Inside a metal shed in the Tibetan highlands of western China, thousands of microprocessors flank narrow corridors, generating a constant hum and stifling waves of heat.
Outside, the sky is clear and blue, with a mountain peak looming at the top of a narrow wooded valley. A flock of goats ambles idly past a pile of discarded foam packaging. Inside, though, tranquility is transformed into clamor. Red, blue and green lights constantly flash; cooling water trickles down the walls, and large ventilation fans thrum as they struggle to shift the hot air produced by all this concentrated computing power.
This is a bitcoin “mine,” the engine room of the world’s leading digital currency. The microprocessors here approve and record all the transactions that keep the bitcoin system running. They also compete to solve complex mathematical problems and are rewarded with bitcoins: That’s a way of putting fresh digital currency into circulation and incentivizing more people to set up “mining” operations.
Bitcoin began as a utopian,