extraterrestrial life

first, an apology. i haven't been posting much because i've been studying for the bar exam, which i will be sitting for in two weeks. hooray.

so, i just wanted to let everyone know i'm still alive and thinking, by submitting a theory, for your collective consideration.

it occurs to me that extraterrestrial life, whatever its manifestation, must necessarily be similar to ours in that it requires energy to sustain itself. this should be especially true in the case of anything we would call a "civilization."

also, it appears that nuclear fusion is the most efficient method of energy production possible. but even if nuclear fusion could be sustained without gravity, it could only use light elements, which would be relatively scarce on a planet that can support life. thus, the most abundant and efficient source of energy for a civilization, no matter how technologically advanced, would have to be its star.

that being the case, i would posit that if an alien civilization is significantly advanced, it would have arrived at a point where, in order to sustain its energy needs, it could not rely only on the radiation arriving on the planet, but would have to envelop its sun to capture energy radiating in all directions.

this leads me to wonder whether, in our search for extraterrestrial life, we may be overlooking such a civilization, because shielding would make it difficult to detect.