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🔗 Biography

Joybubbles ((1949-05-25)May 25, 1949 – (2007-08-08)August 8, 2007), born Josef Carl Engressia Jr. in Richmond, Virginia, was an early phone phreak. Born blind, he became interested in telephones at age four. He had absolute pitch, and was able to whistle 2600 hertz into a telephone, an operator tone also used by blue box phreaking devices. Joybubbles said that he had an IQ of "172 or something". Joybubbles died at his Minneapolis home on August 8, 2007(2007-08-08) (aged 58). According to his death certificate, he died of natural causes with congestive heart failure as a contributing condition.

🔗 Energy

In utility-scale electricity generation, the duck curve is a graph of power production over the course of a day that shows the timing imbalance between peak demand and renewable energy production. The term was coined in 2012 by the California Independent System Operator.

🔗 Electronic music

I am sitting in a room is a sound art piece composed in 1969 and one of composer Alvin Lucier's best known works.

The piece features Lucier recording himself narrating a text, and then playing the tape recording back into the room, re-recording it. The new recording is then played back and re-recorded, and this process is repeated. Due to the room's particular size and geometry, certain frequencies of the recording are emphasized while others are attenuated. Eventually the words become unintelligible, replaced by the characteristic resonant frequencies of the room itself.

In his book on the origins of minimalism, Edward Strickland wrote that "In its repetition and limited means, I am sitting in a room ranks with the finest achievements of Minimal tape music. Furthermore, in its ambient conversion of speech modules into drone frequencies, it unites the two principal structural components of Minimal music in general."

🔗 Cryptography 🔗 Cryptography/Computer science

The MD6 Message-Digest Algorithm is a cryptographic hash function. It uses a Merkle tree-like structure to allow for immense parallel computation of hashes for very long inputs. Authors claim a performance of 28 cycles per byte for MD6-256 on an Intel Core 2 Duo and provable resistance against differential cryptanalysis. The source code of the reference implementation was released under MIT license.

Speeds in excess of 1 GB/s have been reported to be possible for long messages on 16-core CPU architecture.

In December 2008, Douglas Held of Fortify Software discovered a buffer overflow in the original MD6 hash algorithm's reference implementation. This error was later made public by Ron Rivest on 19 February 2009, with a release of a corrected reference implementation in advance of the Fortify Report.

MD6 was submitted to the NIST SHA-3 competition. However, on July 1, 2009, Rivest posted a comment at NIST that MD6 is not yet ready to be a candidate for SHA-3 because of speed issues, a "gap in the proof that the submitted version of MD6 is resistant to differential attacks", and an inability to supply such a proof for a faster reduced-round version, although Rivest also stated at the MD6 website that it is not withdrawn formally. MD6 did not advance to the second round of the SHA-3 competition. In September 2011, a paper presenting an improved proof that MD6 and faster reduced-round versions are resistant to differential attacks was posted to the MD6 website.

🔗 Africa 🔗 Geology 🔗 Africa/Central African Republic

The Bangui magnetic anomaly is a local variation in the Earth's magnetic field centered at Bangui, the capital of Central African Republic. The magnetic anomaly is roughly elliptical, about 700 km × 1,000 km (430 mi × 620 mi), and covers most of the country, making it one of the "largest and most intense crustal magnetic anomalies on the African continent". The anomaly was discovered in the late 1950s, explored in the 1970s, and named in 1982. Its origin remains unclear.

🔗 Cognitive science

The Sussman anomaly is a problem in artificial intelligence, first described by Gerald Sussman, that illustrates a weakness of noninterleaved planning algorithms, which were prominent in the early 1970s. In the problem, three blocks (labeled A, B, and C) rest on a table. The agent must stack the blocks such that A is atop B, which in turn is atop C. However, it may only move one block at a time. The problem starts with B on the table, C atop A, and A on the table:

However, noninterleaved planners typically separate the goal (stack A atop B atop C) into subgoals, such as:

1. get A atop B
2. get B atop C

Suppose the planner starts by pursuing Goal 1. The straightforward solution is to move C out of the way, then move A atop B. But while this sequence accomplishes Goal 1, the agent cannot now pursue Goal 2 without undoing Goal 1, since both A and B must be moved atop C:

If instead the planner starts with Goal 2, the most efficient solution is to move B. But again, the planner cannot pursue Goal 1 without undoing Goal 2:

The problem was first identified by Sussman as a part of his PhD research. Sussman (and his supervisor, Marvin Minsky) believed that intelligence requires a list of exceptions or tricks, and developed a modular planning system for "debugging" plans. Most modern planning systems can handle this anomaly, but it is still useful for explaining why planning is non-trivial.

🔗 Technology 🔗 Environment 🔗 Science Fiction 🔗 Astronomy 🔗 Transhumanism 🔗 Futures studies 🔗 Energy

The Kardashev scale is a method of measuring a civilization's level of technological advancement based on the amount of energy they are able to use. The measure was proposed by Soviet astronomer Nikolai Kardashev in 1964. The scale has three designated categories:

• A Type I civilization, also called a planetary civilization—can use and store all of the energy available on its planet.
• A Type II civilization, also called a stellar civilization—can use and control energy at the scale of its stellar system.
• A Type III civilization, also called a galactic civilization—can control energy at the scale of its entire host galaxy.

🔗 Internet 🔗 Computing 🔗 Antarctica

.aq is the Internet country code top-level domain (ccTLD) for Antarctica (itself not a country). It is derived from the French Antarctique and is reserved for organizations that work in Antarctica or promote the Antarctic and Southern Ocean regions. It is administered by Peter Mott of Antarctica Network Information Centre Limited from Christchurch, New Zealand.

.aq domain names are available free of charge, and registration is granted for a period of 24 months. As a general rule, registrants are only allocated a single .aq domain name. The registry does not have a website. Registration is only possible by contacting Antarctica Network Information Centre Limited.

🔗 Apple Inc./Macintosh 🔗 Apple Inc. 🔗 Computing 🔗 Computing/Software

OpenDoc is a multi-platform software componentry framework standard created by Apple for compound documents, intended as an alternative to Microsoft's Object Linking and Embedding (OLE). As part of the AIM alliance between Apple, IBM, and Motorola, OpenDoc is one of Apple's earliest experiments with open standards and collaborative development methods with other companies—effectively starting an industry consortium. Active development was discontinued in March 1997.

The core idea of OpenDoc is to create small, reusable components, responsible for a specific task, such as text editing, bitmap editing, or browsing an FTP server. OpenDoc provides a framework in which these components can run together, and a document format for storing the data created by each component. These documents can then be opened on other machines, where the OpenDoc frameworks substitute suitable components for each part, even if they are from different vendors. In this way users can "build up" their documents from parts. Since there is no main application and the only visible interface is the document itself, the system is known as document centered.

At its inception, it was envisioned that OpenDoc would allow smaller, third-party developers to enter the then-competitive office software market, able to build one good editor instead of having to provide a complete suite.