What can simultaneously solve both the flatness and horizon problems in cosmology?
A) GUTs
B) Quantum mechanics
C) Inflation
D) Dark energy

Question

Quizplus · Accepted Answer

Inflation is proposed as a mechanism that can simultaneously solve both the flatness and horizon problems in cosmology. The flatness problem refers to the observation that the universe appears to be flat, meaning that parallel lines never meet or diverge. In a universe with matter and radiation, the energy density should be changing over time, and for the universe to remain flat, it would need to be fine-tuned to incredible precision. The horizon problem refers to the observation that regions of the universe that are far apart appear to have the same temperature, even though there has not been enough time for them to communicate with each other. Inflation is proposed as a period of rapid expansion of the universe in the early stages, which would cause the universe to become flat and smooth out temperature variations.

What Can Simultaneously Solve Both the Flatness and Horizon Problems