Lights and vessels. Energy and the containers that hold it. That’s the tension that pervades all of existence. Too little energy, you die. Too much energy, you explode. So we build structures to hold and contain the energy. But building structures takes energy too. Structures need to be maintained or they fall apart. At some point the energy required for maintaining the structure exceeds the energy that the structure can hold. It’s a fundamental law of nature. It’s why perpetual motion is impossible. It’s why all living beings eventually wear out and die. We can grow and regenerate but only to a point.
Structures, energy vessels, need to be self-contained enough to survive on their own but also be able to exchange energy with the surrounding environment. Without interaction, without give and take, eventually they die too. A rock is inert but eventually it gets worn down by wind and water, its minerals feeding back into the earth and waters. Existence is a constant cycle, structures broken down, reverting to dust and pure energy, being recreated anew.