Many years ego, Earth was hot. Over time, it has lost energy and has become colder. Is it now in equilibrium or is its total energy changing?
Lightning contains a lot of energy, so where does this energy go after lightning has hit the ground? Does it travel all the way to the core? What happens after that?
What is the most energy-efficient way to crush the hardest bedrock on earth while assuming it is impossible to use the chain reaction energy from that bedrock? How many energy is needed?