Showing posts with label art. Show all posts
Showing posts with label art. Show all posts

Sagitarius A*: Van Gogh in the Milky Way


The colour scale in the image shows the amount of infrared (heat) radiation coming from warm dust particles in the filaments and luminous stars within a light year of the Galactic centre. The position of the black hole is indicated by an asterisk. The lines trace the magnetic field directions and reveal the complex interactions between the stars and the dusty filaments, and the impact that they and the gravitational force has on them. The observations were made with the largest telescope in Europe, which allowed details of the fine structure in the magnetic fields to be revealed for the first time.
- E. Lopez-Rodriguez / NASA Ames / University of Texas at San Antonio
A paper published on the Monthly Notices of the Royal Astronomical Society describes tha detailed mapping of the magnetic field around Sagittarius A*, or Sgr A*, the supermassive black hole at the center of the Milky Way. A researchers' team used the infrared camera CanariCam instaled on the Great Canary Telescope to obtain the data needed to reproduce the magnetic lines of gas and dusts that orbit around the center of the galaxy. The colors chosen by the researchers to visualize the structure of the magnetic lines give the result a style that recalls Vincent Van Gogh's paintings.
P F Roche, E Lopez-Rodriguez, CM Telesco, R Schödel, C Packham; The Magnetic Field in the central parsec of the Galaxy, Monthly Notices of the Royal Astronomical Society, sty129, 10.1093/mnras/sty129

Balloon, art and mathematics

After (or before?) @StartsWithABang's balloon animals' post?
A couple of week ago Ethan Siegel published a post about ballon animals, so I decide to repost an old piece that I wrote in 2011 for my italian blog: the english version is lost, but it is magically reposted here!

Two one-balloon constructions and their associated graphs
I recently discovered this interesting site, vihart. In the site there are some interesting paper and today I want to write something about Computational Balloon Twisting: The Theory of Balloon Polyhedra by Erik and Martin Demaine and Vi Hart (the paper was reported in 2010 by the Improbable Research blog).
The interest about ballon twisting was motivated by...
Balloon twisting is fun: the activity can both entertain and engage children of all ages. Thus balloon twisting can be a vehicle for teaching mathematical concepts inherent in balloons. As we will see, these topics include graph theory, graph algorithms, Euler tours, Chinese postman tours, polyhedra (both 3D and 4D), coloring, symmetry, and even NP-completeness. Even the models alone are useful for education, e.g., in illustrating molecules in chemistry.
There's also a second motivation: building architectural structures with air beams (Army blows up building, Center manages technology of inflatable composite structures).
Our approach suggests that one long, low-pressure tube enables the temporary construction of inflatable shelters, domes, and many other polyhedral structures, which can be later reconfigured into different shapes and re-used at different sites. In contrast to previous work, which designs a different inflatable shape specifically for each desired structure, we show the versatility of a single tube.

Twisting baloons
The problem of the researchers is to determine the twistable graphs. Referring to a phisical balloon like a bloon, we have the following definitions:
(...) a bloon is a (line) segment which can be twisted at arbitrary points to form vertices at which the bloon can be bent like a hinge. The endpoints of a bloon are also vertices. Two vertices can be tied to form permanent point connections. A twisted bloon is stable if every vertex is either tied to another vertex or held at a nonzero bending angle.
The three researchers also defined two models

Poincaré, Einstein and Picasso: children of time

posted by @ulaulaman about #cubism #PabloPicasso #AlbertEinstein #HenriPoincaré #mathematics #art #relativity
A great thanks to Marco Fulvio Barozzi: his post(1) about Miller's book is the main inspiration of my post.

Yesterday, on the Guardian, Arthur I. Miller, the author of the book Einstein, Picasso: Space, Time and the Beauty that Causes Havoc, wrote a briefly article in which he resumed his thesis about the connections between Poincaré and Einstein, between Poincaré and Picasso and, for translation, between Einstein and Picasso.
Henri Poincaré was one of the most important mathematician of the early XX century: his most important contributions, that have a great impact also in physics, are in group theory and representation theory. His work was indeed important for the birth of the ray representations (the theory was developed in particular by Valentine Bargmann starting from Weyl and Wigner's works) and basic for special relativity and in particular for general relativity. Poincaré was the first to propose the symmetrical form of the Lorentz transformations, and his work was important for the creation of the Poincaré group, the symmetry group of the general relativity. In particular about the relativity, Poincaré written on his book Science and Hypothesis (1902)
Our Euclidean geometry is itself a sort of linguistic convention; we may state the facts of mechanics in relation to a non-Euclidean space, but this would be a less convenient reference, although legitimate like our ordinary space.(1)
He also defined the principle of relative motion like
the physical impossibility of observing absolute motion.(1)
Two years later he named it Principle of Relativity.
At the other hand, Einstein did not cite Poincaré's works in his paper published in 1905 by Annalen der Physik and only in a conference in 1921 Einstein confirmed his debt to the french mathematician, but only about general relativity and non-euclidean geometry. And this is the only documented connection between Einstein and Poincaré: we must suppose that the two scientists worked indipendetly and also after his first paper Einstein used Poincaré's discoveries in order to develop the mathematical formalism of the general relativity.
Some years later the first Einstein's paper, the cubism was born in France:
A circle of poets and critics, and followers of the philosopher Bergson, stood up for cubism in the visual arts. This group became known as the Cubists. The poet and publicist G. Apollinaire became the undisputed leader of this movement.(2)
It seems that relativity played a relevant role in the phylosophy of the artistic movement
Like the scientists, the artists has come to recognize thatclassic conceptions of space and volume are limited and one-sided. (...) The presentation of objects from several point of view introduces a principle which is intimately bound up with modern life - simultaenity. It is a temporal coincidence that Einstein should havebegan his famous work (...) with a careful definition of simultaneity.(5)
In this quotation by Sigfried Giedion, the connection was simply casual, only a temporal coincidence, but a lot of art historians think that the connection is not so casual. One of this is Paul M. Laporte, who published two paper about cubism and relativity, and submitted them to Albert Einstein. The great physicist reply with a long letter, in which he concludes:
This new artistic "language" has nothing in common with the Theory of Relativity.(5)
And probably it is so. Indeed in 1903 the Introduction to Metaphysics by Henri Bergson was published. In the book Bergson argued that
human consciousness experiences space and time as ever-changing and heterogeneous. With the passage of time, an observer accumulates in his memory a store of perceptual information about a given object in the external visible world, and this accumulated experience becomes the basis for the observer’s conceptual knowledge of that object. By contrast, the intellect or reasoning faculty always represents time and space as homogenous. Bergson argued that intellectual perception led to a fundamentally false representation of the nature of things, that in nature nothing is ever absolutely still. Instead the universe is in a constant state of change or flux. An observer views an object and its surrounding environment as a continuum, fusing into one another. The task of metaphysics, according to Bergson, is to find ways to capture this flux, especially as it is expressed in consciousness. To represent this flux of reality, Picasso began to make references to the fourth dimension by "sticking together" several three-dimensional spaces in a row.(4)