Does the expansion of Space require continuous energy?? I'm curious; does the expansion of Space require energy? I'm assuming that the expansion of space must have some kind of 'momentum' (the big bang must have required an input of inertial energy directly into the geometrical expansion of space itself). I guess my question is; does this expansion require a continuous input of energy to keep it expanding? My intuition tells me 'No' only because GR is supposed to behave similar to any Newtonian equivalent, but this still requires a kind of inertia behind the expansion, right? Do we have a theory of how this came to be? Was there some instantaneous and temporary Lambda-like 'jolt' that got everything moving right at the first instance of time? My next question is, is this energy positive? If the universe is now being accelerated by a Lambda-like force, is this force also a form of energy, and if so, is this energy positive or negative? Any input is appreciated. Clarification: I have heard that the Lambda energy is tension energy in theory, and therefore is a negative form of energy, and therefore is repulsive and not attractive like gravity. BUT, I have also heard that gravity is a negative form of energy in the first place. Does this make Lambda a 'double-negative' and therefore it is a positive form of energy?