How does nuclear fusion in stars contribute to the universe?

Nuclear fusion in stars plays a fundamental role in both the energy production and elemental creation in the universe. In the cores of stars, immense pressure and high temperatures allow hydrogen nuclei to fuse together to form helium, releasing a tremendous amount of energy in the process. This energy is what powers stars, providing the light and heat that make life possible on planets like Earth.

Additionally, nuclear fusion is responsible for the formation of heavier elements. As stars evolve, they can fuse helium into heavier elements like carbon, oxygen, and even up to iron in larger stars. When these stars reach the end of their life cycles, they can explode in supernovae, dispersing these newly formed elements throughout the universe. This process enriches the interstellar medium with the building blocks necessary for the creation of new stars, planets, and potentially, life itself.

Thus, the contribution of nuclear fusion is crucial, as it not only provides the energy that sustains stars but also facilitates the chemical evolution of the universe through the creation of new elements.