Explaining Solar System Formation: The Nebular Hypothesis

The question asks for the theory that best explains how our solar system formed from a spinning cloud made of gas and dust. Let's examine the options to see which one fits this description.

Understanding the Nebular Hypothesis

The Nebular Hypothesis is the leading scientific theory for how stars and planetary systems form. It suggests that:

• Our solar system began as a huge, slowly rotating cloud of interstellar gas and dust, known as a solar nebula.
• Due to some disturbance (like a nearby supernova explosion), this cloud began to collapse under its own gravity.
• As it collapsed, the cloud spun faster (conserving angular momentum) and flattened into a rotating disk, with a dense center.
• The central mass eventually became hot and dense enough to ignite nuclear fusion, forming the Sun.
• In the surrounding disk, dust particles stuck together, forming larger clumps called planetesimals.
• These planetesimals collided and merged over millions of years, eventually growing into the planets, moons, and other bodies we see today.

This process directly aligns with the idea of forming from a rotating cloud of gas and dust.

Evaluating Other Theories

Let's look at why the other options are not the correct explanation for the solar system's formation from a gas cloud:

• Big Bang Theory: This theory explains the origin and evolution of the entire universe itself, starting from an extremely hot and dense state about 13.8 billion years ago. It doesn't specifically detail the formation of individual solar systems from nebulae.
• Continental Drift Theory: Proposed by Alfred Wegener, this theory explains that the Earth's continents have moved over geologic time relative to each other. It deals with Earth's geology, not the formation of the entire solar system.
• Plate Tectonics Theory: This is a more modern and comprehensive theory that explains the large-scale movements of Earth's lithosphere. It builds upon continental drift but focuses on geological processes within the Earth, not the formation of the solar system.

Conclusion

Based on the descriptions, the Nebular Hypothesis is the theory specifically designed to explain the formation of solar systems, including our own, from the gravitational collapse and evolution of a rotating nebula of gas and dust.