“The idea of having an ambient space-time of some specific dimension seems to play less of a role of string theory than in conventional physics, and certainly less than the kind of role that I would myself feel comfortable with. It is particularly difficult to assess the functional freedom that is involved in a physical theory unless one has a clear idea of its actual space-time dimensionality.”
Ch. 1, Mathematical Elegance as a Driving Force, p. 62 https://books.google.com/books?id=T09kCwAAQBAJ&pg=PA62.
Fashion, Faith, and Fantasy in the New Physics of the Universe (2016)
Help us to complete the source, original and additional information
Roger Penrose 15
English mathematical physicist, recreational mathematician … 1931Related quotes
Aerts, D. (1996). " Relativity theory: what is reality? http://www.vub.ac.be/CLEA/aerts/publications/1996RelReal.pdf". Foundations of Physics, 26, pp. 1627-1644

"Einstein and the Search for Unification", p. 11 https://books.google.com/books?id=rEaUIxukvy4C&pg=PA11, in The legacy of Albert Einstein: a collection of essays in celebration of the year of physics (2007)

Foreward, written June 30, 1999, to Supersymmetry: Unveiling the Ultimate Laws of Nature (2000) by Gordon Kane

[1992, Intersection Theory, Integrable Hierarchies and Topological Field Theory by Robbert Dijkgraaf, Fröhlich J., ’t Hooft G., Jaffe A., Mack G., Mitter P.K., Stora R. (eds.), New Symmetry Principles in Quantum Field Theory, NATO ASI Series (Series B: Physics), vol. 295, 95–158, Springer, Boston, MA, 10.1007/978-1-4615-3472-3_4]

as quoted by K.C. Cole, "A Theory of Everything" New York Times Magazine (1987) Oct.18