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🔗 Mathematics

An emirp (prime spelled backwards) is a prime number that results in a different prime when its decimal digits are reversed. This definition excludes the related palindromic primes. The term reversible prime is used to mean the same as emirp, but may also, ambiguously, include the palindromic primes.

The sequence of emirps begins 13, 17, 31, 37, 71, 73, 79, 97, 107, 113, 149, 157, 167, 179, 199, 311, 337, 347, 359, 389, 701, 709, 733, 739, 743, 751, 761, 769, 907, 937, 941, 953, 967, 971, 983, 991, ... (sequence A006567 in the OEIS).

All non-palindromic permutable primes are emirps.

As of November 2009, the largest known emirp is 10¹⁰⁰⁰⁶+941992101×10⁴⁹⁹⁹+1, found by Jens Kruse Andersen in October 2007.

The term 'emirpimes' (singular) is used also in places to treat semiprimes in a similar way. That is, an emirpimes is a semiprime that is also a (distinct) semiprime upon reversing its digits.

🔗 Insects

The emerald cockroach wasp or jewel wasp (Ampulex compressa) is a solitary wasp of the family Ampulicidae. It is known for its unusual reproductive behavior, which involves stinging a cockroach and using it as a host for its larvae. It thus belongs to the entomophagous parasites.

🔗 Novels 🔗 Comedy 🔗 Middle-earth 🔗 Novels/Fantasy

Bored of the Rings is a parody of J. R. R. Tolkien's The Lord of the Rings. This short novel was written by Henry Beard and Douglas Kenney, who later founded National Lampoon. It was published in 1969 by Signet for the Harvard Lampoon. In 2013, an audio version was produced by Orion Audiobooks, narrated by Rupert Degas.

🔗 Internet culture 🔗 Environment 🔗 Skepticism 🔗 Chemicals 🔗 Sociology

The dihydrogen monoxide parody involves calling water by an unfamiliar chemical name, most often "dihydrogen monoxide" (DHMO), and listing some of water's well-known effects in a particularly alarming manner, such as accelerating corrosion and causing suffocation. The parody often calls for dihydrogen monoxide to be banned, regulated, or labeled as dangerous. It demonstrates how a lack of scientific literacy and an exaggerated analysis can lead to misplaced fears.

The parody has been used with other chemical names, including "dihydrogen oxide", "hydroxyl acid", and "hydroxylic acid".

🔗 New York City 🔗 Architecture 🔗 Skyscrapers 🔗 Telecommunications

33 Thomas Street (formerly the AT&T Long Lines Building) is a 550-foot-tall (170 m) skyscraper in Civic Center, Lower Manhattan, New York City. It stands on the east side of Church Street, between Thomas Street and Worth Street. The building is an example of the Brutalist architectural style. It is a telephone exchange or wire center building which contained three major 4ESS switches used for interexchange (long distance) telephony, as well as a number of other switches used for competitive local exchange carrier services. However, it is not used for incumbent local exchange carrier services, and is not a central office. The CLLI code for this facility is NYCMNYBW. The building has also been described as the likely location of a National Security Agency (NSA) mass surveillance hub codenamed TITANPOINTE.

🔗 United States 🔗 Biography 🔗 Biography/science and academia

Michael J. (Mike) Karels (August 2, 1956 – June 2, 2024) was an American software engineer and one of the key figures in history of BSD UNIX.

In 1993, the USENIX Association gave a Lifetime Achievement Award (Flame) to the Computer Systems Research Group at University of California, Berkeley, honoring 180 individuals, including Karels, who contributed to the CSRG's 4.4BSD-Lite release.

In February 1992 Karels moved to BSDi (Berkeley Software Design) and designed BSD/OS, which, for years, was the only commercially available BSD style Unix on Intel platform. BSDi's software assets were bought by Wind River in April 2001, and Karels joined Wind River as the Principal Technologist for the BSD/OS platform.

Following his time at Wind River, Karels joined Secure Computing Corporation in 2003 as a Sr. Principal Engineer. Secure Computing used BSD/OS as the basis for SecureOS, the operating system of its Sidewinder firewall, later known as McAfee Firewall Enterprise. However, BSD/OS development had ceased, so Karels was involved in transitioning SecureOS to use FreeBSD as its base, and porting its unique features over to the new kernel. Secure Computing and the Sidewinder firewall team went through a series of acquisitions and spinoffs, including McAfee, Intel, and Forcepoint, so while Karels appeared to have several different jobs from that point onward, he had remained in roughly the same role from 2003 until his retirement in 2021.

The Sidewinder product was eventually discontinued, though Karels fed some SecureOS changes back into the main FreeBSD codebase. Karels officially became a FreeBSD committer in 2017. He continued working on FreeBSD in his spare time following retirement.

🔗 Death 🔗 Ancient Egypt 🔗 Ancient Egypt/Egyptian religion

The Coffin Texts are a collection of ancient Egyptian funerary spells written on coffins beginning in the First Intermediate Period. They are partially derived from the earlier Pyramid Texts, reserved for royal use only, but contain substantial new material related to everyday desires, indicating a new target audience of common people. Ordinary Egyptians who could afford a coffin had access to these funerary spells and the pharaoh no longer had exclusive rights to an afterlife.

As the modern name of this collection of some 1,185 spells implies, they were mostly inscribed on Middle Kingdom coffins. They were also sometimes written on tomb walls, stelae, canopic chests, papyri and mummy masks. Due to the limited writing surfaces of some of these objects, the spells were often abbreviated, giving rise to long and short versions, some of which were later copied in the Book of the Dead.

🔗 Technology

A planimeter, also known as a platometer, is a measuring instrument used to determine the area of an arbitrary two-dimensional shape.

🔗 Biography 🔗 China/Chinese history 🔗 Italy 🔗 China

Katarina Vilioni (died 1342) was one of the first Europeans known to have resided in China. She was apparently a member of a Genoese trading family that lived in Yangzhou during the mid-14th century.

Vilioni is known through her tombstone, which was rediscovered at Yangzhou in 1951. It suggests that Vilioni died in 1342 and was the daughter of a man named Domenico Vilioni.

🔗 Lists 🔗 Countries

The following nations prohibit civilians wearing or possessing camouflage print clothing:

• Azerbaijan
• Antigua and Barbuda
• Bahamas
• Barbados
• Dominica
• Ghana
• Grenada
• Jamaica
• Nigeria
• Oman
• Philippines (uniforms only)
• Saint Lucia
• Saint Vincent and the Grenadines
• Saudi Arabia
• Trinidad and Tobago
• Uganda
• Zambia
• Zimbabwe