Sean M. Carroll
Encyclopedia
Sean Michael Carroll is a senior research associate in the Department of Physics at the California Institute of Technology
. He is a theoretical cosmologist
specializing in dark energy
and general relativity
. He is also a contributor to the physics blog
Cosmic Variance
, and has published in scientific journals and magazines such as Nature
, Seed
, Sky & Telescope
, and New Scientist
.
Described as a gifted science communicator, he has appeared on the History Channel's The Universe
, Science Channel's Through the Wormhole with Morgan Freeman
, and Comedy Central's The Colbert Report. Carroll is the author of Spacetime And Geometry, a graduate-level textbook in general relativity, and has also recorded a set of lectures for the Teaching Company
entitled Dark Matter, Dark Energy: The Dark Side of the Universe. His most recent book, released in January 2010, is on the arrow of time
entitled From Eternity to Here.
, where his advisor was George B. Field
. His dissertation's title is "Cosmological Consequences of Topological and Geometric Phenomena in Field Theories". He worked as a postdoctoral researcher at the Massachusetts Institute of Technology
and Kavli Institute for Theoretical Physics
at the University of California, Santa Barbara
, and as an assistant professor at the University of Chicago
until 2006 when he was denied tenure.
.
; the appearance of closed timelike curve
s in general relativity; varieties of topological defect
s in field theory; and cosmological dynamics of extra spacetime dimensions. In recent years he has written extensively on models of dark energy
and its interactions with ordinary matter and dark matter
, as well as modifications of general relativity
in cosmology.
Carroll has also worked on the arrow of time
problem. He and Jennifer Chen posit that the Big Bang
is not a unique occurrence as a result of all of the matter and energy in the universe originating in a singularity at the beginning of time, but rather one of many cosmic inflation
events resulting from quantum fluctuation
s of vacuum energy
in a cold De Sitter space
. Carroll and Chen claim that the universe is infinitely old, but never reaches thermodynamic equilibrium
as entropy increases continuously without limit due to the decreasing matter and energy density attributable to recurrent cosmic inflation. They assert that the universe is "statistically time-symmetric" insofar as it contains equal progressions of time "both forward and backward".
.
, on the grounds that he did not want to appear to be supporting a reconciliation between science and religion. In 2004 he and Shadi Bartsch
taught an undergraduate course at the University of Chicago on the history of atheism.
California Institute of Technology
The California Institute of Technology is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering...
. He is a theoretical cosmologist
Physical cosmology
Physical cosmology, as a branch of astronomy, is the study of the largest-scale structures and dynamics of the universe and is concerned with fundamental questions about its formation and evolution. For most of human history, it was a branch of metaphysics and religion...
specializing in dark energy
Dark energy
In physical cosmology, astronomy and celestial mechanics, dark energy is a hypothetical form of energy that permeates all of space and tends to accelerate the expansion of the universe. Dark energy is the most accepted theory to explain recent observations that the universe appears to be expanding...
and general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
. He is also a contributor to the physics blog
Blog
A blog is a type of website or part of a website supposed to be updated with new content from time to time. Blogs are usually maintained by an individual with regular entries of commentary, descriptions of events, or other material such as graphics or video. Entries are commonly displayed in...
Cosmic Variance
Cosmic Variance (blog)
Cosmic Variance is a collaborative weblog discussing physics, astrophysics, and other topics, written by , Mark Trodden, Sean Carroll, , Julianne Dalcanton, , and . It is the successor to Carroll's earlier blog , which began in early 2004 and ran through much of 2005...
, and has published in scientific journals and magazines such as Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...
, Seed
Seed (magazine)
Seed is an online science magazine published by Seed Media Group. The magazine looks at big ideas in science, important issues at the intersection of science and society, and the people driving global science culture...
, Sky & Telescope
Sky & Telescope
Sky & Telescope is a monthly American magazine covering all aspects of amateur astronomy, including the following:*current events in astronomy and space exploration;*events in the amateur astronomy community;...
, and New Scientist
New Scientist
New Scientist is a weekly non-peer-reviewed English-language international science magazine, which since 1996 has also run a website, covering recent developments in science and technology for a general audience. Founded in 1956, it is published by Reed Business Information Ltd, a subsidiary of...
.
Described as a gifted science communicator, he has appeared on the History Channel's The Universe
The Universe (TV series)
The Universe is an American documentary television series that features computer-generated imagery and computer graphics of astronomical objects in the universe plus interviews with experts who study in the fields of cosmology, astronomy, and astrophysics...
, Science Channel's Through the Wormhole with Morgan Freeman
Through the Wormhole
Through the Wormhole with Morgan Freeman is an American science documentary television series narrated by American actor Morgan Freeman. It began airing on Science in the United States on June 9, 2010.- Development :...
, and Comedy Central's The Colbert Report. Carroll is the author of Spacetime And Geometry, a graduate-level textbook in general relativity, and has also recorded a set of lectures for the Teaching Company
The Teaching Company
The Teaching Company is a Chantilly, Virginia company that produces recordings of lectures by university professors and high-school teachers. It sells the courses in CD, DVD, MPEG-4, and MP3 formats.- Background :...
entitled Dark Matter, Dark Energy: The Dark Side of the Universe. His most recent book, released in January 2010, is on the arrow of time
Arrow of time
The arrow of time, or time’s arrow, is a term coined in 1927 by the British astronomer Arthur Eddington to describe the "one-way direction" or "asymmetry" of time...
entitled From Eternity to Here.
Career
Carroll received his Ph.D. in Astronomy and Astrophysics in 1993 from Harvard UniversityHarvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
, where his advisor was George B. Field
George B. Field
George B. Field is an American astrophysicist.- Education and career :Field became interested in astronomy at an early age, but at the urging of his father he studied chemical engineering at the Massachusetts Institute of Technology. Disliking engineering, he later switched to astrophysics...
. His dissertation's title is "Cosmological Consequences of Topological and Geometric Phenomena in Field Theories". He worked as a postdoctoral researcher at the Massachusetts Institute of Technology
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...
and Kavli Institute for Theoretical Physics
Kavli Institute for Theoretical Physics
The Kavli Institute for Theoretical Physics is a research institute of the University of California, Santa Barbara. KITP is one of the most renowned institutes for theoretical physics in the world. KITP programs bring theorists in physics and related fields together to work together on topics at...
at the University of California, Santa Barbara
University of California, Santa Barbara
The University of California, Santa Barbara, commonly known as UCSB or UC Santa Barbara, is a public research university and one of the 10 general campuses of the University of California system. The main campus is located on a site in Goleta, California, from Santa Barbara and northwest of Los...
, and as an assistant professor at the University of Chicago
University of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...
until 2006 when he was denied tenure.
Personal life
Carroll is married to Jennifer Ouellette, a science writer and the Director of the Science & Entertainment ExchangeScience & Entertainment Exchange
The Science & Entertainment Exchange is a program ofthe United States National Academy of Sciences developed to increase public awareness, knowledge, and understanding of science through its representation in television, film, and other media...
.
Research
Carroll has worked on a number of topics in theoretical cosmology, field theory, and gravitation theory. His research papers include models of, and experimental constraints on, violations of Lorentz invarianceLorentz covariance
In standard physics, Lorentz symmetry is "the feature of nature that says experimental results are independent of the orientation or the boost velocity of the laboratory through space"...
; the appearance of closed timelike curve
Closed timelike curve
In mathematical physics, a closed timelike curve is a worldline in a Lorentzian manifold, of a material particle in spacetime that is "closed," returning to its starting point...
s in general relativity; varieties of topological defect
Topological defect
In mathematics and physics, a topological soliton or a topological defect is a solution of a system of partial differential equations or of a quantum field theory homotopically distinct from the vacuum solution; it can be proven to exist because the boundary conditions entail the existence of...
s in field theory; and cosmological dynamics of extra spacetime dimensions. In recent years he has written extensively on models of dark energy
Dark energy
In physical cosmology, astronomy and celestial mechanics, dark energy is a hypothetical form of energy that permeates all of space and tends to accelerate the expansion of the universe. Dark energy is the most accepted theory to explain recent observations that the universe appears to be expanding...
and its interactions with ordinary matter and dark matter
Dark matter
In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...
, as well as modifications of general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
in cosmology.
Carroll has also worked on the arrow of time
Arrow of time
The arrow of time, or time’s arrow, is a term coined in 1927 by the British astronomer Arthur Eddington to describe the "one-way direction" or "asymmetry" of time...
problem. He and Jennifer Chen posit that the Big Bang
Big Bang
The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
is not a unique occurrence as a result of all of the matter and energy in the universe originating in a singularity at the beginning of time, but rather one of many cosmic inflation
Cosmic inflation
In physical cosmology, cosmic inflation, cosmological inflation or just inflation is the theorized extremely rapid exponential expansion of the early universe by a factor of at least 1078 in volume, driven by a negative-pressure vacuum energy density. The inflationary epoch comprises the first part...
events resulting from quantum fluctuation
Quantum fluctuation
In quantum physics, a quantum fluctuation is the temporary change in the amount of energy in a point in space, arising from Werner Heisenberg's uncertainty principle.According to one formulation of the principle,energy and time can be related by the relation...
s of vacuum energy
Vacuum energy
Vacuum energy is an underlying background energy that exists in space even when the space is devoid of matter . The concept of vacuum energy has been deduced from the concept of virtual particles, which is itself derived from the energy-time uncertainty principle...
in a cold De Sitter space
De Sitter space
In mathematics and physics, a de Sitter space is the analog in Minkowski space, or spacetime, of a sphere in ordinary, Euclidean space. The n-dimensional de Sitter space , denoted dS_n, is the Lorentzian manifold analog of an n-sphere ; it is maximally symmetric, has constant positive curvature,...
. Carroll and Chen claim that the universe is infinitely old, but never reaches thermodynamic equilibrium
Thermodynamic equilibrium
In thermodynamics, a thermodynamic system is said to be in thermodynamic equilibrium when it is in thermal equilibrium, mechanical equilibrium, radiative equilibrium, and chemical equilibrium. The word equilibrium means a state of balance...
as entropy increases continuously without limit due to the decreasing matter and energy density attributable to recurrent cosmic inflation. They assert that the universe is "statistically time-symmetric" insofar as it contains equal progressions of time "both forward and backward".
From Eternity To Here
From Eternity To Here: The Quest for the Ultimate Theory of Time is a popular cosmology book, by Carroll, published in January 2010. It tackles a fundamental open principle in physics: the arrow of timeArrow of time
The arrow of time, or time’s arrow, is a term coined in 1927 by the British astronomer Arthur Eddington to describe the "one-way direction" or "asymmetry" of time...
.
Religious beliefs
Carroll is an outspoken atheist, who argues that scientific thinking leads one to a materialist worldview. He turned down an invitation to speak at a conference sponsored by the John Templeton FoundationJohn Templeton Foundation
"The John Templeton Foundation is a philanthropic organizationthat funds inter-disciplinary research about human purpose and ultimate reality. It is usually referred to simply as the Templeton Foundation...
, on the grounds that he did not want to appear to be supporting a reconciliation between science and religion. In 2004 he and Shadi Bartsch
Shadi Bartsch
Shadi Bartsch is the Ann L. and Lawrence B. Buttenwieser Professor of Classics at the University of Chicago. She has previously held professorships at the University of California Berkeley and Brown University where she was the W...
taught an undergraduate course at the University of Chicago on the history of atheism.
Publications
- Carroll, Sean, "Spacetime and Geometry: An Introduction to General Relativity". 2003. ISBN 0-8053-8732-3
- Carroll, Sean, "From Eternity To HereFrom Eternity to HereFrom Eternity to Here is a book in which Sean Carroll attempts to address the question of what time is what what what processes make it come into existence.- Part One - Time, Experience, and the Universe :Chapter 1 - The Past is Present Memory...
". 2010. ISBN 0525951334 - List of Publications
External links
- Carroll's web site, Preposterous Universe
- Curriculum Vitae
- Carroll's page at Cosmic Variance
- Dark Matter, Dark Energy: The Dark Side of the Universe, lectures at The Teaching Company.
- Video interviews and discussions with other scientists and science writers on Bloggingheads.tvBloggingheads.tvBloggingheads.tv is a political, world events, philosophy, and science video blog discussion site in which the participants take part in an active back and forth conversation via webcam which is then broadcast online to viewers...
- Video of Sean Carroll's panel discussion, "Quantum to Cosmos," answering the biggest questions in physics today
- Video of Sean Carroll's lecture at the Quantum to Cosmos festival: "The Origin of the Universe and the Arrow of Time"
- Interview on The Colbert Report