Shared posts

26 Aug 04:00

Linear Regression

The 95% confidence interval suggests Rexthor's dog could also be a cat, or possibly a teapot.
24 Aug 15:21

Saturday Morning Breakfast Cereal - Rocks

by tech@thehiveworks.com


Hovertext:
What I do is a draw pictures and people look at the pictures and they like the pictures and so I draw more pictures.

New comic!
Today's News:
23 Aug 17:13

Hearts Jam

by The Awkward Yeti

Hearts-Jam

12 Jul 13:25

A Bird’s-Eye View of Nature’s Hidden Order

by Natalie Wolchover
Artnemiz1

Este es un articulo muy interesante de como la busqueda de conceptos abstractos puede conducir a interesantes aplicaciones. Esta largo pero esta es una guia:
[] - Introduccion y motivacion
[A Secret Order] - Explica que es la hiperuniformidad
[Material Menagerie] - Aplicaciones

Seven years ago, Joe Corbo stared into the eye of a chicken and saw something astonishing. The color-sensitive cone cells that carpeted the retina (detached from the fowl, and mounted under a microscope) appeared as polka dots of five different colors and sizes. But Corbo observed that, unlike the randomly dispersed cones in human eyes, or the neat rows of cones in the eyes of many fish, the chicken’s cones had a haphazard and yet remarkably uniform distribution. The dots’ locations followed no discernible rule, and yet dots never appeared too close together or too far apart. Each of the five interspersed sets of cones, and all of them together, exhibited this same arresting mix of randomness and regularity. Corbo, who runs a biology lab at Washington University in St. Louis, was hooked.

“It’s extremely beautiful just to look at these patterns,” he said. “We were kind of captured by the beauty, and had, purely out of curiosity, the desire to understand the patterns better.” He and his collaborators also hoped to figure out the patterns’ function, and how they were generated. He didn’t know then that these same questions were being asked in numerous other contexts, or that he had found the first biological manifestation of a type of hidden order that has also turned up all over mathematics and physics.

Corbo did know that whatever bird retinas are doing is probably the thing to do. Avian vision works spectacularly well (enabling eagles, for instance, to spot mice from a mile high), and his lab studies the evolutionary adaptations that make this so. Many of these attributes are believed to have been passed down to birds from a lizardlike creature that, 300 million years ago, gave rise to both dinosaurs and proto-mammals. While birds’ ancestors, the dinos, ruled the planetary roost, our mammalian kin scurried around in the dark, fearfully nocturnal and gradually losing color discrimination. Mammals’ cone types dropped to two — a nadir from which we are still clambering back. About 30 million years ago, one of our primate ancestors’ cones split into two — red- and green-detecting — which, together with the existing blue-detecting cone, give us trichromatic vision. But our cones, particularly the newer red and green ones, have a clumpy, scattershot distribution and sample light unevenly.

Bird eyes have had eons longer to optimize. Along with their higher cone count, they achieve a far more regular spacing of the cells. But why, Corbo and colleagues wondered, had evolution not opted for the perfect regularity of a grid or “lattice” distribution of cones? The strange, uncategorizable pattern they observed in the retinas was, in all likelihood, optimizing some unknown set of constraints. What these were, what the pattern was, and how the avian visual system achieved it remained unclear. The biologists did their best to quantify the regularity in the retinas, but this was unfamiliar terrain, and they needed help. In 2012, Corbo contacted Salvatore Torquato, a professor of theoretical chemistry at Princeton University and a renowned expert in a discipline known as “packing.” Packing problems ask about the densest way to pack objects (such as cone cells of five different sizes) in a given number of dimensions (in the case of a retina, two). “I wanted to get at this question of whether such a system was optimally packed,” Corbo said. Intrigued, Torquato ran some algorithms on digital images of the retinal patterns and “was astounded,” Corbo recalled, “to see the same phenomenon occurring in these systems as they’d seen in a lot of inorganic or physical systems.”

Torquato had been studying this hidden order since the early 2000s, when he dubbed it “hyperuniformity.” (This term has largely won out over “superhomogeneity,” coined around the same time by Joel Lebowitz of Rutgers University.) Since then, it has turned up in a rapidly expanding family of systems. Beyond bird eyes, hyperuniformity is found in materials called quasicrystals, as well as in mathematical matrices full of random numbers, the large-scale structure of the universe, quantum ensembles, and soft-matter systems like emulsions and colloids.

Scientists are nearly always taken by surprise when it pops up in new places, as if playing whack-a-mole with the universe. They are still searching for a unifying concept underlying these occurrences. In the process, they’ve uncovered novel properties of hyperuniform materials that could prove technologically useful.

From a mathematical standpoint, “the more you study it, the more elegant and conceptually compelling it seems,” said Henry Cohn, a mathematician and packing expert at Microsoft Research New England, referring to hyperuniformity. “On the other hand, what surprises me about it is the potential breadth of its applications.”

A Secret Order

Torquato and a colleague launched the study of hyperuniformity 13 years ago, describing it theoretically and identifying a simple yet surprising example: “You take marbles, you put them in a container, you shake them up until they jam,” Torquato said in his Princeton office this spring. “That system is hyperuniform.”

“I see hyperuniformity as basically a hallmark of deeper optimization processes…”

– Henry Cohn

The marbles fall into an arrangement, technically called the “maximally random jammed packing,” in which they fill 64 percent of space. (The rest is empty air.) This is less than in the densest possible arrangement of spheres — the lattice packing used to stack oranges in a crate, which fills 74 percent of space. But lattice packings aren’t always possible to achieve. You can’t easily shake a boxful of marbles into a crystalline arrangement. Neither can you form a lattice, Torquato explained, by arranging objects of five different sizes, such as the cones in chicken eyes.

As stand-ins for cones, consider coins on a tabletop. “If you take pennies, and you try to compress the pennies, the pennies like to go into the triangular lattice,” Torquato said. But throw some nickels in with the pennies, and “that stops it from crystallizing. Now if you have five different components — throw in quarters, throw in dimes, whatever — that inhibits crystallization even further.” Likewise, geometry demands that avian cone cells be disordered. But there’s a competing evolutionary demand for the retina to sample light as uniformly as possible, with blue cones positioned far from other blue cones, reds far from other reds, and so on. Balancing these constraints, the system “settles for disordered hyperuniformity,” Torquato said.

Hyperuniformity gives birds the best of both worlds: Five cone types, arranged in near-uniform mosaics, provide phenomenal color resolution. But it’s a “hidden order that you really can’t detect with your eye,” he said.

Determining whether a system is hyperuniform requires algorithms that work rather like a game of ring toss. First, Torquato said, imagine repeatedly tossing a ring onto an orderly lattice of dots, and each time it lands, counting the number of dots inside the ring. The number of captured dots fluctuates from one ring toss to the next — but not by very much. That’s because the interior of the ring always covers a fixed block of dots; the only variation in the number of captured dots happens along the ring’s perimeter. If you increase the size of the ring, you will get variation along a longer perimeter. And so with a lattice, the variation in the number of captured dots (or “density fluctuations” in the lattice) grows in proportion to the length of the ring’s perimeter. (In higher spatial dimensions, the density fluctuations also scale in proportion to the number of dimensions minus one.)

Now imagine playing ring toss with a smattering of uncorrelated dots — a random distribution, marked by gaps and clusters. A hallmark of randomness is that, as you make the ring bigger, the variation in the number of captured dots scales in proportion to the ring’s area, rather than its perimeter. The result is that on large scales, the density fluctuations between ring tosses in a random distribution are much more extreme than in a lattice.

The game gets interesting when it involves hyperuniform distributions. The dots are locally disordered, so for small ring sizes, the number of captured dots fluctuates from one toss to the next more than in a lattice. But as you make the ring bigger, the density fluctuations begin to grow in proportion to the ring’s perimeter, rather than its area. This means that the large-scale density of the distribution is just as uniform as that of a lattice.

Among hyperuniform systems, researchers have found a further “zoology of structures,” said the Princeton physicist Paul Steinhardt. In these systems, the growth of density fluctuations depends on different powers (between one and two) of the ring’s perimeter, multiplied by different coefficients.

“What does it all mean?” Torquato said. “We don’t know. It’s evolving. There are a lot of papers coming out.”

Material Menagerie

Hyperuniformity is clearly a state to which diverse systems converge, but the explanation for its universality is a work in progress. “I see hyperuniformity as basically a hallmark of deeper optimization processes of some sort,” Cohn said. But what these processes are “might vary a lot between different problems.”

Hyperuniform systems fall into two main classes. Those in the first class, such as quasicrystals — bizarre solids whose interlocked atoms follow no repeating pattern, yet tessellate space — appear to be hyperuniform upon reaching equilibrium, the stable configuration that particles settle into of their own accord. In these equilibrium systems, it is mutual repulsions between the particles that space them apart and give rise to global hyperuniformity. Similar math might explain the emergence of hyperuniformity in bird eyes, the distribution of eigenvalues of random matrices, and the zeros of the Riemann zeta function — cousins of the prime numbers.

The other class is not as well understood. In these “nonequilibrium” systems, which include shaken marbles, emulsions, colloids and ensembles of cold atoms, particles bump into one another but otherwise do not exert mutual forces; external forces must be applied to the systems to drive them to a hyperuniform state. Within the nonequilibrium class, there are further, intractable divisions. Last fall, physicists led by Denis Bartolo of the École Normale Supérieure in Lyon, France, reported in Physical Review Letters that hyperuniformity can be induced in emulsions by sloshing them at the exact amplitude that marks the transition between reversibility and irreversibility in the material: When sloshed more gently than this critical amplitude, the particles suspended in the emulsion return to their previous relative positions after each slosh; when sloshed harder, the particles’ motions do not reverse. Bartolo’s work suggests a fundamental (though not fully formed) connection between the onset of reversibility and the emergence of hyperuniformity in such nonequilibrium systems. Maximally random jammed packings, meanwhile, are a whole different story. “Can we connect the two physics?” Bartolo said. “No. Not at all. We have absolutely no idea why hyperuniformity shows up in these two very different sets of physical systems.”

As they strive to link these threads, scientists have also encountered surprising properties of hyperuniform materials — behaviors that are normally associated with crystals, but which are less susceptible to fabrication errors, more like properties of glass and other uncorrelated disordered media. In a paper expected to be published this week in Optica, French physicists led by Rémi Carminati report that dense hyperuniform materials can be made transparent, whereas uncorrelated disordered materials with the same density would be opaque. The hidden order in the particles’ relative positions causes their scattered light to interfere and cancel out. “The interferences destroy scattering,” Carminati explained. “Light goes through, as if the material was homogeneous.” It’s too early to know what dense, transparent, noncrystalline materials might be useful for, Carminati said, but “there are certainly potential applications,” particularly in photonics.

And Bartolo’s recent finding about how hyperuniformity is generated in emulsions translates into an easy recipe for stirring concrete, cosmetic creams, glass and food. “Whenever you want to disperse particles inside a paste, you have to deal with a hard mixing problem,” he said. “This could be a way to disperse solid particles in a very uniform fashion.” First, you identify a material’s characteristic amplitude, then you drive it at that amplitude a few dozen times, and an evenly mixed, hyperuniform distribution emerges. “I should not tell you this for free, but rather start a company!” Bartolo said.

Torquato, Steinhardt and associates have already done so. Their start-up, Etaphase, will manufacture hyperuniform photonic circuits — devices that transmit data via light rather than electrons. The Princeton scientists discovered a few years ago that hyperuniform materials can have “band gaps,” which block certain frequencies from propagating. Band gaps enable controlled transmission of data, since the blocked frequencies can be contained and guided through channels called waveguides. But band gaps were once thought to be unique to crystal lattices and direction-dependent, aligning with the crystal’s symmetry axes. This meant photonic waveguides could only go in certain directions, limiting their use as circuits. Since hyperuniform materials have no preferred direction, their little-understood band gaps are potentially much more practical, enabling not only “wiggly waveguides, but waveguides as you wish,” Steinhardt said.

As for the pattern of five-color mosaics in birds’ eyes, termed “multihyperuniform,” it is, so far, unique in nature. Corbo still hasn’t pinpointed how the pattern forms. Does it emerge from mutual repulsions between cone cells, like other systems in the equilibrium class? Or do cones get shaken up like a box of marbles? His guess is the former. Cells can secrete molecules that repel cells of the same type but have no effect on other types; probably, during embryonic development, each cone cell signals that it is differentiating as a certain type, preventing neighboring cells from doing the same. “That’s a simple model of how this could develop,” he said. “Local action around each cell is creating a global pattern.”

Aside from chickens (the most readily available fowl for laboratory study), the same multihyperuniform retinal pattern has turned up in the three other bird species that Corbo has investigated, suggesting that the adaptation is widespread and not tailored to any particular environment. He wonders whether evolution might have found a different optimal configuration in nocturnal species. “That would be super interesting,” he said. “It’s trickier for us to get our hands on, say, owl eyes.”

This article was reprinted on Wired.com.

Save

Save

22 Aug 04:00

Travel

by The Awkward Yeti

Travel

20 Aug 18:34

enelojodelculo: pdfsistas de los últimos días



enelojodelculo:

pdfsistas de los últimos días

20 Aug 14:52

Saturday Morning Breakfast Cereal - Your Greatest Weakness

by tech@thehiveworks.com


Hovertext:
The opposite of Dunning-Kruger isn't that great either.

New comic!
Today's News:
16 Aug 10:00

Paper Towels

by Justin Boyd

Paper Towels

Peel that thing off and use it!



bonus panel
12 Aug 20:27

12/08/2016 - 20:48:50 - Útiles webmaster - por Oink!

¿Te gusta el rol? ¿Te gustan los mapas? Pues con este generador de mapas de lugares fantásticos sólo tienes que darle a 3 ó 4 botones para tener preparado el terreno en el que Frodo y sus amigos se pierdan y las pasen canutas (gracias excesivo)



13 Aug 07:29

13/08/2016 - 09:24:40 - - por Oink!

El dato: Entre los siglos XVI y XIX existía una raza de perros específica para mantener la carne dando vueltas sobre el fuego. Era alargado y de patas cortas, de forma que pudiese mantenerse dentro de una rueda como las de los hámsters [fuente]



15 Aug 04:00

Horses

Artnemiz1

Hmmm ... "(...) No"

This car has 240% of a horse's decision-making ability and produces only 30% as much poop.
15 Aug 16:45

Saturday Morning Breakfast Cereal - You Are Loved

by tech@thehiveworks.com
Artnemiz1

Never heard a joke about (pa...oice) ... no spoilers



Hovertext:
And don't call me Mom, either.

New comic!
Today's News:
12 Aug 18:00

It Was a Mistake, Dude, She Thought You Were a Dog

12 Aug 16:02

Photo



12 Aug 04:00

Superzoom

*click* Let him know he's got a stain on his shirt, though.
13 Aug 15:00

Saturday Morning Breakfast Cereal - Adam's Rib

by tech@thehiveworks.com
Artnemiz1

Las expresiones del ninio



Hovertext:
Fortunately, as she ages, she will become more porous.

New comic!
Today's News:
08 Aug 15:18

Mastication

by The Awkward Yeti

Mastication

08 Aug 14:39

Saturday Morning Breakfast Cereal - The Resurrection

by tech@thehiveworks.com


Hovertext:
Fun fact: Pastors are always available for on the spot theological discussions.

New comic!
Today's News:
31 Jul 15:06

Saturday Morning Breakfast Cereal - Parenting Game Theory

by tech@thehiveworks.com


Hovertext:
Who says game theory isn't useful in real life?

New comic!
Today's News:
23 Jun 14:55

Saturday Morning Breakfast Cereal - Math Education

by tech@thehiveworks.com


Hovertext:
Until you teach someone calculus, they can't even walk finite distances. But they can get reallllllly close.

New comic!
Today's News:

Submissions are closing soon! Get your proposal in while there's time! 

04 Jul 14:43

Saturday Morning Breakfast Cereal - Self-Driving Car Ethics

by tech@thehiveworks.com


Hovertext:
Then, one day, Jesus Chrysler will come.

New comic!
Today's News:

Hey geeks-- we've been doing some testing and software stuff this week and it's created a lot of issues with bad ads and RSS feed bugs. We are working to get everything ironed out, but if you see something buggy, please let me know. If something has changed for the worse on your end, it is not intentional!

13 Jul 15:00

Saturday Morning Breakfast Cereal - Why You're Attracted to Me

by tech@thehiveworks.com


Hovertext:
Also, I only wash the top part of plates then I put them DIRECTLY on top of other plates in the cupboard.

New comic!
Today's News:

26 Jul 10:00

Time For Sleep

by Justin Boyd

Time For Sleep

Back to posting comics!

Thank you so much for being patient with the update schedule (or lack thereof) over the past 2-3 weeks.

I’m pretty comfortable talking about my own personal life, but the stuff that has been going on impacts me as well as the people I love and care about in my life. So, as a result, I don’t feel it’s right to share the details of what was going on here on this site. I hope you all understand.

However, I will tell you the following, since the following things only involve me

  • I’m good, don’t worry!
  • Twitch streams will start again soon
  • I got a haircut
  • I went to Warped Tour on Friday and drank seven Monsters.

 



bonus panel
01 Jul 10:00

Remember

by Justin Boyd

Remember

It’s fun to, what’s that word, oh yes, remember. It’s fun to remember things.



bonus panel
21 Jul 07:01

I’m So Bored

by alex

I’m So Bored

18 May 04:00

Bun

If a wild bun is sighted, a nice gesture of respect is to send a 'BUN ALERT' message to friends and family, with photographs documenting the bun's location and rank. If no photographs are possible, emoji may be substituted.
10 Sep 12:46

Copian en 3D a partir de una fotografía las llaves maestras utilizadas en los aeropuertos por las agencias de seguridad

by nacho@internality.com (Nacho)

Llave-Maestra-Clonada-WtfEl artículo de The Washington Post The secret life of baggage: Where does your luggage go at the airport? explicaba cómo era el proceso de seguridad aplicado por la TSA (la Transportation Security Administration, la agencia de EE UU encargada allí de la seguridad aérea) al equipaje que se embarcaba en los aviones.

Entre otras cosas el artículo hacía referencia a las llaves maestras que utilizan en la TSA para abrir los candados de equipaje —los candados que la TSA ‘recomienda’ utilizar a la gente para cerrar sus maletas cuando las embarca.

Con este acuerdo entre ambas partes la gente queda tranquila porque puede ponerle un candado al equipaje y además en caso de que una maleta necesite ser revisada por personal de seguridad de los aeropuertos la TSA puede abrir el candado usando una llave maestra — inspeccionar el contenido de la maleta, dejar una tarjeta explicando el procedimiento y volver a dejar el candado como estaba, cerrado.

El artículo en el Washington Post iba acompañado —ya no— de una fotografía del mazo de llaves maestras utilizadas por la TSA.

En Wired, Lockpickers 3-D Print TSA Master Luggage Keys From Leaked Photos,

La TSA acaba de aprender una lección básica de la seguridad física en la era de la impresión 3D: si tienes llaves importantes —digamos, un juego de las llaves maestras que pueden abrir los candados del equipaje de millones de ciudadanos— no publiques fotos de esas llaves en Internet.

Un grupo de entusiastas de la seguridad fue capaz de obtener modelos 3D de las llaves a partir de las fotografías y compartieron los archivos en GitHub, desde donde cualquiera ha podido descargarlas e imprimirlas.

«Madre mía, ¡funciona de verdad!» es el comentario que acompaña a un vídeo publicado en Twitter por alguien que ha descargado esos archivos, ha impreso copia de las llaves con una impresora 3D y ha probado a abrir con ellas uno de esos candados. Y funciona de verdad.

Relacionado,

# Enlace Permanente

04 Feb 02:26

weloveshortvideos: THIS is how to be a rockstar.

Artnemiz1

Esto me sucedera cuando nadie este viendo



weloveshortvideos:

THIS is how to be a rockstar.

22 Jun 16:31

1960, cuando se nacionalizó la energía eléctrica en México.

by Benjamin Arredondo
Artnemiz1

Carlo publico esto exactamente hace dos anios, esta en mi lista de post no leidos....

    Recuerdo que, en aquellas tardes de diaria lectura del Excélsior, el Universal y el Novedades, que llegaban en montón a mi casa, década de los sesenta, me entretenía enormemente viendo fotos y más fotos, que entonces no eran nada claras, pero me enteraba de montones de cosas que ni entendía, ni le daba seguimiento, era un "matatiempos" el que hacía con esas lecturas, en las cuales se incluía una manchada monumental de dedos pues, las tintas eran muy distintas a las actuales. Los periódicos llegaban hechos rollo, difíciles de enderezar pues venían casi sellados y, en ocasiones, en un día llegaban juntos los de toda la semana; otra gran afición que tenía era la de recortar todo cupón que apareciera allí y los enviaba a México, luego recibía montones de folletos turísticos y me dedicaba a viajar por el mundo en mi imaginación.

    Y en una de esas largas sentadas a leer recuerdo haber visto dos cosas que se me quedaron muy grabadas, una la convocatoria para el diseño del logotipo de la CFE, la otra, la oferta de colonización para Quintana Roo y Baja California Sur, en la que convocaban a la ciudadanía que se quisiera ir a vivir allá a cambio de una dotación de terreno, sea en la selva que en el desierto, claro es que levanté la mano de inmediato, me hubiera gustado ir a colonizar aquellas tierras... luego de varias décadas lo hice.

    Sabes bien, (eso espero) que tengo otros blogs, uno de ellos el de Cabezas de Águila trata de la Ruta de Hidalgo, concebida durante la administración del presidente Adolfo López Mateos, por su Secretario de Educación, Jaime Torres Bodet con la que se marcó la "Ruta de la Libertad" a lo largo de once Estados por los que pasó Hidalgo entre 1810 y 1811; cuando comencé a consultar los periódicos de la época, fue que apareció esa nota en donde anunciaba la nacionalización de la industria eléctrica. Me sorprendió pues hemos oído mucho sobre la nacionalización del petróleo, nos tocó vivir la nacionalización de la banca, pero de la energía eléctrica poco se menciona. Eso ocurrió el 27 de septiembre de 1960, año del Sesquicentenario de la Independencia. (Del inicio de la Independencia, dicen los puristas de la Historia).

    Ahora que tengo la oportunidad de consultar el periódico El Nacional, veo una buena cantidad de desplegados que anuncian esa nacionalización. Me parece interesante compartirlos para ver como la propaganda oficial de la época equiparaba ese acto con la Independencia, la Reforma, la Revolución y otros episodios nacionales significativos. Como único dato te digo que esa nacionalización fue hecha a la empresa canadiense Mexican Light and Power Company, que aportaba el 25% del total de lo instalado entonces.

    "En 1960, la población es de 34.9 millones de habitantes; de los 2,308 MW de capacidad instalada en el país, la CFE aporta el 54%, la Mexican Light and Power Co., el 25%, la American and Foreign el 12% y el resto de las compañías el 9%. Solo el 44% de la población cuenta con electricidad. Desde que ha sido creada la CFE, la población ha crecido 91%, acompañada de un vertiginoso desarrollo de la industria, la agricultura y otras actividades urbanas y rurales". Tomado de Memoria Política de México, si quieres leer el artículo completo, entra aquí.






Más datos sobre esta nacionalización los encuentras aquí.


21 Jun 10:00

Common

by Justin Boyd

Common

8 months and counting! I’m pretty sure we’re never gonna acknowledge my frequent appearances.



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