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🔗 Oregon 🔗 Holidays 🔗 Piracy

International Talk Like a Pirate Day is a parodic holiday created in 1995 by John Baur (Ol' Chumbucket) and Mark Summers (Cap'n Slappy), of Albany, Oregon, U.S., who proclaimed September 19 each year as the day when everyone in the world should talk like a pirate. An observer of this holiday would greet friends not with "Hello, everyone!" but with "Ahoy, maties!" or "Ahoy, me hearties!" The holiday, and its observance, springs from a romanticized view of the Golden Age of Piracy.

🔗 Mathematics

A wallpaper group (or plane symmetry group or plane crystallographic group) is a mathematical classification of a two-dimensional repetitive pattern, based on the symmetries in the pattern. Such patterns occur frequently in architecture and decorative art, especially in textiles and tiles as well as wallpaper.

The simplest wallpaper group, Group p1, applies when there is no symmetry other than the fact that a pattern repeats over regular intervals in two dimensions, as shown in the section on p1 below.

Consider the following examples of patterns with more forms of symmetry:

Examples A and B have the same wallpaper group; it is called p4m in the IUC notation and *442 in the orbifold notation. Example C has a different wallpaper group, called p4g or 4*2 . The fact that A and B have the same wallpaper group means that they have the same symmetries, regardless of details of the designs, whereas C has a different set of symmetries despite any superficial similarities.

The number of symmetry groups depends on the number of dimensions in the patterns. Wallpaper groups apply to the two-dimensional case, intermediate in complexity between the simpler frieze groups and the three-dimensional space groups. Subtle differences may place similar patterns in different groups, while patterns that are very different in style, color, scale or orientation may belong to the same group.

A proof that there were only 17 distinct groups of such planar symmeries was first carried out by Evgraf Fedorov in 1891 and then derived independently by George Pólya in 1924. The proof that the list of wallpaper groups was complete only came after the much harder case of space groups had been done. The seventeen possible wallpaper groups are listed below in § The seventeen groups.

Digital Radio Frequency Memory (DRFM) is an electronic method for digitally capturing and retransmitting RF signals. DRFM systems are typically used in radar jamming, although applications in cellular communications are becoming more common.

🔗 Mathematics 🔗 Physics

Shor's algorithm is a polynomial-time quantum computer algorithm for integer factorization. Informally, it solves the following problem: Given an integer ${\displaystyle N}$, find its prime factors. It was invented in 1994 by the American mathematician Peter Shor.

On a quantum computer, to factor an integer ${\displaystyle N}$, Shor's algorithm runs in polynomial time (the time taken is polynomial in ${\displaystyle \log N}$, the size of the integer given as input). Specifically, it takes quantum gates of order ${\displaystyle O\!\left((\log N)^{2}(\log \log N)(\log \log \log N)\right)}$ using fast multiplication, thus demonstrating that the integer-factorization problem can be efficiently solved on a quantum computer and is consequently in the complexity class BQP. This is almost exponentially faster than the most efficient known classical factoring algorithm, the general number field sieve, which works in sub-exponential time — ${\displaystyle O\!\left(e^{1.9(\log N)^{1/3}(\log \log N)^{2/3}}\right)}$. The efficiency of Shor's algorithm is due to the efficiency of the quantum Fourier transform, and modular exponentiation by repeated squarings.

If a quantum computer with a sufficient number of qubits could operate without succumbing to quantum noise and other quantum-decoherence phenomena, then Shor's algorithm could be used to break public-key cryptography schemes, such as the widely used RSA scheme. RSA is based on the assumption that factoring large integers is computationally intractable. As far as is known, this assumption is valid for classical (non-quantum) computers; no classical algorithm is known that can factor integers in polynomial time. However, Shor's algorithm shows that factoring integers is efficient on an ideal quantum computer, so it may be feasible to defeat RSA by constructing a large quantum computer. It was also a powerful motivator for the design and construction of quantum computers, and for the study of new quantum-computer algorithms. It has also facilitated research on new cryptosystems that are secure from quantum computers, collectively called post-quantum cryptography.

In 2001, Shor's algorithm was demonstrated by a group at IBM, who factored ${\displaystyle 15}$ into ${\displaystyle 3\times 5}$, using an NMR implementation of a quantum computer with ${\displaystyle 7}$ qubits. After IBM's implementation, two independent groups implemented Shor's algorithm using photonic qubits, emphasizing that multi-qubit entanglement was observed when running the Shor's algorithm circuits. In 2012, the factorization of ${\displaystyle 15}$ was performed with solid-state qubits. Also, in 2012, the factorization of ${\displaystyle 21}$ was achieved, setting the record for the largest integer factored with Shor's algorithm.

🔗 United States 🔗 Biography 🔗 Internet 🔗 Computing 🔗 Internet culture 🔗 New York City 🔗 Biography/science and academia 🔗 Biography/arts and entertainment 🔗 United States/Massachusetts 🔗 Chicago 🔗 Open 🔗 United States/Massachusetts - Boston 🔗 Open Access

Aaron Hillel Swartz (November 8, 1986 – January 11, 2013) was an American computer programmer, entrepreneur, writer, political organizer, and Internet hacktivist. He was involved in the development of the web feed format RSS, the Markdown publishing format, the organization Creative Commons, and the website framework web.py, and joined the social news site Reddit six months after its founding. He was given the title of co-founder of Reddit by Y Combinator owner Paul Graham after the formation of Not a Bug, Inc. (a merger of Swartz's project Infogami and Redbrick Solutions, a company run by Alexis Ohanian and Steve Huffman). Swartz's work also focused on civic awareness and activism. He helped launch the Progressive Change Campaign Committee in 2009 to learn more about effective online activism. In 2010, he became a research fellow at Harvard University's Safra Research Lab on Institutional Corruption, directed by Lawrence Lessig. He founded the online group Demand Progress, known for its campaign against the Stop Online Piracy Act.

In 2011, Swartz was arrested by Massachusetts Institute of Technology (MIT) police on state breaking-and-entering charges, after connecting a computer to the MIT network in an unmarked and unlocked closet, and setting it to download academic journal articles systematically from JSTOR using a guest user account issued to him by MIT. Federal prosecutors, led by Carmen Ortiz, later charged him with two counts of wire fraud and eleven violations of the Computer Fraud and Abuse Act, carrying a cumulative maximum penalty of $1 million in fines, 35 years in prison, asset forfeiture, restitution, and supervised release. Swartz declined a plea bargain under which he would have served six months in federal prison. Two days after the prosecution rejected a counter-offer by Swartz, he was found dead by suicide in his Brooklyn apartment. In 2013, Swartz was inducted posthumously into the Internet Hall of Fame.

🔗 Video games

Darwin was a programming game invented in August 1961 by Victor A. Vyssotsky, Robert Morris Sr., and M. Douglas McIlroy. (Dennis Ritchie is sometimes incorrectly cited as a co-author, but was not involved.) The game was developed at Bell Labs, and played on an IBM 7090 mainframe there. The game was only played for a few weeks before Morris developed an "ultimate" program that eventually brought the game to an end, as no-one managed to produce anything that could defeat it.

🔗 Rocketry

A rolleron is a type of aileron used for rockets, placed at the trailing end of each fin, and used for passive stabilization against rotation. Inherent to the rolleron is a metal wheel with notches along the circumference. On one side, the notches protrude into the airflow. During flight, this will spin the wheels up to a substantial speed. The wheels then act as gyroscopes. Any tendency of the rocket to rotate around its major axis will be counteracted by the rollerons: the gyroscopic precession acts to move the rolleron in the opposite direction to the rotation.

Rollerons were first used in the AIM-9 Sidewinder missile.

🔗 Trains 🔗 Ships

A train ferry is a ship (ferry) designed to carry railway vehicles. Typically, one level of the ship is fitted with railway tracks, and the vessel has a door at the front and/or rear to give access to the wharves. In the United States, train ferries are sometimes referred to as "car ferries", as distinguished from "auto ferries" used to transport automobiles. The wharf (sometimes called a "slip") has a ramp, and a linkspan or "apron", balanced by weights, that connects the railway proper to the ship, allowing for the water level to rise and fall with the tides.

While railway vehicles can be and are shipped on the decks or in the holds of ordinary ships, purpose-built train ferries can be quickly loaded and unloaded by roll-on/roll-off, especially as several vehicles can be loaded or unloaded at once. A train ferry that is a barge is called a car float or rail barge.

🔗 Internet culture 🔗 Songs 🔗 Electronic music

"The Most Mysterious Song on the Internet" (also known as "Like the Wind", "Blind the Wind", "Check It In, Check It Out" or "Take It In, Take It Out" after lines in fan-interpreted lyrics; acronymed as TMMSOTI or TMS) is the nickname given to an unidentified song recording, most likely composed in the 1980s.

The song was reportedly recorded from a Norddeutscher Rundfunk (NDR) broadcast sometime in the mid-1980s, likely during or after 1984. Since 2019, this song has been the subject of a viral Internet phenomenon, with many users of sites such as Reddit and Discord involved in a collaborative effort to search for the origins of the song. Through the search, other unknown songs were discovered. Users have coined the term "Lostwave" to describe songs of this nature.

🔗 Mathematics 🔗 Physics

Stochastic resonance (SR) is a phenomenon where a signal that is normally too weak to be detected by a sensor, can be boosted by adding white noise to the signal, which contains a wide spectrum of frequencies. The frequencies in the white noise corresponding to the original signal's frequencies will resonate with each other, amplifying the original signal while not amplifying the rest of the white noise (thereby increasing the signal-to-noise ratio which makes the original signal more prominent). Further, the added white noise can be enough to be detectable by the sensor, which can then filter it out to effectively detect the original, previously undetectable signal.

This phenomenon of boosting undetectable signals by resonating with added white noise extends to many other systems, whether electromagnetic, physical or biological, and is an area of research.