Question 1: Define dark mass and dark energy, highlighting their roles in the universe.

Answer: Dark mass, also known as dark matter, is a form of matter that does not emit, absorb or reflect light, but exerts gravitational effects. Dark energy is a mysterious form of energy that causes the accelerated expansion of the universe.

Question 2: Explain how dark energy affects the expansion rate of the universe.

Answer: Dark energy contributes a repulsive effect that accelerates the expansion of the universe, counteracting gravity from matter.

Question 1: Given that the current density parameter for dark energy, ΩΛ, is approximately 0.7, and the critical density of the universe is 8.5 × 10⁻²⁷ kg/m³, estimate the density of dark energy in kg/m³.

Answer: 5.95 × 10⁻²⁷ kg/m³

Question 2: If the total mass of dark matter in the observable universe is approximately 2 × 10²⁰ solar masses, calculate this mass in kilograms. (1 solar mass = 1.989 × 10³⁰ kg)

Answer: 3.978 × 10⁵⁰ kg

Question 1: Outline the key variables to control and safety precautions required when conducting experiments aimed at detecting dark matter particles.

Answer: Variables include shielding from cosmic rays, temperature, and detector sensitivity. Safety precautions involve radiation shielding and proper handling of sensitive equipment.

Question 1: A cosmological observation reports that the universe's expansion rate is increasing over time. Explain how this supports the existence and effects of dark energy.

Answer: The increasing expansion rate suggests a repulsive force counteracting gravity, consistent with dark energy driving accelerated expansion.

Question 1: Describe how the presence of dark matter and dark energy affects the overall dynamics and fate of the universe. Include relevant formulas and concepts. (6 marks)

Answer: Dark matter contributes to the gravitational attraction that influences galaxy formation and the structure of the universe, increasing its overall mass density. Dark energy exerts a repulsive effect, causing the universe's expansion to accelerate. The balance between these components determines the universe's ultimate fate—whether it will continue expanding forever or eventually contract. The Friedmann equations incorporate these effects through density parameters Ω, influencing the scale factor's evolution over time.

Question 1: Discuss how research into dark energy influences the development of advanced cosmological models and the potential future technologies they might enable.

Answer: Research into dark energy refines cosmological models, improving our understanding of the universe's expansion and evolution, which could lead to breakthroughs in space travel, energy harnessing, and understanding fundamental physics.