### De mundi systemate

by @ulaulaman about #IsaacNewton #physics #gravity
I published this post some years ago (archived version), but for unilateral decision of the online publisher, it is deleted, so I decide to recover it.
It's the third pard o Newton's Philosophiae Naturalis Principia Mathematica, one of the most famous physics tractatus (latin world to treatise). In 2010 Dave Richeson proposes An amazing paragraph from Euler's Introductio, a wonderful post in which he extraxts some Euler's quotes from Introductio in analysin infinitorum (Introduction to analysis of the infinite). So, because I'm working on a learning project about gravity, I decide to propose an analouge post about De mundi systemate (On worlds' system). For english version of the following Newton's quotes I'll ask help to Andrew Motte.
We began with Propositio II (Proposition II):

### The infinite inflation and the end of time

by @ulaulaman about #cosmology #mathematics #inflation #Hawking #AlanGuth
I published this post some years ago (archived version), but for unilateral decision of the online publisher, it is deleted, so I decide to recover it.
In the early years of the 3rd millennium there was a discussion about eternal inflation. This theoric ipothesis was introduce by Alan Guth and other physicists. In particular you can read Guth's paper Eternal Inflation(1):
The basic workings of inflationary models are summarized, along with the arguments that strongly suggest that our universe is the product of inflation. It is argued that essentially all inflationary models lead to (future-)eternal inflation, which implies that an infinite number of pocket universes are produced. Although the other pocket universes are unobservable, their existence nonetheless has consequences for the way that we evaluate theories and extract consequences from them. The question of whether the universe had a beginning is discussed but not definitively answered. It appears likely, however, that eternally inflating universes do require a beginning.
We have a lot of observations that confirms not only the big bang theory, but also the inflation period: in some time after the first expansion of the universe, there is a faster expansion of space time. The most important observation that supports inflation is the anisotropy of the cosmic background radiation (we could add also the absence of magnetic monopole...).
The background of eternal inflation ipothesis is the existence of repulsive-gravity material, that is unstable and decay with an exponential law (like any radiactive atom). In every decay process the volume of repulsive-gravity material grow instead decrease and prodece a never ending series of pocket universes(1, 2):
In Cosmology from the Top Down, a talk presented at Davis Inflation Meeting in 2003, Stephen Hawking speak about some criticism on eternal inflation:

### The Universe in a glass of wine

by @ulaulaman about #RichardFeynman #physics #universe #wine
Once upon a time, Richard Feynman telled a story about the universe and a glass of wine:
A poet once said, "The whole universe is in a glass of wine." We will probably never know in what sense he said that, for poets do not write to be understood. But it is true that if we look in glass of wine closely enough we see the entire universe.
There are the things of physics: the twisting liquid which evaporates depending on the wind and weather, the reflections in the glass, and our imagination adds the atoms. The glass is a distillation of the earth’s rocks, and in its composition we see the secrets of the universe’s age, and the evolution of the stars. What strange array of chemicals are in the wine? How did they come to be? There are the ferments, the enzymes, the substrates, and the products. There in wine is found the great generalization: all life is fermentation. Nobody can discover the chemistry of wine without discovering the cause of much disease. How vivid is the claret, pressing its existence into the consciousness that watches it!
If in our small minds, for some convenience, divide this glass of wine, this universe, into parts - physics, biology, geology, astronomy, psychology, and so on - remember that nature does not know it! So let us put it all back together, not forgetting ultimately what it is for. Let us give one more final pleasure: drink it and forget it all!
You can find the text and the audio on the site of Efthymios Kallos, but... The Universe in a glass of wine is also an artist exposition: see, for example, the Life cycle of a star by Natalie Kay Thatcher. And it is interesting that Natalie realized two comics about Feynman: How to start a Feynman (preview), and the Feynman zine (review by Pete Willis) about the universe and the glass of wine:

### Neural networks and astronomy

by @ulaulaman about #astronomy #mathematics #NeuralNetwork #Saturn
I published this post some years ago (archived version), but for unilateral decision of the online publisher, it is deleted, so I decide to recover it.
Neural network is one of the most powered method to analize data. It can be use in most research subject, for example in astronomy: in this case, we can use NNs to examine astronomical images or also the red shift effect. For example, in 2003 Jorge Núñez (Universitad de Barcelona) and Jorge Llacer (EC Engineering Consultants LLC) published a paper(1) in which they describe the develop of an algorithm to study astronomical image segmentation that uses a self-organizing neural network as basis. In their work, the scientists examine the separation between some stars and also a Saturn's image: the alghoritm seems quite robust against noise and fragmentation.
In the same year, a group of italian astronomers published a review of the models used in astronomy and examined some data used by AstroNeural collaboration. Finally in 2004 a collaboration between researchers in Italy, Germany and France perform an application of NNs to redshift calculations(3).
Now you can quest: What is a neural network?

### Pulsars to detect Earth's motion

by @ulaulaman about #astronomy #pulsars #mathematics #earth
I published this post some years ago (archived version), but for unilateral decision of the online publisher, it is deleted, so I decide to recover it now.

A Pulsar's Hand P. Slane et. al (Apod)

We all known the story of the little green men: in 1967 Jocelyn Bell and Antony Hewish discovered a strange, regular cosmic signal, a periodic bep. They consulted Fred Hoyle, astronomers and sci-fi writer, and he understood that the signal was emitted by a neutrons' star, a pulsar. An italian research team, composed by Matteo Luca Ruggiero, Emiliano Capolongo, Angelo Tartaglia, published the following paper, Pulsars as celestial beacons to detect the motion of the Earth (arXiv). In their paper, researchers propose to apply some relativistic mathematical tools to calculate Earth position using pulsars signals.

### The beauty of mathematics: the spinning tops

See in fullscreen mode:

(video by from PARACHUTES.TV).

### Edison's medicine

#NikolaTesla #ThomasEdison #GeorgeWestinghouse #rock #video #Tesla

From Rasl #5 by Jeff Smith
Until Nikola Tesla's invention of a workable A.C. electrical power system (which was in direct competition with Thomas Edison's D.C. power system), the ability to generate, transmit, and use electricity as we do today was impossible.
George Westinghouse, Westinghouse Corporation

### The modular robot

by @ulaulaman about #MIT #robot #technology #modular
Starting from a famous speech by Richard Feynman (pdf), it was born nanotechnology. One day in future we'll probably have nano-chip, nano-computer, nano-bot, but for now we must content ourselves with the robots with wheels and legs that explore the remote corners of the Earth, and also arriving on Mars in the past years.
A possible evolution of robots is described in science fiction: for example in Alan Moore's Tom Strong, one of the enemy of the hero is the Modular Man, an electronic entity consistuted by many memory modules, separated but which together realized one of the most advanced and deadliest artificial intelligence in the world. Using the Modular Man, Moore brings back a classic of the genre: the revolt of the technology against mankind. A variation of this idea is proposed by Frank Schatzing in The Swarm, but in this last case the superintelligent entity is constituted by a lot of single-celled organisms that are separately very simple, but together extremely complex. In some sense also the swarms of insects could be understood like a single entity.
Let us suppose now that every single part of similar entity is electronic, and, for some reason, that the experiment is beyond the control of the toy factory that developed it: the consequence is a catastrofic novel, The Reproductive System (a.k.a. Mechasm)(1), written with a lot of humor by John Sladek, in which the writer describes some mechanism that are just a bit more advanced version of the Molecule, a self-assemble modular robot developed by Keith Kotay and Daniela Rus at MIT:

### On impact factor

We recommend that the term "impact factor" be abolished and that this measure be renamed in keeping with its actual role, that merely of a time-specific "citation rate index" and nothing more. What is currently called the "impact factor" should not be misused to evaluate journals or to validate the scientific relevance of a particular researcher or research program, especially in decisions regarding employment, funding, and tenure.
(from The journal "impact factor": a misnamed, misleading, misused measure by Hecht F, et al.)
Impact Factors reflect the journal not the article, vary with time and correlate only poorly with perceived excellence. Simple comparison of impact factors in different specialties may be misleading. Review journals often have higher Impact Factors than those with original data. Both authors and editors can try to manipulate journal Impact Factors
(from Impact factors: uses and abuses by James Neuberger and Christopher Counsell - pdf)

Contrary to the custom at this conference, I want first of all to disclaim priority for some of the concepts to which my name is commonly attached in the literature. For this exaggerated view of my originality I have to thank the late Ben Lee, who at the 1972 High Energy Physics Conference at Fermilab plastered my name over almost everything concerned with spontaneous synlnetry breaking.
"Higgs fields", for example, are just the scalar fields of a linear sigma model, which was discussed in 1960 by Gell-Mann and Lévy but had been introduced three years earlier by Schwinger. And "the Higgs mechanism" was first described by Philip Anderson: perhaps it should be called "the ABEGHHK'tH ....mechanism" after all the people (Anderson, Brout, Englert, Guralnik, Hagen, Higgs, Kibble, 't Hooft) who have discovered or rediscovered it! However, I do accept responsibility for the Higgs boson; I believe that I was the first to draw attention to its existence in spontaneously broken gauge theories.
Higgs P. (1993). SBGT and all that, AIP Conference Proceedings, 300 159-163. DOI:

### Milano street art: Albert Einstein

posted by @ulaulaman #AlbertEinstein #StreetArt #Milano
In Paolo Sarpi, a street of Milano, there is a street artist who sketches a lot of subject (for example Iron Man or this iconic space monkey). In particular today I find a beautiful reproduction of the most famous photograph about Albert Einstein:
On Einstein's 72nd birthday on March 14, 1951, UPI photographer Arthur Sasse was trying to persuade him to smile for the camera, but having smiled for photographers many times that day, Einstein stuck out his tongue instead. This photograph became one of the most popular ever taken of Einstein, often used in merchandise depicting him in a lighthearted sense. Einstein enjoyed this photo and requested UPI to give him nine copies for personal use, one of which he signed for a reporter.
Source: Wikipedia
Sulmondo, the nick of the street artists, add only one little detail to the original photo!

### Some quotations about the amplituhedron

posted by @ulaulaman via @tanzmax about #amplituhedron
However, the calculation using the shape in an infinite-dimensional space, the amplituhedron, should provide us with completely new perspectives how to look at the dynamics – perspective that is timeless, obscures the location of objects and events in the space and time, and obscures the unitarity (the requirement that the total quantum-calculated probability of all possibilities remains 100%), but it unmasks some other key structures that dictate what the probabilities should be, structures we were largely ignorant about.
If the new picture becomes sufficiently generalized, you could perhaps throw away the old books because you will get an entirely new framework to compute these things and to think about all these things. But once again, you don't have to throw them away because the physical results are the same.
(Luboš Motl on physics.stackexchange.com)
The amplituhedron is not built out of space-time and probabilities; these properties merely arise as consequences of the jewel’s geometry. The usual picture of space and time, and particles moving around in them, is a construct.
(from Quanta Magazine via Marginal Revolution)
This rich structure is also completely new to the mathematicians.
(Jaroslav Trnka - pdf)

### Friday the 13th in science

posted by @ulaulaman about #superstitions #friday13th #mathematics #economics #socialscience
Men would never be superstitious, if they could govern all their circumstances by set rules, or if they were always favoured by fortune: but being frequently driven into straits where rules are useless, and being often kept fluctuating pitiably between hope and fear by the uncertainty of fortune’s greedily coveted favours, they are consequently, for the most part, very prone to credulity.
Benedict de Spinoza, A Theologico-Political Treatise, Preface Part 1.
In Italy 13 is considered a lucky number, so the unlucky day for us is Friday the 17th, but in the last decades also Friday the 13th becames an unlucky day. Following wiki.en, the origin of this superstition is unknown: the earliest evidence about it is referred in the biografy of Gioacchino Rossini written by Henry Sutherland Edwards in 1869: indeed Rossini died on a Friday 13th
He [Rossini] was surrounded to the last by admiring friends; and if it be true that, like so many Italians, he regarded Fridays as an unlucky day and thirteen as an unlucky number, it is remarkable that one Friday 13th of November he died.
Now, from an economical point of view, could be interesting the following abstract:
The Friday the 13th anomaly of Kolb and Rodriguez (1987) is revisited in an international context. Drawing on the philosophy of science approach of Lakatos (1978), the paper argues the importance of “anomalies” and the need for triangulation. Using the FTSE world indices over 1988–2000 for 19 countries, it is found that there is some evidence that returns on Friday the 13th are statistically different from, and generally greater than, returns on other Fridays.(1, 2)
Lucey's results seem a confirmation of the results of another work by Andrew Coutts:
In recent years much evidence has been documented of the existence of regularities in security price returns. However, one of the least investigated anomalies concerns the socalled ‘Friday the 13th’ effect, where returns on Fridays which fall on the 13th of the month display significantly lower returns than other Fridays. Employing daily logarithmic returns from the Financial Times Industrial Ordinary Shares Index (FT 30) for the period July 1935 through December 1994, we find no evidence of a Friday the 13th effect. Indeed, if anything, we find returns are higher on Friday the 13th than on other Fridays. We then partition the sample into six subsamples each of ten years, again concluding that there is no evidence of a Friday the 13th effect, and that once again returns on Friday the 13th tend to be higher than on other Fridays. Finally, we conclude that our results support the extremely limited evidence documented for the UK market concerning the Friday the 13th effect.
So the ancient superstitions could have an influence also in our advanced society:

### Tetris is Hard, Even to Approximate

Before today I thought that tetris was a really simple game...
In the popular computer game of Tetris, the player is given a sequence of tetromino pieces and must pack them into a rectangular gameboard initially occupied by a given configuration of filled squares; any completely filled row of the gameboard is cleared and all pieces above it drop by one row. We prove that in the offline version of Tetris, it is NP-complete to maximize the number of cleared rows, maximize the number of tetrises (quadruples of rows simultaneously filled and cleared), minimize the maximum height of an occupied square, or maximize the number of pieces placed before the game ends. We furthermore show the extreme inapproximability of the first and last of these objectives to within a factor of p^(1-epsilon), when given a sequence of p pieces, and the inapproximability of the third objective to within a factor of (2 - epsilon), for any epsilon>0. Our results hold under several variations on the rules of Tetris, including different models of rotation, limitations on player agility, and restricted piece sets.(1)
Tetris is a puzzle video game originally designed and programmed by Alexey Pajitnov and it could be used to learn to a neural network:

### The black hole in the center of the galaxy

posted by @ulaulaman about #astronomy #SagittariusA #BlackHole #MilkyWay
Sagittarius A* (pronounced "Sagittarius A-star", standard abbreviation Sgr A*) is a bright and very compact astronomical radio source at the center of the Milky Way Galaxy, near the border of the constellations Sagittarius and Scorpius. It is part of a larger astronomical feature known as Sagittarius A. Sagittarius A* is believed to be the location of a supermassive black hole,(1, 2) like those that are now generally accepted to be at the centers of most spiral and elliptical galaxies. Observations of the star S2 in orbit around Sagittarius A* have been used to show the presence of, and produce data about, the Milky Way's central supermassive black hole, and have led to the conclusion that Sagittarius A* is the site of that black hole(3).
In the image there is an x-ray photo of Sgr A* from the paper by Wang et al. published on Science(4).
the x-ray emission from Sgr A* can be described as the superposition of a pointlike source from the black hole itself, and a much larger extended cloud of emission about 2″ across. Within this cloud, we can identify over a hundred individually resolved bright stars, and infer thousands more that are too dim to detect.(5)
They also infer that
the temperature and density profile of the gas cloud surrounding Sgr A*. They show that over 99% of the gas never reaches the central black hole, but rather is ejected from the system(5)
There are also some unresolved questions: for example if the observed accretion rate is dued exclusively by Sgr A* or if there is another source for the data; or his low luminosity, orders of magnitude below its theoretical potential(5).

### LHComedy: CERN After Dark

LHComedy brings science-themed stand-up comedy to the Geneva area. Bringing our audience a mixture of laughs and insight, we bring our passion about science and technology to the world with our own stories and experiences of life at CERN.
(more at lhcomedy.web.cern.ch)

### Neutrinos: between Pontecorvo and Majorana

Neutrinos are the most elusive elementary particles in the whole zoo. The reasons are simple: first of all neutrinos don't have electric charge, so physicists cannot use electromagnetic experiments in order to detect them, and they must design indirect measures; furthermore they interact with other particles only with weak interaction. At the other hand, neutrino is, in Standard Model, massless, while from an experimental point of view, he has a really small mass: at the beginning of 2000, Mainz and Troitsk experiment measured a maximum value at 2.2 eV, that is about 4 milion less that the electron mass!

Carlo Franzinetti (left) and Bruno Pontecorvo (Right)
The idea of neutrino's mass is dued by Bruno Pontecorvo that introduced in 1957 the so called neutrino's oscillations(1, 2): in this model is expected the existence of three type of neutrinos that, combining with each other, giving rise to neutrinos usually observed in experiments. The thoery was further developed in 1962 by Ziro Maki, Masami Nakagawa and Shoici Sakata(3): $\begin{pmatrix} \nu_e \\ \nu_\mu \\ \nu_\tau \end{pmatrix} = \begin{pmatrix} U_{e_1} & U_{e_2} & U_{e_3} \\ U_{\mu_1} & U_{\mu_2} & U_{\mu_3} \\ U_{\tau_1} & U_{\tau_2} & U_{\tau_3} \end{pmatrix} \begin{pmatrix} \nu_1 \\ \nu_2 \\ \nu_3 \end{pmatrix}$ where $e$, $\mu$, $\tau$ indicate the three different leptons (electron, muon and tau), $\nu$ are neutrinos, with $\nu_i$, where $i = 1,2,3$, the fundamental neutrinos.
But, if the Pontecorvo–Maki–Nakagawa–Sakata matrix describes neutrinos' oscillations, we could describe the neutrino also using a particular equation: the Majorana equation(4): $i \gamma^\mu \partial_\mu \psi - m \psi_c = 0$ where $\psi_c = \gamma^2 \psi^*$ is the so called conjugated charge.
Now, if a wave function $\psi$ respects the Majorana equation, then $m$ is called Majorana mass; if $\psi$ coincides with $\psi_c$, then $\psi$ is said Majorana spinor; finally, if there is a particle that can be described with the Majorana equation, then this is called a Majorana particle, i.e. a particle that coincides with its antiparticle. The leading candidate to be a Majorana particle is, look at the case, the neutrino, whose mass is probably not so important with regard to the ultimate fate of the universe. In fact, the astronomical data suggest a flat universe, where flat universe means a substantial balance between gravitational attraction and expansion of spacetime.
Conclusion: the importance of neutrino oscillations are related to the property to possess a mass: experiments confirmed that property, owned by all three neutrinos in the game. The astronomical data, however, assign this property a minor role for the ultimate fate of the universe, while its mass shows instead of the Standard Model, at present, still does not understand much of the physics of our universe. Among the facts not included in the Standard Model are the Majorana particles: in particular, the neutrino could be one of them and if this is confirmed, then we would have a great step in order to know the symmetry breaking between matter and antimatter.

### What makes a good math teacher?

• Motivates students to learn by making the subject interesting;
• Is knowledgeable;
• Presents the material clearly;
• Is available to students;
• Is intellectually challenging;
• Cultivates thinking skills;
• Sets high standards; and
• Encourages self-initiated learning.

### L1448-MM: water in space

One of the most interesting research topics is the star formation. The high weigth chemistry elements could diffusein the universe only with the life cycle of the stars: the birth, the syntesis of helium and of the other elements, the great explosion that (diffusero) in space carbon, iron and so on. But also the early stages in star formation could send in cosmic vacuum some light elements like hydrogen, or also water!
One place in which it can observe not only star formation but also water jets is the L1448 dark cloud in Perseus molecular cloud
In particular there is an interesting object, L1448-MM that presents two bright spots of emission, the cross (A) and the star (B) in the following figure

### The B mesons and the new physics

posted by @ulaulaman via @LHCbExperiment #newphysics #Bmesons #LHC #CERN #particlephysics
The search about B mesons decays has a great importance in physics for the possible clues of new physics that could be discovered. So theoretical phisicists have developed some new observables in order to test this possibility. LHCb produced new results about these new parameters, in particular the so called $P_5'$.
According to Joaquim Matias from Universitat Autonoma de Barcelona and colleagues the deviation in $P_5'$ and small discrepancies in the other angular observables for this decay, follow a pattern. In a recent paper the authors claim that a global analysis of the LHCb data, together with previous measurements, show a deviation of $4.5 \sigma$ with respect to Standard Model expectations, which can be explained with the same mechanism. This demands further investigation, in particular to re-evaluate all the sources of theoretical uncertainty, and to understand the effects of correlations between the experimental measurements.
(via LHCb)
The image shows the distribution of the $P_5'$ observable as a function of the $\mu^+ \mu^-$ invariant mass squared $q^2$. The black data points are compared with the Standard Model prediction.

### Paul Dirac and the relativistic world

posted by @ulaulaman #PaulDirac #DiracDay #DiracEquation #Klein-GordonEquation #relativity #physics
It seems to be one of the fundamental features of nature that fundamental physical laws are described in terms of a mathematical theory of great beauty and power, needing quite a high standard of mathematics for one to understand it.
(Paul Dirac)
For a physicists the beauty of an equation is often in its conciseness and in the amount of physical information that is able to synthesize, and so the wide variety of systems that it can be represented. For example, the Schrodinger equation, in its most synthetic form, is able to describe a disparate number of systems, and only descending the details of each system, physicists are able to describe the system with with more or less complicated solutions. $i \frac{\partial}{\partial t} \psi = H \psi$ Something like that it's maked by the equations discovered by Klein-Gordon and Dirac, but for the relativistic motion: indeed particles are able to travel even at near the speed of light, and in that case the Schrodinger equation is no longer sufficient to describe their dynamics.
From this we need to describe the world from the point of view of quantum relativistic: the Klein-Gordon equation is born: $\partial^\mu \partial_\mu \phi + m^2 \phi = 0$ It has two drawbacks: negative energy as a solution and interpretation of the wave function. If, as in quantum mechanics, we associate the wave function with probability, or rather the probability's density, it happens that this can also take on negative values. At this point arrived the Dirac equation: $\left ( i \gamma^\mu \partial_\mu - m \right ) \psi = 0$ Thanks to the Dirac equation, whose one of the first success was the explanation of half-integer spin of the electron, we now have two fundamental tools: the first for the description of bosons (particles with integer spin), the second for the description of fermions (half-integer spin particles).
Read also: The Relation between Mathematics and Physics, a lecture by Dirac
In the image: Paul Dirac by George Gamow

### Turing, Fibonacci and the sunflowers

posted by @ulaulaman about #FibonacciDay #AlanTuring #TuringSunflower
Today is the american Fibonacci's day, so it could be a good day to write something about one of the last work by Alan Turing.
One of a number of problems [Alan Turing] was trying to solve was the appearence of Fibonacci numbers in the structure of plants.(1)
The problem was knwon as the Fibonacci phyllotaxis, and we can state it in this way:
the spiral shapes on the heads of sunflowers seemed to follow the Fibonacci sequence, prompting [Turing's] proposal that by studying sunflowers we might better understand how plants grow
Turing wrote his interest in a letter to the zoologist JZ Young:
About the point (iii) Turing wrote in another letter:
Our new machine is to start arriving on Monday. I am hoping to do something about 'chemical embyology'. In particular I think I can account for the appearence of Fibonacci numbers in connection with fir-cones.(1)
The last year Jonathan Swinton, during the Manchester Science Festival in October, announced the results of the great experiment about the Turing's sunflower:

### Zero

#video posted by @ulaulaman about #mathematics #zero

via Chris Sorrentino

### The equation of everything

posted by @ulaulaman about #EulerEquation #CedricVillani #mathematics #physics
Following Cedric Villani, let you imagine a pond. Everything is calm and quiet, without a breath of wind, but at acertain point the pond surface is perturbed by a wave, without any external force. The next minute everything returns calm and quiet.
Villani used this poetical picture in order to describe some results about the Euler equation for an incompressible fluid: $\frac{\partial v}{\partial t} + \nabla \cdot \left ( v \times v \right ) + \nabla p = f$ $\nabla \cdot v = 0$ About this equation (or this sistem of wave equations), Scheffer (in 1993) found that the equation permit the spontaneous creation of energy form nothing, while Shnirelman (in 1997), found a new proof of this fact and proposed to enforce a criterion for physically prevent this kind of mathematical solutions. Sheffer and Shnirelman Theorem:
There is a weak solution of the Euler incompressible equation in 2-dimensions, without forcing ($f \equiv 0$) with compact support in space-time.
Between 2007 and 2008 De Lellis and Szekelyhidi proofed a more general theorem that establishes, among other things, that the criterion of Shnirelman is not valid, or, in other world, that the solutions of the Euler incompressible equation without forcing are physically acceptable.

### First evidence of photon polarisation in a quark transition

There are a lot of model about physics beyond standard model, and the experimental work is concentrate to search signals to select the new models for the future. LHCb has recently released a press release about the transition of a b-quark to an s-quark with the emission of a photon. This transition
is considered a very important process to investigate possible manifestation of new physics. This decay process is forbidden in the first approximation in the Standard Model (SM) of particle physics and moreover in the second-order processes that govern the process in the SM the emitted photon is expected to be strongly polarised. Therefore it is very sensitive to new physics effects arising from the exchange of new heavy particles in electroweak penguin diagrams (see 14 June 2013 news). Indeed, several models of new physics predict that the emitted photon should be less polarised than in the SM. Up to now different experiments have measured the decay rate of this process, ruling out significant deviations of the rate from the SM prediction and strongly reducing the allowed parameter space of new physics models. The photon polarisation was, however, never previously observed.
I think that this is a really intriguing news for a particle physics point of view.

### A trip to the aquarium

Yesterday I gone to the Civic Aquarium of Milano. It was a very interesting tour, between aquariums and the reconstructed natural habitats. In particular I shotted a video of the tropical fishes (I used Giochi di luce - Game of light - by Andrea Carri like soundtrack):
Near to the acquarium there is a poster about the tropicalisation of the mediterranean sea:

### Epsilon Aurigae

A little tribute to Margherita Hack
The bright star Epsilon Aurigae (HD 31964) is a single-lined spectroscopic binary that is famous for its long orbital period (27.1 yr), which is punctuated by an almost two-year long eclipse caused by an essentially invisible object.
By examining the optical spectra of Epsilon Aurigae near the end of its 1954-1956 eclipse, Hack(1) was able to deduce the electron density and develop the hypothesis of a Be-star-like hot object at the center of a large disk of occulting material(2).
(from Hoard D.W., Howell S.B. & Stencel R.E. (2010). Taming the invisible monster: Systme parameter constraints for ϵ Aurigae from the far-ultraviolet to the mid-infrared, The Astrophysical Journal, 714 (1) 549-560. DOI:

### A grave alarm

My invention relates to improvements in grave alarms, whereby persons who are prematurely buried before life is extinct, can sound an alarm, thus notifying the cemetery officials of the fact.
The object of my invention, is not only to provide means for sounding an alarm, but also to provide an improved construction whereby fresh air is supplied to the person prematurely buried, whereby life may be sustained until help arrives.
from the patent by August Lindquist
Read also: Grave Alarm, 10 medical and scientific discovery in weird history
via greatgrottu

### Physics and multidimensions

One of the most famous theoretical physicist in the world, Lisa Randall, was yesterday in Milano for the Wired's Next Fest with a conference about Physics, technology and multidimensions. The physicist talked about LHC, the Standard Model and the Higgs boson and the connections between his research work.
The starting point is a light introduction about the scales in our universe: we known the cosmic and macroscopic scales, and the microscopic scale, and it is really important for us to understand what is the more appropriate scale in order to study a particular phenomenon. An beautiful example is the Eiffel Tower in Paris:

### Music and fractal landscapes

For the #towelday I publish the paper by Richard MacDuff extracted from from "Dirk Gently's Holistic Detective Agency" by Douglas Adams

Mathematical analysis and computer modelling are revealing to us that the shapes and processes we encounter in nature—the way that plants grow, the way that mountains erode or rivers flow, the way that snowflakes or islands achieve their shapes, the way that light plays on a surface, the way the milk folds and spins into your coffee as you stir it, the way that laughter sweeps through a crowd of people—all these things in their seemingly magical complexity can be described by the interaction of mathematical processes that are, if anything, even more magical in their simplicity.
Shapes that we think of as random are in fact the products of complex shifting webs of numbers obeying simple rules. The very word “natural” that we have often taken to mean “unstructured” in fact describes shapes and processes that appear so unfathomably complex that we cannot consciously perceive the simple natural laws at work.
They can all be described by numbers.
We know, however, that the mind is capable of understanding these matters in all their complexity and in all their simplicity. A ball flying through the air is responding to the force and direction with which it was thrown, the action of gravity, the friction of the air which it must expend its energy on overcoming, the turbulence of the air around its surface, and the rate and direction of the ball’s spin.
And yet, someone who might have difficulty consciously trying to work out what 3 × 4 × 5 comes to would have no trouble in doing differential calculus and a whole host of related calculations so astoundingly fast that they can actually catch a flying ball.
People who call this “instinct” are merely giving the phenomenon a name, not explaining anything.
I think that the closest that human beings come to expressing our understanding of these natural complexities is in music. It is the most abstract of the arts—it has no meaning or purpose other than to be itself.
Every single aspect of a piece of music can be represented by numbers. From the organisation of movements in a whole symphony, down through the patterns of pitch and rhythm that make up the melodies and harmonies, the dynamics that shape the performance, all the way down to the timbres of the notes themselves, their harmonics, the way they change over time, in short, all the elements of a noise that distinguish between the sound of one person piping on a piccolo and another one thumping a drum—all of these things can be expressed by patterns and hierarchies of numbers.
And in my experience the more internal relationships there are between the patterns of numbers at different levels of the hierarchy, however complex and subtle those relationships may be, the more satisfying and, well, whole, the music will seem to be.
In fact the more subtle and complex those Relationships, and the further they are beyond the grasp of the conscious mind, the more the instinctive part of your mind—by which I mean that part of your mind that can do differential calculus so astoundingly fast that it will put your hand in the right place to catch a flying ball—the more that part of your brain revels in it.
Music of any complexity (and even “Three Blind Mice” is complex in its way by the time someone has actually performed it on an instrument with its own individual timbre and articulation) passes beyond your conscious mind into the arms of your own private mathematical genius who dwells in your unconscious responding to all the inner complexities and relationships and proportions that we think we know nothing about.
Some people object to such a view of music, saying that if you reduce music to mathematics, where does the emotion come into it? I would say that it’s never been out of it.
The things by which our emotions can be moved—the shape of a flower or a Grecian urn, the way a baby grows, the way the wind brushes across your face, the way clouds move, their shapes, the way light dances on the water, or daffodils flutter in the breeze, the way in which the person you love moves their head, the way their hair follows that movement, the curve described by the dying fall of the last chord of a piece of music—all these things can be described by the complex flow of numbers.
Thatís not a reduction of it, thatís the beauty of it. Ask Newton.
Ask the poet (Keats) who said that what the imagination seizes as beauty must be truth.
He might also have said that what the hand seizes as a ball must be truth, but he didnít, because he was a poet and preferred loafing about under trees with a bottle of laudanum and a notebook to playing cricket, but it would have been equally true.
Because that is at the heart of the relationship between on the one hand our “instinctive” understanding of shape, form, movement, light, and on the other hand our emotional responses to them.
And that is why I believe that there must be a form of music inherent in nature, in natural objects, in the patterns of natural processes. A music that would be as deeply satisfying as any naturally occurring beauty - and our own deepest emotions are, after all, a form of naturally occurring beauty...

### Elasticity of the air

Text extracted from "The magician's own book, or The whole art of conjuring" (1862) by George Arnold
This can be shown by a beautiful philosophical toy which may easily be constructed. Procure a glass jar, such as is here represented. Then mould three or four little figures in wax, and make them hollow within, and having each a minute opening at the heel, by which water may pass in and out. Place them in the jar, as seen in the figure, and adjust them by the quantity of water admitted to them, so that in specific gravity they differ a little from each other. The mouth of the jar should now be covered with a piece of skin or India-rubber, and then, if the hand be pressed upon the top or mouth of the jar, the figures will be seen to rise or descend as the pressure is gentle or heavy, rising and falling, or standing still, according to the pressure made.

### The bidimensional motions of a heavy metal moshing

During the APS March Meeting 2013, Matthew Bierbaum with Jesse Silverberg, James P. Sethna and Itai Cohen from Cornell University, presented a curious study about the heavy metal mosh pits: studing the people during the moshing, the researchers find two types of collective motions:
mosh pits, in which participants collide with each other randomly in a manner resembling an ideal gas, and circle pits, in which participants run collectively in a circle forming a vortex of people.
The results are published on arXiv (Collective Motion of Moshers at Heavy Metal Concerts):
Human collective behavior can vary from calm to panicked depending on social context. Using videos publicly available online, we study the highly energized collective motion of attendees at heavy metal concerts. We find these extreme social gatherings generate similarly extreme behaviors: a disordered gas-like state called a mosh pit and an ordered vortex-like state called a circle pit. Both phenomena are reproduced in flocking simulations demonstrating that human collective behavior is consistent with the predictions of simplified models.
(via Lucia Marino)

### The circle of life

An electron encountered a positron: they are inexorably drawn towards each other, but their combination is intended to be fatal, and from their union remains only a photon, traveling... and traveling... and traveling... and occasionally it disappears, it decomposes into an electron and a positron. These, however, are futile images, as long as they do not possess enough energy to go away, to far away from each other.
Until the next waltz.
The image (via Quantum Diaries) represent a Feynman's diagram about the electron-positron annihilation and a next pair production. In the middle of the diagram, there is the auto energy of the photon, and it is named loop, and the diagram, loop diagram.
Read also: Let’s draw Feynman diagrams! | Feynman diagrams (pdf)

### The boson, the spin and the graviton

Some days ago, ATLAS has been released a draft about the spin of the new boson. The decay channels studied are the fab four: $H \rightarrow \gamma \gamma$, $H \rightarrow WW^*$, $H \rightarrow l\nu l\nu$, $H \rightarrow ZZ^* \rightarrow 4l$. The idea is combining data from the four channels in order to understand the spin of the new boson, in detail to distinguish between two cases: spin 0 ($J^P = 0^+$), and so a boson compatible with the Standard Model, and spin 2 ($J^P = 2^+$), that it could be connected with a model (arXiv) that represents a light coupling between the Standard Model's fields and the hypothetical graviton.
These the ATLAS' conclusions:
The data are in good agreement with the expected distributions of a $J^P=0^+$ particle while the graviton-inspired $J^P=2^+$ model, that is expected to be produced dominantly via the gluon fusion process, is excluded at more than 99.9% conﬁdence level.
We could say that it starting the elimination process of the models that would lead the research of the new physics beyond the Standard Model for the next years. A good luck to all of them, but we don't forget the key role of the Standard Model, that is in some sense confirmed by this last draft from ATLAS.

### Turmoil in the heavens

This one-page comic story published on Race to the Moon #2, that is now in public domain, is referred to an old theory proposed by Heinrich Wilhelm Matthäus Olbers, a german astronomer:
His bold hypothesis of their origin by the disruption of a primitive large planet, although now discarded, received countenance from the finding of Juno by Harding, and of Vesta by himself, in the precise regions of Cetus and Virgo where the nodes of such supposed planetary fragments should be situated.
The hypothetical planet, instead of Polis like suggested in the comic, was named Phaeton by Yevgeny Leonidovich Krinov. Olbers' model is today substituted by the accretion model.

### Ted Turner Interviews Carl Sagan

Carl Sagan and Ted Turner discuss the issues that are vital to the survival of our species on earth. Sagan explains the benefits of our space program, the fascinating possibility of time travel, and our search for life on other worlds.

### Play the game with the Higgs boson

In the mid-March at Moriond 2013 ATLAS and CMS presented the last results about the research of the Higgs' boson. While CMS reduced the excess for the $H \rightarrow \gamma \gamma$ decay channell, ATLAS continued to observe it. This result could be a clue that the boson discovered and announced last year is only the first of a series of Higgs' bosons. Indeed, following Albert De Roeck of CSM, the photon decay could be connected with...
new physics and there are a great deal of models that can come with such a number
In order to resolve the question (is the new boson the only Higgs' boson or simply a Higgs' boson?) we have to wait the end of the maintenance work of LHC, but in the meantime we could play with the Quark Matter Card Game, in particular the variant named Higgs Boson - on Your Own!
Object of the game: to win, by detecting a decay of a Higgs boson. If this does not happen in a given game, one can win by statistics, by collecting the largest number of particle cards.
The proposed game is a variation of Memory

### Pierre Deligne and the Weil conjectures

Pierre Deligne, a belgian mathematician, wins the Abel Prize 2013
for seminal contributions to algebraic geometry and for their transformative impact on number theory, representation theory, and related fields
One of the most famous contribution by Deligne was the proof of one of the three Weil conjectures. These conjectures was stated by Andre Weil, the mathematician who proofed the Fermat's last theorem, in 1949 (Numbers of solutions of equations in finite fields) in order to solve the following problem:
how to count the number of solutions to systems of polynomial equations over finite fields(1)
In particular
Weil conjectured that such zeta-functions should be rational functions, should satisfy a form of functional equation, and should have their zeroes in restricted places. The last two parts were quite consciously modeled on the Riemann zeta function and Riemann hypothesis. The rationality was proved by Dwork (1960), the functional equation by Grothendieck (1965), and the analogue of the Riemann hypothesis was proved by Deligne (1974)

### A very brief story of the Pi

Warped by Mike Cavna via Bamdad's Math Comics
As you know, the $\pi$ is defined as the ratio of the circumference to its diameter. This number, which is transcendental, was, apparently, known since ancient times. There are, in fact, some Egyptologists who believe that $\pi$, or perhaps $\tau = 2 \pi$, was known to them since the age og the Giza's pyramid, built between 2589 and 2566 BC, because the relationship between the perimeter and the height is 6.2857.
There are no explicit proof of the fact that, at the time, Egyptian mathematics became aware of a number such as $\pi$, however, between 600 and 1000 years later on a Babylonian tablet it is geometrically established the first value of $\pi$: $25/8 = 3.1250$. From documents written more or less in the same period it can be deduced that also the Egyptians calculated the value of $\pi$, obtaining $(16/9)^2 \simeq 3.1605$.
Indian mathematics, however, seems a little late: in 600 BC on Shulba Sutras, it is calculated for the $\pi$ value like $(9785/5568)^2 \simeq 3.088$, which will be updated later in 150 BC as $\sqrt{10} \simeq 3.1622$, which is a value much closer to the value calculated by the Egyptians.
A good approximation of $\pi$ value is in Mishnat ha-Middot, a geometric treatise by Rabbi Nehemiah: $3 + 1/7 \simeq 3.14286$.
The approximation, however, the most amazing not only for accuracy but also for the method is that proposed by Archimedes, the italo-greek mathematician who invented the method of polygons in order to calculate $\pi$, a costant that for a millennium became known simply as the Archimedes' constant.
He simply calculated the perimeter of polygons inscribed and circumscribed in a circle, thus obtaining a lower and an upper estimate of the value of the constant: $223/71 < \pi < 22/7$ or $3.1408 < \pi < 3.1429$ It's clear that his method of calculation is very modern and above suggests that Archimedes was well aware of the transcendental nature of the constant, which could be known only through approximations.
Today $\pi$ is known to 5 trillion digits and if you try to type the symbol $\pi$ on modern scientific calculators, the value they give you is, to the first decimal place, 3.14159265...

### A pretty picture of the Solar System

[Benjamin W. Betts] has made some studies of the Solar System, and endeavoured to find the law by which the intervals between the planets are regulated. He considers that the planets mark points of undeterminateness in the circuit of the polar forces of attraction and repulsion. Gravitation lie considers as the resultant of a proportional relation of these forces and not as an independent force in itself.
He believes the form of the Solar System, by which he means the invisible form of the activities immediately concerned in its production, and of which certain points are marked by the position of the planets, to be a nine-petaled lily similar to the Ond Corollas(1). Every Solar System in the sky he supposes to be the counterpart of some flower at our feet. Our Solar System is an Alpha or male universe. Others he believes may be Omega or female forms. The systems with dual suns he thinks may resemble his diagrams of bi-axial corollas.
(1) The Ond Corolla, or simlply Ond, is the name given by Betts to form such the figure presented here.
Image source: The public domain review
Text source: Geometrical psychology, or, The science of representation - An abstract of the theories and diagrams of B. W. Betts by Louisa S. Cook (1887)
Read also: barin pickings and Dataisnature

### Calculating machines

The Museum of Science and Technology Leonardo da Vinci in Milano was founded 60 years ago on the 15th February and yesterday this birthday was celebrated with a free admission from 14:30 until 23:30. Inside the museum you can participate in various interactive laboratories usually offered to visitors and visit exhibitions presented in the rooms of the Museum. While some of the exhibits are permanent, such as the one dedicated to Leonardo da Vinci, others are temporary, such as the one dedicated to Alan Turing, which centenary was celebrated during the last year.
The exhibit occupies three small rooms, nothing incredibly wide or long to see, but certainly very interesting. The exhibition, in fact, tells about the evolution of calculating machines, starting from pascaline by Pascal until you reach the final room, explicitly dedicated to the great British mathematician and logician, where thanks to some infographics, the life of Turing is telled to the visitors. Meanwhile on the wall a series of videos posted to YouTube and dedicated to the great scientist are projected.
To complete the room there is also an Enigma machine:
The Enigma machine was patented in 1918 by the German Arthur Scherbius which takes and expand the operating principle of the Italian Leon Battista Alberti's cipher disk.
Created to facilitate the encryption of communications in the financial and commercial, it was officially presented to the Berne International Postal Congress in 1923. Continuously improved, it is adopted first by the German navy and later by the army to make secret military communications. Easy to use, it enjoys a solid reputation as indecipherable that it ensure the wide diffusion.
Enigma is based on the whole system of secrecy of Nazi Germany. The attempt to break the cipher is one of the most famous stories of counterintelligence of the twentieth century. The first attempts are due to the Polish Marian Rejewski but with the capture of the specimen aboard the German submarine U-boat 110, which is able to provide important information to the team of scientists at Bletchley Park, working night and day to this purpose. Alan Turing is among these. Thanks to his skills as a mathematician and cryptographer, Turing can make an electromechanical computer, The Bombs, ables to perform the task with a remarkably efficient. Subsequently he developed a more powerful computer, Colossus, that at the end of the war will be destroyed on the orders of Winston Churchill, and its existence is only made ​​public uprisings years after the end of the war.
In the gallery below there are the photos I took during the visit to the museum:

### Proofs without words: the rolling circle

A rolling circle squares itself.

Elsner T. (1977). The Rolling Circle Squares Itself, Mathematics Magazine, 50 (3) 162. DOI:

### The art of the Higgs boson

by the Zim & Zou design studio for the french magazine Le Monde - via Lucia Marino | io9.com

### Extraction of square roots

Oppenheim A. (1955). 2553. Extraction of Square Roots, The Mathematical Gazette, 39 (329) 237. DOI:
At the end of his article on the extraction of square roots(1) Professor Haldane writes:
The methods here given are probably now of no practical importance. Had they been discovered in the 17th century, as they might have been, they would have saved a good deal of computation.
In point of fact Brook Taylor in 1717 gave "A general Series for expressing the Root of any Quadtratick Equation". It will be found towards the end of his paper
An attempt towards the Improvement of the Method of approximating, in the Extraction of the Roots of Equations in Numbers(2).
In modern notation Taylor's solution of the quadratic equation $xx - akx + akk = 0$ is $x = k + \frac{k}{c} + \frac{k}{cc'} + \frac{k}{cc'c''} + \cdots$ where $c=a-2$, $c' = c^2 -2$, $c'' = c'^2 -2$, $\cdots$ He gives the example $1 + \sqrt{2} = \frac{1}{2}-\frac{1}{2\cdot 6}-\frac{1}{2 \cdot 6 \cdot 34}-\frac{1}{2 \cdot 6 \cdot 34 \cdot 1154}-\frac{1}{2 \cdot 6 \cdot 34 \cdot 1154 \cdot 1331714} - \cdots$ and concludes
The Fractions here wrote down giving the Root true to twenty three Places(2)

(1) Haldane J.B.S. (1951). The Extraction of Square Roots, The Mathematical Gazette, 35 (312) 89. DOI: (pdf)
(2) Taylor B. (1717). An Attempt towards the Improvement of the Method of Approximating, in the Extraction of the Roots of Equations in Numbers. By Brook Taylor, Secretary to the Royal Society, Philosophical Transactions of the Royal Society of London, 30 (351-363) 610-622. DOI:

### The electric science of Captain Swing

Later that year [1830], there was a spate of riots by farm workers in the south of England who were reduced to starvation by the introduction of machinery that could do their jobs cheply and tirelessly. They destroyed threshers, burned workhouses and sent manifestos of fiery intent to the landlords and magistrates.
These letters were signed: "Captain Swing".
In this way Warren Ellis tells us the main inspiration for his story, Captain Swing and the Electrical Pirates of Cindery Island, drawned by Raulo Caceres: the protests by farmers against the introduction of machinery in country work. But Ellis' graphic novel is not an historical novel, but, first of all, a teslatopia (or a teslapunk novel) or an electrical romance of a pirate utopia thwarted, following Ellis' definition. If you want, from a more simple point of view, the Electric Pirates is a steampunk novel, but it is also a scientific comics. The fil rouge of the novel is, indeed, the electromagnetism research, and the diary of Captain Swing is a source of precious information that the reader could study in deep as soon as the closing of the book.
For example the reader could say himself if a ship could fly thanks to the electromagnetic force, or if the instruments illustrated in the pages of Captain's diary are true or not (in this last case the main source is probably Joseph Priestley's books, see for example The History and Present State of Electricity). Or we could ask if Ellis/Swing is lieing when he writes, for example, the following passage:
Ionic air propulsion(1). Electrostatic levitation(2). Electrogravitics. The Biefeld-Brown Effect and the electro-fluid-dynamics(3). Nothing here is invented. It simply appears to be uchronic, counterfactual, sitting in the break of a time out of joint.
In fact, many of the questions mentioned by Ellis are really studied by physics and electromagnetism.
Electromagnetism is the branch of physics that deals with the study of electric and magnetic fields. As demonstrated by James Clerck Maxwell, the two fields, electric and magnetic, are very closely related to each other and only in a static situation can, with good approximation, be considered separately.
In fact, however, the two concepts of electricity and magnetism were initially separated, and in particular the first observations about electricity date back to the Ancient Greece:
Thales first transcribed the induction of static electricity in 600 BC.
Only about one thousand of years we have a significative progress in the field:
Otto von Guericke built friction-machines for the accumulation of static electrical charge around 1650 AD.
Guericke, a prussian phisicist, is known primarily for his experiments on the air, which actually dates back to 1650 (according to the Britannica). In particular, he realized a famous experiment with a hollow sphere inside which was a vacuum: the horses tied to the two spherical caps that made the ball could not to separate them, thus demonstrating the tremendous pressure exerted by the air on the objects.
The invention cited by Warren Ellis come from 1663, which is the first electric generator in history.
The real high jump, however, comes with 1800s:
Upon thye founding date of the Metropolitan Police, Francesco Zantedeschi discovered electromagnetic induction (although, in this slow world, Michael Faraday would have been unaware of this when he published his more famous discovery of same, a year from now).
A simple experiment of electric induction (in this case electrostatic) is rub a pen on a knitted wool and then see his effects on some pieces of paper. Or you can try to do the same thing with a ball and a rod, using different materials to determine which of these is able to attract the ball after a suitable scrubbing:

### We want a theory

We want a theory. An uncommon want
When every year and month sends forth a new one
Till after cloying the gazettes with cant
The age discovers it is not the true one.

Hannes Alfven from On the Origin of the Solar System