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 an extremely hot and dense state and has been expanding since.

Question 2: Explain how redshift supports the expansion of the universe.

Answer: Redshift occurs when light from distant galaxies shifts to longer wavelengths, indicating they are moving away, which supports the idea that the universe is expanding.

Question 1: The current measured rate of expansion of the universe is given by Hubble's constant, approximately 70 km/s/Mpc. Calculate the approximate age of the universe in billion years, using the formula: Age ≈ 1 / Hubble's constant. (Note: convert Hubble's constant to SI units: 1 Mpc = 3.086 × 10^22 m).

Answer: Approximately 13.9 billion years

Question 2: If a galaxy is observed to have a redshift z = 0.5, estimate its recessional velocity using the approximation v ≈ z × c, where c = 3.00 × 10^8 m/s. Show your working.

Answer: v ≈ 0.5 × 3.00 × 10^8 m/s = 1.50 × 10^8 m/s

Question 1: Describe the key safety precautions scientists must follow when operating large telescopes for astronomical observations.

Answer: Precautions include ensuring proper electrical safety, maintaining stable mountings, protecting sensitive equipment from environmental damage, and following protocols to prevent exposure to hazardous materials.

Question 2: Identify variables that would affect measurements of cosmic microwave background radiation in an experimental setup.

Answer: Variables include temperature stability, electromagnetic interference, calibration of instruments, and atmospheric conditions.

Question 1: A distant galaxy shows a measured redshift of z = 2.0. Discuss what this indicates about its relative motion and the state of the universe at the time the light was emitted.

Answer: A redshift of z = 2.0 indicates the galaxy is moving away at a significant fraction of the speed of light, implying the universe was much smaller and denser at the time the light was emitted. This supports the theory that the universe is expanding from an initial hot, dense state.

Question 1: Explain how the observation of cosmic microwave background radiation provides evidence for the Big Bang Theory. (6 marks)

Answer: The cosmic microwave background (CMB) is residual radiation from the early universe, detected as a uniform background in all directions. Its temperature and properties match predictions made by the Big Bang Theory, providing strong evidence that the universe began from a hot, dense state and has been expanding and cooling since.

Question 1: Describe how understanding the expansion of the universe has impacted the development of modern cosmology and technology, such as satellite-based telescopes.

Answer: Understanding the universe's expansion has led to advancements in observational technology, like satellite telescopes, which allow astronomers to study distant objects with greater precision, improving our knowledge of cosmology and the universe's origin.