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🔗 Biography 🔗 Aviation 🔗 France 🔗 Biography/science and academia 🔗 Brazil 🔗 Aviation/aerospace biography 🔗 Brazil/Education and Science in Brazil

Alberto Santos-Dumont (Brazilian Portuguese: [awˈbɛɾtu ˈsɐ̃tus duˈmõ]; 20 July 1873 – 23 July 1932) was a Brazilian inventor and aviation pioneer, one of the very few people to have contributed significantly to the development of both lighter-than-air and heavier-than-air aircraft.

The heir of a wealthy family of coffee producers, Santos-Dumont dedicated himself to aeronautical study and experimentation in Paris, where he spent most of his adult life. In his early career he designed, built, and flew hot air balloons and early dirigibles, culminating in his winning the Deutsch de la Meurthe prize on 19 October 1901 for a flight that rounded the Eiffel Tower. He then turned to heavier-than-air machines, and on 23 October 1906 his 14-bis made the first powered heavier-than-air flight in Europe to be certified by the Aéro-Club de France and the Fédération Aéronautique Internationale. His conviction that aviation would usher in an era of worldwide peace and prosperity led him to freely publish his designs and forego patenting his various innovations.

Santos-Dumont is a national hero in Brazil, where it is popularly held that he preceded the Wright brothers in demonstrating a practical airplane. Countless roads, plazas, schools, monuments, and airports there are dedicated to him, and his name is inscribed on the Tancredo Neves Pantheon of the Fatherland and Freedom. He was a member of the Brazilian Academy of Letters from 1931 until his suicide in 1932.

🔗 Biology 🔗 Cognitive science 🔗 Neuroscience

The free energy principle tries to explain how (biological) systems maintain their order (non-equilibrium steady-state) by restricting themselves to a limited number of states. It says that biological systems minimise a free energy function of their internal states, which entail beliefs about hidden states in their environment. The implicit minimisation of variational free energy is formally related to variational Bayesian methods and was originally introduced by Karl Friston as an explanation for embodied perception in neuroscience, where it is also known as active inference.

The free energy principle is that systems—those that are defined by their enclosure in a Markov blanket—try to minimize the difference between their model of the world and their sense and associated perception. This difference can be described as "surprise" and is minimized by continuous correction of the world model of the system. As such, the principle is based on the Bayesian idea of the brain as an “inference engine”. Friston added a second route to minimization: action. By actively changing the world into the expected state, systems can also minimize the free energy of the system. Friston assumes this to be the principle of all biological reaction.. Friston also believes his principle applies to mental disorders as well as to artificial intelligence. AI implementations based on the active inference principle have shown advantages over other methods.

The free energy principle has been criticized for being very difficult to understand, even for experts. Discussions of the principle have also been criticized as invoking metaphysical assumptions far removed from a testable scientific prediction, making the principle unfalsifiable. In a 2018 interview, Friston acknowledged that the free energy principle is not properly falsifiable: "the free energy principle is what it is — a principle. Like Hamilton’s Principle of Stationary Action, it cannot be falsified. It cannot be disproven. In fact, there’s not much you can do with it, unless you ask whether measurable systems conform to the principle."

🔗 Computing 🔗 Robotics

The Viterbi algorithm is a dynamic programming algorithm for obtaining the maximum a posteriori probability estimate of the most likely sequence of hidden states—called the Viterbi path—that results in a sequence of observed events, especially in the context of Markov information sources and hidden Markov models (HMM).

The algorithm has found universal application in decoding the convolutional codes used in both CDMA and GSM digital cellular, dial-up modems, satellite, deep-space communications, and 802.11 wireless LANs. It is now also commonly used in speech recognition, speech synthesis, diarization, keyword spotting, computational linguistics, and bioinformatics. For example, in speech-to-text (speech recognition), the acoustic signal is treated as the observed sequence of events, and a string of text is considered to be the "hidden cause" of the acoustic signal. The Viterbi algorithm finds the most likely string of text given the acoustic signal.

🔗 Computing 🔗 Mathematics 🔗 Crime 🔗 Cryptography 🔗 Cryptography/Computer science

An illegal prime is a prime number that represents information whose possession or distribution is forbidden in some legal jurisdictions. One of the first illegal primes was found in 2001. When interpreted in a particular way, it describes a computer program that bypasses the digital rights management scheme used on DVDs. Distribution of such a program in the United States is illegal under the Digital Millennium Copyright Act. An illegal prime is a kind of illegal number.

🔗 Psychology 🔗 Sociology 🔗 Media

The spiral of silence theory is a political science and mass communication theory proposed by the German political scientist Elisabeth Noelle-Neumann. It states that an individual's perception of the distribution of public opinion influences that individual's willingness to express their own opinions, which in turn affects the perceptions and, ultimately, willingness of others to express their opinions. The main idea is that people influence each other's willingness to express opinions through social interaction. According to the spiral of silence theory, individuals will be more confident and outward with their opinion when they notice that their personal opinion is shared throughout a group. But if the individual notices that their opinion is unpopular with the group they will be more inclined to be reserved and remain silent. In other words, from the individual's perspective, "not isolating himself is more important than his own judgement", meaning his perception of how others in the group perceive him is more important to himself than the need for his opinion to be heard.

According to Glynn (1995), "the major components of the spiral of silence include (1) an issue of public interest; (2) divisiveness on the issue; (3) a quasi-statistical sense that helps an individual perceive the climate of opinion as well as estimate the majority and minority opinion; (4) 'fear of isolation' from social interaction "(though, whether this is a causal factor in the willingness to speak out is contested)"; (5) an individual's belief that a minority (or 'different') opinion isolates oneself from others; and (6) a 'hardcore' group of people whose opinions are unaffected by others' opinions."

🔗 Sociology

Xennials or xennials (also known as the Oregon Trail Generation and Generation Catalano) are the micro-generation of people on the cusp of the Generation X and Millennial demographic cohorts. Researchers and popular media use birth years from the late 1970s to the early 1980s. Xennials are described as having had an analog childhood and a digital young adulthood.

In 2020, xennial was included in the Oxford Dictionary of English.

🔗 Books 🔗 Comics 🔗 Comics/DC Comics

Understanding Comics: The Invisible Art is a 1993 non-fiction work of comics by American cartoonist Scott McCloud. It explores formal aspects of comics, the historical development of the medium, its fundamental vocabulary, and various ways in which these elements have been used. It expounds theoretical ideas about comics as an art form and medium of communication, and is itself written in comic book form.

Understanding Comics received praise from notable comic and graphic novel authors such as Art Spiegelman, Will Eisner, Alan Moore, Neil Gaiman, and Garry Trudeau (who reviewed the book for the New York Times). Although the book has prompted debate over many of McCloud’s conclusions, its discussions of "iconic" art and the concept of "closure" between panels have become common reference points in discussions of the medium.

The title of Understanding Comics is an homage to Marshall McLuhan's seminal 1964 work Understanding Media.

🔗 Medicine 🔗 Ageing and culture

Old person smell is the characteristic odor of elderly humans. Much like many animal species, human odor undergoes distinct stages based on chemical changes initiated through the aging process. Research suggests that this enables humans to determine the suitability of potential partners based on age, in addition to other factors.

One study suggested that old person smell may be the result of 2-nonenal, an unsaturated aldehyde which is associated with human body odor alterations during aging; however, there are other hypotheses. Another study failed to detect 2-nonenal at all, but found significantly increased concentrations of benzothiazole, dimethylsulphone, and nonanal on older subjects.

In 2012 the Monell Chemical Senses Center published a press release claiming that the human ability to identify information such as age, illness, and genetic suitability from odor is responsible for the distinctive "old man smell". Sensory neuroscientist Johan Lundström stated, "Elderly people have a discernible underarm odor that younger people consider to be fairly neutral and not very unpleasant."

Old person smell is known as kareishū (加齢臭) in Japan, where much social value is placed on personal grooming, and specific upmarket odor-eliminating soaps are targeted at more elderly consumers.

🔗 Library of Congress 🔗 Classical music 🔗 Albums

In C is a musical piece composed by Terry Riley in 1964 for an indefinite number of performers. He suggests "a group of about 35 is desired if possible but smaller or larger groups will work". A series of short melodic fragments that can be repeated at the discretion of musicians, In C is often cited as the first minimalist composition to make a significant impact on the public consciousness.

The piece was first performed by Steve Reich, Jon Gibson, Pauline Oliveros, Stuart Dempster, Morton Subotnick and others at the San Francisco Tape Music Center. It received its first recorded release in 1968 on CBS Records. Subsequent performances have been recorded many times since.

In 2022, the 1968 LP recording of In C was selected by the Library of Congress for preservation in the United States National Recording Registry as being "culturally, historically, or aesthetically significant.".