IB MYP 4-5 Physics | Astrophysics | The Big Bang theory Practice Question

Ans:

The steady-state theory and the Big Bang theory are two contrasting explanations for the origin and evolution of the universe. Here are two ways in which the steady-state theory differs from the Big Bang theory:

1. Universe’s Origin and Expansion: The steady-state theory proposes that the universe has no beginning or end, implying that it has existed infinitely. In contrast, the Big Bang theory suggests that the universe originated from a singular, incredibly dense and hot state approximately 13.8 billion years ago. According to the Big Bang theory, the universe has been expanding and evolving since its initial explosion.

2. Conservation of Matter and Density: The steady-state theory postulates that as the universe expands, new matter is continuously created to maintain a constant density. This theory rejects the notion that the density of matter decreases over time due to the expansion. Conversely, the Big Bang theory posits that matter and energy were created during the initial singularity and have been gradually spreading out and becoming less dense as the universe expands. It does not require the continuous creation of matter.

Overall, the key differences lie in the concepts of the universe’s origin and the conservation of matter and density. The steady-state theory suggests a constant, eternal universe with continuous matter creation, while the Big Bang theory proposes a singular origin, expansion, and a decrease in matter density over time.