Leonard Susskind (; born June 16, 1940)
[his 60th birthday was celebrated with a special symposium at Stanford University.][in Geoffrey West's introduction, he gives Suskind's current age as 74 and says his birthday was recent.] is an American physicist, who is a professor of
theoretical physics
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experi ...
at
Stanford University, and founding director of the
Stanford Institute for Theoretical Physics. His research interests include
string theory,
quantum field theory
In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines classical field theory, special relativity, and quantum mechanics. QFT is used in particle physics to construct physical models of subatomic particles a ...
,
quantum statistical mechanics
Quantum statistical mechanics is statistical mechanics applied to quantum mechanical systems. In quantum mechanics a statistical ensemble (probability distribution over possible quantum states) is described by a density operator ''S'', which is ...
and
quantum cosmology
Quantum cosmology is the attempt in theoretical physics to develop a quantum theory of the universe. This approach attempts to answer open questions of classical physical cosmology, particularly those related to the first phases of the universe. ...
.
He is a member of the US
National Academy of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nat ...
, and the
American Academy of Arts and Sciences
The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, ...
,
[ an associate member of the faculty of ]Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...
's Perimeter Institute for Theoretical Physics
Perimeter Institute for Theoretical Physics (PI, Perimeter, PITP) is an independent research centre in foundational theoretical physics located in Waterloo, Ontario, Canada. It was founded in 1999. The institute's founding and major benefactor is ...
, and a distinguished professor of the Korea Institute for Advanced Study.
Susskind is widely regarded as one of the fathers of string theory. He was the first to give a precise string-theoretic interpretation of the holographic principle
The holographic principle is an axiom in string theories and a supposed property of quantum gravity that states that the description of a volume of space can be thought of as encoded on a lower-dimensional boundary to the region — such as a ...
in 1995 and the first to introduce the idea of the string theory landscape
The string theory landscape or landscape of vacua refers to the collection of possible false vacua in string theory,The number of metastable vacua is not known exactly, but commonly quoted estimates are of the order 10500. See M. Douglas, "The ...
in 2003.
Susskind was awarded the 1998 J. J. Sakurai Prize,[ and the 2018 Oskar Klein Medal.
]
Early life and education
Leonard Susskind was born to a Jewish
Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The ...
family from the South Bronx
The South Bronx is an area of the New York City borough of the Bronx. The area comprises neighborhoods in the southern part of the Bronx, such as Concourse, Mott Haven, Melrose, and Port Morris.
In the early 1900s, the South Bronx was or ...
in New York City
New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the U ...
. He began working as a plumber
A plumber is a tradesperson who specializes in installing and maintaining systems used for potable (drinking) water, and for sewage and drainage in plumbing systems. at the age of 16, taking over from his father who had become ill.[ Later, he enrolled in the ]City College of New York
The City College of the City University of New York (also known as the City College of New York, or simply City College or CCNY) is a public university within the City University of New York (CUNY) system in New York City. Founded in 1847, Cit ...
as an engineering student, graduating with a B.S. in physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which rel ...
in 1962. In an interview in the ''Los Angeles Times
The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper that started publishing in Los Angeles in 1881. Based in the LA-adjacent suburb of El Segundo since 2018, it is the sixth-largest newspaper by circulation in the ...
'', Susskind recalls a discussion with his father that changed his career path: "When I told my father I wanted to be a physicist, he said, 'Hell no, you ain't going to work in a drug store.' I said, 'No, not a pharmacist.' I said, 'Like Einstein.' He poked me in the chest with a piece of plumbing pipe. 'You ain't going to be no engineer,' he said. 'You're going to be Einstein.'"[ Susskind then studied at ]Cornell University
Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to ...
under Peter A. Carruthers, where he earned his Ph.D. in 1965.
Career
Susskind was an assistant professor of physics, then an associate professor at Yeshiva University
Yeshiva University is a private Orthodox Jewish university with four campuses in New York City.["About YU]
on the Yeshiva Universi ...
(1966–1970), after which he went for a year to the Tel Aviv University
Tel Aviv University (TAU) ( he, אוּנִיבֶרְסִיטַת תֵּל אָבִיב, ''Universitat Tel Aviv'') is a public research university in Tel Aviv, Israel. With over 30,000 students, it is the largest university in the country. Locate ...
(1971–72), returning to Yeshiva to become a professor of physics (1970–1979). Since 1979 he has been professor of physics at Stanford University,[ and since 2000 has held the ]Felix Bloch
Felix Bloch (23 October 1905 – 10 September 1983) was a Swiss- American physicist and Nobel physics laureate who worked mainly in the U.S. He and Edward Mills Purcell were awarded the 1952 Nobel Prize for Physics for "their development of n ...
professorship of physics.
Susskind was awarded the 1998 J. J. Sakurai Prize for his "pioneering contributions to hadronic string models, lattice gauge theories, quantum chromodynamics
In theoretical physics, quantum chromodynamics (QCD) is the theory of the strong interaction between quarks mediated by gluons. Quarks are fundamental particles that make up composite hadrons such as the proton, neutron and pion. QCD is a ty ...
, and dynamical symmetry breaking." Susskind's hallmark, according to colleagues, has been the application of "brilliant imagination and originality to the theoretical study of the nature of the elementary particles and forces that make up the physical world."
In 2007, Susskind joined the faculty of Perimeter Institute for Theoretical Physics
Perimeter Institute for Theoretical Physics (PI, Perimeter, PITP) is an independent research centre in foundational theoretical physics located in Waterloo, Ontario, Canada. It was founded in 1999. The institute's founding and major benefactor is ...
in Waterloo, Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...
, Canada, as an associate member. He has been elected to the National Academy of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nat ...
and the American Academy of Arts and Sciences
The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, ...
. He is also a distinguished professor
Distinguished Professor is an academic title given to some top tenured professors in a university, school, or department. Some distinguished professors may have endowed chairs.
In the United States
Often specific to one institution, titles such ...
at Korea Institute for Advanced Study.
Scientific career
Susskind was one of at least three physicists, alongside Yoichiro Nambu
was a Japanese-American physicist and professor at the University of Chicago. Known for his contributions to the field of theoretical physics, he was awarded half of the Nobel Prize in Physics in 2008 for the discovery in 1960 of the mechanism ...
and Holger Bech Nielsen, who independently discovered during or around 1970 that the Veneziano dual resonance model
In theoretical physics, a dual resonance model arose during the early investigation (1968–1973) of string theory as an S-matrix theory of the strong interaction.
Overview
The dual resonance model was based upon the observation that the amplitud ...
of strong interactions
The strong interaction or strong force is a fundamental interaction that confines quarks into proton, neutron, and other hadron particles. The strong interaction also binds neutrons and protons to create atomic nuclei, where it is called the ...
could be described by a quantum mechanical model of oscillating strings, and was the first to propose the idea of the string theory landscape
The string theory landscape or landscape of vacua refers to the collection of possible false vacua in string theory,The number of metastable vacua is not known exactly, but commonly quoted estimates are of the order 10500. See M. Douglas, "The ...
. Susskind has also made important contributions in the following areas of physics:
* The independent discovery of the string theory model of particle physics
* The theory of quark
A quark () is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. All common ...
confinement
* The development of Hamiltonian lattice gauge theory
In physics, Hamiltonian lattice gauge theory is a calculational approach to gauge theory and a special case of lattice gauge theory in which the space is discretized but time is not. The Hamiltonian is then re-expressed as a function of degrees ...
known as Kogut–Susskind fermions
* The theory of scaling violations in deep inelastic electroproduction
* The theory of symmetry breaking sometimes known as "technicolor
Technicolor is a series of color motion picture processes, the first version dating back to 1916, and followed by improved versions over several decades.
Definitive Technicolor movies using three black and white films running through a special ...
theory"
* The second, yet independent, theory of cosmological baryogenesis
In physical cosmology, baryogenesis (also known as baryosynthesis) is the physical process that is hypothesized to have taken place during the Big Bang, early universe to produce baryonic asymmetry, i.e. the imbalance of matter (baryons) and anti ...
(Andrei Sakharov
Andrei Dmitrievich Sakharov ( rus, Андрей Дмитриевич Сахаров, p=ɐnˈdrʲej ˈdmʲitrʲɪjevʲɪtɕ ˈsaxərəf; 21 May 192114 December 1989) was a Soviet nuclear physicist, dissident, nobel laureate and activist for nu ...
's work was first, but was mostly unknown in the Western hemisphere)
* String theory of black hole
A black hole is a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can defo ...
entropy
* The principle of black hole complementarity
* The causal patch
A causal patch is a region of spacetime connected within the relativistic framework of causality (causal light cones).
Background
After Leonard Susskind proposed the black hole complementarity conjecture for black holes in quantum gravity, he r ...
hypothesis
* The holographic principle
The holographic principle is an axiom in string theories and a supposed property of quantum gravity that states that the description of a volume of space can be thought of as encoded on a lower-dimensional boundary to the region — such as a ...
* M-theory
M-theory is a theory in physics that unifies all consistent versions of superstring theory. Edward Witten first conjectured the existence of such a theory at a string theory conference at the University of Southern California in 1995. Witte ...
, including development of the matrix model
* Introduction of holographic entropy
Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodyna ...
bounds in physical cosmology
Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of f ...
* Cool horizons for entangled black holes
* The idea of an anthropic string theory landscape
The string theory landscape or landscape of vacua refers to the collection of possible false vacua in string theory,The number of metastable vacua is not known exactly, but commonly quoted estimates are of the order 10500. See M. Douglas, "The ...
* The Census Taker's Hat ( FRW/CFT duality)
* Most recently, application of ideas from information and computation theory, such as the complexity equals action conjecture, to the physics and thermodynamics of black holes, and holographic theories in general.
Books
Susskind is the author of several popular science books.
''The Cosmic Landscape''
''The Cosmic Landscape: String Theory and the Illusion of Intelligent Design'' is Susskind's first popular science book, published by Little, Brown and Company on December 12, 2005.
/ref> It is Susskind's attempt to bring his idea of the anthropic landscape of string theory to the general public. In the book, Susskind describes how the string theory landscape was an almost inevitable consequence of several factors, one of which was Steven Weinberg
Steven Weinberg (; May 3, 1933 – July 23, 2021) was an American theoretical physicist and Nobel laureate in physics for his contributions with Abdus Salam and Sheldon Glashow to the unification of the weak force and electromagnetic inter ...
's prediction of the cosmological constant
In cosmology, the cosmological constant (usually denoted by the Greek capital letter lambda: ), alternatively called Einstein's cosmological constant,
is the constant coefficient of a term that Albert Einstein temporarily added to his field eq ...
in 1987. The question addressed here is why our universe is fine-tuned for our existence. Susskind explains that Weinberg calculated that if the cosmological constant was just a little different, our universe would cease to exist.
''The Black Hole War''
''The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics'' is Susskind's second popular science book, published by Little, Brown, and Company on July 7, 2008.
/ref> The book is his most famous work and explains what he thinks would happen to the information and matter stored in a black hole when it evaporates. The book sparked from a debate that started in 1981, when there was a meeting of physicists to try to decode some of the mysteries about how particles of particular elemental compounds function. During this discussion Stephen Hawking stated that the information inside a black hole is lost forever as the black hole evaporates. It took 28 years for Leonard Susskind to formulate his theory that would prove Hawking wrong. He then published his theory in his book, ''The Black Hole War''. Like ''The Cosmic Landscape'', ''The Black Hole War'' is aimed at the lay reader. He writes: "The real tools for understanding the quantum universe are abstract mathematics: infinite dimensional Hilbert spaces, projection operators, unitary matrices and a lot of other advanced principles that take a few years to learn. But let's see how we do in just a few pages".
''The Theoretical Minimum'' book series
Susskind co-authored a series of companion books to his lecture series #The Theoretical Minimum lecture series, ''The Theoretical Minimum''. The first of these, '' The Theoretical Minimum: What You Need to Know to Start Doing Physics'', was published in 2013 and presents the modern formulations of classical mechanics. The second of these, ''Quantum Mechanics: The Theoretical Minimum'', was published in February 2014. The third book, ''Special Relativity and Classical Field Theory: The Theoretical Minimum'' (September 26, 2017), introduces readers to Einstein's special relativity and Maxwell's classical field theory.
''The Theoretical Minimum'' lecture series
Susskind teaches a series of Stanford Continuing Studies courses about modern physics referred to as '' The Theoretical Minimum''. The title of the series is a clear reference to Landau
Landau ( pfl, Landach), officially Landau in der Pfalz, is an autonomous (''kreisfrei'') town surrounded by the Südliche Weinstraße ("Southern Wine Route") district of southern Rhineland-Palatinate, Germany. It is a university town (since 1990 ...
's famous comprehensive exam called the "Theoretical Minimum" which students were expected to pass before admission to his school. ''The Theoretical Minimum'' lectures later formed the basis for the books of the same name. The goal of the courses is to teach the basic but rigorous theoretical foundations required to study certain areas of physics. The sequence covers classical mechanics
Classical mechanics is a physical theory describing the motion of macroscopic objects, from projectiles to parts of machinery, and astronomical objects, such as spacecraft, planets, stars, and galaxies. For objects governed by classical ...
, relativity, quantum mechanics
Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, q ...
, statistical mechanics, and cosmology
Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', and in 1731 taken up in Latin by German philosophe ...
, including the physics of black holes
A black hole is a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can defo ...
.
These courses are available on ''The Theoretical Minimum'' website, on iTunes, and on YouTube
YouTube is a global online video sharing and social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by Google, and is the second most ...
. The courses are intended for the mathematically literate public as well as physical science/mathematics students. Susskind aims the courses at people with prior exposure to algebra, and calculus. Homework and study outside of class is otherwise unnecessary. Susskind explains most of the mathematics used, which form the basis of the lectures.
Cornell Messenger Lectures
Susskind gave 3 lectures
The Birth of the Universe and the Origin of Laws of Physics
April 28-May 1, 2014 in the Cornell Messenger Lecture series which are posted on a Cornell website
A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google, Facebook, Amazon, and Wikip ...
.
Smolin–Susskind debate
The Smolin–Susskind debate refers to the series of intense postings in 2004 between Lee Smolin
Lee Smolin (; born June 6, 1955) is an American theoretical physicist, a faculty member at the Perimeter Institute for Theoretical Physics, an adjunct professor of physics at the University of Waterloo and a member of the graduate faculty of th ...
and Susskind, concerning Smolin's argument that the "anthropic principle
The anthropic principle, also known as the "observation selection effect", is the hypothesis, first proposed in 1957 by Robert Dicke, that there is a restrictive lower bound on how statistically probable our observations of the universe are, beca ...
cannot yield any falsifiable predictions, and therefore cannot be a part of science." It began on July 26, 2004, with Smolin's publication of "Scientific alternatives to the anthropic principle." Smolin e-mailed Susskind asking for a comment. Having not had the chance to read the paper, Susskind requested a summarization of his arguments. Smolin obliged, and on July 28, 2004, Susskind responded, saying that the logic Smolin followed "can lead to ridiculous conclusions."[ The next day, Smolin responded, saying that "If a large body of our colleagues feels comfortable believing a theory that cannot be proved wrong, then the progress of science could get stuck, leading to a situation in which false, but unfalsifiable theories dominate the attention of our field." This was followed by another paper by Susskind which made a few comments about Smolin's theory of "cosmic natural selection." The Smolin–Susskind debate finally ended with each of them agreeing to write a final letter which would be posted on the edge.org website, with three conditions attached: (1) No more than one letter each; (2) Neither sees the other's letter in advance; (3) No changes after the fact.
]
Personal life
He has been married twice, first in 1960,[www.edge.org]
• ''Leonard Susskind - A Biography'' (last accessed August 12, 2007). and he has four children. Susskind is a great-grandfather.
See also
*Supersymmetry
In a supersymmetric theory the equations for force and the equations for matter are identical. In theoretical and mathematical physics, any theory with this property has the principle of supersymmetry (SUSY). Dozens of supersymmetric theories e ...
*List of theoretical physicists
The following is a partial list of notable theoretical physicists. Arranged by century of birth, then century of death, then year of birth, then year of death, then alphabetically by surname. For explanation of symbols, see Notes at end of this art ...
References
Further reading
* Chown, Marcus
"Our world may be a giant hologram"
''New Scientist
''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publish ...
'', 15 January 2009, issue 2691: "The holograms you find on credit cards and banknotes are etched on two-dimensional plastic films. When light bounces off them, it recreates the appearance of a 3D image. In the 1990s physicists Leonard Susskind and Nobel prize winner Gerard 't Hooft
Gerardus (Gerard) 't Hooft (; born July 5, 1946) is a Dutch theoretical physicist and professor at Utrecht University, the Netherlands. He shared the 1999 Nobel Prize in Physics with his thesis advisor Martinus J. G. Veltman "for elucidating th ...
suggested that the same principle might apply to the universe as a whole. Our everyday experience might itself be a holographic projection of physical processes that take place on a distant, 2D surface."
External links
Leonard Susskind's Faculty Page (Stanford University)
Susskind's Blog: Physics for Everyone
''The Theoretical Minimum''
website, with the full set of free lectures
Radio Interview: Leonard Susskind discusses his life as a physicist, string theory and the holographic principle
on The 7th Avenue Project radio show
*''The Edge'':
*
*
Susskind and Lee Smolin
Lee Smolin (; born June 6, 1955) is an American theoretical physicist, a faculty member at the Perimeter Institute for Theoretical Physics, an adjunct professor of physics at the University of Waterloo and a member of the graduate faculty of th ...
debate the Anthropic principle
The anthropic principle, also known as the "observation selection effect", is the hypothesis, first proposed in 1957 by Robert Dicke, that there is a restrictive lower bound on how statistically probable our observations of the universe are, beca ...
Radio Interview
from This Week in Science March 14, 2006 Broadcast
*"Father of String Theory Muses on the Megaverse"
Podcast
*
* - A Ted talk
{{DEFAULTSORT:Susskind, Leonard
1940 births
City College of New York alumni
Cornell University alumni
Jewish American scientists
American physicists
Jewish physicists
Amer
Scientists
A scientist is a person who conducts scientific research to advance knowledge in an area of the natural sciences.
In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophi ...
Stanford University Department of Physics faculty
American string theorists
Living people
Holography
Members of the United States National Academy of Sciences
J. J. Sakurai Prize for Theoretical Particle Physics recipients
The Bronx High School of Science alumni
21st-century American Jews