The problem is that we have no idea what the physics is off the 'real world'. There is no rule at all that says 'physics inside the simulation' must obey some '

The problem is that we have no idea what the physics is off the 'real world'. There is no rule at all that says 'physics inside the simulation' must obey some 'real world physics' also. Nothing. Because we don't have any knowledge of the relationship between the simulation and the 'real'. The world in Minecraft is the size of 64K Earths (or something). I do not need the amount of energy to create that amount of 'matter', in my laptop to play it. The Minecraft world has gravity, is huge, and yet, my computer didn't need that amount of energy to simulate it. Note. I don't think we are in a simulation, and a lot of the arguments for it are weak. But any of the physics based rejections, are in themselves assuming too much about what we know about whatever the outside world is.