Question 1: The Big Bang Theory suggests that the universe originated from an extremely hot and dense state approximately 13.8 billion years ago. It explains the observed expansion of galaxies and the cosmic microwave background radiation.

Answer: The universe started from a hot, dense state about 13.8 billion years ago and is expanding, as evidenced by galaxy movement and cosmic microwave background radiation.

Question 1: Define the Big Bang Theory in your own words.

Answer: The Big Bang Theory is the scientific explanation that the universe began from a hot, dense state and has been expanding ever since.

Question 2: Explain why the cosmic microwave background radiation is important evidence for the Big Bang Theory.

Answer: Cosmic microwave background radiation is the residual heat from the early universe, providing strong evidence that the universe was once in a hot, dense state and has been expanding.

Question 1: Using Hubble's Law, v = H₀ × d, where v is the recession velocity, H₀ is Hubble's constant (70 km/s/Mpc), and d is the distance in megaparsecs, calculate the recession velocity of a galaxy 100 Mpc away.

Answer: v = 70 km/s/Mpc × 100 Mpc = 7000 km/s

Question 2: If the universe is approximately 13.8 billion years old, convert this age into seconds. (1 year = 3.154 × 10⁷ seconds).

Answer: 13.8 × 10⁹ years × 3.154 × 10⁷ s/year ≈ 4.35 × 10^{17} seconds

Question 1: Describe an experiment that could be used to detect the cosmic microwave background radiation. Include the main variables involved and safety precautions.

Answer: An experiment involves using a highly sensitive radio telescope to detect microwave radiation from space. Variables include the frequency of the microwave signals and the sensitivity of the detector. Safety precautions include shielding equipment from electromagnetic interference and ensuring proper handling of electronic components to prevent electrical hazards.

Question 1: A set of galaxies has measured recession velocities ranging from 1,000 km/s to 20,000 km/s. The corresponding distances range from 15 Mpc to 300 Mpc. What does this data suggest about the relationship between galaxy distance and recession velocity?

Answer: The data suggests a direct proportional relationship, indicating that as the distance increases, the recession velocity also increases, supporting the idea of an expanding universe.

Question 1: Explain how observations of the cosmic microwave background radiation support the Big Bang Theory and discuss its significance in cosmology. (6 marks)

Answer: Observations of the cosmic microwave background radiation provide evidence of the universe's hot, dense origin, as this radiation is a remnant of the early universe's thermal energy. Its uniformity and spectrum match predictions made by the Big Bang Theory, confirming that the universe has been expanding and cooling since its inception. This background radiation is crucial for understanding the early conditions of the universe and supports models of cosmological evolution.

Question 1: How does the understanding of the universe's expansion influence the development of modern technology, such as satellite communication or space exploration?

Answer: Understanding the universe's expansion helps in predicting cosmic phenomena, guiding satellite deployment and navigation systems, and informing space exploration missions by providing insights into cosmic distances and the universe's evolution.