In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects called strings. In string theory, the different types of observed elementary particles arise from the different quantum states of these strings. In addition to the types of particles postulated by the standard model of particle physics, string theory naturally incorporates gravity, and is therefore a candidate for a theory of everything, a self-contained mathematical model that describes all fundamental forces and forms of matter. Aside from this hypothesized role in particle physics, string theory is now widely used as a theoretical tool in physics, and it has shed light on many aspects of quantum field theory and quantum gravity.
String theory was first studied in the late 1960’s as a theory of the strong nuclear force, before being abandoned in favor of the theory of quantum chromodynamics. Subsequently, it was realized that the very properties that made string theory unsuitable as a theory of nuclear physics made it an outstanding candidate for a quantum theory of gravity. Five consistent versions of string theory were developed before it was realized in the mid-1990’s that these theories could be obtained as different limits of a conjectured eleven-dimensional theory called M-theory.
Many theoretical physicists (among them Stephen Hawking, Edward Witten, and Juan Maldacena) believe that string theory is a step towards the correct fundamental description of nature. This is because string theory allows for the consistent combination of quantum field theory and general relativity, agrees with general insights in quantum gravity such as the holographic principle and black hole thermodynamics, and because it has passed many non-trivial checks of its internal consistency. According to Hawking in particular, “M-theory is the only candidate for a complete theory of the universe.” Other physicists, such as Richard Feynman, Roger Penrose, and Sheldon Lee Glashow, have criticized string theory for not providing novel experimental predictions at accessible energy scales and they say that it is a failure as a theory of everything.
Levels of magnification:
1. Macroscopic level – Matter
2. Molecular level
3. Atomic level – Protons, neutrons, and electrons
4. Subatomic level – Electron
5. Subatomic level – Quarks
6. String level
The starting point for string theory is the idea that the point-like particles of elementary particle physics can also be modeled as one-dimensional objects called strings. According to string theory, strings can oscillate in many ways. On distance scales larger than the string radius, each oscillation mode gives rise to a different species of particle, with its mass, charge, and other properties determined by the string’s dynamics. Splitting and recombination of strings correspond to particle emission and absorption, giving rise to the interactions between particles. An analogy for strings’ modes of vibration is a guitar string’s production of multiple distinct musical notes. In this analogy, different notes correspond to different particles.
In string theory, one of the modes of oscillation of the string corresponds to a massless, spin-2 particle. Such a particle is called a graviton since it mediates a force which has the properties of gravity. Since string theory is believed to be a mathematically consistent quantum mechanical theory, the existence of this graviton state implies that string theory is a theory of quantum gravity.
Since string theory incorporates all of the fundamental interactions, including gravity, many physicists hope that it fully describes our universe, making it a theory of everything. One of the goals of current research in string theory is to find a solution of the theory that is quantitatively identical with the standard model, with a small cosmological constant, containing dark matter and a plausible mechanism for cosmic inflation. It is not yet known whether string theory does not have such a solution, nor is it known how much freedom the theory allows to choose the details.
In quantum mechanics, one computes the probability for a point particle to propagate from one point to another by summing certain quantities called probability amplitudes. Each amplitude is associated with a different worldline of the particle. This process of summing amplitudes over all possible worldlines is called path integration. In string theory, one computes probabilities in a similar way, by summing quantities associated with the world sheets joining an initial string configuration to a final configuration. It is in this sense that string theory extends quantum field theory, replacing point particles by strings. As in quantum field theory, the classical behavior of fields is determined by an action functional, which in string theory can be either the Nambu-Goto action or the Polyakov action.
Interaction in the subatomic world: world lines of point-like particles in the Standard Model or a world sheet swept up by closed strings in string theory
History of string theory:
String theory has come under fire in recent years.
1943-1958: S-Matrix: String theory is an outgrowth of a research program begun by Werner
Heisenberg in 1943, picked it up and it was advocated by many prominent theorists starting in the late 1950’s and throughout the 1960’s, and it was discarded and marginalized in the 1970’s to disappear by the 1980’s. It was forgotten because a few of the ideas were deeply mistaken, because some of its mathematical methods were alien, and because quantum chromodynamics supplanted it as an approach to the strong interactions.
1958-1968: Regge theory and bootstrap models
1968-1974: Dual resonance model
1974-1984: Superstring theory
1984-1989: first superstring revolution
1994-2000: second superstring revolution
2000’s: In the 2000’s, the discovery of the string theory landscape, which suggests that string theory has a large number of inequivalent vacua, led to much discussion of what string theory might eventually be expected to predict, and how cosmology can be incorporated into the theory.
Testability and experimental predictions
Although a great deal of recent work has focused on using string theory to construct realistic models of particle physics, several major difficulties complicate efforts to test models based on string theory. The most significant is the extremely small size of the Planck length, which is expected to be close to the string length (the characteristic size of a string, where strings become easily distinguishable from particles). Another issue is the huge number of metastable vacua of string theory, which might be sufficiently diverse to accommodate almost any phenomena we might observe at lower energies.
Ø String harmonics
One unique prediction of string theory is the existence of string harmonics. At sufficiently high energies, the string-like nature of particles would become obvious. There should be heavier copies of all particles, corresponding to higher vibration harmonics of the string. It is not clear how high these energies are. In most conventional string models, they would be close to the Planck energy, which is 1014 times higher than the energies accessible in the newest particle accelerator, the LHC, making this prediction impossible to test with any particle accelerator in the near future. However, in models with large extra dimensions they could potentially be produced at the LHC, or at energies not far above its reach.
String theory as currently understood makes a series of predictions for the structure of the universe at the largest scales. Many phases in string theory have very large, positive vacuum energy. Regions of the universe that are in such a phase will inflate exponentially rapidly in a process known as eternal inflation. As such, the theory predicts that most of the universe is very rapidly expanding. However, these expanding phases are not stable, and can decay via the nucleation of bubbles of lower vacuum energy. Since our local region of the universe is not very rapidly expanding, string theory predicts we are inside such a bubble. The spatial curvature of the “universe” inside the bubbles that form by this process is negative, a testable prediction. Moreover, other bubbles will eventually form in the parent vacuum outside the bubble and collide with it. These collisions lead to potentially observable imprints on cosmology. However, it is possible that neither of these will be observed if the spatial curvature is too small and the collisions are too rare.
If confirmed experimentally, supersymmetry could also be considered evidence, because all consistent string theories are supersymmetric. However, the absence of supersymmetric particles at energies accessible to the LHC would not necessarily disprove string theory, since the energy scale at which supersymmetry is broken could be well above the accelerator’s range.
CO-RELATION BETWEEN HOMOEOPATHY AND STRING THEORY:
Einstein taught us that energy equals matter and light, but because matter can be condensed down to a very small space if one removes all the empty space between the elementary particles, we can mostly ignore matter. Therefore energy is light, and we are all made of energy – not matter (or at least so little matter, we can ignore it). Stephen Hawking then came up with string theory, which tells us that all matter (which we can ignore) is made of vibrating strings. Therefore we are made of vibrating energy. All diseases are therefore caused by unhealthy vibrational states, and all disease can be treated by returning the body to a previous healthy vibrational state. This can be done with homeopathy, which extracts the vibrational energy out of stuff and places it in a small pill that can be used at any time.
Homeopathy is a holistic approach to disease, based on the Gestalt theory, and asserts that no disease is local without affecting the whole body.
The discovery of relativity theory and quantum theory (the theory of atomic phenomena) in the 20th century ceased the classical concept of solid substances of the Newtonian model. The light quanta, which gave the name of quantum theory, have since been accepted as bona fide particles and are now called photons. At the subatomic level, the solid material objects of classical physics dissolve into wave like patterns that represent the probabilities of interconnections. In modern physics, the universe is thus experienced as a dynamic, inseparable whole, interconnected and there are no completely independent parts and human consciousness is not independent of the Universe either.
Hahnemann’s theory of vitality indicates that Life is a substantial, objective entity; a primary originating power or principle. Dynamical theory of disease is always primarily a morbid dynamical or functional disturbance of the vital principle (6th edition of Organon of Medicine); and upon this is reared the entire edifice of therapeutic medication, governed by the law of Similia as a selective principle.
The immaterial, invisible, conceptual, inherent energy of our vital force (F.N of §11), as similar as vibrational energy of string, animates the material body in health and in disease. In section 9 of Organon, Hahnemann said “In the healthy condition of man, the spiritual vital force (autocracy), the dynamis that animates the material body (organism), rules with unbounded sway, and retains all the parts of the organism in admirable, harmonious, vital operation, as regards both sensations and functions, so that our reason gifted mind can freely employ this living, healthy instrument for the higher purposes of our existence.”
An instinctively perceiving and regulating vital force (§6) maintains the harmony or balance in the individual, also maintains homoeostasis between internal and external environment of a person, between the macro-cosmos and micro-cosmos. This reflects string harmonics of classical physics.
In homoeopathy, cure takes place by administration of the simillimum in minimum dose. That smallest dose can therefore contain almost entirely only the pure, freely developed, conceptual medicinal energy, and brings about only dynamically such great effects as can never be reached by the crude medicinal substance itself taken in large doses.
According to string theory, strings can oscillate in many ways. Similar echo is also observed in homoeopathy where the autocratic, automatic energy of vital force, everywhere present in the organism derives all sensations and performs all functions of life.
On distance scales larger than the string radius, each oscillation mode gives rise to a different species of particle, with its mass, charge, and other properties determined by the string’s dynamics. Splitting and recombination of strings correspond to particle emission and absorption, giving rise to the interactions between particles. It can be correlated with the doctrine of homoeopathic posology where Jahr said “By continual diluting and succussing remedies get neither stronger nor weaker, but their individual peculiarities become more and more developed’. In other words, their sphere of action is enlarged, as represented by the concentric circles.
The living organism is a development, an evolution from a microscopic cell, which is itself an organism composed of living matter and a nucleus, developed from invisible, living substance (like string), which attracts to itself, assimilates and transforms tangible elements from the material world. Everything living comes from preceding life in an unbroken chain, the last conceivable link of which is in the one Infinite and Eternal Source of Life, the Supreme Being. Metaphysical science recognizes this conception under the term of “The Cosmic Life.”
The concept of string theory reflects the basis of homoeopathy like the theory of vital force, doctrine of posology, individualization, theory of dynamism etc. – the wheels; on which homoeopathy revolves.
1.Klebanov, Igor and Maldacena, Juan (2009). “Solving Quantum Field Theories via Curved Spacetimes” (PDF). Physics Today 62: 28. doi:10.1063/1.3074260. Retrieved May, 2013.
2. Schwarz, John H. (1999). “From Superstrings to M Theory”. Physics Reports 315: 107. arXiv:hep-th/9807135. doi:10.1016/S0370-1573(99)00016-2.
3. Hawking, Stephen (2010). The Grand Design. Bantam Books. ISBN 055338466X.
4.Woit, Peter (2006). Not Even Wrong – The Failure of String Theory And the Search for Unity in Physical Law. London: Jonathan Cape &: New York: Basic Books. p. 174. ISBN 0-465-09275-6.
5. Penrose, Roger (2005). The Road to Reality: A Complete Guide to the Laws of the Universe. Knopf. ISBN 0-679-45443-8.
6. Sheldon Glashow. “NOVA – The elegant Universe”. Pbs.org. Retrieved on 2012-07-11.
7. Kachru, Shamit; Kallosh, Renata; Linde, Andrei; Trivedi, Sandip (2003). “De Sitter vacua in string theory”. Physical Review D 68 (4). arXiv:hep-th/0301240. Bibcode:2003PhRvD..68d6005K. doi:10.1103/PhysRevD.68.046005.
8. Freivogel, Ben; Kleban, Matthew; Martínez, María Rodríguez; Susskind, Leonard (2006).
“Observational consequences of a landscape”. Journal of High Energy Physics 2006 (3): 039. arXiv:hep-th/0505232. Bibcode:2006JHEP…03..039F. doi:10.1088/1126-6708/2006/03/039.
9. Kleban, Matthew; Levi, Thomas S.; Sigurdson, Kris (2013). “Observing the multiverse with cosmic wakes”. Physical Review D 87 (4). arXiv:1109.3473. doi:10.1103/PhysRevD.87.041301
10. Hahnemann’s; Organon of Medicine; translated from the 5th edition, with an appendix by R.E Dudgeon, with additions and alterations as per 6th edition translated by William Boericke, and introduction by James Krauss; B.Jain Publisher’s (P) Ltd; New Delhi; 2000.
11. Close S ; The Genius of Homoeopathy, Lectures and Essays on Homoeopathic Philosophy ; B. Jain Publisher’s (P) Ltd., New Delhi: ISBN ; 81-7021-108-5; Book Code :BC-9010