Ir al contenido principal


Mostrando las entradas con la etiqueta Ciencia

El origen del N95 es un bra

La forma del cubrebocas por excelencia del coronavirus asemeja un brasiere. Todo el mundo lo ve, intuitivamente. Es correcta esa observación.
Like most nondescript and pervasive products, not many people stop to think about where it came from. Now, owing to the attention placed on it as a key tool in the health care professional’s fight against coronavirus, the woman behind the mask has come to the forefront. Her name is Sara Little Turnbull, and she designed what would become the N95 based on the shape of a bra cup.

Link: Remembering Sara Little Turnbull, Whose Bra Cup Design Became the N95 Mask

La biodiversidad del mar profundo

Un elemento fascinante de la vida ultramarina, aquella que habita en las profundidades de los mares, es que antes de ver estos videos la humanidad no había tenido contacto con estas formas de vida.

Link: Deep-Sea Exploration in the Ningaloo Canyons Unveils Gripping Footage of Undiscovered Aquatic Life

El telescopio Hubble y sus imágenes

Hay un nuevo libro por la editorial Taschen sobre el telescopio Hubble, que este 2020 cumple 30 años en funcionamiento. 
Launched in April 1990, the telescope sits above the Earth’s rainclouds and polluted skies, which allows it to capture an unobstructed view of distant stars, galaxies, and planets that make up the rich tapestry of our solar system. Alongside the arresting images, the book features texts that unravel some of the most compelling questions of space and time, including words by photography critic Owen Edwards, Hubble astronauts Charles F. Bolden, Jr., John Mace Grunsfeld, and Zoltan Levay.
La publicación, titulada Expanding Universe: The Hubble Space Telescope, cuenta con 30 imágenes inéditas.

Link: Explore 30 Years of Arresting Images Captured by the Hubble Space Telescope in a New Book

La explosión del Monte Saint Helens, 40 años después

En Twitter hay un breve hilo sobre la explosión del monte Santa Helena, ocurrida hace 40 años. 
Este monte se encuentra ubicado en el estado de Washington, en el Pacífico Noroeste de Estados Unidos.
40 years ago, May 18th 1980. Mt. Saint Helens erupted, and NOAA's GOES-3 visible captured it.— BJ Marraccini (@bjmarra) May 18, 2020

La vida que florece sin el Sol

La fotosíntesis es extremadamente sencilla y eficiente. No obstante, también existe la vida dependiente de la radiolisis.
That is, it’s possible that life might have gotten its start on the surface of the Earth, where it found creative ways to survive and spread, including to deeper environments. But it’s also possible that life began underground, at some fortuitous juncture between rock and water — eventually also making its way to the surface and figuring out how to harness the sun’s energy. (On that note, photosynthesis-dependent surface life and radiolysis-dependent subsurface life have so far been found to have an ancient, shared ancestry — but some researchers are intrigued by the possibility that life could have evolved more than once on Earth, in a “second genesis.”)

Link: Inside Deep Undersea Rocks, Life Thrives Without the Sun

Congreso sobre la física del tiempo

Mi aportación es que el tiempo es contingente. Un epifenómeno dentro de la segunda Ley de la Termodinámica.
Those in attendance wrestled with several questions: the distinction between past, present and future; why time appears to move in only one direction; and whether time is fundamental or emergent. Most of those issues, not surprisingly, remained unresolved. But for four days, participants listened attentively to the latest proposals for tackling these questions — and, especially, to the ways in which we might reconcile our perception of time’s passage with a static, seemingly timeless universe.
Para este encuentro faltó la presencia de Plotino y Boecio.
Link: A Debate Over the Physics of Time

¿Qué acelera la expansión del Universo?

Hay una aparente contradicción: de acuerdo a  las teorías cosmológicas más aceptadas, el Universo que conocemos tiene una edad de 13 mil millones de años. El "espacio" conocible abarca 40 mil años luz.
Alongside early dark energy, theorists have put forward other exotic forms of dark energy — such as quintessence and phantom dark energy — that also change as the universe ages. While these extensions to the standard model relieve the Hubble tension, they are regarded by many cosmologists as fine-tuned — opportune mathematical additions that have no clear justification.

Link: What Might Be Speeding Up the Universe’s Expansion?

¿Por qué existe el sexo como mecanismo y no sólo la reproducción asexual, la cual tiene, también, sus beneficios?

Sex might be biology’s most difficult enigma. The downsides of relying on sex to reproduce are undeniable: It takes two individuals, each of whom gets to pass on only part of their genome. Because these individuals generally have to get fairly intimate, they make themselves vulnerable to physical harm or infections from their partner. Asexual reproduction, or self-cloning, has none of these disadvantages. Clones can be made anywhere and anytime, and they receive the full complement of an individual’s genes.
Yet despite all its benefits, asexual reproduction is the exception, not the norm, among organisms that have compartmentalized cells (eukaryotes). In plants, for example — which are somewhat known for their genetic flexibility — less than 1% of species are thought to reproduce asexually often. Among animals, only one out of every thousand known species is exclusively asexual. For centuries, biologists have pondered this apparent paradox.

• Even the idea that sex is for …

Agujeros negros al ritmo de Elvis Presley

Researchers with the world’s gravitational wave detectors said today they had picked up vibrations from a cosmic collision that harmonized with the opening notes of an Elvis Presley hit. The source was the most exotic merger of two black holes detected yet—a pair in which one weighed more than three times as much as the other. Because of the stark mass imbalance, the collision generated gravitational waves at multiple frequencies, in a harmony Elvis fans would recognize. The chord also confirms a prediction of Albert Einstein’s theory of gravity, or general relativity.
Such mismatched mass events could help theorists figure out how pairs of black holes form in the first place. “Anything that seems to be at the edge of our predictions is most interesting,” says Chris Belczynski, a gravitational theorist at the Polish Academy of Sciences, who was not involved in the observation. But the one event is “not quite in the regime where you can tell the different formation [routes] apart.”


Asimetría de neutrinos que explica por qué hay materia en el Universo

Se superpone la voluntad de los neutrinos sobre los antineutrinos.
The T2K team started seeing signs of a discrepancy in the behavior of neutrinos and antineutrinos in 2016. Their new result, following years of additional data collection and improvements to the data-analysis techniques, rises to a statistical level that physicists regard as official evidence of a physical effect. “The significance of [the effect] increases with the collected data, which is what one expects when the result is correct,” said Werner Rodejohann, a neutrino physicist at the Max Planck Institute for Nuclear Physics in Germany who was not involved in the experiment.
The data implies that neutrinos have a higher probability of oscillating than antineutrinos, a distinction expressed by a quantity called the CP-violating phase. If this phase were zero and neutrinos and antineutrinos behaved the same, the experiment would have detected roughly 68 electron neutrinos and 20 electron antineutrinos. Instead, it found…