About 10,000 years ago, hunter-gatherers, aided by rudimentary agriculture, moved to semi-permanent villages and never looked back. With further developments came food surpluses, leading to commerce, specialization and, many years later with the Industrial Revolution, the modern city. Vance Kite plots our urban past and how we can expect future cities to adapt to our growing populations.
The Earth intercepts a lot of solar power: 173,000 terawatts. That’s 10,000 times more power than the planet’s population uses. So is it possible that one day the world could be completely reliant on solar energy? Richard Komp examines how solar panels convert solar energy to electrical energy.