Aug 26, · String theory is the only idea about quantum gravity with any substance. One sign is that where critics have had interesting ideas (non-commutative geometry, black hole entropy, twistor theory) they have tended to be absorbed as part of string theory. and David Gross: So you don’t think that other approaches like loop quantum gravity have Sep 08, · The experiment, performed by the scientists at Berkeley Lab and the National Institute of Standards and Technology (NIST), takes advantage of two of the weirdest properties of quantum theory: the superposition principle and entanglement. In theories of quantum gravity, the graviton is the hypothetical quantum of gravity. It mediates the force Quantum information and quantum computations is a new, rapidly developing branch of physics that has arisen from quantum mechanics, mathematical physics and classical information theory. Significant interest in this area is explained by the great prospects that will open upon the implementation of its ideas, capturing almost all areas of human
Theory of everything - Wikipedia
A theory of everything TOE [1] or ToEfinal theoryultimate theorytheory of the world or master theory is a hypothetical, singular, all-encompassing, researches on the quantum theory, coherent theoretical framework of physics that fully explains and links together all physical aspects of the universe. Over the past few centuries, two theoretical frameworks have been developed that, together, most researches on the quantum theory resemble a TOE.
These two theories upon which all modern physics rests are general relativity and quantum mechanics. General relativity is a theoretical framework that only focuses on gravity for understanding the universe in regions of both large scale and high mass: starsgalaxiesclusters of galaxies etc.
On the other hand, quantum mechanics is a theoretical framework that only focuses on three non-gravitational forces for understanding the universe in regions of both small scale and low mass: sub-atomic particlesatomsresearches on the quantum theory, moleculesetc. Quantum mechanics successfully implemented the Standard Model that describes the three non-gravitational forces — strong nuclearweak nuclearand electromagnetic force — as well as all observed elementary particles, researches on the quantum theory.
General relativity and quantum mechanics have been thoroughly proven in their separate fields of relevance. Since the usual domains of applicability of general relativity and quantum mechanics are so different, most situations require that only one of the two theories be used. To resolve the incompatibility, researches on the quantum theory, a theoretical framework revealing a deeper underlying reality, unifying gravity with the other three interactions, must be discovered to harmoniously integrate the realms of general relativity and quantum mechanics into a seamless whole: the TOE is a single theory that, in principle, is capable of describing all phenomena in the universe.
In pursuit of this goal, quantum gravity has become one area of active research. One example is string theory, which evolved into a candidate for the TOE, but not without drawbacks most notably, its lack of currently testable predictions and controversy. According to string theory, every particle in the universe, at its most microscopic level Planck lengthconsists of varying combinations of vibrating strings or strands with preferred patterns of vibration.
String theory further claims that it is through these specific oscillatory patterns of strings that a particle of unique mass and force charge is created that is to say, the electron is a type of string that vibrates one way, while the up quark is a type of string vibrating another way, and so forth, researches on the quantum theory.
Initially, the term theory of everything was used with an ironic reference to various overgeneralized theories. For example, a grandfather of Ijon Tichy — a character from a cycle of Stanisław Lem 's science fiction stories of the s — was known to work on the " General Theory of Everything ". Physicist Harald Fritzsch used the term in his lectures in Varenna.
Many ancient cultures such as Babylonian astronomersIndian astronomy studied the pattern researches on the quantum theory the Seven Classical Planets against the researches on the quantum theory of starswith their interest being to relate celestial movement to human events astrologyand the goal being to predict events by recording events against a time measure and then look for recurrent patterns. The debate between the universe having either a beginning or eternal cycles can be traced back to ancient Babylonia.
Its cycles run from our ordinary day and night to a day and night of Brahma, 8. The natural philosophy of atomism appeared in several ancient traditions. In ancient Greek philosophythe pre-Socratic philosophers speculated that the apparent diversity of observed phenomena was due to a single type of interaction, namely the motions and collisions of atoms. The concept of 'atom' proposed by Democritus was an early philosophical attempt to unify phenomena observed in nature.
The concept of 'atom' also appeared in the Nyaya - Vaisheshika school of ancient Indian philosophy. Archimedes was possibly the first philosopher to have described nature with axioms or principles and then deduce new results from them. Any "theory of everything" is similarly expected to be based on axioms and to deduce all observable phenomena from them.
Following earlier atomistic thought, the mechanical philosophy of the 17th century posited that researches on the quantum theory forces could be ultimately reduced to contact forces between the atoms, then imagined as tiny solid particles. In the late 17th century, researches on the quantum theory, Isaac Newton 's description researches on the quantum theory the long-distance force of gravity implied that not all forces in nature result from things coming into contact.
Newton's work in his Mathematical Principles of Natural Philosophy dealt with this in a further example of unification, in this case unifying Galileo 's work on terrestrial gravity, Kepler 's laws of planetary motion and the phenomenon of tides by explaining these apparent actions at a distance under one single law: the law of universal gravitation.
An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.
Laplace thus envisaged a combination of gravitation and mechanics as a theory of everything. Modern quantum mechanics implies that uncertainty is inescapableand thus that Laplace's vision has to be amended: a theory of everything must include gravitation and quantum mechanics. Even ignoring quantum mechanics, chaos theory is sufficient to guarantee that researches on the quantum theory future of any sufficiently complex mechanical or astronomical system is unpredictable.
InHans Christian Ørsted discovered a connection between electricity and magnetism, triggering decades of work that culminated inin James Clerk Maxwell 's theory of electromagnetism. During the 19th and early 20th centuries, it gradually became apparent that many common examples of forces — contact forces, elasticityviscosityfrictionand pressure — researches on the quantum theory from electrical interactions between the smallest particles of matter. In his experiments of —50, Michael Faraday was the first to search for a unification of gravity with electricity and magnetism.
InDavid Hilbert published a famous list of mathematical problems. In Hilbert's sixth problemhe challenged researchers to find an axiomatic basis to all of physics. In this problem he thus asked for what today would be called a theory of everything. In the late s, the new quantum mechanics showed that the chemical bonds between atoms were examples of quantum electrical forces, justifying Dirac 's boast that "the underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known".
Afterwhen Albert Einstein published the theory of gravity general relativitythe search for a unified field theory combining gravity with electromagnetism began with a renewed interest. In Einstein's day, the strong and the weak forces had not yet been discovered, yet he found the potential existence of two other distinct forces, gravity and electromagnetism, far more alluring.
This launched his thirty-year voyage in search of the so-called "unified field theory" that he hoped would show researches on the quantum theory these two forces are really manifestations of one grand, underlying principle. During the last few decades of his life, this ambition alienated Einstein from the rest of mainstream of physics, as the mainstream was instead far more excited about the emerging framework of quantum mechanics.
Einstein wrote to a friend in the early s, "I have become a lonely old chap who is mainly known because he doesn't wear socks and who is exhibited as a curiosity on special occasions. In the twentieth century, the search for a unifying theory was interrupted by the discovery of the strong and weak nuclear forces, which differ both from gravity and from electromagnetism.
A further hurdle was the acceptance that in a TOE, quantum mechanics had to be incorporated from the outset, researches on the quantum theory, rather than emerging as a consequence of a deterministic unified theory, as Einstein had hoped. Gravity and electromagnetism are able to coexist as entries in a list of classical forces, but for many years it seemed that gravity could not be incorporated into the quantum framework, let alone unified with the other fundamental forces.
For this reason, work on unification, researches on the quantum theory, for much of the twentieth century, focused on understanding the three forces described by quantum mechanics: electromagnetism and the weak and strong forces. The first two were combined in —68 by Sheldon GlashowSteven Weinbergand Abdus Salam into the electroweak force.
At higher energies W bosons and Z bosons can be created easily and the unified nature of the force becomes apparent. While the strong and electroweak forces coexist under the Standard Model of particle physics, they remain distinct. Thus, the pursuit of a theory of everything remains unsuccessful: neither a unification of the strong and electroweak forces — which Laplace would have called 'contact forces' — nor a unification of these forces with gravitation has been achieved, researches on the quantum theory.
A Theory of Everything would unify all the fundamental interactions of nature: gravitationresearches on the quantum theory, the strong interactionthe weak interactionand electromagnetism. Because the weak interaction can transform elementary particles from one kind into another, the TOE should also predict all the various different kinds of particles possible.
The usual assumed path of theories is given in the following graph, where each unification step leads one level up on the graph. In this graph, electroweak unification occurs at around GeV, grand unification is predicted to occur at 10 16 GeV, and unification of the GUT force with gravity is expected at the Planck energyroughly 10 19 GeV.
Several Grand Unified Theories GUTs have been proposed to unify electromagnetism and the weak and researches on the quantum theory forces. Grand unification would imply the existence of an electronuclear force; it is expected to set in at energies of the researches on the quantum theory of 10 16 GeV, far greater than could be reached by any currently feasible particle accelerator.
Although the simplest GUTs have been experimentally ruled out, the idea of a grand unified theory, especially when linked with supersymmetryremains a favorite candidate in the theoretical physics community. Supersymmetric GUTs seem plausible not only for their theoretical "beauty", but because they naturally produce large quantities of dark matter, researches on the quantum theory, and because the inflationary force may be related to GUT physics although it does not seem to form an inevitable part of the theory.
Yet GUTs are clearly not the final answer; both the current standard model and all proposed GUTs are quantum field theories which require the problematic technique of renormalization to yield sensible answers. This is usually regarded as a sign that these are only effective field theoriesomitting crucial phenomena relevant only at very high energies.
The final researches on the quantum theory in the graph requires resolving the separation between quantum mechanics and gravitation, often equated with general relativity. Numerous researchers concentrate their efforts on this specific step; nevertheless, no accepted theory of quantum gravityand thus no accepted theory of everything, has emerged. Researches on the quantum theory is usually assumed that the TOE will also solve the remaining problems of GUTs, researches on the quantum theory.
In addition to explaining the forces listed in the graph, a TOE may also explain the status of at least two candidate forces suggested by modern cosmology : an inflationary force and dark energy. Furthermore, cosmological experiments also suggest the existence of dark mattersupposedly composed of fundamental particles outside the scheme of the standard model, researches on the quantum theory.
However, the existence of these forces and particles has not been proven. Is string theorysuperstring theoryor M-theoryor some other variant on this theme, a step on the road to a "theory of everything", or just a blind alley?
Since the s, some physicists such as Edward Witten believe that dimensional M-theorywhich is described in some limits by one of the five perturbative superstring theoriesand in another by the maximally- supersymmetric dimensional supergravityis the theory of everything.
There is no widespread consensus on this issue. In this regard, string theory can be seen as building on the insights of the Kaluza—Klein theoryresearches on the quantum theory, in which it was realized that applying general relativity to a five-dimensional universe with one of them small and curled up [ clarification needed ] looks from the four-dimensional perspective like the usual general relativity together with Maxwell's electrodynamics.
This lent credence to the idea of unifying gauge and gravity interactions, and to researches on the quantum theory dimensions, but did not address the detailed experimental requirements. Another important property of string theory is its supersymmetrywhich together with extra dimensions are the two main proposals for resolving the hierarchy problem of the standard modelwhich is roughly the question of why gravity is so much weaker than any other force.
The extra-dimensional solution involves allowing gravity to propagate into the other dimensions while keeping other forces confined to a four-dimensional spacetime, an researches on the quantum theory that has been realized with explicit stringy mechanisms.
Research into string theory has been encouraged by a variety of theoretical and experimental factors. On the experimental side, the particle content of the standard model supplemented with neutrino masses fits into a spinor representation of SO 10a subgroup of E8 that routinely emerges in string theory, such as in heterotic string theory [26] or sometimes equivalently in F-theory.
In the late s, it was noted that one major hurdle in this endeavor is that the number of possible four-dimensional universes is incredibly large. The small, "curled up" extra dimensions can be compactified in an enormous number of different ways one estimate is 10 each of which leads to different properties for the low-energy particles and forces.
This array of models is known as the string theory landscape. One proposed solution is that many or all of these possibilities are realised in one or another of a huge number of universes, but that only a small number of them are habitable, researches on the quantum theory.
Hence what we normally conceive as the fundamental constants of the universe are ultimately the result of the anthropic principle rather than dictated by theory.
This has led to criticism of string theory, [35] arguing that it cannot make useful i. Others disagree, [36] and string theory remains an active topic of investigation in theoretical physics.
Current research on loop quantum gravity may eventually play a fundamental role in a TOE, but that is not its primary aim. There have been recent claims that loop quantum gravity may be able to reproduce features resembling the Standard Model.
So far only the first generation of fermions leptons and quarks with correct parity properties have been modelled by Sundance Bilson-Thompson using preons constituted of braids of spacetime as the building blocks. Utilization of quantum computing concepts made it possible to demonstrate that the particles are able to survive quantum fluctuations. This model leads to an interpretation of electric and colour charge as topological quantities electric as number and chirality of twists carried on the individual ribbons and colour as variants of such twisting for fixed electric charge, researches on the quantum theory.
Bilson-Thompson's original paper suggested that the higher-generation fermions could be represented by more complicated braidings, although explicit constructions of these researches on the quantum theory were not given.
The electric charge, colour, and parity properties of such fermions would arise in the same way as for the first generation. The model was expressly generalized for an infinite number of generations and for the weak force bosons but not for photons or gluons in a paper by Bilson-Thompson, Hackett, Kauffman and Smolin. Among other attempts to develop a theory of everything is the theory of causal fermion systems[42] giving the two current physical theories general relativity and quantum field theory as limiting cases.
Another theory is called Causal Sets. As some of the approaches mentioned above, its direct goal isn't necessarily to achieve a TOE researches on the quantum theory primarily a working theory of quantum gravity, which might eventually include the standard model and become a candidate for a TOE. Its founding principle is that spacetime is fundamentally discrete and that the spacetime events are related by a partial order. This partial order has the physical meaning of the causality relations between relative past and future distinguishing spacetime events.
Causal dynamical triangulation does not assume any pre-existing arena dimensional spaceresearches on the quantum theory rather attempts to show how the spacetime fabric itself evolves. At present, there is no candidate theory of everything that includes the standard model of particle physics and general relativity and that, at the same time, is able to calculate the fine-structure constant or the mass of the electron.
If You Don't Understand Quantum Physics, Try This!
, time: 12:45Albert Einstein - Biographical - blogger.com
A theory of everything (TOE or ToE), final theory, ultimate theory, theory of the world or master theory is a hypothetical, singular, all-encompassing, coherent theoretical framework of physics that fully explains and links together all physical aspects of the universe.: 6 Finding a TOE is one of the major unsolved problems in physics. String theory and M-theory have been Aug 26, · String theory is the only idea about quantum gravity with any substance. One sign is that where critics have had interesting ideas (non-commutative geometry, black hole entropy, twistor theory) they have tended to be absorbed as part of string theory. and David Gross: So you don’t think that other approaches like loop quantum gravity have May 15, · His theory has effectively given the great foundation to understanding about atomic. Democritus theory of atoms successfully motivated other scientists to conduct other experiments and researches in atomic field. This article will cover the principles in Democritus theory of atoms, Democritus history, and other basic atomic theory
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