Geometric model of particles: a didactical approach

About ten years ago Giovanni Guido proposed me a new model to describe particles. Under certain aspects it remembers to me a string model: simplifying as much as possible, Giovanni's model supposes the presence of small quantum oscillators connected to each other by lines that run along a space-time lattice; these lines form geometric figures, golden triangles to be precise, which constitute the geometric structure of particles, elementary and otherwise. I have never had the opportunity to actively work on the model: the commitments in outreach with INAF have always been somehow a priority due to the type of contract that, in some way, pushes me to give priority to these aspects. However, despite everything, we have used his vision to describe a universe that is in a certain sense cyclical that you can find in the following two articles: The Universe at Lattice-Fields and Variational Principle in an Expanding Universe.
Working on Guido's particle model, however, has always been a worry of mine, so a couple of years ago I proposed to him to try to develop a didactic formulation of the model that could be used to bring elementary particles not only to university, but also to high school. From that idea, although my contributions to the writing were minimal, a triptych of articles came out, of which you can find the links below, and which received a particular review that made me very happy:

The Authors propose a didactic model representative of the particles described of the Standard Model. In this approach, particles result to be geometric forms corresponding to geometric structures of coupled quantum oscillators. An in-depth phenomenology of particles surfaces and this seems fully compatible with that of the Standard Model. Consequently, it is possible to calculate the mass of Higgs's Boson and the mass of the pair "muon and muonic neutrino" in "geometrical" sense. Via this geometric approach, it seems also possible to solve crucial aspects of the Standard Model. as the neutrinos’ oscillations and the intrinsic chirality of the neutrino and antineutrino. The paper is very interesting and deserves immediate publication in JHEPGC.

I don't consider the work finished and indeed I would like to be able to bring these ideas into practice in schools. For now I'm happy to share this happiness here on the blog.

The Geometric Model of Particles: An Original Didactic about Standard Model -> The Quarks | Nucleons and K-Mesons | Leptons and Bosons

Leonardo's gears

The Madrid Codices I and II are two collections of Leonardo da Vinci's manuscripts found in a collection in the National Library of Madrid at the end of the 1960s. In particular, the Madrid Codex I consists of 382 pages of notes accompanied by something like 1600 between sketches and drawings and addresses a problem for which Leonardo is in some way particularly known as an engineer and designer: gears.
Leonardo's starting point is the study of friction. This is a force that opposes motion, but thanks to its opposition it is possible for us to walk without slipping or losing balance. As we all know today, however, the intensity of the frictional force depends on the surfaces that are in contact with each other, on how smooth or rough they are, which is independent of the area in contact and which can be reduced by using, for example, a lubricant or cylinders. All this, however, was already known to Leonardo, as it is possible to observe from the reading of the Madrid Code I. Furthermore, it is always Leonardo who introduced the concept of friction coefficient, defining it as the ratio between the force required to slide two surfaces horizontally on top of each other and the pressure between the two surfaces. Leonardo also estimated the value of this friction coefficient in 1/4, consistent with the materials best known to the florentine and with which he could carry out experiments (wood on wood, bronze on steel, etc.)⁽¹⁾.
At this point Leonardo is ready to develop a series of gears capable of carrying mechanical energy and producing motion, minimizing friction with the use of spheres and cylinders, as can be seen from his numerous drawings. In particular, however, it is Leonardo's mechanical use of two particular geometric shapes that is striking, because it anticipates their actual adoption by centuries: the epicloidal teeth and the globoidal gear.

The architecture of Pi Mensae

Few days before the formal acceptance of this paper, an independent study about the architecture of the π Men planetary system was published⁽¹⁾. The results of that work, based on public data and not including the ESPRESSO observations, confirm the high mutual inclination of the orbital planes of π Men b and c. Our results are in agreement with those of Xuan & Wyatt and are characterized by a better formal precision.⁽²⁾

Pi Mensae, or π Men, is a yellow dwarf star in the constellation of Mensa. We know that it has a little planetary system, constituted by two planets (or, if you prefer, we discover only two planets orbiting around Pi Mensae): Pi Mensae b, one of the most massive planets ever discovered, about 14.1 the mass of Jupiter, and Pi Mensae c, a super-Earth, about 4.5 the mass of our planet.
In 2020, an analysis with Gaia DR2 and Hipparcos astrometry showed that planets b and c are located on orbits mutually inclined by 49°-131°, which causes planet c to not transit most of the time, and acquire large misalignments with its host star's spin axis⁽¹⁾.
This result was discovered also by an italian team⁽²⁾, but published just few days after on arXiv, using ESPRESSO (Echelle Spectrograph for Rocky Exoplanet- and Stable Spectroscopic Observations), a sèectrograph designed and developed in Italy by researchers of Brera's Astronomical Observatory at the Merate's laboratories. The instrument, mounted on the Very Large Telescope, has in a certain sense been tested with the planetary system of Pi Mensae, therefore, even coming seconds for a few, the result can be considered a success for the young ESPRESSO.

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1. Xuan, J. W., & Wyatt, M. C. (2020). Evidence for a high mutual inclination between the cold Jupiter and transiting super Earth orbiting π Men. Monthly Notices of the Royal Astronomical Society, 497(2), 2096-2118. doi:10.1093/mnras/staa2033 (arXiv) ↩︎ ↩︎

2. Damasso, M., Sozzetti, A., Lovis, C., Barros, S. C. C., Sousa, S. G., Demangeon, O. D. S., ... & Rebolo, R. (2020). A precise architecture characterization of the $\pi$ Men planetary system. A&A, Forthcoming article doi:10.1051/0004-6361/202038416 (arXiv) ↩︎ ↩︎

Portrait of a Jovian satellite

The Jovian moon Io, imaged by SHARK-VIS@LBT on January 10, 2024. The red, green, and blue channels of this tri-color image show the I (infrared), R (red), and V (green) spectral bands, respectively (corresponding at wavelengths of 755, 620 and 550 nanometers). This is the highest resolution image of Io ever obtained from a ground-based telescope.

The breath of the ancestors

A research team led by the INAF (Istituto Nazionale di Astrofisica) and the University of Trieste has once again harnessed the very distant and energetic relativistic winds generated by a distant but decidedly active quasar (one of the brightest discovered so far). A study published in The Astrophysical Journal reports the first observation at different wavelengths of the interaction between the black hole and the quasar of the host galaxy J0923+0402 during the initial phases of the Universe, about 13 billion years ago (when the Universe was less than a billion years old). In addition to evidence of a gas storm generated by the black hole, experts have discovered for the first time a halo of gas extending well beyond the galaxy, suggesting the presence of material ejected from the galaxy itself via winds generated by the black hole.

Our study helps us understand how gas is expelled or captured by galaxies in the young Universe and how black holes grow and can impact the evolution of galaxies. We know that the fate of galaxies such as the Milky Way is closely linked to that of black holes, since these can generate galactic storms capable of extinguishing the formation of new stars. Studying the primordial eras allows us to understand the initial conditions of the Universe we see today. - Manuela Bischetti

Good bye, Arno Penzias

Unfortunately I heared of this news now through the Physics World newsletter, whose releases from the beginning of the year I am guilty of catching up with a guilty delay.
On January 22, 2024 Arno Penzias left us. He was 90 years old and had been awarded the Nobel Prize for Physics in 1978 for the discovery, together with Robert Wilson, of the cosmic microwave background radiation.
As the story goes, their discovery came by chance, while they were trying to eliminate background noise from the signals that the Bell Labs radio astronomy antenna was receiving.
In fact, another group of astronomers, headed by Robert Dicke, was also busy working on the question, and in the end he was "satisfied" with correctly interpreting the origin of the signal measured by the two researchers. The two articles, the observational one and the interpretative one, were published in the same issue of the Astrophysical Journal.
The story, as well as being told in the Physics World article linked at the beginning of this post, is also summarized in the video that you can see below:

Alan Turing and the sunflowers

Alan Turing was fascinated by mathematical patterns found in nature. In particular, he noticed that the Fibonacci sequence often occurred in sunflower seed heads. However, his theory that sunflower heads featured Fibonacci number sequences was left unfinished when he died in 1954, but some years ago a citizen science project led by the Museum of Science and Industry in Manchester and the Manchester Science Festival has found examples of Fibonacci sequences and other mathematical sequences in more than 500 sunflowers.
Inspired by this, I suggest a prompt to NightCafe, a text-to-image generator to celbrate Turing and his unstoppable mind: