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🔗 Biography 🔗 Apple Inc.

Jordan K. Hubbard (born April 8, 1963) is an open source software developer, authoring software such as the Ardent Window Manager and various other open source tools and libraries before co-founding the FreeBSD project with Nate Williams and Rodney W. Grimes in 1993, for which he contributed the initial FreeBSD Ports collection, package management system and sysinstall. In July 2001 Hubbard joined Apple Computer in the role of manager of the BSD technology group. In 2005, his title was "Director of UNIX Technology" and in October 2007, Hubbard was promoted to "Director of Engineering of Unix Technologies" at Apple where he remained until June 2013.

On July 15, 2013, he became CTO of iXsystems where he also led the FreeNAS open source project.

On March 24, 2017, he announced his plan to depart from iXsystems and that he would be joining TwoPoreGuys, a Biotechnology company, as VP of Engineering. From January 2019 - April 2020 he was part of the Engineering Leadership team at Uber and, as of April 2020, is currently Sr. Director for GPU Compute SW at NVidia [1].

🔗 Mathematics

A Penrose tiling is an example of an aperiodic tiling. Here, a tiling is a covering of the plane by non-overlapping polygons or other shapes, and aperiodic means that shifting any tiling with these shapes by any finite distance, without rotation, cannot produce the same tiling. However, despite their lack of translational symmetry, Penrose tilings may have both reflection symmetry and fivefold rotational symmetry. Penrose tilings are named after mathematician and physicist Roger Penrose, who investigated them in the 1970s.

There are several different variations of Penrose tilings with different tile shapes. The original form of Penrose tiling used tiles of four different shapes, but this was later reduced to only two shapes: either two different rhombi, or two different quadrilaterals called kites and darts. The Penrose tilings are obtained by constraining the ways in which these shapes are allowed to fit together. This may be done in several different ways, including matching rules, substitution tiling or finite subdivision rules, cut and project schemes, and coverings. Even constrained in this manner, each variation yields infinitely many different Penrose tilings.

Penrose tilings are self-similar: they may be converted to equivalent Penrose tilings with different sizes of tiles, using processes called inflation and deflation. The pattern represented by every finite patch of tiles in a Penrose tiling occurs infinitely many times throughout the tiling. They are quasicrystals: implemented as a physical structure a Penrose tiling will produce diffraction patterns with Bragg peaks and five-fold symmetry, revealing the repeated patterns and fixed orientations of its tiles. The study of these tilings has been important in the understanding of physical materials that also form quasicrystals. Penrose tilings have also been applied in architecture and decoration, as in the floor tiling shown.

🔗 Mathematics 🔗 Physics

Earnshaw's theorem states that a collection of point charges cannot be maintained in a stable stationary equilibrium configuration solely by the electrostatic interaction of the charges. This was first proven by British mathematician Samuel Earnshaw in 1842. It is usually referenced to magnetic fields, but was first applied to electrostatic fields.

Earnshaw's theorem applies to classical inverse-square law forces (electric and gravitational) and also to the magnetic forces of permanent magnets, if the magnets are hard (the magnets do not vary in strength with external fields). Earnshaw's theorem forbids magnetic levitation in many common situations.

If the materials are not hard, Braunbeck's extension shows that materials with relative magnetic permeability greater than one (paramagnetism) are further destabilising, but materials with a permeability less than one (diamagnetic materials) permit stable configurations.

🔗 Aviation 🔗 Disaster management 🔗 Aviation/Aviation accident 🔗 England

British Airways Flight 5390 was a flight from Birmingham Airport in England for Málaga Airport in Spain that suffered explosive decompression, with no loss of life, shortly after takeoff on 10 June 1990. An improperly installed windscreen panel separated from its frame, causing the plane's captain to be blown partially out of the aircraft. With the captain pinned against the window frame for twenty minutes, the first officer landed at Southampton Airport.

🔗 Italy 🔗 Food and drink

Radiatori are small, squat pasta shapes that are said to resemble radiators. Although it is rumored that they were created in the 1960s by an industrial designer, their invention was actually between the First and Second World War. They are often used in similar dishes as rotelle or fusilli, because their shape works well with thicker sauces. They are also used in casseroles, salads, and soups. The form is sometimes called pagoda pasta..

🔗 Anthroponymy

A naming law restricts the names that parents can legally give to their children, usually to protect the child from being given an offensive or embarrassing name. Many countries around the world have such laws, with most governing the meaning of the name, while some only govern the scripts in which it is written.

🔗 Aviation 🔗 Military history 🔗 Military history/Military aviation 🔗 Aviation/aircraft 🔗 Military history/Maritime warfare 🔗 Military history/Russian, Soviet and CIS military history 🔗 Aviation/Soviet aviation

The Lun-class ekranoplan is a ground effect vehicle (GEV) designed by Rostislav Evgenievich Alexeyev in 1975 and used by the Soviet and Russian navies from 1987 until sometime in the late 1990s.

It flew using the lift generated by the ground effect of its large wings when within about four metres (13 ft) above the surface of the water. Although they might look similar to regular aircraft, and have related technical characteristics, ekranoplans like the Lun are not aircraft, seaplanes, hovercraft, nor hydrofoils. Rather, "ground effect" is a distinct technology. The International Maritime Organization classifies these vehicles as maritime ships.

The name Lun comes from the Russian word for harrier.

🔗 Business

Management f-Laws are subversive epigrams about common management practices. Based on observation and experience, they are used to draw attention to entrenched ways of thinking about management and business that are often at odds with common sense or our actual experience.

Systems theorist Russell L. Ackoff, his co-author Herbert J. Addison and Sally Bibb invented the term in 2006 to describe their series of over 100 distilled observations of bad leadership and the misplaced wisdom that often surrounds management in organizations. Ackoff and Addison's f-Laws might seem counter-intuitive. They are designed to challenge organizations' unquestioning adherence to established management habits or beliefs. Many of the f-Laws describe a relationship of inverse proportionality, in example: "The lower the rank of managers, the more they know about fewer things."

The f-Laws advocate adopting a positive, forward-looking and interactive approach to structural or systematic change within organizations, following the principles of idealized design. This is a process that "involves redesigning the organization on the assumption that it was destroyed last night... The most effective way of creating the future is by closing or reducing the gap between the current state and the idealized design".

Three collections of f-Laws entitled A Little Book of f-Laws: 13 Common Sins of Management, Management f-Laws: How Organizations Really Work and Systems Thinking for Curious Managers have been published. While, if read in isolation, each f-Law is a witty and thought-provoking axiom, the books provide a context that draws upon systems thinking and the debate over the importance of developing soft skills in business environments.

🔗 France 🔗 Transport

The carrosses à cinq sols (English: five-sol coaches) were the first modern form of public transport in the world, developed by mathematician and philosopher Blaise Pascal.

🔗 Physics 🔗 Energy

Thorium-based nuclear power generation is fueled primarily by the nuclear fission of the isotope uranium-233 produced from the fertile element thorium. According to proponents, a thorium fuel cycle offers several potential advantages over a uranium fuel cycle—including much greater abundance of thorium found on Earth, superior physical and nuclear fuel properties, and reduced nuclear waste production. However, development of thorium power has significant start-up costs. Proponents also cite the low weaponization potential as an advantage of thorium due to how difficult it is to weaponize the specific uranium-233/232 and plutonium-238 isotopes produced by thorium reactors, while critics say that development of breeder reactors in general (including thorium reactors, which are breeders by nature) increases proliferation concerns. As of 2020, there are no operational thorium reactors in the world.

A nuclear reactor consumes certain specific fissile isotopes to produce energy. Currently, the most common types of nuclear reactor fuel are:

• Uranium-235, purified (i.e. "enriched") by reducing the amount of uranium-238 in natural mined uranium. Most nuclear power has been generated using low-enriched uranium (LEU), whereas high-enriched uranium (HEU) is necessary for weapons.
• Plutonium-239, transmuted from uranium-238 obtained from natural mined uranium.

Some believe thorium is key to developing a new generation of cleaner, safer nuclear power. According to a 2011 opinion piece by a group of scientists at the Georgia Institute of Technology, considering its overall potential, thorium-based power "can mean a 1000+ year solution or a quality low-carbon bridge to truly sustainable energy sources solving a huge portion of mankind’s negative environmental impact."

After studying the feasibility of using thorium, nuclear scientists Ralph W. Moir and Edward Teller suggested that thorium nuclear research should be restarted after a three-decade shutdown and that a small prototype plant should be built.