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π Last and First Men
Last and First Men: A Story of the Near and Far Future is a "future history" science fiction novel written in 1930 by the British author Olaf Stapledon. A work of unprecedented scale in the genre, it describes the history of humanity from the present onwards across two billion years and eighteen distinct human species, of which our own is the first. The book employs a narrative conceit that, under subtle inspiration, the novelist has unknowingly been dictated a channelled text from the last human species.
Stapledon's conception of history is based on the Hegelian Dialectic, following a repetitive cycle with many varied civilisations rising from and descending back into savagery over millions of years, but it is also one of progress, as the later civilisations rise to far greater heights than the first. The book anticipates the science of genetic engineering, and is an early example of the fictional supermind; a consciousness composed of many telepathically linked individuals.
In 1932, Stapledon followed Last and First Men with the far less acclaimed Last Men in London. Another Stapledon novel, Star Maker (1937), could also be considered a sequel to Last and First Men (mentioning briefly man's evolution on Neptune), but is even more ambitious in scope, being a history of the entire universe.
It is the 11th title in the SF Masterworks series.
Discussed on
- "Last and First Men" | 2020-02-22 | 92 Upvotes 26 Comments
π Joybubbles
Joybubbles ((1949-05-25)May 25, 1949 β (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) (agedΒ 58). According to his death certificate, he died of natural causes with congestive heart failure as a contributing condition.
Discussed on
- "Joybubbles" | 2021-10-17 | 84 Upvotes 6 Comments
π Digital sundial
A digital sundial is a clock that indicates the current time with numerals formed by the sunlight striking it. Like a classical sundial, the device contains no moving parts. It uses no electricity nor other manufactured sources of energy. The digital display changes as the sun advances in its daily course.
Discussed on
- "Digital sundial" | 2014-07-16 | 232 Upvotes 47 Comments
π Battle of Athens (1946)
The Battle of Athens (sometimes called the McMinn County War) was a rebellion led by citizens in Athens and Etowah, Tennessee, United States, against the local government in August 1946. The citizens, including some World WarΒ II veterans, accused the local officials of predatory policing, police brutality, political corruption, and voter intimidation.
π KlΓ‘ra DΓ‘n Von Neumann
KlΓ‘ra DΓ‘n von Neumann (born KlΓ‘ra DΓ‘n; 18 August 1911 β 10 November 1963) was a Hungarian-American mathematician, self-taught engineer and computer scientist, noted as one of the first computer programmers. She was the first woman to execute modern-style code on a computer. KlΓ‘ra made significant contributions to the world of programming, including work on the Monte Carlo method, ENIAC, and MANIAC I.
Discussed on
- "KlΓ‘ra DΓ‘n Von Neumann" | 2024-06-28 | 168 Upvotes 52 Comments
π Whirlwind I
Whirlwind I was a Cold War-era vacuum tube computer developed by the MIT Servomechanisms Laboratory for the U.S. Navy. Operational in 1951, it was among the first digital electronic computers that operated in real-time for output, and the first that was not simply an electronic replacement of older mechanical systems.
It was one of the first computers to calculate in bit-parallel (rather than bit-serial), and was the first to use magnetic-core memory.
Its development led directly to the Whirlwind II design used as the basis for the United States Air Force SAGE air defense system, and indirectly to almost all business computers and minicomputers in the 1960s, particularly because of the mantra "short word length, speed, people."
Discussed on
- "Whirlwind I" | 2023-10-25 | 18 Upvotes 3 Comments
π Brownian Ratchet
In the philosophy of thermal and statistical physics, the Brownian ratchet or FeynmanβSmoluchowski ratchet is an apparent perpetual motion machine of the second kind, first analysed in 1912 as a thought experiment by Polish physicist Marian Smoluchowski. It was popularised by American Nobel laureate physicist Richard Feynman in a physics lecture at the California Institute of Technology on May 11, 1962, during his Messenger Lectures series The Character of Physical Law in Cornell University in 1964 and in his text The Feynman Lectures on Physics as an illustration of the laws of thermodynamics. The simple machine, consisting of a tiny paddle wheel and a ratchet, appears to be an example of a Maxwell's demon, able to extract mechanical work from random fluctuations (heat) in a system at thermal equilibrium, in violation of the second law of thermodynamics. Detailed analysis by Feynman and others showed why it cannot actually do this.
Discussed on
- "Brownian Ratchet" | 2021-08-16 | 13 Upvotes 2 Comments
π Silphium: Did Greek science die out because their elite discovered The Pill?
Silphium (also known as silphion, laserwort, or laser) was a plant that was used in classical antiquity as a seasoning, perfume, as an aphrodisiac, or as a medicine. It also was used as a contraceptive by ancient Greeks and Romans. It was the essential item of trade from the ancient North African city of Cyrene, and was so critical to the Cyrenian economy that most of their coins bore a picture of the plant. The valuable product was the plant's resin (laser, laserpicium, or lasarpicium).
Silphium was an important species in prehistory, as evidenced by the Egyptians and Knossos Minoans developing a specific glyph to represent the silphium plant. It was used widely by most ancient Mediterranean cultures; the Romans who mentioned the plant in poems or songs, considered it "worth its weight in denarii" (silver coins), or even gold. Legend said that it was a gift from the god Apollo.
The exact identity of silphium is unclear. It is commonly believed to be a now-extinct plant of the genus Ferula, perhaps a variety of "giant fennel". The still-extant plants Margotia gummifera and Ferula tingitana have been suggested as other possibilities. Another plant, asafoetida, was used as a cheaper substitute for silphium, and had similar enough qualities that Romans, including the geographer Strabo, used the same word to describe both.
Discussed on
- "Silphium" | 2021-04-08 | 158 Upvotes 46 Comments
- "Silphium: Did Greek science die out because their elite discovered The Pill?" | 2007-08-15 | 10 Upvotes 1 Comments
π Bell Labs Holmdel Complex
The Bell Labs Holmdel Complex, in Holmdel Township, Monmouth County, New Jersey, United States, functioned for 44 years as a research and development facility, initially for the Bell System and later Bell Labs. The centerpiece of the campus is an Eero Saarinenβdesigned structure that served as the home to over 6,000 engineers and researchers. This modernist building, dubbed "The Biggest Mirror Ever" by Architectural Forum due to its mirror box exterior, was the site of a Nobel Prize discovery, the laser cooling work of Steven Chu.
Restructuring of the company's research efforts reduced the use of the Holmdel Complex, and in 2006 the building was put up for sale. The building has undergone renovations into a multi-purpose living and working space, dubbed Bell Works by its redevelopers. Since 2013 it has been operated by Somerset Development, who redeveloped the building into a mixed-use office for high-tech startup companies. The complex was listed on the National Register of Historic Places in 2017. A number of movies, television programs, and commercials have been filmed at Bell Works, including Severance, The Crowded Room, and Law & Order: Organized Crime.
Discussed on
- "Bell Labs Holmdel Complex" | 2025-03-31 | 30 Upvotes 7 Comments
π TLA+
TLA+ is a formal specification language developed by Leslie Lamport. It is used to design, model, document, and verify programs, especially concurrent systems and distributed systems. TLA+ has been described as exhaustively-testable pseudocode, and its use likened to drawing blueprints for software systems; TLA is an acronym for Temporal Logic of Actions.
For design and documentation, TLA+ fulfills the same purpose as informal technical specifications. However, TLA+ specifications are written in a formal language of logic and mathematics, and the precision of specifications written in this language is intended to uncover design flaws before system implementation is underway.
Since TLA+ specifications are written in a formal language, they are amenable to finite model checking. The model checker finds all possible system behaviours up to some number of execution steps, and examines them for violations of desired invariance properties such as safety and liveness. TLA+ specifications use basic set theory to define safety (bad things won't happen) and temporal logic to define liveness (good things eventually happen).
TLA+ is also used to write machine-checked proofs of correctness both for algorithms and mathematical theorems. The proofs are written in a declarative, hierarchical style independent of any single theorem prover backend. Both formal and informal structured mathematical proofs can be written in TLA+; the language is similar to LaTeX, and tools exist to translate TLA+ specifications to LaTeX documents.
TLA+ was introduced in 1999, following several decades of research into a verification method for concurrent systems. A toolchain has since developed, including an IDE and distributed model checker. The pseudocode-like language PlusCal was created in 2009; it transpiles to TLA+ and is useful for specifying sequential algorithms. TLA+2 was announced in 2014, expanding language support for proof constructs. The current TLA+ reference is The TLA+ Hyperbook by Leslie Lamport.