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🔗 Literature

Some writers have had prolific careers with hundreds of their works being published. While some best-selling authors have written a small number of books that have sold millions of copies, others have had lengthy careers and maintained a high level of output year after year. Dame Agatha Christie, the most-published novelist in history, is estimated to have sold 4 billion books, having written 69 novels and 19 plays. Her works were published between 1920 and 1976, equating to around three publications every two years. Dame Barbara Cartland has also sold millions of copies of her books but wrote many more than Christie. She spent 80 years as a novelist with 722 books published, averaging one book released every 40 days of her career. While Cartland wrote a significant number of full-length novels, other authors have been published many more times but have specialised in short stories. Spanish author Corín Tellado wrote over 4,000 novellas, selling 400 million copies of her books.

Not all authors work alone. Groups of writers, sometimes led by one central figure, have published under shared pseudonyms. The Stratemeyer Syndicate, started by Edward Stratemeyer in 1905, created numerous book series including 190 volumes of The Hardy Boys and 175 volumes of Nancy Drew. More than 1,300 books were published by the group, and although Edward L. Stratemeyer wrote several hundred, he also employed ghostwriters to keep up with the demand. These writers were given storylines and strict guidelines to follow to ensure a level of consistency within each series. Amongst the writing team was Howard R. Garis, who contributed several hundred books to the collection, one of the most active authors. Sales were estimated at over two hundred million copies before the syndicate was sold to Simon & Schuster in 1984.

Most authors carefully craft their work, writing and rewriting several times before publication. Some authors simply use pen and paper, while others such as Isaac Asimov spent hours at a stretch working at a typewriter. Philip M. Parker, by one measure the world's most prolific author, has an entirely different approach. Parker has over 200,000 titles listed on Amazon.com, having developed an algorithm to gather publicly available data and compile it into book form. The computer-generated nature of the books is not detailed on the sales page and the books are printed only when ordered.

🔗 United States 🔗 Spaceflight

The 100 Year Starship (100YSS) is a joint U.S. Defense Advanced Research Projects Agency (DARPA) and National Aeronautics and Space Administration (NASA) grant project to a private entity. The goal of the study is to create a business plan that can foster the research and technology needed for interstellar travel within 100 years.

🔗 Mathematics

In geometric topology, the Clifford torus is the simplest and most symmetric flat embedding of the cartesian product of two circles S¹_a and S¹_b (in the same sense that the surface of a cylinder is "flat"). It is named after William Kingdon Clifford. It resides in R⁴, as opposed to in R³. To see why R⁴ is necessary, note that if S¹_a and S¹_b each exist in their own independent embedding spaces R²_a and R²_b, the resulting product space will be R⁴ rather than R³. The historically popular view that the cartesian product of two circles is an R³ torus in contrast requires the highly asymmetric application of a rotation operator to the second circle, since that circle will only have one independent axis z available to it after the first circle consumes x and y.

Stated another way, a torus embedded in R³ is an asymmetric reduced-dimension projection of the maximally symmetric Clifford torus embedded in R⁴. The relationship is similar to that of projecting the edges of a cube onto a sheet of paper. Such a projection creates a lower-dimensional image that accurately captures the connectivity of the cube edges, but also requires the arbitrary selection and removal of one of the three fully symmetric and interchangeable axes of the cube.

If S¹_a and S¹_b each has a radius of ${\displaystyle \textstyle {\sqrt {1/2}}}$, their Clifford torus product will fit perfectly within the unit 3-sphere S³, which is a 3-dimensional submanifold of R⁴. When mathematically convenient, the Clifford torus can be viewed as residing inside the complex coordinate space C², since C² is topologically equivalent to R⁴.

The Clifford torus is an example of a square torus, because it is isometric to a square with opposite sides identified. It is further known as a Euclidean 2-torus (the "2" is its topological dimension); figures drawn on it obey Euclidean geometry as if it were flat, whereas the surface of a common "doughnut"-shaped torus is positively curved on the outer rim and negatively curved on the inner. Although having a different geometry than the standard embedding of a torus in three-dimensional Euclidean space, the square torus can also be embedded into three-dimensional space, by the Nash embedding theorem; one possible embedding modifies the standard torus by a fractal set of ripples running in two perpendicular directions along the surface.

🔗 Medicine 🔗 Food and drink 🔗 Sweden 🔗 Food and drink/Beverages

Gustav III of Sweden's coffee experiment was a twin study ordered by the king to study the health effects of coffee. Although the authenticity of the event has been questioned, the experiment, which was conducted in the second half of the 18th century, failed to prove that coffee was a dangerous beverage.

🔗 Computing 🔗 Computing/Computer hardware 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Computer Security 🔗 Computer Security/Computing 🔗 Computing/Software 🔗 Military history/Intelligence 🔗 Computing/Computer Security 🔗 Computing/Networking

NOBUS ("nobody but us") are security vulnerabilities which the United States National Security Agency (NSA) believes that only it can exploit. As such, NSA sometimes chooses to leave such vulnerabilities open if NSA finds them, in order to exploit them against NSA's targets. More broadly, it refers to the notion that some signals intelligence capabilities are so powerful or otherwise inaccessible that only the NSA will be able to deploy them, though recent analyses suggest that this advantage may be under stress.

🔗 Computing

A stack-oriented programming language is one that relies on a stack machine model for passing parameters. Several programming languages fit this description, notably Forth, RPL, PostScript, BibTeX style design language and many assembly languages (on a much lower level).

Stack-oriented languages operate on one or more stacks, each of which may serve a different purpose. Thus, programming constructs in other programming languages may need to be modified for use in a stack-oriented system. Further, some stack-oriented languages operate in postfix or Reverse Polish notation, that is, any arguments or parameters for a command are stated before that command. For example, postfix notation would be written 2, 3, multiply instead of multiply, 2, 3 (prefix or Polish notation), or 2 multiply 3 (infix notation).

🔗 Ships

Storm oil is the deliberate use of oil to calm an area of water. It has been claimed that it has been used to calm seas to facilitate rescues. Oil was usually carried in a bag which would be released onto the water or in a container which would slowly deploy the oil.

🔗 Psychology

An autostereogram is a single-image stereogram (SIS), designed to create the visual illusion of a three-dimensional (3D) scene from a two-dimensional image. In order to perceive 3D shapes in these autostereograms, one must overcome the normally automatic coordination between accommodation (focus) and horizontal vergence (angle of one's eyes). The illusion is one of depth perception and involves stereopsis: depth perception arising from the different perspective each eye has of a three-dimensional scene, called binocular parallax.

The simplest type of autostereogram consists of horizontally repeating patterns (often separate images) and is known as a wallpaper autostereogram. When viewed with proper convergence, the repeating patterns appear to float above or below the background. The well-known Magic Eye books feature another type of autostereogram called a random dot autostereogram. One such autostereogram is illustrated above right. In this type of autostereogram, every pixel in the image is computed from a pattern strip and a depth map. A hidden 3D scene emerges when the image is viewed with the correct convergence.

Autostereograms are similar to normal stereograms except they are viewed without a stereoscope. A stereoscope presents 2D images of the same object from slightly different angles to the left eye and the right eye, allowing us to reconstruct the original object via binocular disparity. When viewed with the proper vergence, an autostereogram does the same, the binocular disparity existing in adjacent parts of the repeating 2D patterns.

There are two ways an autostereogram can be viewed: wall-eyed and cross-eyed. Most autostereograms (including those in this article) are designed to be viewed in only one way, which is usually wall-eyed. Wall-eyed viewing requires that the two eyes adopt a relatively parallel angle, while cross-eyed viewing requires a relatively convergent angle. An image designed for wall-eyed viewing if viewed correctly will appear to pop out of the background, while if viewed cross-eyed it will instead appear as a cut-out behind the background and may be difficult to bring entirely into focus.

🔗 Technology

Deep borehole disposal (DBD) is the concept of disposing high-level radioactive waste from nuclear reactors in extremely deep boreholes instead of in more traditional deep geological repositories that are excavated like mines. Deep borehole disposal seeks to place the waste as much as five kilometres (3.1 mi) beneath the surface of the Earth and relies primarily on the thickness of the natural geological barrier to safely isolate the waste from the biosphere for a very long period of time so that it should not pose a threat to humans and the environment. The concept was originally developed in the 1970s, but in 2014 a proposal for a first experimental borehole was proposed by a consortium headed by Sandia National Laboratories.

The waste would be put into the lower mile of such a hole, within crystalline rock to isolate it from the environment. The upper two miles of the borehole would be filled with protective layers including asphalt, bentonite, concrete and crushed rock that are expected to protect the environment during geologic time, and the hole would be lined with steel casing.

A pair of proposed test boreholes in the United States were cancelled due to public opposition and lack of funding in 2016 and 2017.

🔗 Microbiology

Archaeal Richmond Mine acidophilic nanoorganisms (ARMAN) were first discovered in an extremely acidic mine located in northern California (Richmond Mine at Iron Mountain) by Brett Baker in Jill Banfield's laboratory at the University of California Berkeley. These novel groups of archaea named ARMAN-1, ARMAN-2 (Candidatus Micrarchaeum acidiphilum ARMAN-2 ), and ARMAN-3 were missed by previous PCR-based surveys of the mine community because the ARMANs have several mismatches with commonly used PCR primers for 16S rRNA genes. Baker et al. detected them in a later study using shotgun sequencing of the community. The three groups were originally thought to represent three unique lineages deeply branched within the Euryarchaeota, a subgroup of the Archaea. However, this has been revised, based on more complete archaeal genomic tree, that they belong to a super phylum named DPANN. The ARMAN groups now comprise deeply divergent phyla named Micrarchaeota and Parvarchaeota. Their 16S rRNA genes differ by as much as 17% between the three groups. Prior to their discovery all of the Archaea shown to be associated with Iron Mountain belonged to the order Thermoplasmatales (e.g., Ferroplasma acidarmanus).