To stay up to date you can also follow on Mastodon.

🔗 Computing 🔗 Microsoft Windows 🔗 Microsoft Windows/Computing

The AARD code was a segment of code in a beta release of Microsoft Windows 3.1 that would determine whether Windows was running on MS-DOS or PC DOS, rather than a competing workalike such as DR-DOS, and would result in a cryptic error message in the latter case. This XOR-encrypted, self-modifying, and deliberately obfuscated machine code used a variety of undocumented DOS structures and functions to perform its work, and appeared in the installer, WIN.COM, and several other executables in the OS.

The AARD code was originally discovered by Geoff Chappell on 17 April 1992 and then further analyzed and documented in a joint effort with Andrew Schulman. The name was derived from Microsoft programmer Aaron R. Reynolds (1955–2008), who used "AARD" to sign his work; "AARD" was found in the machine code of the installer. Microsoft disabled the AARD code for the final release of Windows 3.1, but did not remove it, so that it could have become reactivated later by the change of a single byte in an installed system, thereby constituting a "smoking gun".

DR-DOS publisher Digital Research released a patch named "business update" in 1992 to enable the AARD tests to pass on its operating system.

The rationale for the AARD code came to light when internal memos were released during the United States v. Microsoft Corp. antitrust case in 1999. Internal memos released by Microsoft revealed that the specific focus of these tests was DR-DOS. At one point, Microsoft CEO Bill Gates sent a memo to a number of employees, reading "You never sent me a response on the question of what things an app would do that would make it run with MS-DOS and not run with DR-DOS. Is there [sic] feature they have that might get in our way?" Microsoft Senior Vice President Brad Silverberg later sent another memo, stating: "What the [user] is supposed to do is feel uncomfortable, and when he has bugs, suspect that the problem is DR-DOS and then go out to buy MS-DOS."

Following the purchase of DR-DOS by Novell and its renaming to "Novell DOS", Microsoft Co-President Jim Allchin stated in a memo, "If you're going to kill someone there isn't much reason to get all worked up about it and angry. Any discussions beforehand are a waste of time. We need to smile at Novell while we pull the trigger."

What had been DR-DOS changed hands again. The new owner, Caldera, Inc., began a lawsuit against Microsoft over the AARD code, Caldera v. Microsoft, which was later settled. It was believed that the settlement ran in the order of $150 million, but was revealed in November 2009 with the release of the Settlement Agreement to be $280 million.

🔗 China 🔗 Writing systems

Since the second half of the 20th century, inscriptions have been found on pottery in a variety of locations in China, such as Banpo near Xi'an, as well as on bone and bone marrows at Hualouzi, Chang'an County near Xi'an. These simple, often geometric, marks have been frequently compared to some of the earliest known Chinese characters appearing on the oracle bones, and some have taken them to mean that the history of Chinese writing extends back over six millennia. However, only isolated instances of these symbols have been found, and they show no indication of representing speech or of the non-pictorial processes that a writing system requires.

🔗 Novels 🔗 Books 🔗 Science Fiction 🔗 LGBT studies 🔗 Women writers 🔗 Gender Studies 🔗 Feminism

Beatrice the Sixteenth: Being the Personal Narrative of Mary Hatherley, M.B., Explorer and Geographer is a 1909 feminist utopian novel by the English transgender lawyer and writer Irene Clyde, about a time traveller who discovers a lost world, which is an egalitarian postgender society.

🔗 United States 🔗 Military history 🔗 Disaster management 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Terrorism 🔗 New York City 🔗 Military history/World War I 🔗 New Jersey 🔗 Public Art 🔗 New Jersey/Hudson County

The Black Tom explosion was an act of sabotage by German agents to destroy U.S.-made munitions that were to be supplied to the Allies in World War I. The explosions, which occurred on July 30, 1916, in the New York Harbor, killed four people and destroyed some $20,000,000 worth of military goods. This incident, which happened prior to U.S. entry into World War I, also damaged the Statue of Liberty. It was one of the largest artificial non-nuclear explosions to have ever occurred.

🔗 Spaceflight 🔗 Physics 🔗 Rocketry

The Tsiolkovsky rocket equation, classical rocket equation, or ideal rocket equation is a mathematical equation that describes the motion of vehicles that follow the basic principle of a rocket: a device that can apply acceleration to itself using thrust by expelling part of its mass with high velocity can thereby move due to the conservation of momentum.

${\displaystyle \Delta v=v_{\text{e}}\ln {\frac {m_{0}}{m_{f}}}=I_{\text{sp}}g_{0}\ln {\frac {m_{0}}{m_{f}}}}$

where:

${\displaystyle \Delta v\ }$ is delta-v – the maximum change of velocity of the vehicle (with no external forces acting).

${\displaystyle m_{0}}$ is the initial total mass, including propellant, also known as wet mass.

${\displaystyle m_{f}}$ is the final total mass without propellant, also known as dry mass.

${\displaystyle v_{\text{e}}=I_{\text{sp}}g_{0}}$ is the effective exhaust velocity, where:

${\displaystyle I_{\text{sp}}}$ is the specific impulse in dimension of time.

${\displaystyle g_{0}}$ is standard gravity.

${\displaystyle \ln }$ is the natural logarithm function.

🔗 Norse history and culture 🔗 Ancient Germanic studies

The sequence alu (ᚨᛚᚢ) is found in numerous Elder Futhark runic inscriptions of Germanic Iron Age Scandinavia (and more rarely in early Anglo-Saxon England) between the 3rd and the 8th century. The word usually appears either alone (such as on the Elgesem runestone) or as part of an apparent formula (such as on the Lindholm "amulet" (DR 261) from Scania, Sweden). The symbols represent the runes Ansuz, Laguz, and Uruz. The origin and meaning of the word are matters of dispute, though a general agreement exists among scholars that the word represents an instance of historical runic magic or is a metaphor (or metonym) for it. It is the most common of the early runic charm words.

The word disappears from runic inscriptions shortly after Migration Period, even before the Christianization of Scandinavia. It may have lived on beyond this period with an increasing association with ale, appearing in stanzas 7 and 19 of the Old Norse poem Sigrdrífumál, compiled in the 13th century Poetic Edda, where knowledge of invocative "ale runes" (Old Norse ölrúnar) is imparted by the Valkyrie Sigrdrífa. Theories have been suggested that the unique term ealuscerwen (possibly "pouring away of alu"), used to describe grief or terror in the epic poem Beowulf, recorded around the 9th to 11th century, may be directly related.

🔗 Spaceflight 🔗 Physics 🔗 Rocketry

Direct Fusion Drive (DFD) is a conceptual low radioactivity, nuclear-fusion rocket engine designed to produce both thrust and electric power for interplanetary spacecraft. The concept is based on the Princeton field-reversed configuration reactor invented in 2002 by Samuel A. Cohen, and is being modeled and experimentally tested at Princeton Plasma Physics Laboratory, a US Department of Energy facility, and modeled and evaluated by Princeton Satellite Systems. As of 2018, the concept has moved on to Phase II to further advance the design.

🔗 Time

The Shortt–Synchronome free pendulum clock was a complex precision electromechanical pendulum clock invented in 1921 by British railway engineer William Hamilton Shortt in collaboration with horologist Frank Hope-Jones, and manufactured by the Synchronome Co., Ltd. of London, UK. They were the most accurate pendulum clocks ever commercially produced, and became the highest standard for timekeeping between the 1920s and the 1940s, after which mechanical clocks were superseded by quartz time standards. They were used worldwide in astronomical observatories, naval observatories, in scientific research, and as a primary standard for national time dissemination services. The Shortt was the first clock to be a more accurate timekeeper than the Earth itself; it was used in 1926 to detect tiny seasonal changes in the Earth's rotation rate. Shortt clocks achieved accuracy of around a second per year, although a recent measurement indicated they were even more accurate. About 100 were produced between 1922 and 1956.

Shortt clocks kept time with two pendulums, a master pendulum swinging in a vacuum tank and a slave pendulum in a separate clock, which was synchronized to the master by an electric circuit and electromagnets. The slave pendulum was attached to the timekeeping mechanisms of the clock, leaving the master pendulum virtually free of external disturbances.

🔗 Meteorology 🔗 Paranormal

New England's Dark Day occurred on May 19, 1780, when an unusual darkening of the day sky was observed over the New England states and parts of Canada. The primary cause of the event is believed to have been a combination of smoke from forest fires, a thick fog, and cloud cover. The darkness was so complete that candles were required from noon on. It did not disperse until the middle of the next night.

🔗 Environment 🔗 London 🔗 History of Science

Fumifugium, or, The inconveniencie of the aer and smoak of London dissipated together with some remedies humbly proposed by J.E. esq. to His Sacred Majestie, and to the Parliament now assembled is a pamphlet published in London, 1661 (see 1661 in literature), by John Evelyn. It is one of the earliest known works on air pollution and is broken down into three parts which explain the problem, a proposed solution, and a way of improvement upon the air in London. The letter was specifically addressed to King Charles II of England and discussed problems with the capital's air pollution dating back to medieval times. Evelyn refers to Greek philosophers, who once believed that air was the principle of the earth and primary substance of the soul up until the time that air pollution began to cause ill health.

Evelyn was appointed to the newly formed Royal Society, and both Society and pamphlet are celebrated in the 1663 "Ballad of Gresham College". Stanza 23 (given here in modern English) describes how Evelyn

[...] shows that 'tis the sea-coal smoke

That always London does environ,
Which does our lungs and spirits choke,
Our hanging spoil, and rust our iron.
Let none at Fumifuge be scoffing

Who heard at Church our Sunday's coughing.

The sea-coal to which Evelyn referred was appropriately named because it came by sea from Newcastle. When burned, it gave off a terrible smell because of high amounts of sulfur in its composition. When burned the sea coal released sulfur dioxide, carbon dioxide, nitric oxide, soot, and particulates of organic matter into the atmosphere. The pamphlet suggests that burning wood, particularly aromatic woods, will be less harmful to the lungs and recommends relocating some of London's more polluting industries outside the capital, in particular lime-burning and brewing.