Universe [ENDORSED]

[Mia Navarro 1D]

What type of system is the universe, and how do you know?

[Isita Tripathi 2E]

The universe is an isolated system because it cannot exchange heat or matter with its surroundings, as technically it has no "boundary" where you could distinguish external surroundings.

[Hailey Johnson]

The universe is an isolated system because it has no boundaries that could be used to distinguish it from its surroundings, and, therefore, it cannot exchange energy or matter with its surroundings.

[Jessica Benitez 1K]

Since the universe is an isolated system, it follows the first law of thermodynamics which is that the internal energy of an isolated system is constant. Therefore, the energy of the universe is constant.