We limit ourselves by our level of intelligence. If we had the ability to look at things differently than what laws govern our world (physically and metaphysically) then technological possibilities are endless. We limit ourselves by what boundaries we have established and are given. That is why some of the greatest minds in the world operate unrestricted. Aliens could very well operate unrestricted and have the ability to function and operate differently. Much as they probably have different needs in terms of food, shelter, etc.