Cycles of Time: An Extraordinary New View of the
Universe is a science
book by mathematical physicist
Roger Penrose published by The Bodley
Head in 2010. The book outlines Penrose's Conformal Cyclic Cosmology
(CCC) model, which is an extension of general relativity but opposed
to the widely supported multidimensional string theories and
cosmological inflation following the Big Bang.
Penrose examines implications of the Second Law of Thermodynamics and
its inevitable march toward a maximum entropy state of the universe.
Penrose illustrates entropy in terms of information state phase space
(with 1 dimension for every degree of freedom) where particles end up
moving through ever larger grains of this phase space from smaller
grains over time due to random motion. He disagrees with Stephen
Hawking's back-track over whether information is destroyed when
matter enters black holes. Such information loss would non-trivially
lower total entropy in the universe as the black holes wither away due
to Hawking radiation, resulting in a loss in phase space degrees of
Penrose goes on further to state that over enormous scales of time
(beyond 10100 years), distance ceases to be meaningful as all mass
breaks down into extremely red-shifted photon energy, whereupon time
has no influence, and the universe continues to expand without event
→∞. This period from
Big Bang to infinite expansion Penrose
defines as an aeon. The smooth “hairless” infinite oblivion of the
previous aeon becomes the low-entropy
Big Bang state of the next aeon
Conformal geometry preserves the angles but not the distances
of the previous aeon, allowing the new aeon universe to appear quite
small at its inception as its phase space starts anew.
Penrose cites concentric rings found in the
WMAP cosmic microwave
background survey as preliminary evidence for his model, as he
predicted black hole collisions from the previous aeon would leave
such structures due to ripples of gravitational waves.
Most nonexpert critics (nonscientists) have found the book a challenge
to fully comprehend; a few such as Kirkus Reviews and Doug
Johnstone for The Scotsman appreciate the against the grain
innovative ideas Penrose puts forth. Manjit Kumar reviewing for The
Guardian admires the
Russian doll geometry play of the CCC concept,
framing it as an idea of which
M. C. Escher
M. C. Escher "would have approved".
Graham Storrs for the New York Journal of Books concedes that this is
not the book that an unambitious lay person should plunge into. The
American fiction writer
Anthony Doerr in
The Boston Globe
The Boston Globe writes
"Penrose has never shied away from including mathematics in his texts,
and kudos to his publisher for honoring that wish. That said, the
second half of
Cycles of Time
Cycles of Time offers some seriously hard sledding";
"If you'll forgive a skiing metaphor,
Cycles of Time
Cycles of Time is a black
diamond of a book."
^ Hawking, S.W. (18 July 2005). "Information Loss in Black Holes".
Physical Review D. 72 (8): 084013. arXiv:hep-th/0507171 .
^ "Cycles of Time: An Extraordinary New View of the
Review". Kirkus Reviews. 1 April 2011.
^ Johnstone, Doug (19 September 2010). "Book reviews: The Grand Design
Cycles of Time". The Scotsman. Retrieved 26 May 2011.
^ Kumar, Manjit (16 October 2010). "Cycles of Time: An Extraordinary
New View of the
Roger Penrose – review". The Guardian.
Retrieved 27 May 2011.
^ Storrs, Graham (3 May 2011). "Cycles of Time: An Extraordinary New
View of the Universe". New York Journal of Books. Retrieved 26 May
^ Doerr, Anthony (15 May 2011). "The music of physics". The Boston
Globe. (subscription required). Retrieved 15 April 2012.
Works by Roger Penrose
The Emperor's New Mind (1989)
Shadows of the Mind
Shadows of the Mind (1994)
The Road to Reality
The Road to Reality (2004)
Cycles of Time
Cycles of Time (2010)
Fashion, Faith, and Fantasy in the New
Physics of the
The Nature of Space and Time
The Nature of Space and Time (with Stephen Hawking) (1996)
The Large, the Small and the Human Mind (with Abner Shimony, Nancy
Cartwright and Stephen Hawking) (1997)
White Mars or, The Mind Set Free (with Brian W. Aldiss) (1999)
Techniques of Differential Topology in Relativity (1972)
Spinors and Space-Time: Volume 1, Two-Spinor Calculus and Relativistic
Fields (with Wolfgang Rindler) (1987)
Spinors and Space-Time: Volume 2, Spinor and Twistor Methods in
Space-Time Geometry (with Wolfga