Phys. Rev. E 83, 017101 (2011)

Universal patterns in sound amplitudes of songs and music genres

We report a statistical analysis of more than eight thousand songs. Specifically, we investigated the probability
distribution of the normalized sound amplitudes. Our findings suggest a universal form of distribution that agrees
well with a one-parameter stretched Gaussian. We also argue that this parameter can give information on music
complexity, and consequently it helps classify songs as well as music genres. Additionally, we present statistical
evidence that correlation aspects of the songs are directly related to the non-Gaussian nature of their sound
amplitude distributions.


***

LQ12585

Emergence and Decline of Scientific Paradigms

Scientific paradigms have a tendency to rise fast and decline slowly. This asymmetry reflects the difficulty in developing a truly original idea, compared to the ease at which a concept can be eroded by numerous modifications. Here we formulate a model for the emergence and spread of ideas which deals with this asymmetry by constraining the ability of agents to return to already abandoned concepts. The model exhibits a fairly regular pattern of global paradigm shifts, where older paradigms are eroded and subsequently replaced by new ones. The model sets the theme for a new class of pattern formation models, where local dynamics breaks the detailed balance in a way that prevents old states from defending themselves against new nucleating or invading states. The model allows for frozen events in terms of the coexistence of multiple metastable states.

***

LW12017

MISSING INFORMATION LOCATED EXPERIMENTALLY

There are many physical processes in nature which lead to apparent loss of
information. In the present paper, for the first time, we have
experimentally located the missing information and demonstrated the
validity of quantum no-hiding theorem. To test this we have considered
randomization of a qubit as a prime example of the bleaching process and
reconstructed the missing information from the simplest possible
environment which in our case is a two-qubit system. In the quantum world
if a system interacts with the environment it looses the purity and even
it might end up being in a completely mixed (unpolarized) state that has
no information about the original. Then one may wonder where is the
missing information. The no-hiding theorem is a fundamental result in
quantum information theory which addresses this issue precisely. To put
it simply, the theorem tells us that if any physical process leads to loss
of quantum information, then it must be found in the rest of the
environment with no information being hidden in the correlations. The
result can be applied to many physical scenarios starting from quantum
state randomization, thermalization, decoherence, quantum teleportation,
black hole evaporation and many more. Furthermore, the no-hiding theorem
generalizes the Landauer erasure principle where an arbitrary quantum
state transforms to a fixed mixed state. Indeed, this will have wide
impact whenever one encounters the issue of information loss. The
no-hiding theorem also demonstrates the notion of conservation of quantum
information. Since this is universally valid in quantum world we believe
that its experimental test constitutes an important step.

***

LZ12219

Rotate the multiferroic blues away

For decades, researchers have looked for multiferroic materials in which the
magnetization could be controlled with an electric field. But finding a
material with the right combination of properties for practical applications
- a large polarization and a strong polarization-magnetization coupling -
has proven a difficult challenge. In our Letter, we identify a class of
multiferroics in which combinations of certain atomic displacement patterns
- octahedral rotation distortions - give rise to both a large polarization
and ferromagnetism. This result is remarkable because octahedral rotations
usually cannot individually produce a polarization. Most importantly, the
rotations are coupled to the magnetization in such a way that when an
electric field is used to change the direction of the polarization, the
magnetization also changes direction. This is precisely the type of
electric-field controllable magnetic material that scientists have long
searched for. Our work opens a new direction for the discovery of these
technologically important materials.

AX10557

ULTRALONG-RANGE CASIMIR FORCE CAN MAKE OBJECTS FLY

The elusive Casimir effect is one of the most intriguing physical
phenomena, which, due to the quantum fluctuations of the electromagnetic
field, results in the attraction or repulsion of uncharged bodies. This
tiny force is only relevant in the nanoscale, since it invariably decays
with the fourth power of the distance between the bodies. Or at least,
that was thought to be the case until some time ago. Indeed, recently it
was suggested that by guiding the quantum fluctuations of the
electromagnetic field with an array of metallic nanorods it is possible
to boost the strength of the Casimir force by several orders of
magnitude. Here, we demonstrate how this ultra-long range force can be
put into work and used to levitate objects! We show that the plane at
which the nanorods are cut acts as a mirror for the waves propagating
inside the nanorods crystal. However, unlike the usual metallic mirrors,
the wave reflected at the tips of the nanorods is in phase with the
impinging wave. Such a crucial property results in a repulsive Casimir
force that pushes conducting bodies embedded into the nanorods crystal
away from the mirror. This purely quantum force may be strong enough to
act against the gravity and lift up metallic pieces. For example, we
show that a 200 nm-thick tungsten film can be lift up to 1 micron within
a crystal composed of silver nanorods of 40 nm in diameter.


***

LY12700

A NEUTRON STAR TURNING SUPERFLUID

Ten years of Chandra observations of the neutron star "Cas A" have revealed
that it is cooling rapidly, an unusual behavior never observed previously.
We present a natural explanation based on neutron superfluidity and proton
superconductivity. These quantum phenomena set in when the temperature drops below some critical value. We propose that neutrons inside Cas A are presently developing a superfluid phase and emitting copius amounts of neutrinos which are cooling the star. Cas A has an age of 330 yrs and no other neutron star is known that is young enough to observe the onset of superfluidity. From Cas A's age, we deduce the neutron p-wave superfluid critical temperature to be a half billion degrees. Furthermore, the combination of the star's high surface temperature, about 2 million degrees, and large cooling rate implies that protons are in an s-wave superconducting state.

The transition to superconductivity has a larger critical temperature because it occurred prior to now when the star's core was warmer. This is the first direct evidence that these phenomena, predicted by theoretical models of high energy-density matter, occur within neutron stars.


***

AY10627

Propagation of relativistic charged particles in ultracold atomic gases with Bose-Einstein condensates

At the present moment the Bose-condensation phenomenon in gases of atoms
and molecules is experimentally realized in extreme physical conditions
(ultralow temperatures). A Bose-Einstein condensate (BEC) is a coherent
state of matter, i.e., the state with practically identical behaviour of
particles that form it. The consequence of the external extreme conditions
and coherent behaviour is the manifestation of different phenomena that
are difficult or impossible to observe in other conditions.

To the vivid effects related to the BEC phase one should also add some
peculiarities of a propagation of the relativistic charged particles
through a condensed gas. Most probably, this sort of problem is considered
for the first time in the framework of the present paper. The main
attention was paid to the energy change of the propagating particles. This
change results from the Cherenkov effect in the gas with a BEC. The most
uncommon result of the consideration is that at the certain conditions the
particle not only emits the energy, but it also can be accelerated by the
ulltracold gas. We define the conditions for the particle acceleration and
discuss also the possibility of defining the spectral characteristics of
atoms forming BEC by registering the Cherenkov radiation.


***


BW11359

Revealing the Carrier density and mobility of the Graphene layers in Graphite

Using an experimentally simple method to obtain the mean free path and density of electrical carriers of the graphene layers inside a thin graphite flake without adjustable parameters, a team from Germany and Spain demonstrated that these carriers can move several micrometers without having scattering whereas their density remains extremely small and all at room temperature. The obtained values overwhelm by orders of magnitude those obtained in single graphene layers of micrometer size revealing that ballistic electronics in graphite is feasible. From the basic research point of view, the results cast now strong doubts on the validity of the commonly used electronic band structure of graphite assuming values for the carrier density that appear to be non-intrinsic of the ideal graphite structure. The figure shows scanning electron microscope pictures of two samples showing the constrictions used to restrict the flow of the carriers and obtain directly their mean free path through the measurement of the electrical resistance.



***

EY10601

Non-classical transport in anisotropic fractal media

Numerous observations show that impurity transport in geologic media, as a rule, is not described by the classical diffusion laws, according to which the mean-square displacement of the particles grows linearly with time. Instead the transport process occurs in the regime of super-diffusion when mean-square displacement grows proportionally to the time in a power greater than unity, or sub-diffusion with the time exponent less than unity. A fractal geometry of fractures leading to long-range correlations of infiltrating moisture velocities may be the physical background of super-diffusion. Researchers have now shown that the presence of anisotropy and directedness of moisture infiltration due to the gravity lead to a number of interesting peculiarities in the impurity transport phenomena in fractal media. Among them are anomalous drift and coexistence of super-diffusive regime in vertical direction and classical diffusion in horizontal plane. In the case of strong anisotropy a considerable contraction of concentration distribution occurs in horizontal plane at large vertical distances. The peculiarities stated above are important for the safety problem of radioactive waste disposal in geologic media.

***

LX12087

Theory of Everything Finding a Way to Describe Life

String theory is said to be the theory of everything. But
until now its realm has been very far away from the life of ordinary
people. Not so anymore, as a group of theoretical physicists at
Uppsala University in Sweden and CNRS in France argue that
amazingly string theory describes even life itself. For this
they develop a string theory depiction of proteins, the workhorses
of all living cells. In order that life as we know it can take place,
proteins in our cells must each become folded into their own, very
specific shape. If misfolded, a protein can not fulfill its mission.
This can lead to a death of cell or cause tormenting diseases
such as Alzmeimer's, Parkinson's and many cancers. By applying
sophisticated string theory techniques originally introduced to explain
properties of elementary particles like the all-elusive Higgs boson,
and using ordinary personal computers they describe folded proteins
reaching accuracies that occasionally exceed even the most precise
experimental measurements. This can pave a way to a deeper understanding
why and how proteins fold, which in turn may eventually lead to cures
to some of the most unrelenting diseases.