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🔗 Travel and Tourism 🔗 Backpacking

A Swedish torch (also Swedish candle, Finn candle, Swedish fire, Siberian tree torch or Russian tree torch; German: Schwedenfeuer) is a source of heat and light from a vertically set tree trunk, incised and burning in the middle. It became known in Europe during the 1600s and is now used by forest workers, and for leisure activities (especially in southern Germany). Due to its flat surface and good embers, it can also be used for cooking. Compared to a campfire, it is more compact, and therefore several small heat sources can be distributed over an area.

Oral tradition attributes the development of the torch to the Swedish military during the Thirty Years' War; using a saw or hacksaw or an axe, the Swedes are said to have made burning and glowing logs to warm their soldiers. This method of providing heat meant that their troops did not have to carry their own firewood with them but were able to get supplies on site, as the freshly cut, green wood can burn due to the chimney effect.

🔗 Astronomy

In astronomy, the lithium problem or lithium discrepancy refers to the discrepancy between the primordial abundance of lithium as inferred from observations of metal-poor (Population II) halo stars in our galaxy and the amount that should theoretically exist due to Big Bang nucleosynthesis+WMAP cosmic baryon density predictions of the CMB. Namely, the most widely accepted models of the Big Bang suggest that three times as much primordial lithium, in particular lithium-7, should exist. This contrasts with the observed abundance of isotopes of hydrogen (¹H and ²H) and helium (³He and ⁴He) that are consistent with predictions. The discrepancy is highlighted in a so-called "Schramm plot", named in honor of astrophysicist David Schramm, which depicts these primordial abundances as a function of cosmic baryon content from standard BBN predictions.

🔗 Mathematics 🔗 Statistics

The secretary problem is a problem that demonstrates a scenario involving optimal stopping theory. The problem has been studied extensively in the fields of applied probability, statistics, and decision theory. It is also known as the marriage problem, the sultan's dowry problem, the fussy suitor problem, the googol game, and the best choice problem.

The basic form of the problem is the following: imagine an administrator who wants to hire the best secretary out of ${\displaystyle n}$ rankable applicants for a position. The applicants are interviewed one by one in random order. A decision about each particular applicant is to be made immediately after the interview. Once rejected, an applicant cannot be recalled. During the interview, the administrator gains information sufficient to rank the applicant among all applicants interviewed so far, but is unaware of the quality of yet unseen applicants. The question is about the optimal strategy (stopping rule) to maximize the probability of selecting the best applicant. If the decision can be deferred to the end, this can be solved by the simple maximum selection algorithm of tracking the running maximum (and who achieved it), and selecting the overall maximum at the end. The difficulty is that the decision must be made immediately.

The shortest rigorous proof known so far is provided by the odds algorithm (Bruss 2000). It implies that the optimal win probability is always at least ${\displaystyle 1/e}$ (where e is the base of the natural logarithm), and that the latter holds even in a much greater generality (2003). The optimal stopping rule prescribes always rejecting the first ${\displaystyle \sim n/e}$ applicants that are interviewed and then stopping at the first applicant who is better than every applicant interviewed so far (or continuing to the last applicant if this never occurs). Sometimes this strategy is called the ${\displaystyle 1/e}$ stopping rule, because the probability of stopping at the best applicant with this strategy is about ${\displaystyle 1/e}$ already for moderate values of ${\displaystyle n}$. One reason why the secretary problem has received so much attention is that the optimal policy for the problem (the stopping rule) is simple and selects the single best candidate about 37% of the time, irrespective of whether there are 100 or 100 million applicants.

🔗 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".

🔗 Technology 🔗 Physics 🔗 Energy

The Crookes radiometer (also known as a light mill) consists of an airtight glass bulb containing a partial vacuum, with a set of vanes which are mounted on a spindle inside. The vanes rotate when exposed to light, with faster rotation for more intense light, providing a quantitative measurement of electromagnetic radiation intensity.

The reason for the rotation was a cause of much scientific debate in the ten years following the invention of the device, but in 1879 the currently accepted explanation for the rotation was published. Today the device is mainly used in physics education as a demonstration of a heat engine run by light energy.

It was invented in 1873 by the chemist Sir William Crookes as the by-product of some chemical research. In the course of very accurate quantitative chemical work, he was weighing samples in a partially evacuated chamber to reduce the effect of air currents, and noticed the weighings were disturbed when sunlight shone on the balance. Investigating this effect, he created the device named after him.

It is still manufactured and sold as an educational aid or for curiosity.

🔗 Companies 🔗 Germany 🔗 Transport 🔗 Energy 🔗 Transport/Maritime 🔗 Ships

SkySails GmbH & Co. KG is a Hamburg-based company that sells kite rigs to propel cargo ships, large yachts and fishing vessels by wind energy. Ships are pulled by an automatically-controlled foil kite of some hundreds of square meters. For multiple reasons, they give many times the thrust per unit area of conventional mast-mounted sails.

The systems save fuel, and reduce carbon emissions and shipping costs, but have not been widely adopted.

🔗 Terrorism 🔗 Watches 🔗 Brands

The Casio F-91W is a digital watch manufactured by Japanese electronics company Casio. Introduced in 1989, it is popular for its low price and long battery life. Annual production is 3 million units per year.

🔗 Sociology 🔗 Organizations 🔗 Media 🔗 Culture 🔗 Sociology/social movements 🔗 Toys

The Barbie Liberation Organization or BLO, sponsored by RTMark, were a group of artists and activists involved in culture jamming. They gained notoriety in 1993 after switching voice boxes in talking G.I. Joes and Barbie dolls. The BLO performed "surgery" on a reported 300–500 dolls from retail and returned them to shelves, an action they refer to as shopgiving. Thus, Teen Talk Barbie dolls would say phrases such as "Vengeance is mine", while G.I. Joe dolls would say phrases such as "The beach is the place for summer!"

🔗 Computing

Modelica is an object-oriented, declarative, multi-domain modeling language for component-oriented modeling of complex systems, e.g., systems containing mechanical, electrical, electronic, hydraulic, thermal, control, electric power or process-oriented subcomponents. The free Modelica language is developed by the non-profit Modelica Association. The Modelica Association also develops the free Modelica Standard Library that contains about 1360 generic model components and 1280 functions in various domains, as of version 3.2.1.

🔗 Food and drink 🔗 Food and drink/Foodservice

An automat is a fast food restaurant where simple foods and drink are served by vending machines. The world's first automat was named Quisisana, which opened in Berlin, Germany in 1895.