Have a deep view into what people are curious about.

🔗 Technology

A blast valve is used to protect a shelter, such as a fallout shelter or bunker, from the effects of sudden outside air pressure changes. A nuclear weapon creates a shock wave, which may produce sudden pressure changes of more than an atmosphere (about 1 bar) even several kilometres from the detonation point. After the shock wave passes, a sudden negative pressure follows.

If such pressure waves enter a shelter, they will likely do substantial harm to occupants and equipment. A blast valve is placed in air intake/exhaust pipes, that remains open normally, but automatically closes when strong pressure is applied in either direction. Blast dampers operate in the same fashion and are related or identical to blast valves, the former name however is generally used to describe blast mitigation devices, for more conventional explosive events.

A typical blast valve has entries of 15–30 cm diameter, and a larger centre section. Within the centre section is a disk mounted on an axle, with weak springs that keep it centred, away from both entries. Pressure displaces the disk along the axle, until it plugs one entry or the other. After the blast, the springs return the disk to the centre, re-opening the valve.

Another type of blast valve employs rounded metal tubes held in place by springs. As pressure rises it pushes the tubes against the frame of the valve closing the opening. These valves are typically unidirectional in airflow and are employed in large wall structures where large amounts of airflow is required.

One form of blast valve, popularized by the book Nuclear War Survival Skills and tested by ORNL is worn flat rubber tire treads nailed or bolted to frames strong enough to resist the maximum overpressure, with tested closing times cited as being identical to commercial grade blast valves, however the use of this form of blast valve design must also take the risk of the flammable rubber catching fire into consideration.

🔗 Computing 🔗 Computing/Software 🔗 Computing/Amiga

Amiga Unix (informally known as Amix) is a discontinued full port of AT&T Unix System V Release 4 operating system developed by Commodore-Amiga, Inc. in 1990 for the Amiga computer family as an alternative to AmigaOS, which shipped by default. Bundled with the Amiga 3000UX, Commodore's Unix was one of the first ports of SVR4 to the 68k architecture. The Amiga A3000UX model even got the attention of Sun Microsystems, though ultimately nothing came of it.

Unlike Apple's A/UX, Amiga Unix contained no compatibility layer to allow AmigaOS applications to run under Unix. With few native applications available to take advantage of the Amiga's significant multimedia capabilities, it failed to find a niche in the quite-competitive Unix workstation market of the early 1990s. The A3000UX's price tag of $4,998 (equivalent to $9,382 in 2019) was also not very attractive compared to other Unix workstations at the time, such as the NeXTstation ($5,000 for a base system, with a full API and many times the number of applications available), the SGI Indigo (starting at $8,000), or the Personal DECstation 5000 Model 25 (starting at $5,000). Sun, HP, and IBM had similarly priced systems. The A3000UX's 68030 was noticeably underpowered compared to most of its RISC-based competitors.

Unlike typical commercial Unix distributions of the time, Amiga Unix included the source code to the vendor-specific enhancements and platform-dependent device drivers (essentially any part that wasn't owned by AT&T), allowing interested users to study or enhance those parts of the system. However this source code was subject to the same license terms as the binary part of the system – it was not free software. Amiga Unix also incorporated and depended upon many open source components, such as the GNU C Compiler and X Window System, and included their source code.

Like many other proprietary Unix variants with small market shares, Amiga Unix vanished into the mists of computer history when its vendor, Commodore, went out of business. Today, Unix-like operating systems such as Minix, NetBSD, and Linux are available for the Amiga platform.

🔗 Computing

SQRL (pronounced "squirrel") or Secure, Quick, Reliable Login (formerly Secure QR Login) is a draft open standard for secure website login and authentication. The software typically uses a link of the scheme sqrl:// or optionally a QR code, where a user identifies via a pseudonymous zero-knowledge proof rather than providing a user ID and password. This method is thought to be impervious to a brute force password attack or data breach. It shifts the burden of security away from the party requesting the authentication and closer to the operating system implementation of what is possible on the hardware, as well as to the user. SQRL was proposed by Steve Gibson of Gibson Research Corporation in October 2013 as a way to simplify the process of authentication without the risk of revelation of information about the transaction to a third party.

🔗 Sexology and sexuality 🔗 Japan 🔗 Japan/History 🔗 Japan/Culture 🔗 Japan/Law and government 🔗 Gender Studies 🔗 Sexology and sexuality/Sex work

Prostitution in modern Japan, as defined under Japanese law, is the illegal practice of sexual intercourse with an 'unspecified' (unacquainted) person in exchange for monetary compensation, which was criminalised in 1956 by the introduction of article 3 of the Anti-Prostitution Law (売春防止法, Baishun bōshi hō). However, the definition of prostitution made illegal under this law is strictly limited to sexual intercourse with an 'unspecified person', and does not criminalise the sale of numerous other acts performed by sex workers in exchange for compensation, such as oral sex, anal sex, mammary intercourse, and other non-coital sex acts; the Businesses Affecting Public Morals Regulation Law of 1948 (風俗営業取締法, Fūzoku eigyō torishimari hō), also known as the "Law to Regulate Adult Entertainment Businesses", amended in 1985, 1999 and 2005, regulates these businesses, making only one definition of prostitution in Japan illegal.

Following the criminalisation of payment for sexual intercourse, the sex industry in Japan has developed into a number of varied businesses and offering services not prohibited under Japanese law. These fall into a number of categories known by various euphemistic names, such as soaplands, fashion health shops, and pink salons, with the term "health" commonly being a euphemism for sexual services. These businesses typically operate out of physical premises, either with their own employees or freelancers such as call girls, who may operate via Internet dating sites known as deai sites (Internet dating sites) or via delivery health services.

🔗 Fashion

The Great Male Renunciation (French: Grande Renonciation masculine) is the historical phenomenon at the end of the 18th century in which Western men stopped using bright colours, elaborate shapes and variety in their dress, which were left to women's clothing. Instead men concentrated on minute differences of cut, and the quality of the plain cloth.

Coined by the Anglo-German psychologist John Flügel in 1930, it is considered a major turning point in the history of clothing in which the men relinquished their claim to adornment and beauty. Flugel asserted that men "abandoned their claim to be considered beautiful" and "henceforth aimed at being only useful". The Great Renunciation encouraged the establishment of the suit's monopoly on male dress codes at the beginning of the 19th century.

🔗 Psychology 🔗 Neuroscience 🔗 Physiology 🔗 Physiology/neuro

An amygdala hijack refers to a personal, emotional response that is immediate, overwhelming, and out of measure with the actual stimulus because it has triggered a much more significant emotional threat. The term was coined by Daniel Goleman in his 1996 book Emotional Intelligence: Why It Can Matter More Than IQ.

🔗 Numismatics

The EURion constellation (also known as Omron rings or doughnuts) is a pattern of symbols incorporated into a number of banknote designs worldwide since about 1996. It is added to help imaging software detect the presence of a banknote in a digital image. Such software can then block the user from reproducing banknotes to prevent counterfeiting using colour photocopiers. According to research from 2004, the EURion constellation is used for colour photocopiers but probably not used in computer software. It has been reported that Adobe Photoshop will not allow editing of an image of a banknote, but in some versions this is believed to be due to a different, unknown digital watermark rather than the EURion constellation.

🔗 Fishes 🔗 Psychoactive and Recreational Drugs 🔗 Altered States of Consciousness

Several species of fish are claimed to produce hallucinogenic effects when consumed. For example, Sarpa salpa, a species of sea bream, is commonly claimed to be hallucinogenic. These widely distributed coastal fish are normally found in the Mediterranean and around Spain, and along the west and south coasts of Africa. Occasionally they are found in British waters. They may induce hallucinogenic effects that are purportedly LSD-like if eaten. In 2006, two men who apparently ate the fish experienced hallucinations lasting for several days. The likelihood of hallucinations depends on the season. Sarpa salpa is known as "the fish that makes dreams" in Arabic.

Other species claimed to be capable of producing hallucinations include several species of sea chub from the genus Kyphosus. It is unclear whether the toxins are produced by the fish themselves or by marine algae in their diet. Other hallucinogenic fish are Siganus spinus, called "the fish that inebriates" in Reunion Island, and Mulloidichthys flavolineatus (formerly Mulloidichthys samoensis), called "the chief of ghosts" in Hawaii.

🔗 Novels 🔗 Novels/Science fiction 🔗 Novels/Short story

"The Murderer" (1953) is a short story by Ray Bradbury, published in his collection The Golden Apples of the Sun.

🔗 Time 🔗 Solar System/Mars 🔗 Solar System

Various schemes have been used or proposed for timekeeping on the planet Mars independently of Earth time and calendars.

Mars has an axial tilt and a rotation period similar to those of Earth. Thus, it experiences seasons of spring, summer, autumn and winter much like Earth. Coincidentally, the duration of a Martian day is within a few percent of that of an Earth day, which has led to the use of analogous time units. A Mars year is almost twice as long as Earth's, and its orbital eccentricity is considerably larger, which means that the lengths of various Martian seasons differ considerably, and sundial time can diverge from clock time more than on Earth.