Experimental Search for Quantum Gravity

 Sabine Hossenfelder "ESQG Summary and Outlook"

Talk on 16 July 2010 at the workshop "Experimental Search for Quantum Gravity", 12-16 July, 2010, at Nordita in Stockholm, Sweden.

http://www.nordita.org/esqg2010

See Also:

Bee Writes:I like this example of neutral Kaon oscillations because it demonstrates so clearly that quantum gravitational effects are not necessarily too small to be detected in experiments, and it is likely we'll hear more about this in the soon future.Neutral Kaons and Quantum Gravity Phenomenology

The KLOE detector on the DAFNE interaction region (INFN - Frascati National Laboratories)

DAFNE or DAΦNE, the Double Annular Φ Factory for Nice Experiments, is an electron-positron collider at the INFN Frascati National Laboratory in Frascati, Italy. Since 1999 it has been colliding electrons and positrons at a center of mass energy of 1.02 GeV to create phi (φ) mesons. 85% of these decay into kaons (K), whose physics is the subject of most of the experiments at DAFNE.
There are five experiments at DAFNE:

• KLOE, or K LOng Experiment, which has been studying CP violation in kaon decays and rare kaon decays since 2000. This is the largest of DAFNE experiments.
• FINUDA, or FIsica NUcleare a DAFNE, studies the spectra and nonmesonic decays of Lambda (Λ)-hypernuclei produced by negatively charged kaons (K−) striking a thin target.
• DEAR, or DAFNE Exotic Atoms Research experiment, determines scattering lengths in atoms made from a kaon and a proton or deuteron.
• DAFNE Light Laboratory consists of 3 lines of synchrotron radiation emitted by DAFNE, a fourth is under construction.
• SIDDHARTA, or SIlicon Drift Detectors for Hadronic Atom Research by Timing Application, aims to improve the precision measurements of X-ray transitions in kaon atoms studied at DEAR.

 See: Neutral kaon interferometry at KLOE and KLOE-2

Near-Future Photon-Collider Setups

In the search for a quantum theory of gravity it is crucial to find experimental access to quantum gravitational effects. Since these are expected to be very small at observationally accessible scales it is advantageous to consider processes with no tree-level contribution in the Standard Model, such as photon-photon scattering. We examine the implications of asymptotically safe quantum gravity in a setting with extra dimensions for this case, and point out that various near-future photon-collider setups, employing either electron or muon colliders, or even a purely laser-based setup, could provide a first observational window into the quantum gravity regime. Can we see quantum gravity? Photons in the asymptotic-safety scenario

Experimental Search for Quantum Gravity: the hard facts 


October 22-25, 2012
Perimeter Institute
Scientific area: quantum gravity

 Quantum Gravity tries to answer some of the most fundamental questions about the quantum nature of spacetime. To make progress in this area it is mandatory to establish a contact to observations and experiments and to learn what the "hard facts" on quantum gravity are, that nature provides us with.

Quantum Gravity is a field where several approaches, based on different principles and assumptions, develop in parallel. At present it is not clear whether and how some of the approaches are compatible, and might share common properties. This meeting will draw on a diverse set of physicists who come to make proposals for quantum gravity phenomenology from a broad range of perspectives, including path-integral-inspired as well as canonical, and discrete as well as continuum-based approaches, providing a platform to exchange ideas with researchers working on theoretical and experimental aspects of different proposals.

This will be the third in a series of meetings, the first of which was held at PI (2007), the second at NORDITA (2010).

This meeting looks to the future and has two primary goals: 1) to assess the status of different proposals for QG phenomenology in the light of recent experimental results from Fermi, Auger, LHC etc. and 2) to discuss and stimulate new ideas and proposals, coming from a diverse set of viewpoints about quantum spacetime.

In order to allow for a fruitful exchange of ideas across different approaches, and between experimental and theoretical researchers, the workshop will lay a main focus on structured discussion sessions with short (15 min.) presentations. These are mainly intended for an exchange of ideas, and a discussion and development of new possibilities, thus participants are strongly encouraged to present new ideas and work in progress.

See Also:

• Probing Planck-scale physics with quantum optics

• An optical probe of quantum gravity?

• A Blast of Gamma Rays and Positrons

• Experimental Search for Quantum Gravity 2012

Explanation on Quantum Gravity in a Nutshell

Although Aristotle in general had a more empirical and experimental attitude than Plato, modern science did not come into its own until Plato's Pythagorean confidence in the mathematical nature of the world returned with Kepler, Galileo, and Newton. For instance, Aristotle, relying on a theory of opposites that is now only of historical interest, rejected Plato's attempt to match the Platonic Solids with the elements -- while Plato's expectations are realized in mineralogy and crystallography, where the Platonic Solids occur naturally.Plato and Aristotle, Up and Down-Kelley L. Ross, Ph.D.

The goal of string theory is to explain the "?" in the above diagram.

 I enjoyed the Livescribe demonstration by Clifford of  Asymptotia along with the explanation for Quantum Gravity. The two pillars for me were very emblematic with regards to "pillars of science."  This as well as the arch  is very fitting to me of what becomes self evident. If  under such an examination of the two areas Clifford is talking about,  Quantum Mechanics and General Relativity then are the attempts at unification.

 
The Yorck Project: 10.000 Meisterwerke der Malerei. DVD-ROM, 2002. ISBN 3936122202. Distributed by DIRECTMEDIA Publishing GmbH.

That question mark can be demonstrated above as to where in the location in Cliffords diagrams is related to the Aristotelian Arch in my view?

See:

•  Clifford Scribbling About Quantum Gravity
•  Quantum Gravity in a Nutshell

Holometer

Holometer Revised

This plot shows the sensitivity of various experiments to fluctuations in space and time. Horizontal axis is the log of apparatus size (or duration time the speed of light), in meters; vertical axis is the log of the rms fluctuation amplitude in the same units. The lower left corner represents the Planck length or time. In these units, the size of the observable universe is about 26. Various physical systems and experiments are plotted. The "holographic noise" line represents the rms transverse holographic fluctuation amplitude on a given scale. The most sensitive experiments are Michelson interferometers.

The Fermilab Holometer in Illinois is currently under construction and will be the world's most sensitive laser interferometer when complete, surpassing the sensitivity of the GEO600 and LIGO systems, and theoretically able to detect holographic fluctuations in spacetime.^[1][2][3]

The Holometer may be capable of meeting or exceeding the sensitivity required to detect the smallest units in the universe called Planck units.^[1] Fermilab states, "Everyone is familiar these days with the blurry and pixelated images, or noisy sound transmission, associated with poor internet bandwidth. The Holometer seeks to detect the equivalent blurriness or noise in reality itself, associated with the ultimate frequency limit imposed by nature."^[2]
Craig Hogan, a particle astrophysicist at Fermilab, states about the experiment, "What we’re looking for is when the lasers lose step with each other. We’re trying to detect the smallest unit in the universe. This is really great fun, a sort of old-fashioned physics experiment where you don’t know what the result will be."

Experimental physicist Hartmut Grote of the Max Planck Institute in Germany, states that although he is skeptical that the apparatus will successfully detect the holographic fluctuations, if the experiment is successful "it would be a very strong impact to one of the most open questions in fundamental physics. It would be the first proof that space-time, the fabric of the universe, is quantized."^[1]

References

1. ^ ^{a b c} Mosher, David (2010-10-28). "World’s Most Precise Clocks Could Reveal Universe Is a Hologram". Wired. http://www.wired.com/wiredscience/2010/10/holometer-universe-resolution/. 
2. ^ ^{a b} "The Fermilab Holometer". Fermi National Accelerator Laboratory. http://holometer.fnal.gov/. Retrieved 2010-11-01. 
3. ^ Dillow, Clay (2010-10-21). "Fermilab is Building a 'Holometer' to Determine Once and For All Whether Reality Is Just an Illusion". Popular Science. http://www.popsci.com/science/article/2010-10/fermilab-building-holometer-determine-if-universe-just-hologram.

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Fermilab Holometer

About a hundred years ago, the German physicist Max Planck introduced the idea of a fundamental, natural length or time, derived from fundamental constants. We now call these the Planck length, lp = √hG/2π c3 = 1.6 × 10-35 meters. Light travels one Planck length in the Planck time, tp = √hG/2π c⁵ = 5.4 × 10^-44seconds. 

The physics of space and time is expected to change radically on such small scales. For example, a particle confined to a Planck volume automatically collapses to a black hole. 

See: Fermilab Holometer

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A Conceptual Drawing of the 'Holometer' via Symmetry

“The shaking of spacetime occurs at a million times per second, a thousand times what your ear can hear,” said Fermilab experimental physicist Aaron Chou, whose lab is developing prototypes for the holometer. “Matter doesn’t like to shake at that speed. You could listen to gravitational frequencies with headphones.”

The whole trick, Chou says, is to prove that the vibrations don’t come from the instrument. Using technology similar to that in noise-cancelling headphones, sensors outside the instrument detect vibrations and shake the mirror at the same frequency to cancel them. Any remaining shakiness at high frequency, the researchers propose, will be evidence of blurriness in spacetime

“With the holometer’s long arms, we’re magnifying spacetime’s uncertainty,” Chou said.

See: Hogan’s holometer: Testing the hypothesis of a holographic universe

***

Conclusion:

• The Hoganmeter

• Hogan's holographic noise doesn't exist

Gravimetry

For the chemical analysis technique, see Gravimetric analysis.

Gravity map of the Southern Ocean around the Antarctic continent

Author-Hannes Grobe, AWI

This gravity field was computed from sea-surface height measurements collected by the US Navy GEOSAT altimeter between March, 1985, and January, 1990. The high density GEOSAT Geodetic Mission data that lie south of 30 deg. S were declassified by the Navy in May of 1992 and contribute most of the fine-scale gravity information.

The Antarctic continent itself is shaded in blue depending on the thickness of the ice sheet (blue shades in steps of 1000 m); light blue is shelf ice; gray lines are the major ice devides; pink spots are parts of the continent which are not covered by ice; gray areas have no data.

Gravimetry is the measurement of the strength of a gravitational field. Gravimetry may be used when either the magnitude of gravitational field or the properties of matter responsible for its creation are of interest. The term gravimetry or gravimetric is also used in chemistry to define a class of analytical procedures, called gravimetric analysis relying upon weighing a sample of material.

Contents 1 Units of measurement 2 How gravity is measured 3 Microgravimetry 4 History 5 See also

Units of measurement

Gravity is usually measured in units of acceleration. In the SI system of units, the standard unit of acceleration is 1 metre per second squared (abbreviated as m/s²). Other units include the gal (sometimes known as a galileo, in either case with symbol Gal), which equals 1 centimetre per second squared, and the g (g_n), equal to 9.80665 m/s². The value of the g_n approximately equals the acceleration due to gravity at the Earth's surface (although the actual acceleration g varies fractionally from place to place).

How gravity is measured

An instrument used to measure gravity is known as a gravimeter, or gravitometer. Since general relativity regards the effects of gravity as indistinguishable from the effects of acceleration, gravimeters may be regarded as special purpose accelerometers. Many weighing scales may be regarded as simple gravimeters. In one common form, a spring is used to counteract the force of gravity pulling on an object. The change in length of the spring may be calibrated to the force required to balance the gravitational pull. The resulting measurement may be made in units of force (such as the newton), but is more commonly made in units of gals.

More sophisticated gravimeters are used when precise measurements are needed. When measuring the Earth's gravitational field, measurements are made to the precision of microgals to find density variations in the rocks making up the Earth. Several types of gravimeters exist for making these measurements, including some that are essentially refined versions of the spring scale described above. These measurements are used to define gravity anomalies.

Besides precision, also stability is an important property of a gravimeter, as it allows the monitoring of gravity changes. These changes can be the result of mass displacements inside the Earth, or of vertical movements of the Earth's crust on which measurements are being made: remember that gravity decreases 0.3 mGal for every metre of height. The study of gravity changes belongs to geodynamics.

The majority of modern gravimeters use specially-designed quartz zero-length springs to support the test mass. Zero length springs do not follow Hooke's Law, instead they have a force proportional to their length. The special property of these springs is that the natural resonant period of oscillation of the spring-mass system can be made very long - approaching a thousand seconds. This detunes the test mass from most local vibration and mechanical noise, increasing the sensitivity and utility of the gravimeter. The springs are quartz so that magnetic and electric fields do not affect measurements. The test mass is sealed in an air-tight container so that tiny changes of barometric pressure from blowing wind and other weather do not change the buoyancy of the test mass in air.

Spring gravimeters are, in practice, relative instruments which measure the difference in gravity between different locations. A relative instrument also requires calibration by comparing instrument readings taken at locations with known complete or absolute values of gravity. Absolute gravimeters provide such measurements by determining the gravitational acceleration of a test mass in vacuum. A test mass is allowed to fall freely inside a vacuum chamber and its position is measured with a laser interferometer and timed with an atomic clock. The laser wavelength is known to ±0.025 ppb and the clock is stable to ±0.03 ppb as well. Great care must be taken to minimize the effects of perturbing forces such as residual air resistance (even in vacuum) and magnetic forces. Such instruments are capable of an accuracy of a few parts per billion or 0.002 mGal and reference their measurement to atomic standards of length and time. Their primary use is for calibrating relative instruments, monitoring crustal deformation, and in geophysical studies requiring high accuracy and stability. However, absolute instruments are somewhat larger and significantly more expensive than relative spring gravimeters, and are thus relatively rare.

Gravimeters have been designed to mount in vehicles, including aircraft, ships and submarines. These special gravimeters isolate acceleration from the movement of the vehicle, and subtract it from measurements. The acceleration of the vehicles is often hundreds or thousands of times stronger than the changes being measured. A gravimeter (the Lunar Surface Gravimeter) was also deployed on the surface of the moon during the Apollo 17 mission, but did not work due to a design error. A second device (the Traverse Gravimeter Experiment) functioned as anticipated.

Microgravimetry

Microgravimetry is a rising and important branch developed on the foundation of classical gravimetry.

Microgravity investigations are carried out in order to solve various problems of engineering geology, mainly location of voids and their monitoring. Very detailed measurements of high accuracy can indicate voids of any origin, provided the size and depth are large enough to produce gravity effect stronger than is the level of confidence of relevant gravity signal.

History

The modern gravimeter was developed by Lucien LaCoste and Arnold Romberg in 1936.

They also invented most subsequent refinements, including the ship-mounted gravimeter, in 1965, temperature-resistant instruments for deep boreholes, and lightweight hand-carried instruments. Most of their designs remain in use (2005) with refinements in data collection and data processing.

See also

• Physical geodesy
• Gravity Recovery and Climate Experiment

It's Still A Elephant

A sensible reductionist perspective would be something like “objects are completely defined by the states of their components.” The dialogue uses elephants as examples of complex objects, so Rosenberg imagines that we know the state (position and momentum etc.) of every single particle in an elephant. Now we consider another collection of particles, far away, in exactly the same state as the ones in the elephant. Is there any sense in which that new collection is not precisely the same kind of elephant as the original?

Physicalist Anti-Reductionism

Most know the "general area" we are talking about, and since Quantum gravity rests on a lot of minds, we have to see methods of materiality as measure in which to express that reality?




The Six Men and the Elephant

So what are the ways in which modern day theorists and scientists detest the insight that such designs are inherent in the very symmetrical views with which all symmetry breaking phases can materialize? Do they?

So I raise the thought of still a elephant in the room:)


"If you constraint the idea of the elephant as a picture of the quantum gravity regime then it is highly likely one would seek to use that elephant in thought experiments to progress such thinking about possible methods to describing that determination within that given environment? How many methods?

One, and only one blind man's description in hand?:) It's still a elephant:)"

Virasoro algebra

Black hole thermodynamics

From Wikipedia, the free encyclopedia

In physics, black hole thermodynamics is the area of study that seeks to reconcile the laws of thermodynamics with the existence of black hole event horizons. Much as the study of the statistical mechanics of black body radiation led to the advent of the theory of quantum mechanics, the effort to understand the statistical mechanics of black holes has had a deep impact upon the understanding of quantum gravity, leading to the formulation of the holographic principle.

 It is important that ones is able to see the progression from abstraction to a interpretation of foundational approach.

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Andy Strominger:

This was a field theory that lived on a circle, which means it has one spatial dimension and one time dimension. We derived the fact that the quantum states of the black hole could be represented as the quantum states of this one-plus-one dimensional quantum field theory, and then we counted the states of this theory and found they exactly agreed with the Bekenstein-Hawking entropy.See:Quantum Microstates: Gas Molecules in the Presence of a Gravitational Field

See:Microscopic Origin of the Bekenstein-Hawking Entropy

Of course I am interested the mathematical framework as it might be compared to some phenomenological approach that gives substance to any theoretical thought.

For example, Tommaso Dorigo is a representative of the type of people who may affect the general distribution of "subjects" that may grow at CERN or the Fermilab in the next decade or two. And he just published a quote by Sherlock Holmes - no kidding - whose main point is that it is a "capital mistake" to work on any theory before the data are observed.See:Quantum gravity: minority report

I think you were a little harsh on Tommaso Dorigo  Lubos because he is really helping us to understand the scientific process at Cern. But you are right about theory in my mind, before the phenomenological approach can be seen. The mind need to play creatively in the abstract notions before it can be seen in it's correlations in reality.

***

Virasoro algebra

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v • d • e

In mathematics, the Virasoro algebra (named after the physicist Miguel Angel Virasoro) is a complex Lie algebra, given as a central extension of the complex polynomial vector fields on the circle, and is widely used in string theory.

Contents 1 Definition 2 Representation theory 3 Generalizations 4 History 5 See also 6 References

Definition

The Virasoro algebra is spanned by elements

L_i for

and c with

L_n + L _{− n}

and c being real elements. Here the central element c is the central charge. The algebra satisfies

[c,L_n] = 0

and

The factor of 1/12 is merely a matter of convention.
The Virasoro algebra is a central extension of the (complex) Witt algebra of complex polynomial vector fields on the circle. The Lie algebra of real polynomial vector fields on the circle is a dense subalgebra of the Lie algebra of diffeomorphisms of the circle.
The Virasoro algebra is obeyed by the stress tensor in string theory, since it comprises the generators of the conformal group of the worldsheet, obeys the commutation relations of (two copies of) the Virasoro algebra. This is because the conformal group decomposes into separate diffeomorphisms of the forward and back lightcones. Diffeomorphism invariance of the worldsheet implies additionally that the stress tensor vanishes. This is known as the Virasoro constraint, and in the quantum theory, cannot be applied to all the states in the theory, but rather only on the physical states (confer Gupta-Bleuler quantization).

Representation theory

A lowest weight representation of the Virasoro algebra is a representation generated by a vector v that is killed by L_i for i ≥1 , and is an eigenvector of L₀ and c. The letters h and c are usually used for the eigenvalues of L₀ and c on v. (The same letter c is used for both the element c of the Virasoro algebra and its eigenvalue.) For every pair of complex numbers h and c there is a unique irreducible lowest weight representation with these eigenvalues.
A lowest weight representation is called unitary if it has a positive definite inner product such that the adjoint of L_n is L_−n. The irreducible lowest weight representation with eigenvalues h and c is unitary if and only if either c≥1 and h≥0, or c is one of the values

for m = 2, 3, 4, .... and h is one of the values

for r = 1, 2, 3, ..., m−1 and s= 1, 2, 3, ..., r. Daniel Friedan, Zongan Qiu, and Stephen Shenker (1984) showed that these conditions are necessary, and Peter Goddard, Adrian Kent and David Olive (1986) used the coset construction or GKO construction (identifying unitary representations of the Virasoro algebra within tensor products of unitary representations of affine Kac-Moody algebras) to show that they are sufficient. The unitary irreducible lowest weight representations with c < 1 are called the discrete series representations of the Virasoro algebra. These are special cases of the representations with m = q/(p−q), 0<r<q, 0< s<p for p and q coprime integers and r and s integers, called the minimal models and first studied in Belavin et al. (1984).
The first few discrete series representations are given by:

• m = 2: c = 0, h = 0. The trivial representation.
• m = 3: c = 1/2, h = 0, 1/16, 1/2. These 3 representations are related to the Ising model
• m = 4: c = 7/10. h = 0, 3/80, 1/10, 7/16, 3/5, 3/2. These 6 representations are related to the tri critical Ising model.
• m = 5: c = 4/5. There are 10 representations, which are related to the 3-state Potts model.
• m = 6: c = 6/7. There are 15 representations, which are related to the tri critical 3-state Potts model.

The lowest weight representations that are not irreducible can be read off from the Kac determinant formula, which states that the determinant of the invariant inner product on the degree h+N piece of the lowest weight module with eigenvalues c and h is given by

which was stated by V. Kac (1978), (see also Kac and Raina 1987) and whose first published proof was given by Feigin and Fuks (1984). (The function p(N) is the partition function, and A_N is some constant.) The reducible highest weight representations are the representations with h and c given in terms of m, c, and h by the formulas above, except that m is not restricted to be an integer ≥ 2 and may be any number other than 0 and 1, and r and s may be any positive integers. This result was used by Feigin and Fuks to find the characters of all irreducible lowest weight representations.

Generalizations

There are two supersymmetric N=1 extensions of the Virasoro algebra, called the Neveu-Schwarz algebra and the Ramond algebra. Their theory is similar to that of the Virasoro algebra.
The Virasoro algebra is a central extension of the Lie algebra of meromorphic vector fields on a genus 0 Riemann surface that are holomorphic except at two fixed points. I.V. Krichever and S.P. Novikov (1987) found a central extension of the Lie algebra of meromorphic vector fields on a higher genus compact Riemann surface that are holomorphic except at two fixed points, and M. Schlichenmaier (1993) extended this to the case of more than two points.

History

The Witt algebra (the Virasoro algebra without the central extension) was discovered by E. Cartan (1909). Its analogues over finite fields were studied by E. Witt in about the 1930s. The central extension of the Witt algebra that gives the Virasoro algebra was first found (in characteristic p>0) by R. E. Block (1966, page 381) and independently rediscovered (in characteristic 0) by I. M. Gelfand and D. B. Fuks (1968). Virasoro (1970) wrote down some operators generating the Virasoso algebra while studying dual resonance models, though he did not find the central extension. The central extension giving the Virasoro algebra was rediscovered in physics shortly after by J. H. Weis, according to Brower and Thorn (1971, footnote on page 167).

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See:Quantum Gravity Summer School Also pictures by Hecaicedo Photostream

The Cross Over Point and Time Travel

One of the issues that is evoked by any faster-than-light transport is time paradoxes: causality violations and implications of time travel. As if the faster than light issue wasn’t tough enough, it is possible to construct elaborate scenarios where faster-than-light travel results in time travel. Time travel is considered far more impossible than light travel.

I mean sure how is it one can measure time in energy particulate views when it appears all smeared out? It is the collision process itself and what I see in nature as Cascading particles as microscopic blackholes created and then quickly dissipated as decay in those particle showers.

Seeing muon detections that tunnel, and find their way across the globe is something that is interesting, as we can now use them in measure, as to what passes through to what is fabricated there in the LHC, becomes an interesting new tool of climate change or even gravitational inclination in relativistic approaches.

Length contractions is a key word here in microscopic measure.

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Juan Martín Maldacena and Joseph Polchinski

Dr. Maldacena and Dr. Polchinski each gave brief lectures related to their work. Both included broad overviews of string theory basics, with Dr. Polchinski noting the importance of "thought experiments" to help physicists make advances in the field. He said that physicists are excited about future experiments using particle accelerators such as the Large Hadron Collider at CERN, where some of these "thought experiments" could be validated.

Dr. Maldacena, who was born in Buenos Aires, also spoke about ICTP's important influence on physics in Argentina, noting that many of his professors had spent time at the Centre. Dr. Maldacena himself has participated in ICTP training programmes and was a director of the Spring School on String Theory for four years.

The Dirac Medal is given in honour of P.A.M. Dirac, one of the greatest physicists of the 20th century and a staunch friend of ICTP, to scientists who have made significant contributions to physics. Recipients are announced annually on Dirac's birthday, 8 August. The Medallists also receive a prize of US $5,000.Noted physicists awarded Dirac Medal

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Juan Martín Maldacena, Institute for Advanced Study, Princeton
Joseph Polchinski, Kavli Institute for Theoretical Physics, University of California at Santa Barbara
and
Cumrun Vafa, Harvard University

Professors Maldacena, Polchinski and Vafa are being honored for their fundamental contributions to superstring theory. Their studies range from early work on orbifold compactifications, physics and mathematics of mirror symmetry, D-branes and black hole physics, as well as gauge theory-gravity correspondence. Their contributions in uncovering the strong-weak dualities between seemingly different string theories have enabled us to learn about regimes of quantum field theory which are not accessible to perturbative analysis. These profound achievements have helped us to address outstanding questions like confinement of quarks and QCD mass spectrum from a new perspective and have found applications in practical calculations in the fluid dynamics of quark gluon plasma.

The dualities have also led string theorists to conjecture that the five different superstring theories in ten space-time dimensions are manifestations of one underlying theory, yet undiscovered, which has been named the M-theory.See:Dirac Medalists 2008

***

Another deep quantum mystery for which physicists have no answer has to do with "tunneling" -- the bizarre ability of particles to sometimes penetrate impenetrable barriers. This effect is not only well demonstrated; it is the basis of tunnel diodes and similar devices vital to modern electronic systems.

Tunneling is based on the fact that quantum theory is statistical in nature and deals with probabilities rather than specific predictions; there is no way to know in advance when a single radioactive atom will decay, for example.

The probabilistic nature of quantum events means that if a stream of particles encounters an obstacle, most of the particles will be stopped in their tracks but a few, conveyed by probability alone, will magically appear on the other side of the barrier. The process is called "tunneling," although the word in itself explains nothing.

Chiao's group at Berkeley, Dr. Aephraim M. Steinberg at the University of Toronto and others are investigating the strange properties of tunneling, which was one of the subjects explored last month by scientists attending the Nobel Symposium on quantum physics in Sweden.

"We find," Chiao said, "that a barrier placed in the path of a tunnelling particle does not slow it down. In fact, we detect particles on the other side of the barrier that have made the trip in less time than it would take the particle to traverse an equal distance without a barrier -- in other words, the tunnelling speed apparently greatly exceeds the speed of light. Moreover, if you increase the thickness of the barrier the tunnelling speed increases, as high as you please.

"This is another great mystery of quantum mechanics."Signal Travels Farther and Faster Than Light By MALCOLM W. BROWNE

You and I know it as a time machine. Physicists, on the other hand, call it a "closed timelike curve." Below, feast on the concepts and conjectures, the dialects and definitions that physicists rely on when musing about the possibility of time travel. If this list only whets your appetite for more, we recommend you have a gander at the book from which we excerpted this glossary: Black Holes and Time Warps: Einstein's Outrageous Legacy, by Kip S. Thorne (Norton, 1994).

***

See Also:

Tunnelling in Faster then Light

Status of "Warp Drive"

Result of Effective Changes in the Cosmos

TimeSpeak

The Ring of Truth

Savas Dimopoulos:Here’s an analogy to understand this: imagine that our universe is a two-dimensional pool table, which you look down on from the third spatial dimension. When the billiard balls collide on the table, they scatter into new trajectories across the surface. But we also hear the click of sound as they impact: that’s collision energy being radiated into a third dimension above and beyond the surface. In this picture, the billiard balls are like protons and neutrons, and the sound wave behaves like the graviton.

On the title it is important to understand what is being implied within the context of this post. What came to mind immediately when Bee wrote"Ring of Truth" in her post, "A Theoretically Simple Exception of Everything." Joseph Weber came to mind.

Joseph Weber 1919 - 2000

Joseph Weber, the accomplished physicist and electrical engineer, has died at the age of 81. Weber's diverse research interests included microwave spectroscopy and quantum electronics, but he is probably best known for his investigations into gravitational waves.

In the late 1950s, Weber became intrigued by the relationship between gravitational theory and laboratory experiments. His book, General Relativity and Gravitational Radiation, was published in 1961, and his paper describing how to build a gravitational wave detector first appeared in 1969. Weber's first detector consisted of a freely suspended aluminium cylinder weighing a few tonnes. In the late 1960s and early 1970s, Weber announced that he had recorded simultaneous oscillations in detectors 1000 km apart, waves he believed originated from an astrophysical event. Many physicists were sceptical about the results, but these early experiments initiated research into gravitational waves that is still ongoing. Current gravitational wave experiments, such as the Laser Interferometer Gravitational Wave Observatory (LIGO) and Laser Interferometer Space Antenna (LISA), are descendants of Weber's original work.

Weber was born in 1919 in Paterson, New Jersey, and graduated in 1940. He spent eight years as an electrical engineer in the US Navy, and was assigned as navigator on the aircraft carrier Lexington during World War II. After his resignation from the Navy in 1948, Weber went on to obtain his PhD in 1951 from the Catholic University of America. He was appointed professor of electrical engineering at the University of Maryland, and he moved into the physics department in 1961 when he began his investigations into gravitational waves.

Weber died on 30 September in Pittsburgh, Pennsylvania. He is survived by his wife, the astrophysicist Virginia Trimble.

Bee writes about "Ring of Truth" from Lee Smolin's book,

"But we are also fairly sure that we do not yet have all the pieces. Even with the recent successes, no idea yet has that absolute ring of truth." p. 255 (US hardcover).

So I pulled this above from Bee's comment blog for further reference. To help make my point about gravitational wave detection and all the kinds of wav(Y)es in which gravity can now be looked at.

So of course it is necessary to include the commentary from Bee's reference too, Garrett Lisi's comment section, to help one see the complex rotations that speaks to all manifestations(geometrical foresight on complex rotations in dimensional spaces), from the origins of all a particle creations to the elemental understanding given in context of the post by Bee.

"With the discovery of sound waves in the CMB, we have entered a new era of precision cosmology in which we can begin to talk with certainty about the origin of structure and the content of matter and energy in the universe-Wayne Hu

Stefan,

Maybe I have a better chance to understand them when their relation to the original post is more than just the word "gravity" in both of them?

Your "toying with the way we see gravitational and gravity waves?" Dealing with the objective world with ancient ideas?

I pointed to the differences.

Plato:Wherever there are no gravitational waves the spacetime is flat. One would have to define these two variances. One from understanding the relation to "radiation" and the other, "to the perfectly spherically symmetric."

But still to see such dynamics in terms of the "mathematical abstract" I see see no reason why you would "lesson my points" on helping one to see these differences in the space around us.

This recording was produced by converting into audible sounds some of the radar echoes received by Huygens during the last few kilometres of its descent onto Titan. As the probe approaches the ground, both the pitch and intensity increase. Scientists will use intensity of the echoes to speculate about the nature of the surface.

So I may point to the ways in which one may synthesized the views of the world in relation to not only "sound" as Kris just talks about, but also about how one may transform that sound "to colour."

3.1 As Cytowic notes, Plato and Socrates viewed emotion and reason as in a kind of struggle, one in which it was vitally important for reason to win out. Aristotle took a more moderate view, that both emotion and reason are integral parts of a complex human soul--a theory proposed by Aristotle in explicit opposition to Platonism (De Anima 414a 19ff). Cytowic appears to endorse the Platonic line, with the notable difference that he would apparently rather have emotion win out.

Cosmic variance may talk about synesthesia yet you cannot stop the changes such understanding brings to the emotive forces that surround earth and us.

Such a shift to bulk perspective is not without it's lessons on progressing the views of gravity in "all situations."

I am not so smart, just that I may see differently then you Stefan. :)

We can't actually hear gravitational waves, even with the most sophisticated equipment, because the sounds they make are the wrong frequency for our ears to hear. This is similar in principle to the frequency of dog whistles that canines can hear, but are too high for humans. The sounds of gravitational waves are probably too low for us to actually hear. However, the signals that scientists hope to measure with LISA and other gravitational wave detectors are best described as "sounds." If we could hear them, here are some of the possible sounds of a gravitational wave generated by the movement of a small body in spiralling into a black hole.

Does anybody really understand what is happening when the conceptual foundation allows new perspective to form? New theories to make their way into challenging the very foundations of our reality?

Every step in the production of the "conceptual framework" is an exercise in how perception is being changed. Can be changed.

There are moderators of all sorts who govern the information that is being written. How one view can be portrayed and sits in contradiction to the way String theory uses E8 is not the reason one might of suspected problems with acceptance here or there.

It s a organizational method on how to respond and place it accordingly. Peter is being paranoid? :)

Where Spacetime is flat?

......A Condensative Result exists. Where "energy concentrates" and expresses outward.

I mean if I were to put on my eyeglasses, and these glasses were given to a way of seeing this universe, why not look at the whole universe bathed in such spacetime fabric?

This a opportunity to get "two birds" with one stone?

I was thinking of Garrett's E8 Theory article and Stefan's here.

On March 31, 2006 the high-resolution gravity field model EIGEN-GL04C has been released. This model is a combination of GRACE and LAGEOS mission plus 0.5 x 0.5 degrees gravimetry and altimetry surface data and is complete to degree and order 360 in terms of spherical harmonic coefficients.

High-resolution combination gravity models are essential for all applications where a precise knowledge of the static gravity potential and its gradients is needed in the medium and short wavelength spectrum. Typical examples are precise orbit determination of geodetic and altimeter satellites or the study of the Earth's crust and mantle mass distribution.

But, various geodetic and altimeter applications request also a pure satellite-only gravity model. As an example, the ocean dynamic topography and the derived geostrophic surface currents, both derived from altimeter measurements and an oceanic geoid, would be strongly correlated with the mean sea surface height model used to derive terrestrial gravity data for the combination model.

Therefore, the satellite-only part of EIGEN-GL04C is provided here as EIGEN-GL04S1. The contributing GRACE and Lageos data are already described in the EIGEN-GL04C description. The satellite-only model has been derived from EIGEN-GL04C by reduction of the terrestrial normal equation system and is complete up to degree and order 150.

How many really understand/see the production of gravitational waves in regards to Taylor and Hulse?

To see Stefan's correlation in terms of "wave production" is a dynamical quality to what is still be experimentally looked for by LIGO?

As scientists, do you know this?

6:41 AM, November 11, 2007

See here

Thus the binary pulsar PSR1913+16 provides a powerful test of the predictions of the behavior of time perceived by a distant observer according to Einstein's Theory of Relativity.

Since we know the theory of Relativity is about Gravity, then how is it the applications can be extended to the way we see "anew" in our world?

A sphere, our earth, not so round anymore.

Uncle has tried to correct me on "isostatic adjustment."

Derek Sears, professor of cosmochemistry at the University of Arkansas, explains. See here

Planets are round because their gravitational field acts as though it originates from the center of the body and pulls everything toward it. With its large body and internal heating from radioactive elements, a planet behaves like a fluid, and over long periods of time succumbs to the gravitational pull from its center of gravity. The only way to get all the mass as close to planet's center of gravity as possible is to form a sphere. The technical name for this process is "isostatic adjustment."

With much smaller bodies, such as the 20-kilometer asteroids we have seen in recent spacecraft images, the gravitational pull is too weak to overcome the asteroid's mechanical strength. As a result, these bodies do not form spheres. Rather they maintain irregular, fragmentary shapes. K. Shumacker. Scientific America

Do not have time to follow up at this moment.

7:02 AM, November 11, 2007

.....and here.


In context of the post and differences, I may not have pointed to the substance of the post, yet I would have dealt with my problem in seeing.

In general terms, gravitational waves are radiated by objects whose motion involves acceleration, provided that the motion is not perfectly spherically symmetric (like a spinning, expanding or contracting sphere) or cylindrically symmetric (like a spinning disk).

A simple example is the spinning dumbbell. Set upon one end, so that one side of the dumbell is on the ground and the other end is pointing up, the dumbbell will not radiate when it spins around its vertical axis but will radiate if it tumbles end-over-end. The heavier the dumbbell, and the faster it tumbles, the greater is the gravitational radiation it will give off. If we imagine an extreme case in which the two weights of the dumbbell are massive stars like neutron stars or black holes, orbiting each other quickly, then significant amounts of gravitational radiation would be given off.

Given the context of the "whole universe" what is actually pervading, if one did not include gravity?



So singularities are pointing to the beginning(i), yet, we do not know if we should just say, the Big Bang, because, one would had to have calculated the energy used and where did it come from "previous" to manifest?

So some will have this philosophical position about "nothing(?)," and "everything as already existing."

Wherever there are no gravitational waves the space time is flat. One would have to define these two variances. One from understanding the relation to "radiation" and the other "perfectly spherically symmetric."

Production of Gravitational Waves

"My heart leaps up when I behold A rainbow in the sky."
William Wordsworth-- My Heart Leaps Up

This post is based on "the production" and not the detection of gravitational waves.

It does serve it's purpose, that I explain what I have in terms of detection, that one moves from that process, to actual production of them.:) Now I am not talking about Taylor and Hulse and PSR 1913+16 either.


Dr. Kip Thorne, Caltech 01-Relativity-The First 20th Century Revolution

Weber developed an experiment using a large suspended bar of aluminum, with a high resonant Q at a frequency of about 1 kH; the oscillation of the bar after it had been excited could be measured by a series of piezoelectric crystals mounted on it. The output of the system was put on a chart recorder like those used to record earthquakes. Weber studied the excursions of the pen to look for the occasional tone of a gravitational wave passing through the bar...

Einstein@Home

LIGO:

Nor am I talking about Kip Thorne, Webber, or Ligo operation for that matter.

I am actually talking about the creation of gravitational waves.

Now imagine that you see this "slide of light," and you were to think that in front of you, this would help you see where the gravitational field would be falling away from you. You would be sliding "ahead" from where you pointed and created this effect.

So now you get the idea here of what I propose in the production of gravitational waves versus the detection of them?:)

Up until this point in time, I've used the term "generate" to describe the capability of producing a gravitational field, but since I'm not aware of any way of creating a gravitational field from nothing, a more accurate term might be to "access and amplify" a gravitational field. And this is what I mean when I use the term "generate". To understand how gravity is generated or "accessed and amplified", you must first know what gravity is.

While watching a television program I listened to what he had to say. For people interested in gravity, Quantum or otherwise, this topic helped captured my change in thinking that is postulated, and one I am giving thought right now.

The Problem

Gravitational waves are produced when there is a change in the curvature of spacetime. Since the shape of spacetime depends only on how mass is distributed, events that change the distribution of mass cause gravitational waves. It takes events with a lot of energy to make gravitational waves that we can detect because spacetime is not very elastic. Remember the bowling ball analogy? Space-time is like a stiff trampoline, one that only sinks when you put something very heavy on it.

So if we are to consider such a thing how would I go about it? Perhaps, "jumping up and down?":)

“Every time you accelerate—say by jumping up and down—you’re generating gravitational waves,” says Rainer Weiss, Professor Emeritus of Physics at MIT. “There’s no doubt of it.” But just standing there won’t cut the mustard. To make a wave, your mass has to both move (have velocity) and have acceleration (change the rate of motion, direction, or both).

Still, don’t get your hopes up. No matter how fast you jump, sprint, or cartwheel, the resulting warp your waves make on space is so weak that it’s utterly unmeasurable—perhaps 100,000,000,000,000,000,000,000 times less so than the warp made by massive exploding space objects. And LIGO has a tough enough time measuring those.

So there are questions on my mind, about gravity creation.

Plato writes:

Dorigo,

I am interested as a lay person in the collider experiments and wondered about "gravitational wave production."

Considering quark gluon levels reached I wondered about the strength and the weakness as a measure of gravitational waves within that collider action. If microscopic blackhole are created then would it be wrong to observe, variation of gravity within the domain of the collider itself?

regards,

See following comment posted here.

Dear Plato,

quarks are microscopic bodies. The gravitational effects associated with the motion and interaction of masses that small are ridiculously small.

In theories contemplating a low quantum gravity scale, black holes could in principle be created in high energy collisions, but if a chance of detecting their creation exists, it is not by gravitational effects, which remain billions of billions of billions of billions (and then some) of times smaller than those caused by strong interactions.

Please check my post on Lisa Randall’s seminar (Sept. 29th), or the one on the seminar given by Steve Giddings last March. There is reading material that I tried to make accessible to most there.

Cheers,
T.

I will be loking at this in much more detail. Something that immediately came to mind is Gran Sasso. "Muon creation" from the particle collisions. See: Neutrino Mixing in Sixty Seconds.

This summer, CERN gave the starting signal for the long-distance neutrino race to Italy. The CNGS facility (CERN Neutrinos to Gran Sasso), embedded in the laboratory's accelerator complex, produced its first neutrino beam. For the first time, billions of neutrinos were sent through the Earth's crust to the Gran Sasso laboratory, 732 kilometres away in Italy, a journey at almost the speed of light which they completed in less than 2.5 milliseconds. The OPERA experiment at the Gran Sasso laboratory was then commissioned, recording the first neutrino tracks. See Strangelets and Strange Matter


The Distorted Lense

It would seem to me that if any lens could direct "the focus of our vision" then why not the focus of the gravitational waves? I mean if there is a "inverse calculation" to waves, it would seem t me that such a process could point to a heavy concentration in terms of blackhole production?


As one of the fields which obey the general inverse square law, the gravity field can be put in the form shown above, showing that the acceleration of gravity, g, is an expression of the intensity of the gravity field.

As I am reading different thoughts are manifesting and one of these has to do with the "escape velocity of the photon." Why I am not sure at the moment. This used as a measure of determination of whether a blackhole exists? How did we arrive at such a point?


Albert Einstein (1879–1955)

One part of the theory of Relativity was inspired when a painter fell off a roof. Einstein found out that while the painter was falling freely, he felt weightless. This led Einstein to realize that gravity was a form of inertia, a result of the way things moved through space - and General Relativity was born.

It is important for me to recognize the collider process in context of what it is experimentally doing. For me this is demonstrating a "geometrical process" even if it is being taken down to the such "weak gravitational ranges" that I would point to what would manifest,if a tunnelling effect occurred from one location to the next.

Time travel

Plato:Thus the initial idea here to follow is that the process had to have a physics relation. This is based on the understanding of anti-particle/particle, and what becomes evident in the cosmos as a closed loop process. Any variation within this context, is the idea of "blackhole anti-particle expression" based on what can be seen at the horizon?Tunneling in Faster then Light

Warp Drives", "Hyperspace Drives", or any other term for Faster-than-light travel is at the level of speculation, with some facets edging into the realm of science. We are at the point where we know what we do know and know what we don’t, but do not know for sure if faster than light travel is possible.

The bad news is that the bulk of scientific knowledge that we have accumulated to date concludes that faster than light travel is impossible. This is an artifact of Einstein’s Special Theory of Relativity. Yes, there are some other perspectives; tachyons, wormholes, inflationary universe, spacetime warping, quantum paradoxes...ideas that are in credible scientific literature, but it is still too soon to know if such ideas are viable.

One of the issues that is evoked by any faster-than-light transport is time paradoxes: causality violations and implications of time travel. As if the faster than light issue wasn’t tough enough, it is possible to construct elaborate scenarios where faster-than-light travel results in time travel. Time travel is considered far more impossible than light travel.

It would be suspect to me that such travelling in space would allow for the manufacture of gravitational influences to be pointed in the "direction of travel" and allow such slippage away from that current position.

Gravitational Mass for a Photon

The relativistic energy expression attributes a mass to any energetic particle, and for the photon



The gravitational potential energy is then



When the photon escapes the gravity field, it will have a different frequency




Since it is reduced in frequency, this is called the gravitational red shift or the Einstein red shift.

Escape Energy for Photon

If the gravitational potential energy of the photon is exactly equal to the photon energy then



Note that this condition is independent of the frequency, and for a given mass M establishes a critical radius. Actually, Schwarzchilds's calculated gravitational radius differs from this result by a factor of 2 and is coincidently equal to the non-relativistic escape velocity expression

A black hole is an object so massive that even light cannot escape from it. This requires the idea of a gravitational mass for a photon, which then allows the calculation of an escape energy for an object of that mass. When the escape energy is equal to the photon energy, the implication is that the object is a "black hole."

For more see "Time as a measure.

By allowing new physics to emerge, what basis is being held relevant then to what is being created in the particle collisions that are indeed faster then light?

As we know from Einstein’s theory of special relativity, nothing can travel faster than c, the velocity of light in a vacuum. The speed of the light that we see generally travels with a slower velocity c/n where n is the refractive index of the medium through which we view the light (in air at sea level, n is approximately 1.00029 whereas in water n is 1.33). Highly energetic, charged particles (which are only constrained to travel slower than c) tend to radiate photons when they pass through a medium and, consequently, can suddenly find themselves in the embarrassing position of actually travelling faster than the light they produce!

The result of this can be illustrated by considering a moving particle which emits pulses of light that expand like ripples on a pond, as shown in the Figure (right). By the time the particle is at the position indicated by the purple spot, the spherical shell of light emitted when the particle was in the blue position will have expanded to the radius indicated by the open blue circle. Likewise, the light emitted when the particle was in the green position will have expanded to the radius indicated by the open green circle, and so on. Notice that these ripples overlap with each other to form an enhanced cone of light indicated by the dotted lines. This is analogous to the idea that leads to a sonic boom when planes such as Concorde travel faster than the speed of sound in air

See also information on What is Cerenkov Radiation?

Fifth Dimensional General Relativity

It was a gradual process that using Grace to help me see the earth in new ways was paramount to the inclusion principle of electromagnetism contained within the move to GR.I may be mixed up here, and I have no one to say.

"Color of gravity" assumes that you have seen the colour of gravity in relation to this slide of light. So seeing in such a way would seem relevant in the fifth dimensional perspective.

In Kaku's preface of Hyperspace, page ix, we find a innocent enough statement that helps us orientate a view that previous to all understanding, is couched in the work of Kaluza.

In para 3, he writes,

Similarily, the laws of gravity and light seem totally dissimilar. They obey different physical assumptions and different mathematics. Attempts to splice these two forces have always failed. However, if we add one more dimension, a fifth dimension, to the previous four dimensions of space and time, then equations governing light and gravity appear to merge together like two pieces of a jigsaw puzzle. Light, in fact, can be explained in the fifth dimension. In this way, we see the laws of light and gravity become simpler in five dimensions.

I would think such a thought here by Kaku would have stimulated the brains of people to see that a direct result is needed in our reality to which such thoughts I am giving would allow you to see gravity in new ways?



Lagrangian views with regards to relations between the Earth, Moon and Sun would help one to see the general outlay of gravitational influences in space. That is also part of the work I have been following to understand the spacetime fabric and how we may see this in our dealings.