Energy · c. 1 million years ago

Control of fire

Hominins learn to keep and use fire: the first energy technology outside the body.

Burned bone and ash at Wonderwerk Cave in South Africa point to controlled fire about a million years ago. Fire gave warmth, protection and cooked food, which released more calories from the same diet. Every later thermal technology, from kilns to steam turbines, descends from it.

See it in the living tree Wikipedia

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 1

First stone tools 3.3M years ago

What it led to 11

Related measurements

The dashed line marks when it first worked.

World population over a million years Latest: 6.27k million people (2000) Source: DeLong 1998, table 'Total World Population' (Kremer series); Kremer 1993, Population Growth and Technological Change: One Million B.C. to 1990, QJE 108(3)

World GDP over a million years Latest: 41k billion 1990 international $ (2000) Source: DeLong 1998, Estimating World GDP, One Million B.C. - Present; Wikipedia: Gross world product (DeLong table, cross-check)

Efficacy of selected lighting devices Latest: 303 lumens per watt (2014) Source: Nordhaus 1996, Do Real-Output and Real-Wage Measures Capture Reality? The History of Lighting Suggests Not, Table 1.3; Semiconductor Today, 26 Mar 2014: Cree breaks 300 lm/W