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🔗 Computing

The CDC 6600 was the flagship of the 6000 series of mainframe computer systems manufactured by Control Data Corporation. Generally considered to be the first successful supercomputer, it outperformed the industry's prior recordholder, the IBM 7030 Stretch, by a factor of three. With performance of up to three megaFLOPS, the CDC 6600 was the world's fastest computer from 1964 to 1969, when it relinquished that status to its successor, the CDC 7600.

The first CDC 6600s were delivered in 1965 to Livermore and Los Alamos. They quickly became a must-have system in high-end scientific and mathematical computing, with systems being delivered to Courant Institute of Mathematical Sciences, CERN, the Lawrence Radiation Laboratory, and many others. At least 100 were delivered in total.

A CDC 6600 is on display at the Computer History Museum in Mountain View, California. The only running CDC 6000 series machine has been restored by Living Computers: Museum + Labs.

🔗 Physics 🔗 Physics/History 🔗 Physics/Fluid Dynamics

The pitch drop experiment is a long-term experiment which measures the flow of a piece of pitch over many years. 'Pitch' is the name for any of a number of highly viscous liquids which appear solid; most commonly bitumen. At room temperature, tar pitch flows at a very low rate, taking several years to form a single drop.

🔗 Estonia 🔗 Festivals 🔗 Regional and national music

The Estonian Song Festival (in Estonian: laulupidu, Estonian pronunciation: [ˈlɑu.luˈpi.du]) is one of the largest choral events in the world, a Masterpiece of the Oral and Intangible Heritage of Humanity. It is held every five years in July on the Tallinn Song Festival Grounds (Lauluväljak) simultaneously with the Estonian Dance Festival. The joint choir has comprised more than 30,000 singers performing to an audience of 80,000.

Almost every Festival features famous Estonian songs "Ta lendab mesipuu poole", the unofficial national anthem "Mu isamaa on minu arm" and the national anthem "Mu isamaa, mu õnn ja rõõm".

🔗 Physics 🔗 Systems 🔗 Systems/Dynamical systems

In mathematics and physics, the Poincaré recurrence theorem states that certain dynamical systems will, after a sufficiently long but finite time, return to a state arbitrarily close to (for continuous state systems), or exactly the same as (for discrete state systems), their initial state.

The Poincaré recurrence time is the length of time elapsed until the recurrence. This time may vary greatly depending on the exact initial state and required degree of closeness. The result applies to isolated mechanical systems subject to some constraints, e.g., all particles must be bound to a finite volume. The theorem is commonly discussed in the context of ergodic theory, dynamical systems and statistical mechanics. Systems to which the Poincaré recurrence theorem applies are called conservative systems.

The theorem is named after Henri Poincaré, who discussed it in 1890 and proved by Constantin Carathéodory using measure theory in 1919.

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Architecture 🔗 England 🔗 Military history/Fortifications 🔗 Military history/Napoleonic era 🔗 Ireland 🔗 Kent 🔗 Military history/European military history 🔗 Military history/British military history 🔗 Irish Maritime

Martello towers, sometimes known simply as Martellos, are small defensive forts that were built across the British Empire during the 19th century, from the time of the French Revolutionary Wars onwards. Most were coastal forts.

They stand up to 40 feet (12 m) high (with two floors) and typically had a garrison of one officer and 15–25 men. Their round structure and thick walls of solid masonry made them resistant to cannon fire, while their height made them an ideal platform for a single heavy artillery piece, mounted on the flat roof and able to traverse, and hence fire, over a complete 360° circle. A few towers had moats or other batteries and works attached for extra defence.

The Martello towers were used during the first half of the 19th century, but became obsolete with the introduction of powerful rifled artillery. Many have survived to the present day, often preserved as historic monuments.

🔗 Death 🔗 Law 🔗 Lists 🔗 Crime and Criminal Biography

A botched execution is defined by political science professor Austin Sarat as:

Botched executions occur when there is a breakdown in, or departure from, the 'protocol' for a particular method of execution. The protocol can be established by the norms, expectations, and advertised virtues of each method or by the government’s officially adopted execution guidelines. Botched executions are 'those involving unanticipated problems or delays that caused, at least arguably, unnecessary agony for the prisoner or that reflect gross incompetence of the executioner.' Examples of such problems include, among other things, inmates catching fire while being electrocuted, being strangled during hangings (instead of having their necks broken), and being administered the wrong dosages of specific drugs for lethal injections.

🔗 Computing 🔗 Business 🔗 Computing/Software 🔗 Business/Accounting

Lotus 1-2-3 is a discontinued spreadsheet program from Lotus Software (later part of IBM). It was the first killer application of the IBM PC, was hugely popular in the 1980s, and significantly contributed to the success of IBM PC-compatibles in the business market.

The first spreadsheet, VisiCalc, had helped launch the Apple II as one of the earliest personal computers in business use. With IBM's entry into the market, VisiCalc was slow to respond, and when they did, they launched what was essentially a straight port of their existing system despite the greatly expanded hardware capabilities. Lotus's solution was marketed as a three-in-one integrated solution: it handled spreadsheet calculations, database functionality, and graphical charts, hence the name "1-2-3", though how much database capability the product actually had was debatable, given the sparse memory left over after launching 1-2-3. It quickly overtook VisiCalc, as well as Multiplan and SuperCalc, the two VisiCalc competitors.

Lotus 1-2-3 was the state-of-the-art spreadsheet and the standard throughout the 1980s and into the early 1990s, part of an unofficial set of three stand-alone office automation products that included dBase and WordPerfect, to build a complete business platform. Lotus Software had their own word processor named Lotus Manuscript, which was to some extent acclaimed in academia, but did not catch the interest of the business, nor the consumer market. With the acceptance of Windows 3.0 in 1990, the market for desktop software grew even more. None of the major spreadsheet developers had seriously considered the graphical user interface (GUI) to supplement their DOS offerings, and so they responded slowly to Microsoft's own GUI-based products Excel and Word. Lotus was surpassed by Microsoft in the early 1990s, and never recovered. IBM purchased Lotus in 1995, and continued to sell Lotus offerings, only officially ending sales in 2013.

🔗 Philosophy 🔗 Skepticism 🔗 Philosophy/Philosophy of religion 🔗 Alternative Views 🔗 Philosophy/Metaphysics

The Omega Point is a theorized future event in which the entirety of the universe spirals toward a final point of unification. The term was invented by the French Jesuit Catholic priest Pierre Teilhard de Chardin (1881–1955). Teilhard argued that the Omega Point resembles the Christian Logos, namely Christ, who draws all things into himself, who in the words of the Nicene Creed, is "God from God", "Light from Light", "True God from True God", and "through him all things were made". In the Book of Revelation, Christ describes himself thrice as "the Alpha and the Omega, the beginning and the end". Several decades after Teilhard's death, the idea of the Omega Point was expanded upon in the writings of John David Garcia (1971), Paolo Soleri (1981), Frank Tipler (1994), and David Deutsch (1997).

🔗 Computing 🔗 Software 🔗 Software/Computing

"Everything is a file" is an idea that Unix, and its derivatives, handle input/output to and from resources such as documents, hard-drives, modems, keyboards, printers and even some inter-process and network communications as simple streams of bytes exposed through the filesystem name space. Exceptions include semaphores, processes and threads.

The advantage of this approach is that the same set of tools, utilities and APIs can be used on a wide range of resources and a number of file types. When a file is opened, a file descriptor is created, using the file path as an addressing system. The file descriptor is then a byte stream I/O interface on which file operations are performed. File descriptors are also created for objects such as anonymous pipes and network sockets - and therefore a more accurate description of this feature is Everything is a file descriptor.

Additionally, a range of pseudo and virtual filesystems exists which exposes internal kernel data, such as information about processes, to user space in a hierarchical file-like structure. These are mounted into the single file hierarchy.

An example of this purely virtual filesystem is under /proc that exposes many system properties as files. All of these files, in the broader sense of the word, have standard Unix file attributes such as an owner and access permissions, and can be queried by the same classic Unix tools and filters. However, this is not universally considered a fast or portable approach. Some operating systems do not mount /proc by default due to security or speed concerns, relying on system calls instead. It is, though, used heavily by Linux shell utilities, such as procps ps implementation and the widely installed on embedded systems BusyBox. Android Toolbox program depend on it as well.

🔗 Mathematics 🔗 Game theory

Fair cake-cutting is a kind of fair division problem. The problem involves a heterogeneous resource, such as a cake with different toppings, that is assumed to be divisible – it is possible to cut arbitrarily small pieces of it without destroying their value. The resource has to be divided among several partners who have different preferences over different parts of the cake, i.e., some people prefer the chocolate toppings, some prefer the cherries, some just want as large a piece as possible. The division should be unanimously fair – each person should receive a piece believed to be a fair share.

The "cake" is only a metaphor; procedures for fair cake-cutting can be used to divide various kinds of resources, such as land estates, advertisement space or broadcast time.

The prototypical procedure for fair cake-cutting is divide and choose, which is mentioned in the book of Genesis. It solves the fair division problem for two people. The modern study of fair cake-cutting was initiated during World War II, when Hugo Steinhaus asked his students Stefan Banach and Bronisław Knaster to find a generalization of divide-and-choose to three or more people. They developed the last diminisher procedure. Today, fair cake-cutting is the subject of intense research in mathematics, computer science, economics and political science.