"If we could ascend into that higher domain, we would free ourselves from the straitjacket of ordinary space. We could bend our arm through an extra dimension t

"If we could ascend into that higher domain, we would free ourselves from the straitjacket of ordinary space. We could bend our arm through an extra dimension to reach into a locked safe, or see the insides of a human body laid out before us." This is often brought up in discussions on 4th dimensions but think about it: For the 4th dimensional being to see inside a closed 3D space, photons from that space should reach its visual organs. From the viewpoint of beings in 3D these photons would be "lost". This energy discrepancy should be detectable by placing 3D sensors around that space.