What is nebular theory and the four subsystems that people depend on?

Answer 1

NEBULAR THEORY, a theory advanced to account for the origin of the solar system. It is emphatically a speculation; it cannot be demonstrated by observation or established by mathematical calculation. Yet the boldness and the splendour of the nebular theory have always given it a dignity not usually attached to a doctrine which from the very nature of the case can have but little direct evidence in its favour.

Answer 2

The nebular theory is a widely accepted model of how our solar system formed from a large cloud of gas and dust known as a nebula. The four subsystems that people depend on are the lithosphere (Earth's solid outer layer), hydrosphere (all of Earth's water), atmosphere (the gases that surround Earth), and biosphere (the zone of life on Earth). These subsystems interact and support life on our planet.