off the cuff claims made by executives, like "there will never be a need for more than, like, 5 computers in the whole world" are different from calculated engineering limits though. While faster-than-light travel may be possible someday, it's beyond our current technology (though there are some interesting theories at the edge of physics). Fundamental engineering limits tend to be harder to work around. eg despite all our scientific advances, cars engines are still lmited by the Carnot cycle. Moving to electric cars doesn't get rid of that limitation, just makes us subject to other limitations (currently, battery technology).