28 E. Witten, “Reflections on the fate of spacetime,” Physics Today, April 1996, 24 V 30 (1996), 29 See the string theory references in 5, and for cogent criticisms see: Lee Smolin, “The Trouble With Physics,” (Houghton Mifflin, Boston and New York 2006), in particular parts II and III. 30 B. N. Taylor and A. Thompson, “Guide for the Use of the International System of Units,” Special Publication 811 (National Institute of Standards and Technology, Gaithersburg MD 2008), and online discussion at: en.wikipedia.org/wiki/Metre#taylor 2008a 31 J. Y. Ng and H. van Dam, “On Wigner’s clock and the detectability of spacetime foam with gravitational-wave interferometers,” Phys. Lett. B 477 , 429 - 435 (2000); J. Y. Ng and H. van Dam, “Measuring the foaminess of space-time with gravity-wave interferometers,” Found.Phys. 30 , 795-805 (2000); W.A. Christiansen, J. Y. Ng, and H. van Dam, “Probing spacetime foam with extragalactic sources,” Phys. Rev.Lett. 96 , 051301 (2006) 32 See for example the website for LIGO, the Laser Interferometer Gravitational Wave Observatory at: www.ligo.caltech.edu 33 James D. Bjorken and S. D. Drell, “Relativistic Quantum Mechanics,” (McGraw Hill, New York 1964), see chapter 3. 34 James D. Bjorken and S. D. Drell, “Relativistic Quantum Fields,” (McGraw Hill, New York 1964), see chapter 11. Anthony Zee, “Quantum Field Theory in a Nutshell,” (Princeton Uni- versity Press, Princeton N. J. 2003), see chapter 1. 35 See chapter 44 of ref. 21, and chapter 15 of ref. 20. 36 Wheeler coined many descriptive terms in use today, such as quantum foam and black hole. See: C. W. Misner, Kip S. Thorne, and W. H. Zurek, “John Wheeler, relativity, and quantum information,” in “Physics Today,” April 2009. 37 See chapter 11 of ref. 20. 38 Chris Quigg, “Particles and the standard model,” in The New Physics for the Twenty-first Century, edited by Gordon Fraser, (Cambridge University Press, Cambridge UK, 2006). 39 See chapters 7 and 8 of ref. 34. 20