an increasing rate, with galaxies moving away faster as their velocity increases.

Question 1: How has the understanding of cosmic microwave background radiation influenced the development of observational astronomy instruments?

Answer: It has led to the development of highly sensitive microwave detectors and space telescopes designed to measure faint thermal radiation, improving our ability to study the early universe.

Question 1: In your opinion, what is the most compelling piece of evidence supporting the Big Bang Theory, and why?

Answer: The most compelling evidence is the cosmic microwave background radiation because it is a remnant from the early universe and is consistent with predictions of the Big Bang model.