> Natsu was worrying about the ability of a technological civilization to function near the heat death of the universe. Unless by "heat death" he meant a cold

> Natsu was worrying about the ability of a technological civilization to function near the heat death of the universe. Unless by "heat death" he meant a cold death, current thinking has it that the universe will gradually cool off, and ultimately freeze, because of the endless expansion provided by Dark Energy. The fact that the universe is expanding exponentially, i.e. with a positive second derivative, was the first shock. The second came when the implications of this observation began to sink in.