The power would be converted to electricity on-board the spacecraft and sent to wherever it is needed on Earth by a large microwave-transmitting antenna or by lasers, then fed into a power grid.

Built to withstand the attack of small armies such as swords and spears, these walls were made mostly by stamping earth and gravel between board frames.

If spaceships that can fly faster than the speed of light were built, a day on board would be equivalent to a year on Earth.