Energy on Earth primarily originates from the sun and the Big Bang, with additional contributions from meteors and radiation from other celestial bodies. The discussion highlights the need for specificity when addressing energy sources, such as fossil fuels or nuclear energy. It emphasizes that most of the Earth's internal energy comes from gravitational potential energy released during its formation. While the sun is the dominant source, other factors also play a role in Earth's energy dynamics. Overall, understanding these sources requires a nuanced approach to the various forms of energy present on Earth.