1. Uhuru satellite, 1
2. ultraviolet light, 1, 2, 3, 4 n. 19
3. uncomputability, 1 n. 4
4. undecidability, 1 n. 4
5. United States, 1
6. Universal Turing Machine, 1
7. Universe: age, 1, 2, 3, 4, 5 n. 18;
   1. and dark energy, 1, 2;
   2. and entropy, 1, 2, 3 n. 12;
   3. expansion, 1, 2, 3, 4, 5, 6 n. 16, 7 n. 9, 8 n. 18;
   4. formation, 1, 2, 3, 4, 5, 6, 7, 8 n. 13, 9 nn. 14, 16;
   5. future of, 1, 2, 3;
   6. and galaxies, 1, 2 n. 4;
   7. as image, 1, 2;
   8. inflation, 1, 2, 3, 4 n. 5;
   9. and light, 1, 2, 3, 4, 5, 6, 7, 8, 9 n. 14, 10 n. 2;
   10. and mass energy, 1, 2;
   11. observable, 1, 2, 3, 4 n. 9, 5 n. 19;
   12. past of, 1, 2, 3, 4, 5 n. 10, 6 n. 5, 7 n. 8;
   13. perception of, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 n. 5, 16 n. 4, 17 n. 4;
   14. and quantum theory, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 n. 12;
   15. scale, 1, 2 n. 9;
   16. temperature, 1, 2, 3 n. 13;
   17. see also big bang, cosmic background radiation, event horizon, galaxies, Hawking radiation, ‘last scattering’, multiverse, red shift
8. University College, London, 1
9. uranium, 1, 2, 3
10. Uranus, 1 n. 2, 2 n. 7
11. US Navy, 1
12. uterus, 1