- absolute zero, 1, 2 n. 7
- AC (alternating current), 1, 2, 3 n. 19
- acceleration, 1, 2, 3, 4 n. 2, 5 n. 6 infra;
- see also gravity
- acetycholine, 1
- acidity, 1
- acids, 1, 2;
- fatty acids, see lipids;
- see also amino acids
- Acorn Computers, 1
- Ada computer language, 1 n. 3
- Adams, Douglas, 1, 2
- Adder’s-tongue fern, see Ophioglossum vulgatum
- adenine, 1
- aeroplanes, 1, 2, 3 n. 9;
- Boeing 747, 1
- Afar, Ethiopia, 1
- Africa, 1, 2, 3, 4, 5, 6, 7, 8;
- see also South Africa
- Agassiz, Louis, 1
- agriculture, see farming
- air, 1, 2, 3, 4;
- convection, 1, 2, 3 n. 8, 4 nn. 10, 12; 5 n. 16;
- pressure, 1;
- pressure equalisation, 1;
- resistance, 1;
- in a thunderstorm, 1, 2 nn. 7, 9;
- see also Earth: atmosphere, Hadley circulation cells, vortices, weather systems, wind
- alchemy, 1
- alcohol, 1
- algae, 1 n. 6;
- blue-green, 1, 2
- alleles, 1
- Allen, Tim, 1
- Allen, Woody, 1
- alpacas, 1
- Alpha Centauri, 1, 2
- alpha particles, 1, 2
- altruism, 1
- alveoli, 1
- Amazon.com, 1
- Americans, Native, 1;
- see also Aztecs, Incas
- Americas, 1;
- see also North America, South America
- amino acids, 1, 2, 3
- amygdala, see limbic system
- ancestry, 1 n. 13
- Anderson, Philip, 1
- Andes, 1, 2
- Andromeda Galaxy, 1, 2
- angular momentum, 1;
- law of conservation of, 1, 2
- animals, 1;
- diseases, 1;
- domestication, 1, 2, 3, 4, 5;
- extinction, 1, 2;
- and food, 1;
- interbreeding, 1;
- mitochondria, 1;
- multicellular, 1, 2;
- as pets, 1;
- as prey, 1;
- reproduction, 1, 2;
- respiration, 1, 2, 3, 4;
- sight, 1;
- single-celled, 1;
- stamina, 1;
- variation, 1, 2, 3;
- see also bones, clothing, meat, natural selection, nervous system
- Antarctic ice sheet, 1
- Antarctica, 1, 2, 3
- antibiotics, 1, 2, 3;
- resistance to, 1
- anticyclones, see weather systems
- antimatter, 1
- antiparticles, 1, 2;
- electrical charge, 1;
- spin, 1
- anti-quarks, 1
- ants, 1
- apes, 1, 2, 3, 4, 5, 6, 7
- Apollo 1, 2
- apoptosis, 1
- archaea bacteria, 1, 2 nn. 5, 6
- Arctic Sea, 1
- argon, 1
- ARM, 1
- Armstrong, Neil, 1
- arsenic, 1
- art and artists, 1, 2
- artificial selection, 1
- asexual reproduction, 1, 2, 3
- Asia, 1, 2, 3, 4
- Aspect, Alain, 1
- asteroids, 1
- astronomy and astronomers, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
- @Katharine_T1m, 2 n. 7
- @MrDFJBaileyEsq, 1 n. 17
- Atkins, Peter, 1, 2
- Atlantic Ocean, 1, 2, 3, 4, 5, 6;
- see also mid-Atlantic Ridge, transatlantic cables
- atomic clock, 1, 2
- atoms, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 n. 2, 15 n. 15, 16 n. 13, 17 n. 4, 18 n. 5, 19 n. 2, 20 n. 10, 21 n. 7, 22 n. 12, 23 n. 14;
- alignment, 1;
- doping, 1, 2;
- electrically charged, 1, 2, 3 n. 6;
- nucleus, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 n. 6, 14 n. 3, 15 n. 14, 16 n. 2, 17 n. 10, 18 nn. 6, 8; 19 n. 14;
- and quantum theory, 1, 2, 3, 4, 5, 6 n. 5;
- structure, 1, 2, 3 n. 3;
- see also electrons, leptons, molecules, muons, neutrons, neutrinos, photons, protons, quarks
- ATP (adenosine triphosphate), 1, 2, 3
- Augarten, Stan, 1
- austerity, 1
- Australia, 1, 2;
- fossils, 1
- australopithecines, 1, 2, 3
- Australopithecus afarensis, 1
- Australopithecus anamensis, 1
- axes, 1
- axons, see nerve cells
- Aztecs, 1