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🔗 Computing 🔗 Computing/Software 🔗 Computing/Amiga 🔗 Project-independent assessment

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 🔗 Computer science

In functional programming, continuation-passing style (CPS) is a style of programming in which control is passed explicitly in the form of a continuation. This is contrasted with direct style, which is the usual style of programming. Gerald Jay Sussman and Guy L. Steele, Jr. coined the phrase in AI Memo 349 (1975), which sets out the first version of the Scheme programming language.John C. Reynolds gives a detailed account of the numerous discoveries of continuations.

A function written in continuation-passing style takes an extra argument: an explicit "continuation"; i.e., a function of one argument. When the CPS function has computed its result value, it "returns" it by calling the continuation function with this value as the argument. That means that when invoking a CPS function, the calling function is required to supply a procedure to be invoked with the subroutine's "return" value. Expressing code in this form makes a number of things explicit which are implicit in direct style. These include: procedure returns, which become apparent as calls to a continuation; intermediate values, which are all given names; order of argument evaluation, which is made explicit; and tail calls, which simply call a procedure with the same continuation, unmodified, that was passed to the caller.

Programs can be automatically transformed from direct style to CPS. Functional and logic compilers often use CPS as an intermediate representation where a compiler for an imperative or procedural programming language would use static single assignment form (SSA). SSA is formally equivalent to a subset of CPS (excluding non-local control flow, which does not occur when CPS is used as intermediate representation). Functional compilers can also use A-normal form (ANF) (but only for languages requiring eager evaluation), rather than with 'thunks' (described in the examples below) in CPS. CPS is used more frequently by compilers than by programmers as a local or global style.

🔗 United States/U.S. Government 🔗 United States 🔗 Cold War 🔗 Conservatism 🔗 United States/U.S. history 🔗 United States/United States Presidents

"We begin bombing in five minutes" is the last sentence of a controversial, off-the-record joke made by U.S. President Ronald Reagan in 1984, during the Cold War.

While preparing for a scheduled radio address from his vacation home in California, President Reagan joked with those present about outlawing and bombing Russia. This joke was not broadcast live, but was recorded and later leaked to the public. The Soviet Union criticized the president's joke, as did Reagan's opponent in the 1984 United States presidential election, Walter Mondale.

🔗 Philosophy 🔗 Cognitive science 🔗 Linguistics 🔗 Linguistics/Applied Linguistics 🔗 Anthropology 🔗 Philosophy/Philosophy of mind 🔗 Neuroscience 🔗 Philosophy/Philosophy of language 🔗 Linguistics/Philosophy of language

The hypothesis of linguistic relativity, part of relativism, also known as the Sapir–Whorf hypothesis , or Whorfianism is a principle claiming that the structure of a language affects its speakers' world view or cognition, and thus people's perceptions are relative to their spoken language.

The principle is often defined in one of two versions: the strong hypothesis, which was held by some of the early linguists before World War II, and the weak hypothesis, mostly held by some of the modern linguists.

• The strong version says that language determines thought and that linguistic categories limit and determine cognitive categories.
• The weak version says that linguistic categories and usage only influence thought and decisions.

The principle had been accepted and then abandoned by linguists during the early 20th century following the changing perceptions of social acceptance for the other especially after World War II. The origin of formulated arguments against the acceptance of linguistic relativity are attributed to Noam Chomsky.

🔗 Cities

The world's most livable cities is an informal name given to any list of cities as they rank on an annual survey of living conditions. In addition to providing clean water, clean air, adequate food and shelter, a ‘livable’ city must also generate a sense of community and offer hospitable settings for all, especially young people, to develop social skills, a sense of autonomy and identity.

Regions with cities commonly ranked in the top 50 include Australia, New Zealand, Canada and Europe. Three examples of such surveys are Monocle's "Most Liveable Cities Index", the Economist Intelligence Unit's "Global Liveability Ranking", and "Mercer Quality of Living Survey". Numbeo has the largest statistics and survey data based on cities and countries. Deutsche Bank's Liveability Survey is another ranking of cities by quality of life.

🔗 Medicine 🔗 Viruses

Variolation or inoculation was the method first used to immunize an individual against smallpox (Variola) with material taken from a patient or a recently variolated individual, in the hope that a mild, but protective, infection would result. The procedure was most commonly carried out by inserting/rubbing powdered smallpox scabs or fluid from pustules into superficial scratches made in the skin. The patient would develop pustules identical to those caused by naturally occurring smallpox, usually producing a less severe disease than naturally acquired smallpox. Eventually, after about two to four weeks, these symptoms would subside, indicating successful recovery and immunity. The method was first used in China and the Middle East before it was introduced into England and North America in the 1720s in the face of some opposition. The method is no longer used today. It was replaced by smallpox vaccine, a safer alternative. This in turn led to the development of the many vaccines now available against other diseases.

🔗 Mathematics

In the computer science subfield of algorithmic information theory, a Chaitin constant (Chaitin omega number) or halting probability is a real number that, informally speaking, represents the probability that a randomly constructed program will halt. These numbers are formed from a construction due to Gregory Chaitin.

Although there are infinitely many halting probabilities, one for each method of encoding programs, it is common to use the letter Ω to refer to them as if there were only one. Because Ω depends on the program encoding used, it is sometimes called Chaitin's construction instead of Chaitin's constant when not referring to any specific encoding.

Each halting probability is a normal and transcendental real number that is not computable, which means that there is no algorithm to compute its digits. Indeed, each halting probability is Martin-Löf random, meaning there is not even any algorithm which can reliably guess its digits.

🔗 Chemical and Bio Engineering

Non-explosive demolition agents are chemicals that are an alternative to explosives and gas pressure blasting products in demolition, mining, and quarrying. To use non-explosive demolition agents in demolition or quarrying, holes are drilled in the base rock as they would be for use with conventional explosives. A slurry mixture of the non-explosive demolition agent and water is poured into the drill holes. Over the next few hours the slurry expands, cracking the rock in a pattern somewhat like the cracking that would occur from conventional explosives.

Non-explosive demolition agents offer many advantages including that they are silent and do not produce vibration the way a conventional explosive would. In some applications conventional explosives are more economical than non-explosive demolition agents. In many countries these are available without restriction, unlike explosives which are highly regulated.

The active ingredient is typically calcium oxide, "burnt lime," and is typically mixed with Portland cement and modifiers.

These agents are much safer than explosives, but they have to be used as directed to avoid steam explosions during the first few hours after being placed.

Many patents describe non-explosive demolition agents containing CaO, SiO₂ and/or cement.

🔗 Disaster management 🔗 Hawaii

On the morning of Saturday, January 13, 2018, a ballistic missile alert was accidentally issued via the Emergency Alert System and Wireless Emergency Alert System over television, radio, and cellphones in the U.S. state of Hawaii. The alert stated that there was an incoming ballistic missile threat to Hawaii, advised residents to seek shelter, and concluded: "This is not a drill". The message was sent at 8:07 a.m. local time. Civil defense outdoor warning sirens were not authorized by the state.

Thirty-eight minutes and 13 seconds later, state officials blamed a miscommunication during a drill at the Hawaii Emergency Management Agency for the first message. Governor David Ige publicly apologized for the erroneous alert. The Federal Communications Commission and the Hawaii House of Representatives launched investigations into the incident, leading to the resignation of the state's emergency management administrator.

🔗 California 🔗 Companies 🔗 Technology 🔗 Private Equity 🔗 California/San Francisco Bay Area

Y Combinator is an American seed accelerator launched in March 2005 and has been used to launch over 2,000 companies including Stripe, Airbnb, Cruise Automation, DoorDash, Coinbase, Instacart, and Dropbox. The combined valuation of the top YC companies was over $155 billion as of October, 2019.