String Theory

SEED'S TEAR-OUTABLE TOOL FOR LIVING IN THE 21ST CENTURY THE KEY QUESTIONS IN STRING THEORY: CRIBSHEET#9 STRING THEORY What are the fundamental components of the universe? Is there a unifying theory that can explain all basic physical phenomena? THE BIG AND THE SMALL In physics, the description of our universe is divided into two incorporates all the forces except gravity, which is curiously weaker seemingly irreconcilable realms: the quantum world of the very than the other forces. Called the standard model, experiments small, and the macroscopic world where gravity reigns. String reveal it as the most accurate scientific theory ever devised. theory is the controversial attempt to unify the two domains into a "theory of everything." force. Physicists have discovered a framework that successfully WHY STRING THEORY? Because it does not indude gravity, the standard model cannot describe the center of a black hole or the Big Bang. It also cannot PARTICLES AND FORCES The universe is made of two groups of tiny fundamental partides: predict the results of some experiments, nor explain several fermions and bosons. Fermions are all observable matter while patterns that exist between particles. String theory is an attempt to bosons transmit the four known forces in nature: electromagne- fix these problems and unify all matter and forces by replacing tism, gravity, the strong nuclear force, and the weak nuclear particles with miniscule vibrating strings. EXTRA DIMENSIONS For consistency, string theory requires six extra dimensions in addition to the familiar four dimensions we perceive (three in time). String theorists believe these extra dimen- space, one sions are folded into imperceptibly small shapes called Calabi- Yau manifolds that exist everywhere in space (see example above). But there are an almost infinite number of unique Calabi-Yau manifolds, and there is no known way to discern which, if any, reproduces what we see in the standard model. SUPERSYMMETRY Most versions of string theory require supersymmetry, the idea that for every particle of matter there is a corresponding force particle, and vice versa. Next-generation particle accelerators, such as the Large Hadron Collider at CERN in Switzerland, could discover some of these supersymmetric particles by smashing together high-energy protons. A string can be any of the fundamental particles, such as photons and electrons, depending on the frequency of its vibration and its spin. Strings come in two forms: opene and closede. Open strings have endpointse, located on membrane-like structures called D-branes0, and their dynamics closely resemble the three forces other than gravity. Closed strings are loops; they aren't bound to D-branes and their dynamics resemble gravity. Closed strings combine and split with each other0, as can of a deeper explanation that does not rely on strings and branes. open strings. Open strings can also become closed strings, showing string theory combines gravity with the other forces. A THEORY OF EVERYTHING? There are five basic versions of the string theory, which hints that string theory itself may not be the final "theory of everything." Profound mathematical relationships called dualities exist between the different string theories, and suggest each is part This ill-understood framework is called M-theory. THE SIZE OF STRINGS DUALITIES IN PHYSICS: M-THEORY Glass of water -101 m Water molecule -10 m Hydroge m Proton 104m String -10 m atom Type I quark Type IIB Type lIA THEORY Heterotic-E O Heterotic-O belectron Strings are the smallest, least accessible objects known to physics. Here, a progressive zoom into a glass of water reveals the relative scales of a water molecule, a hydrogen atom, a proton, an electron, a quark, and a string. The sizes of these objects ranges across thirty-four orders of magnitude. For perspective, it an atom were the size of our solar system, a string would be somewhat larger than an atomic nucleus. The five known formulations of string theory appear distinct at first glance, but closer inspection reveals intimate connections between them, indicating they are different parts of a larger underlying theory. o००- SOUNDBITE W THE ISSUE: IS IT REAL? Directly observing strings is far beyond our capabilities now and for the foreseeable future. Additionally, string theory's rich diversity makes Whether or not strings are validated as a it difficult to derive any clear predictions that apply to all its versions. Still, particle physics experiments being performed with collisions of very "theory of everything," they provide a heavy ions at Brookhaven National Laboratory and with proton collisions at CERN could connect string theory with reality. In particular, two unique set of tools to understand and discoveries, which are supersymmetry and the existence of extra dimensions, would suggest that string theory is on the right track. explore the deep structure of reality. SEED'S TEAR-OUTABLE TOOL FOR LIVING IN THE 21ST CENTURY THE KEY QUESTIONS IN STRING THEORY: CRIBSHEET#9 What are the fundamental STRING THEORY components of the universe? Is there a unifying theory that can explain all basic physical phenomena? THE BIG AND THE SMALL In physics, the description of our universe is divided into two incorporates all the forces except gravity, which is curiously weaker seemingly irreconcilable realms: the quantum world of the very small, and the macroscopic world where gravity reigns. String reveal it as the most accurate scientific theory ever devised. theory is the controversial attempt to unify the two domains into a "theory of everything." force. Physicists have discovered a framework that successfully than the other forces. Called the standard model, experiments WHY STRING THEORY? Because it does not indude gravity, the standard model cannot describe the center of a black hole or the Big Bang. It also cannot PARTICLES AND FORCES The universe is made of two groups of tiny fundamental particles: predict the results of some experiments, nor explain several fermions and bosons. Fermions are all observable matter while patterns that exist between particles. String theory is an attempt to bosons transmit the four known forces in nature: electromagne- fix these problems and unify all matter and forces by replacing tism, gravity, the strong nuclear force, and the weak nuclear particles with miniscule vibrating strings. EXTRA DIMENSIONS For consistency, string theory requires six extra dimensions in addition to the familiar four dimensions we perceive (three in time). String theorists believe these extra dimen- space, one sions are folded into imperceptibly small shapes called Calabi- Yau manifolds that exist everywhere in space (see example above). But there are an almost infinite number of unique Calabi-Yau manifolds, and there is no known way to discern which, if any, reproduces what we see in the standard model. SUPERSYMMETRY Most versions of string theory require supersymmetry, the idea that for every particle of matter there is a corresponding force particle, and vice versa. Next-generation particle accelerators, such as the Large Hadron Collider at CERN in Switzerland, could discover some of these supersymmetric particles by smashing together high-energy protons. A string can be any of the fundamental particles, such as photons and electrons, depending on the frequency of its vibration and its spin. Strings come in two forms: opene and closede. Open strings have endpointse, located on membrane-like structures called D-branes0, and their dynamics closely resemble the three forces other than gravity. Closed strings are loops; they aren't bound to D-branes and their dynamics resemble gravity. Closed strings combine and split with each other0, as can of a deeper explanation that does not rely on strings and branes. open strings. Open strings can also become closed strings, showing string theory combines gravity with the other forces. A THEORY OF EVERYTHING? There are five basic versions of the string theory, which hints that string theory itself may not be the final "theory of everything." Profound mathematical relationships called dualities exist between the different string theories, and suggest each is part This ill-understood framework is called M-theory. THE SIZE OF STRINGS DUALITIES IN PHYSICS: M-THEORY Glass of water -10' m Water molecule -10 m atom Hydroge m Proton 104m String -10m Type I equark Type IB Type IIA THEORY Heterotic-E O Heterotic-O velectron Strings are the smallest, least accessible objects known to physics. Here, a progressive zoom into a glass of water reveals the relative scales of a water molecule, a hydrogen atom, a proton, an electron, a quark, and a string. The sizes of these objects ranges across thirty-four orders of magnitude. For perspective, if an atom were the size of our solar system, a string would be somewhat larger than an atomic nucleus. The five known formulations of string theory appear distinct at first: glance, but closer inspection reveals intimate connections between them, indicating they are different parts of a larger underlying theory. THE ISSUE: IS IT REAL? SOUNDBITE Directly observing strings is far beyond our capabilities now and for the foreseeable future. Additionally, string theory's rich diversity makes Whether or not strings are validated as a it difficult to derive any clear predictions that apply to all its versions. Still, particle physics experiments being performed with collisions of very "theory of everything," they provide a heavy ions at Brookhaven National Laboratory and with proton collisions at CERN could connect string theory with reality. In particular, two unique set of tools to understand and discoveries, which are supersymmetry and the existence of extra dimensions, would suggest that string theory is on the right track. explore the deep structure of reality. Mustrator eu Rich- ww.oybu.ch witers Le Bng a Josh hobeConant Chrord Aoon Univeriy of Southern allomi SEED'S TEAR-OUTABLE TOOL FOR LIVING IN THE 21ST CENTURY THE KEY QUESTIONS IN STRING THEORY: CRIBSHEET#9 What are the fundamental STRING THEORY components of the universe? Is there a unifying theory that can explain all basic physical phenomena? THE BIG AND THE SMALL In physics, the description of our universe is divided into two incorporates all the forces except gravity, which is curiously weaker seemingly irreconcilable realms: the quantum world of the very small, and the macroscopic world where gravity reigns. String reveal it as the most accurate scientific theory ever devised. theory is the controversial attempt to unify the two domains into a "theory of everything." force. Physicists have discovered a framework that successfully than the other forces. Called the standard model, experiments WHY STRING THEORY? Because it does not indude gravity, the standard model cannot describe the center of a black hole or the Big Bang. It also cannot PARTICLES AND FORCES The universe is made of two groups of tiny fundamental particles: predict the results of some experiments, nor explain several fermions and bosons. Fermions are all observable matter while patterns that exist between particles. String theory is an attempt to bosons transmit the four known forces in nature: electromagne- fix these problems and unify all matter and forces by replacing tism, gravity, the strong nuclear force, and the weak nuclear particles with miniscule vibrating strings. EXTRA DIMENSIONS For consistency, string theory requires six extra dimensions in addition to the familiar four dimensions we perceive (three in time). String theorists believe these extra dimen- space, one sions are folded into imperceptibly small shapes called Calabi- Yau manifolds that exist everywhere in space (see example above). But there are an almost infinite number of unique Calabi-Yau manifolds, and there is no known way to discern which, if any, reproduces what we see in the standard model. SUPERSYMMETRY Most versions of string theory require supersymmetry, the idea that for every particle of matter there is a corresponding force particle, and vice versa. Next-generation particle accelerators, such as the Large Hadron Collider at CERN in Switzerland, could discover some of these supersymmetric particles by smashing together high-energy protons. A string can be any of the fundamental particles, such as photons and electrons, depending on the frequency of its vibration and its spin. Strings come in two forms: opene and closede. Open strings have endpointse, located on membrane-like structures called D-branes0, and their dynamics closely resemble the three forces other than gravity. Closed strings are loops; they aren't bound to D-branes and their dynamics resemble gravity. Closed strings combine and split with each other0, as can of a deeper explanation that does not rely on strings and branes. open strings. Open strings can also become closed strings, showing string theory combines gravity with the other forces. A THEORY OF EVERYTHING? There are five basic versions of the string theory, which hints that string theory itself may not be the final "theory of everything." Profound mathematical relationships called dualities exist between the different string theories, and suggest each is part This ill-understood framework is called M-theory. THE SIZE OF STRINGS DUALITIES IN PHYSICS: M-THEORY Glass of water -10' m Water molecule -10 m atom Hydroge m Proton 104m String -10m Type I equark Type IB Type IIA THEORY Heterotic-E O Heterotic-O velectron Strings are the smallest, least accessible objects known to physics. Here, a progressive zoom into a glass of water reveals the relative scales of a water molecule, a hydrogen atom, a proton, an electron, a quark, and a string. The sizes of these objects ranges across thirty-four orders of magnitude. For perspective, if an atom were the size of our solar system, a string would be somewhat larger than an atomic nucleus. The five known formulations of string theory appear distinct at first: glance, but closer inspection reveals intimate connections between them, indicating they are different parts of a larger underlying theory. THE ISSUE: IS IT REAL? SOUNDBITE Directly observing strings is far beyond our capabilities now and for the foreseeable future. Additionally, string theory's rich diversity makes Whether or not strings are validated as a it difficult to derive any clear predictions that apply to all its versions. Still, particle physics experiments being performed with collisions of very "theory of everything," they provide a heavy ions at Brookhaven National Laboratory and with proton collisions at CERN could connect string theory with reality. In particular, two unique set of tools to understand and discoveries, which are supersymmetry and the existence of extra dimensions, would suggest that string theory is on the right track. explore the deep structure of reality. Mustrator eu Rich- ww.oybu.ch witers Le Bng a Josh hobeConant Chrord Aoon Univeriy of Southern allomi SEED'S TEAR-OUTABLE TOOL FOR LIVING IN THE 21ST CENTURY THE KEY QUESTIONS IN STRING THEORY: CRIBSHEET#9 What are the fundamental STRING THEORY components of the universe? Is there a unifying theory that can explain all basic physical phenomena? THE BIG AND THE SMALL In physics, the description of our universe is divided into two incorporates all the forces except gravity, which is curiously weaker seemingly irreconcilable realms: the quantum world of the very small, and the macroscopic world where gravity reigns. String reveal it as the most accurate scientific theory ever devised. theory is the controversial attempt to unify the two domains into a "theory of everything." force. Physicists have discovered a framework that successfully than the other forces. Called the standard model, experiments WHY STRING THEORY? Because it does not indude gravity, the standard model cannot describe the center of a black hole or the Big Bang. It also cannot PARTICLES AND FORCES The universe is made of two groups of tiny fundamental particles: predict the results of some experiments, nor explain several fermions and bosons. Fermions are all observable matter while patterns that exist between particles. String theory is an attempt to bosons transmit the four known forces in nature: electromagne- fix these problems and unify all matter and forces by replacing tism, gravity, the strong nuclear force, and the weak nuclear particles with miniscule vibrating strings. EXTRA DIMENSIONS For consistency, string theory requires six extra dimensions in addition to the familiar four dimensions we perceive (three in time). String theorists believe these extra dimen- space, one sions are folded into imperceptibly small shapes called Calabi- Yau manifolds that exist everywhere in space (see example above). But there are an almost infinite number of unique Calabi-Yau manifolds, and there is no known way to discern which, if any, reproduces what we see in the standard model. SUPERSYMMETRY Most versions of string theory require supersymmetry, the idea that for every particle of matter there is a corresponding force particle, and vice versa. Next-generation particle accelerators, such as the Large Hadron Collider at CERN in Switzerland, could discover some of these supersymmetric particles by smashing together high-energy protons. A string can be any of the fundamental particles, such as photons and electrons, depending on the frequency of its vibration and its spin. Strings come in two forms: opene and closede. Open strings have endpointse, located on membrane-like structures called D-branes0, and their dynamics closely resemble the three forces other than gravity. Closed strings are loops; they aren't bound to D-branes and their dynamics resemble gravity. Closed strings combine and split with each other0, as can of a deeper explanation that does not rely on strings and branes. open strings. Open strings can also become closed strings, showing string theory combines gravity with the other forces. A THEORY OF EVERYTHING? There are five basic versions of the string theory, which hints that string theory itself may not be the final "theory of everything." Profound mathematical relationships called dualities exist between the different string theories, and suggest each is part This ill-understood framework is called M-theory. THE SIZE OF STRINGS DUALITIES IN PHYSICS: M-THEORY Glass of water -10' m Water molecule -10 m atom Hydroge m Proton 104m String -10m Type I equark Type IB Type IIA THEORY Heterotic-E O Heterotic-O velectron Strings are the smallest, least accessible objects known to physics. Here, a progressive zoom into a glass of water reveals the relative scales of a water molecule, a hydrogen atom, a proton, an electron, a quark, and a string. The sizes of these objects ranges across thirty-four orders of magnitude. For perspective, if an atom were the size of our solar system, a string would be somewhat larger than an atomic nucleus. The five known formulations of string theory appear distinct at first: glance, but closer inspection reveals intimate connections between them, indicating they are different parts of a larger underlying theory. THE ISSUE: IS IT REAL? SOUNDBITE Directly observing strings is far beyond our capabilities now and for the foreseeable future. Additionally, string theory's rich diversity makes Whether or not strings are validated as a it difficult to derive any clear predictions that apply to all its versions. Still, particle physics experiments being performed with collisions of very "theory of everything," they provide a heavy ions at Brookhaven National Laboratory and with proton collisions at CERN could connect string theory with reality. In particular, two unique set of tools to understand and discoveries, which are supersymmetry and the existence of extra dimensions, would suggest that string theory is on the right track. explore the deep structure of reality. Mustrator eu Rich- ww.oybu.ch witers Le Bng a Josh hobeConant Chrord Aoon Univeriy of Southern allomi SEED'S TEAR-OUTABLE TOOL FOR LIVING IN THE 21ST CENTURY THE KEY QUESTIONS IN STRING THEORY: CRIBSHEET#9 What are the fundamental STRING THEORY components of the universe? Is there a unifying theory that can explain all basic physical phenomena? THE BIG AND THE SMALL In physics, the description of our universe is divided into two incorporates all the forces except gravity, which is curiously weaker seemingly irreconcilable realms: the quantum world of the very small, and the macroscopic world where gravity reigns. String reveal it as the most accurate scientific theory ever devised. theory is the controversial attempt to unify the two domains into a "theory of everything." force. Physicists have discovered a framework that successfully than the other forces. Called the standard model, experiments WHY STRING THEORY? Because it does not indude gravity, the standard model cannot describe the center of a black hole or the Big Bang. It also cannot PARTICLES AND FORCES The universe is made of two groups of tiny fundamental particles: predict the results of some experiments, nor explain several fermions and bosons. Fermions are all observable matter while patterns that exist between particles. String theory is an attempt to bosons transmit the four known forces in nature: electromagne- fix these problems and unify all matter and forces by replacing tism, gravity, the strong nuclear force, and the weak nuclear particles with miniscule vibrating strings. EXTRA DIMENSIONS For consistency, string theory requires six extra dimensions in addition to the familiar four dimensions we perceive (three in time). String theorists believe these extra dimen- space, one sions are folded into imperceptibly small shapes called Calabi- Yau manifolds that exist everywhere in space (see example above). But there are an almost infinite number of unique Calabi-Yau manifolds, and there is no known way to discern which, if any, reproduces what we see in the standard model. SUPERSYMMETRY Most versions of string theory require supersymmetry, the idea that for every particle of matter there is a corresponding force particle, and vice versa. Next-generation particle accelerators, such as the Large Hadron Collider at CERN in Switzerland, could discover some of these supersymmetric particles by smashing together high-energy protons. A string can be any of the fundamental particles, such as photons and electrons, depending on the frequency of its vibration and its spin. Strings come in two forms: opene and closede. Open strings have endpointse, located on membrane-like structures called D-branes0, and their dynamics closely resemble the three forces other than gravity. Closed strings are loops; they aren't bound to D-branes and their dynamics resemble gravity. Closed strings combine and split with each other0, as can of a deeper explanation that does not rely on strings and branes. open strings. Open strings can also become closed strings, showing string theory combines gravity with the other forces. A THEORY OF EVERYTHING? There are five basic versions of the string theory, which hints that string theory itself may not be the final "theory of everything." Profound mathematical relationships called dualities exist between the different string theories, and suggest each is part This ill-understood framework is called M-theory. THE SIZE OF STRINGS DUALITIES IN PHYSICS: M-THEORY Glass of water -10' m Water molecule -10 m atom Hydroge m Proton 104m String -10m Type I equark Type IB Type IIA THEORY Heterotic-E O Heterotic-O velectron Strings are the smallest, least accessible objects known to physics. Here, a progressive zoom into a glass of water reveals the relative scales of a water molecule, a hydrogen atom, a proton, an electron, a quark, and a string. The sizes of these objects ranges across thirty-four orders of magnitude. For perspective, if an atom were the size of our solar system, a string would be somewhat larger than an atomic nucleus. The five known formulations of string theory appear distinct at first: glance, but closer inspection reveals intimate connections between them, indicating they are different parts of a larger underlying theory. THE ISSUE: IS IT REAL? SOUNDBITE Directly observing strings is far beyond our capabilities now and for the foreseeable future. Additionally, string theory's rich diversity makes Whether or not strings are validated as a it difficult to derive any clear predictions that apply to all its versions. Still, particle physics experiments being performed with collisions of very "theory of everything," they provide a heavy ions at Brookhaven National Laboratory and with proton collisions at CERN could connect string theory with reality. In particular, two unique set of tools to understand and discoveries, which are supersymmetry and the existence of extra dimensions, would suggest that string theory is on the right track. explore the deep structure of reality. Mustrator eu Rich- ww.oybu.ch witers Le Bng a Josh hobeConant Chrord Aoon Univeriy of Southern allomi SEED'S TEAR-OUTABLE TOOL FOR LIVING IN THE 21ST CENTURY THE KEY QUESTIONS IN STRING THEORY: CRIBSHEET#9 What are the fundamental STRING THEORY components of the universe? Is there a unifying theory that can explain all basic physical phenomena? THE BIG AND THE SMALL In physics, the description of our universe is divided into two incorporates all the forces except gravity, which is curiously weaker seemingly irreconcilable realms: the quantum world of the very small, and the macroscopic world where gravity reigns. String reveal it as the most accurate scientific theory ever devised. theory is the controversial attempt to unify the two domains into a "theory of everything." force. Physicists have discovered a framework that successfully than the other forces. Called the standard model, experiments WHY STRING THEORY? Because it does not indude gravity, the standard model cannot describe the center of a black hole or the Big Bang. It also cannot PARTICLES AND FORCES The universe is made of two groups of tiny fundamental particles: predict the results of some experiments, nor explain several fermions and bosons. Fermions are all observable matter while patterns that exist between particles. String theory is an attempt to bosons transmit the four known forces in nature: electromagne- fix these problems and unify all matter and forces by replacing tism, gravity, the strong nuclear force, and the weak nuclear particles with miniscule vibrating strings. EXTRA DIMENSIONS For consistency, string theory requires six extra dimensions in addition to the familiar four dimensions we perceive (three in time). String theorists believe these extra dimen- space, one sions are folded into imperceptibly small shapes called Calabi- Yau manifolds that exist everywhere in space (see example above). But there are an almost infinite number of unique Calabi-Yau manifolds, and there is no known way to discern which, if any, reproduces what we see in the standard model. SUPERSYMMETRY Most versions of string theory require supersymmetry, the idea that for every particle of matter there is a corresponding force particle, and vice versa. Next-generation particle accelerators, such as the Large Hadron Collider at CERN in Switzerland, could discover some of these supersymmetric particles by smashing together high-energy protons. A string can be any of the fundamental particles, such as photons and electrons, depending on the frequency of its vibration and its spin. Strings come in two forms: opene and closede. Open strings have endpointse, located on membrane-like structures called D-branes0, and their dynamics closely resemble the three forces other than gravity. Closed strings are loops; they aren't bound to D-branes and their dynamics resemble gravity. Closed strings combine and split with each other0, as can of a deeper explanation that does not rely on strings and branes. open strings. Open strings can also become closed strings, showing string theory combines gravity with the other forces. A THEORY OF EVERYTHING? There are five basic versions of the string theory, which hints that string theory itself may not be the final "theory of everything." Profound mathematical relationships called dualities exist between the different string theories, and suggest each is part This ill-understood framework is called M-theory. THE SIZE OF STRINGS DUALITIES IN PHYSICS: M-THEORY Glass of water -10' m Water molecule -10 m atom Hydroge m Proton 104m String -10m Type I equark Type IB Type IIA THEORY Heterotic-E O Heterotic-O velectron Strings are the smallest, least accessible objects known to physics. Here, a progressive zoom into a glass of water reveals the relative scales of a water molecule, a hydrogen atom, a proton, an electron, a quark, and a string. The sizes of these objects ranges across thirty-four orders of magnitude. For perspective, if an atom were the size of our solar system, a string would be somewhat larger than an atomic nucleus. The five known formulations of string theory appear distinct at first: glance, but closer inspection reveals intimate connections between them, indicating they are different parts of a larger underlying theory. THE ISSUE: IS IT REAL? SOUNDBITE Directly observing strings is far beyond our capabilities now and for the foreseeable future. Additionally, string theory's rich diversity makes Whether or not strings are validated as a it difficult to derive any clear predictions that apply to all its versions. Still, particle physics experiments being performed with collisions of very "theory of everything," they provide a heavy ions at Brookhaven National Laboratory and with proton collisions at CERN could connect string theory with reality. In particular, two unique set of tools to understand and discoveries, which are supersymmetry and the existence of extra dimensions, would suggest that string theory is on the right track. explore the deep structure of reality. Mustrator eu Rich- ww.oybu.ch witers Le Bng a Josh hobeConant Chrord Aoon Univeriy of Southern allomi