How To Use String theory In A Sentence
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Physicists like the mathematical beauty of string theory because it banishes the absurdities that pop up when quantum mechanics and gravity combine.
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There is a “landscape” of many possible lower-dimensional vacua, just like in string theory.
Making Extra Dimensions Disappear
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Now physicists say they have used one of the most sophisticated pieces of string theory to predict properties of the ultradense matter created in an atom smasher in Long Island, N.Y.
Speedlinking 3/5/07
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String theory is a complete description of reality even though we don't understand its predictions in some extreme situations, especially those that have something to do with the ultratiny expanding universe.
The Reference Frame
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Will modern physicists weaponize String Theory?
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However, I am biasedly encouraged by the recent developments you have pointed out on a Twistor-string Theory that have occurred since The Road to Reality was written.
Are Changes Brewing and How Does the Mind Fit In?
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There still remain unproven conjectures such as the finiteness and consistency of any superstring theory, past the first three terms of a certain approximation scheme.
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In fact, determined efforts by many physicists and mathematicians over a period of more than 20 years have failed to produce a proof of the finiteness or consistency of string theory.
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Regarding these two threads: Doesn't it feel like we've been transported to the surface of some strange planet where, due to a local quirk in neuroanatomy, the inhabitants find the subjective/objective distinction to be as arcane as string theory is on Earth?
Carry-Over Thread
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Some promising ideas, such as inflationary cosmology and string theory, already exist.
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Before string theory won the full attention of the theoretical physics community, the most popular unified theory was an eleven dimensional theory of supergravity, which is supersymmetry combined with gravity.
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Few physicists say they are looking for ways to falsify superstring theory.
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Doesn't it feel like we've been transported to the surface of some strange planet where, due to a local quirk in neuroanatomy, the inhabitants find the subjective/objective distinction to be as arcane as string theory is on Earth?
Carry-Over Thread
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These two types of closed string modes are called right-movers and left-movers, and this difference will be important later in the supersymmetric heterotic string theory.
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The original string theory—called bosonic string theory—was certainly a concoction.
Euclid’s Window
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String theory is supposed to contain the physics of the quantum behavior of gravity.
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One proposed model has been to take the heterotic string theory and make six space dimensions form a small compact space called a Calabi-Yau space.
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In string theory, as in guitar playing, the string must be stretched under tension in order to become excited.
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String theory holds that different modes of vibration reveal themselves in our measly four dimensions of space and time as different particles and forces.
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Dimension 10 or 11 is a key number in string theory.
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That's cartoon physics for you, but it's also a lot like the very serious business of superstring theory.
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In superstring theory, particles are not treated as particles at all but as oscillations in one-dimensional entities called strings.
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That means the status of strings in string theory in physics can become a philosophical topic by way of discussions of realism and nominalism.
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Also, string theory has motivated an understanding of black holes in higher dimensions, and of black extended objects such as strings and branes.
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The best argument against it is the kind of microstate counting from string theory pioneered by Strominger and Vafa — they were always looking precisely at the extremal case, and found a non-zero entropy.
Where Does the Entropy Go?
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Tonight's episode is about string theory, and it's pretty good.
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Yet particle theories like Grand Unified Theories and superstring theory predict magnetic monopoles should exist.
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Yes, I am aware that I already have two physics related threads that have started and ended at “Part I” (false vacua and string theory).
Compactification in String Theory Part I: Motivation « Imaginary Potential
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I already have two physics related threads that have started and ended at “Part I” (false vacua and string theory).
False Vacua I: The End of the Universe As We Know it « Imaginary Potential
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In string theory the known elementary particles are no longer described as dimensionless mathematical point-objects but rather as extended one-dimensional objects (hence the name ‘string’).
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Thus, in one stroke, the superstring theory unites both the theory of Einstein and quantum physics into one coherent, compelling picture.
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String theory by its very definition is based on the conventional rules of quantum mechanics and if Hawking was right, the entire foundation of the theory would be destroyed.
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Manifest diffeomorphism invariance seems too limited if we want to describe string theory.
The String Theory Backlash
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The other main reason I find string theory unattractive is that it introduces a great deal of baggage, e.g., in the form of extra dimensions and extra particles (I have a related objection to all the new parameters introduced by supersymmetry, which is pretty much required by string theory in my understanding).
The String Theory Backlash
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String theory fails to provide any mechanism to generate the very small nonzero masses that are observed in nature, or to remove the exact spacetime supersymmetry, which is not observed in nature.
Two cheers for string theory
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In 1971, Pierre Ramond of the University of Florida derived a string theory for fermions by discovering an early form of a new symmetry called supersymmetry, which connects bosons and fermions.
Euclid’s Window
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Various "supersymmetric" theories (including superstring theory) do combine fermions and bosons as well—but only with a detailed mathematical underpinning that E8 does not provide.
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Also, string theory has motivated an understanding of black holes in higher dimensions, and of black extended objects such as strings and branes.
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I don't know that there will have been a eureka moment for string theory in the same way, so that there will be a specific time, but it could well be that some of the ideas of string theory.
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In modern string theory, the space representing the six hidden dimensions is a space of three complex dimensions known as a Calabi-Yau space.
Are Changes Brewing and How Does the Mind Fit In?
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There are branes to wrap, hierarchies to set, geometry to resolve, supersymmetry to break - a laundry list of processes and transitions that have to be described within in a string theory cosmology.
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This is another reason why physicists have become so impressed by string theory.
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Some valid discoveries have been made, so it is probably better grounded than String Theory, which is still stuck in "devise some explanation to explain the data" mode.
A Disclaimer for Behe?
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She leads us on to superstring theory and ‘brane worlds’, which picture particles as tiny vibrating filaments and the universe itself as a giant wobbly sheet.
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That's an example of a type of science that is fully on the level of particle physics and string theory intellectually but is quite disjoined from them.
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String theory is a quantum theory where the fundamental objects are one dimensional strings and not pointlike particles.
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And so I have to admit I don't see practical applications of string theory at the moment.
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It would be really difficult to summarize the crackpotism received from string theory authors during last decades (of course, this is not a criticism to any string theorist).
The String Theory Backlash
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Always bring the discussion back to the facts and try to cut off planted speculations that spin endlessly, like string theory.
Think Progress » GOP Rep. Jason Chaffetz agrees with concerns of 9/11 truthers: ‘There’s still a lot to learn.’
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Also: Parallel-universe physicist Brian Greene is "nice-looking for a regular guy; babelike for a scientist," and as capable as debating vegan cheese as string theory, reports Monica Hesse...
Read this: Senate insider/outsider Mike Lee, Sarah Palin's trademark, physicist Brian Greene, Dan Snyder talks back
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It is argued that this means that superstring theory is no more a part of science than is Intelligent Design.
Another Look
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The best argument against it is the kind of microstate counting from string theory pioneered by Strominger and Vafa — they were always looking precisely at the extremal case, and found a non-zero entropy.
Where Does the Entropy Go?
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The biggest problem with bosonic string theory (aside from the lack of fermions) is that the lowest energy state was a tachyon, or a particle mode with negative mass squared.
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He proposed the basis of quantum chromodynamics, which is the theory of how quarks interact to form subatomic particles like protons, neutrons and pions, helped found string theory, and discovered spontaneous symmetry breaking in field theory.
Andrew Jaffe: Leaves on the Line
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Because string theory has so much symmetry, it can accommodate the disparate faces of nature displayed by gravity and quantum theory.
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As explained above, superstring theory might allow enough variation in the variations in the constants of physics among bubble universes to make it reasonably likely that a fine-tuned universe would be produced.
A Fine-Tuned Multiverse
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Berkeley National Laboratory in California, and his colleagues have calculated that as it ramps up, the LHC will generate enough collisions to produce clear signatures of a hypothetical "diquark" particle proposed by some forms of string theory.
Scientific American
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Steinhardt's scenario makes use of string theory another attempt to reconcile General Relativity with quantum physics.
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Lurking in the 11 th dimension was an entirely new theory which could reduce down to 11 dimensional supergravity as well as 10 dimensional string theory and p-brane theory.
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Recently, a theory called the superstring theory has attempted to explain that particles are not the smallest form in the world but rather small vibrating loops called strings.
Is Nima Arkani Hamed the Next Albert Einstein?
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His groundbreaking work in the areas of superstring theory, supersymmetry and supergravity has made him a leading expert on the topic.
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String theory and/or supersymmetry, for example, involve higher dimensions of space that introduce new degrees of freedom and possible violations of space-time symmetries such as Lorentz symmetry.
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Maldecena and Lin conjecture that orbifold solutions in String Theory could decay into these soliton states as tachyons condense.
Archive 2006-02-12
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Second, this shaky notion was based on a highly abstract and contentious branch of physics known as string theory.
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In his talk, Harvey will address the anxiety that string theory has produced.
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The best argument against it is the kind of microstate counting from string theory pioneered by Strominger and Vafa - they were always looking precisely at the extremal case, and found a non-zero entropy.
Cosmic Variance
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I've labeled the charges as q and q-bar for quark and antiquark, but that's modern terminology that might not have been present in the early days of string theory.
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The most studied superstring compactification is heterotic string theory compactified on a Calabi-Yau space in six-dimensions (or three complex dimensions).
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The theories on the worldsheet must be conformal which is string theory's way to demand the spacetime equations of motion - the beta-functions are the equations of motion.
The Reference Frame
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The point is that superstring theory was initially thought to only contain strings.
A Conversation with Brian Greene
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“In modern string theory, dark energy also called the cosmological constant is the energy stored in empty space, where pairs of matter and anti-matter particles are spontaneously created and annihilated,” said Baylor researcher Gerald Cleaver.
Researchers Claim Star Trek’s Warp Drive Possible In The Future | Impact Lab
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It has been used in gauge theory, instantons, monopoles, string theory and the theory of anomalies.
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If we presume the twistor-string theory gains acceptence, it will result in something I pointed out multiple times.
Are Changes Brewing and How Does the Mind Fit In?
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Descriptions of Planck scale geometry include quantum gravity, spin networks, twistor theory and string theory.
Deepak Chopra: Can Science Explain the Soul?
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Despite recent encouraging possibilities that superstrings might have observable effects at the TeV scale, string theory remains an almost exclusively mathematical activity isolated from any serious threat of experimental test.
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Yeah , well, it's just some quantum mechanics with a little string theory around the edges.
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String theory makes a beautiful prediction that this chaotic foam is valenced from measurable physics, or in a sense renormalized out.
Einstein Still Rules, Says Fermi Telescope Team | Universe Today
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String theory is false, because no consistent version of the theory exists or no version agrees with all experimental results.
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Not much point in trying to convince you of the untestability of string theory … no one seems to believe this except you (including the referee of the paper ….).
String Theory is Losing the Public Debate
