Scientific American - September 2018

18th century

3rd millennium B.C.

H

UMANS DEMONSTRATE not only an extraordinary capacity for transferring knowledge

from one generation to the next, they are also supremely skilled in building on this know-

how to create novel technology, whether it be an Acheulean hand ax or the modern electri-

cal grid. This vast web of interconnected knowledge and practical capability has required

îšx§CT ̧ßä ̧…­ž§§ž ̧³ä ̧þxßîšx­ž§§x³³žCÍ4šxäøTî§xîžxä ̧…îx_š³ ̧§ ̧žxä…ß ̧­äî ̧³x‹C¦ž³î ̧šžšþ ̧§î-

age transmission lines could take a substantial time to recover if humanity were ever forced to reboot

_žþž§žąCîž ̧³C… îxßC³ø_§xCß_ ̧³‹CßCîž ̧³iC³Cäîxß ̧žläîߞ¦x ̧ßä ̧­x ̧îšxߐ§ ̧TC§_CîCäîß ̧ǚxÍ

The power of teaching, copying and, especially, enhancing the creations of previous generations

sets our species apart from all others. A new invention is rarely ever completely innovative: most often

it is a rearrangement or embellishment of preexisting technologies. The internal-combustion engine

Çßxäx³îäCÇCßîž_ø§Cߧā_§xCßxĀC­Ç§xÍîÿCäž³þx³îxlTāǞ_¦ž³ ̧†îšxäšx§…_ ̧­Ç ̧³x³îä…ß ̧­C

library of existing mechanical modules. If you peel back the metallic skin of the hood and dissect the

x³ž³xCäā ̧øÿ ̧ø§lC³ ̧ߐC³žä­iā ̧øÿž§§‰³lC_ ̧­ÇC_î ̧ߐC³žąCîž ̧³ ̧…ž³lžþžløC§­x_šC³žä­äi

each performing its own function in precise coordination with the other components, each with its

own centuries-long history.

In aggregate, the internal-combustion engine almost miraculously transforms heat released by

burning fuel into the smooth motion of the vehicle. The rapidly beating heart of a car is a set of engine

cylinders and pistons, themselves essentially identical in form to ancient water pumps. The explosive

expansion of hot gases produced by igniting fuel in the cylinders shunts out the pistons, but this back-

and-forth movement must be translated into a rotation of the driveshaft and wheels. Three of the

x³ž³xÜä_ ̧­Ç ̧³x³îäîšx_ßC³¦i_C­äšC…îC³l‹āÿšxx§iC§§ÿžîšC³_žx³îß ̧ ̧îälxäxßþx

special mention in this process.

The story of these parts, illustrated here in a historical chronology, demon-

strates that even though the purring engine in a brand-new sports car may

seem like the height of modern technologic al sophistic ation, it is in fact a mish-

mash of components co-opted from ancient inventions. Some of them

reach back to ancient China or even the very beginnings of civilization itself.

FLYWHEEL

0Ÿåï¹ ́åŸ ́D ́Ÿ ́ïyà ́D ̈ž`¹®Uùå ́y ́‘Ÿ ́yDày¹à`›yåïàDïym﹊ày

in a staggered sequence, but the explosive impulses that turn

ï›y`àD ́§å›D†ïDày¦yà§ĂjD ́mDŒĂĀ›yy ̈Ÿå ́yymymï¹åï¹ày

rotational momentum and smooth out the shaft’s spin.

5›yŒĂĀ›yy ̈jD ́Ÿ ́ ́¹ÿD ́mDïŸ ́‘UD`§ï¹ȹïïyàÝåĀ›yy ̈å

in ancient Egypt (^) ●●●jUy`D®yDåïD ́mDàmŠāïùày¹†ï›y
18th-century steam engine ●●●, a clear forerunner of
the internal-combustion engine.
Lewis Dartnell is author of the New York Times best seller The Knowledge: How to Flywheel
Rebuild Our World from Scratch (Penguin Books, 2014).
TECHNO SAPIENS
TAKING APART THE INTERNAL-COMBUSTION ENGINE
REVEALS OUR COLLECTIVE GENIUS
BY LEWIS DARTNELL
ILLUSTRATIONS BY JOSÉ MIGUEL MAYO (engine)
AND MATTHEW TWOMBLY (insets)
A
B