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🔗 Indigenous peoples of North America

Several Native American tribes within the United States register motor vehicles and issue license plates to those vehicles.

The legal status of these plates varies by tribe, with some being recognized by the federal government and others not. Some nations issue plates for both tribal and personal vehicles, while others issue plates only for official tribal vehicles.

Some nations' plates indicate the U.S. state with which they are most closely associated, while others do not. This variation may even exist among the nations associated with one particular state.

Federally recognized tribes may also lease vehicles through the U.S. General Services Administration under certain circumstances. Such vehicles carry U.S. government license plates.

🔗 International relations 🔗 Spaceflight 🔗 Law 🔗 Politics 🔗 International relations/International law 🔗 British Overseas Territories

The Outer Space Treaty, formally the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, is a treaty that forms the basis of international space law. The treaty was opened for signature in the United States, the United Kingdom, and the Soviet Union on 27 January 1967, and entered into force on 10 October 1967. As of June 2019, 109 countries are parties to the treaty, while another 23 have signed the treaty but have not completed ratification. In addition, Taiwan, which is currently recognized by 14 UN member states, ratified the treaty prior to the United Nations General Assembly's vote to transfer China's seat to the People's Republic of China (PRC) in 1971.

Among the Outer Space Treaty's main points are that it prohibits the placing of nuclear weapons in space, it limits the use of the Moon and all other celestial bodies to peaceful purposes only, and establishes that space shall be free for exploration and use by all nations, but that no nation may claim sovereignty of outer space or any celestial body. The Outer Space Treaty does not ban military activities within space, military space forces, or the weaponization of space, with the exception of the placement of weapons of mass destruction in space. It is mostly a non-armament treaty and offers insufficient and ambiguous regulations to newer space activities such as lunar and asteroid mining.

🔗 Computing 🔗 Computer science

In computer science, program synthesis is the task to construct a program that provably satisfies a given high-level formal specification. In contrast to program verification, the program is to be constructed rather than given; however, both fields make use of formal proof techniques, and both comprise approaches of different degrees of automation. In contrast to automatic programming techniques, specifications in program synthesis are usually non-algorithmic statements in an appropriate logical calculus.

The primary application of program synthesis is to relieve the programmer of the burden of writing correct, efficient code that satisfies a specification. However, program synthesis also has applications to superoptimization and inference of loop invariants.

🔗 Spaceflight 🔗 Astronomy 🔗 Astronomy/Solar System 🔗 Astronomy/Moon

On April 11, 2019, the Israeli spacecraft Beresheet crashed into the Moon during a failed landing attempt. Its payload included a few thousand tardigrades. Initial reports suggested they could have survived the crash landing. If any of them did survive, they would be the second animal species to reach the Moon, after humans.

We believe the chances of survival for the tardigrades... are extremely high.

🔗 Biography 🔗 Espionage 🔗 Military history 🔗 Military history/Military biography 🔗 Biography/military biography 🔗 Military history/Intelligence 🔗 United Kingdom 🔗 Military history/World War II 🔗 Military history/German military history 🔗 Military history/Spanish military history 🔗 Spain 🔗 Military history/European military history 🔗 Military history/British military history

Juan Pujol García (Spanish: [ˈxwan puˈʝol ɣaɾˈθi.a]; 14 February 1912 – 10 October 1988), also known as Joan Pujol i García (Catalan: [ʒuˈan puˈʒɔl i ɣəɾˈsi.ə]), was a Spanish spy who acted as a double agent loyal to Great Britain against Nazi Germany during World War II, when he relocated to Britain to carry out fictitious spying activities for the Germans. He was given the codename Garbo by the British; their German counterparts codenamed him Alaric and referred to his non-existent spy network as "Arabal".

After developing a loathing of political extremism of all sorts during the Spanish Civil War, Pujol decided to become a spy for Britain as a way to do something "for the good of humanity". Pujol and his wife contacted the British Embassy in Madrid, which rejected his offer.

Undeterred, he created a false identity as a fanatically pro-Nazi Spanish government official and successfully became a German agent. He was instructed to travel to Britain and recruit additional agents; instead he moved to Lisbon and created bogus reports about Britain from a variety of public sources, including a tourist guide to Britain, train timetables, cinema newsreels and magazine advertisements.

Although the information would not have withstood close examination, Pujol soon established himself as a trustworthy agent. He began inventing fictitious sub-agents who could be blamed for false information and mistakes. The Allies finally accepted Pujol when the Germans expended considerable resources attempting to hunt down a fictitious convoy. Following interviews by Desmond Bristow of Section V MI6 Iberian Section, Juan Pujol was taken on. The family were moved to Britain and Pujol was given the code name "Garbo". Pujol and his handler Tomás Harris spent the rest of the war expanding the fictitious network, communicating to the German handlers at first by letters and later by radio. Eventually the Germans were funding a network of 27 agents, all fictitious.

Pujol had a key role in the success of Operation Fortitude, the deception operation intended to mislead the Germans about the timing, location and scale of the invasion of Normandy in 1944. The false information Pujol supplied helped persuade the Germans that the main attack would be in the Pas de Calais, so that they kept large forces there before and even after the invasion. Pujol had the distinction of receiving military decorations from both sides of the war – being awarded the Iron Cross and becoming a Member of the Order of the British Empire.

🔗 Linguistics

Initial-stress derivation is a phonological process in English that moves stress to the first syllable of verbs when they are used as nouns or adjectives. (This is an example of a suprafix.) This process can be found in the case of several dozen verb-noun and verb-adjective pairs and is gradually becoming more standardized in some English dialects, but it is not present in all. The list of affected words differs from area to area, and often depends on whether a word is used metaphorically or not. At least 170 verb-noun or verb-adjective pairs exist. Some examples are:

• record.

as a verb, "Remember to recórd the show!".

as a noun, "I'll keep a récord of that request."

• permit.

as a verb, "I won't permít that."

as a noun, "We already have a pérmit."

🔗 Internet

Cicada 3301 is a nickname given to an organization that on three occasions has posted a set of puzzles to recruit codebreakers from the public. The first internet puzzle started on January 4, 2012 on 4chan and ran for approximately one month. A second round began one year later on January 4, 2013, and then a third round following the confirmation of a fresh clue posted on Twitter on January 4, 2014. The stated intent was to recruit "intelligent individuals" by presenting a series of puzzles which were to be solved. No new puzzles were published on January 4, 2015. However, a new clue was posted on Twitter on January 5, 2016. In April 2017 a verified PGP-signed message was found: Beware false paths. Always verify PGP signature from 7A35090F. That message explicitly denies the validity of any unsigned puzzle, as recently as April 2017.

The puzzles focused heavily on data security, cryptography, steganography, internet anonymity, and surveillance.

It has been called "the most elaborate and mysterious puzzle of the internet age" and is listed as one of the "top 5 eeriest, unsolved mysteries of the internet", and much speculation exists as to its function. Many have speculated that the puzzles are a recruitment tool for the NSA, CIA, MI6, a "Masonic conspiracy" or a cyber mercenary group. Others have claimed Cicada 3301 is an alternate reality game. No company or individual has taken credit for it or attempted to monetize it, however.

🔗 Cryptography 🔗 Cryptography/Computer science

In cryptography a blind signature, as introduced by David Chaum, is a form of digital signature in which the content of a message is disguised (blinded) before it is signed. The resulting blind signature can be publicly verified against the original, unblinded message in the manner of a regular digital signature. Blind signatures are typically employed in privacy-related protocols where the signer and message author are different parties. Examples include cryptographic election systems and digital cash schemes.

An often-used analogy to the cryptographic blind signature is the physical act of a voter enclosing a completed anonymous ballot in a special carbon paper lined envelope that has the voter's credentials pre-printed on the outside. An official verifies the credentials and signs the envelope, thereby transferring their signature to the ballot inside via the carbon paper. Once signed, the package is given back to the voter, who transfers the now signed ballot to a new unmarked normal envelope. Thus, the signer does not view the message content, but a third party can later verify the signature and know that the signature is valid within the limitations of the underlying signature scheme.

Blind signatures can also be used to provide unlinkability, which prevents the signer from linking the blinded message it signs to a later un-blinded version that it may be called upon to verify. In this case, the signer's response is first "un-blinded" prior to verification in such a way that the signature remains valid for the un-blinded message. This can be useful in schemes where anonymity is required.

Blind signature schemes can be implemented using a number of common public key signing schemes, for instance RSA and DSA. To perform such a signature, the message is first "blinded", typically by combining it in some way with a random "blinding factor". The blinded message is passed to a signer, who then signs it using a standard signing algorithm. The resulting message, along with the blinding factor, can be later verified against the signer's public key. In some blind signature schemes, such as RSA, it is even possible to remove the blinding factor from the signature before it is verified. In these schemes, the final output (message/signature) of the blind signature scheme is identical to that of the normal signing protocol.

🔗 Physics 🔗 Astronomy

In astrophysics and physical cosmology, Olbers' paradox, named after the German astronomer Heinrich Wilhelm Olbers (1758–1840), also known as the "dark night sky paradox", is the argument that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. In the hypothetical case that the universe is static, homogeneous at a large scale, and populated by an infinite number of stars, then any line of sight from Earth must end at the (very bright) surface of a star and hence the night sky should be completely illuminated and very bright. This contradicts the observed darkness and non-uniformity of the night.

The darkness of the night sky is one of the pieces of evidence for a dynamic universe, such as the Big Bang model. That model explains the observed non-uniformity of brightness by invoking spacetime's expansion, which lengthens the light originating from the Big Bang to microwave levels via a process known as redshift; this microwave radiation background has wavelengths much longer than those of visible light, so appears dark to the naked eye. Other explanations for the paradox have been offered, but none have wide acceptance in cosmology.

🔗 California 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/World War II 🔗 Paranormal 🔗 California/Southern California

The Battle of Los Angeles, also known as the Great Los Angeles Air Raid, is the name given by contemporary sources to a rumored attack on the mainland United States by Imperial Japan and the subsequent anti-aircraft artillery barrage which took place from late 24 February to early 25 February 1942, over Los Angeles, California. The incident occurred less than three months after the U.S. entered World War II in response to the Imperial Japanese Navy's surprise attack on Pearl Harbor, and one day after the bombardment of Ellwood near Santa Barbara on 23 February. Initially, the target of the aerial barrage was thought to be an attacking force from Japan, but speaking at a press conference shortly afterward, Secretary of the Navy Frank Knox called the purported attack a "false alarm". Newspapers of the time published a number of reports and speculations of a cover-up.

When documenting the incident in 1949, the United States Coast Artillery Association identified a meteorological balloon sent aloft at 1:00 am as having "started all the shooting" and concluded that "once the firing started, imagination created all kinds of targets in the sky and everyone joined in". In 1983, the U.S. Office of Air Force History attributed the event to a case of "war nerves" triggered by a lost weather balloon and exacerbated by stray flares and shell bursts from adjoining batteries.