Glossary
in a nuclear explosion, in which the breakdown of each atom triggers the
breakdown of other nearby atoms.Fertile Crescent: The arc of lands around Mesopotamia, which contain the
earliest evidence of agriculture.¿ restick farming: Not a form of farming, but a foraging strategy; foragers
regularly burn the land to prevent wild¿ res, to encourage new growth, and
to attract grazers that can be hunted. Though a form of foraging, it also
counts as a way of manipulating the environment in order to increase the
productivity of resources useful to humans, so it can be regarded as a step
toward farming.¿ ssion: The breaking up of large atoms, such as uranium, releases radioactive
energy; when many atoms are close together, the breakup of one atom can
release subatomic particles that split other atoms, in a chain reaction; this
chain reaction drives nuclear weapons and nuclear reactors.foraging: Technologies that depend on the use of natural resources more
or less in their natural state; hunting and gathering; the dominant type of
technology in the Paleolithic era.fossil fuels: Fuels formed from living organisms fossilized in the remote past,
they are the dominant source of energy today; fossil fuels include coal, oil,
and natural gas; the “fossil fuels revolution” is the transition to dependence
on fossil energy that has occurred since the Industrial Revolution.free energy: Energy distributed unevenly so that it is capable of doing
useful work; a charged battery can do work because negative charges are
concentrated at one of its terminals, but as it does work, the balance of
negative and positive charges evens out, increasing entropy and reducing its
capacity to do more work.free energy rate density: The density of free energy À owing through a
complex entity, measured in units of energy passing through a given mass in
a given amount of time; Eric Chaisson has argued that the free energy rate
density provides a rough measure of levels of complexity.