Have a deep view into what people are curious about.

🔗 Spaceflight 🔗 Moon 🔗 Rocketry 🔗 Solar System/Mars 🔗 Solar System

The SpaceX Starship is a fully-reusable launch vehicle and spacecraft that is being privately developed by SpaceX. It is designed to be a long-duration cargo and passenger-carrying spacecraft. The development of the Starship began in 2014.

🔗 Environment 🔗 Automobiles 🔗 Environment/Green vehicle

The Flocken Elektrowagen is a four-wheeled electric car designed by Andreas Flocken (1845–1913), manufactured in 1888 by Maschinenfabrik A. Flocken in Coburg. It is regarded as the first real electric car.

🔗 Cats 🔗 Malaysia

Operation Cat Drop is the name given to the delivery of some 14,000 cats by the United Kingdom's Royal Air Force to remote regions of the then-British colony of Sarawak (today part of Malaysia), on the island of Borneo in 1960. The cats were flown out of Singapore and delivered in crates dropped by parachutes as part of a broader program of supplying cats to combat a plague of rats. The operation was reported as a "success" at the time. Some newspaper reports published soon after the Operation reference only 23 cats being used. However, later reports state as many as 14,000 cats were used. An additional source references a "recruitment" drive for 30 cats a few days prior to Operation Cat Drop.

🔗 Linguistics 🔗 Linguistics/Etymology

This is a list of etymologies proposed for the word OK or okay. The majority can be easily classified as false etymologies, or possibly folk etymologies. H. L. Mencken, in The American Language, lists serious candidates and "a few of the more picturesque or preposterous". Allen Walker Read surveyed a variety of explanations in a 1964 article titled The Folklore of "O. K." Eric Partridge described O.K. as "an evergreen of the correspondence column."

🔗 Computing 🔗 Computing/Computer hardware

The Dadda multiplier is a hardware binary multiplier design invented by computer scientist Luigi Dadda in 1965. It uses a selection of full and half adders to sum the partial products in stages (the Dadda tree or Dadda reduction) until two numbers are left. The design is similar to the Wallace multiplier, but the different reduction tree reduces the required number of gates (for all but the smallest operand sizes) and makes it slightly faster (for all operand sizes).

Dadda and Wallace multipliers have the same three steps for two bit strings ${\displaystyle w_{1}}$ and ${\displaystyle w_{2}}$ of lengths ${\displaystyle \ell _{1}}$ and ${\displaystyle \ell _{2}}$ respectively:

1. Multiply (logical AND) each bit of ${\displaystyle w_{1}}$, by each bit of ${\displaystyle w_{2}}$, yielding ${\displaystyle \ell _{1}\cdot \ell _{2}}$ results, grouped by weight in columns
2. Reduce the number of partial products by stages of full and half adders until we are left with at most two bits of each weight.
3. Add the final result with a conventional adder.

As with the Wallace multiplier, the multiplication products of the first step carry different weights reflecting the magnitude of the original bit values in the multiplication. For example, the product of bits ${\displaystyle a_{n}b_{m}}$ has weight ${\displaystyle n+m}$.

Unlike Wallace multipliers that reduce as much as possible on each layer, Dadda multipliers attempt to minimize the number of gates used, as well as input/output delay. Because of this, Dadda multipliers have a less expensive reduction phase, but the final numbers may be a few bits longer, thus requiring slightly bigger adders.

🔗 Computing 🔗 Computing/Software

The syntax of the Python programming language is the set of rules that defines how a Python program will be written and interpreted (by both the runtime system and by human readers). The Python language has many similarities to Perl, C, and Java. However, there are some definite differences between the languages.

🔗 United States 🔗 International relations 🔗 Soviet Union 🔗 Agriculture 🔗 Trade 🔗 Soviet Union/economy of Russia

The great grain robbery was the July 1972 purchase of 10 million tons of grain (mainly wheat and corn) from the United States by the Soviet Union at subsidized prices, which caused global grain prices to soar. Crop shortfalls in 1971 and 1972 forced the Soviet Union to look abroad for grain, hoping to prevent famine or crisis. Soviet negotiators worked out a deal to buy grain on credit, but quickly exceeded their credit limit. The American negotiators did not realize that both the Soviets and the world grain market had suffered shortfalls, and thus chose to subsidize the purchase. The strategy backfired and intensified the crisis with global food prices rose at least 30%, and grain stockpiles were decimated.

🔗 Computer science

The General Purpose Analog Computer (GPAC) is a mathematical model of analog computers first introduced in 1941 by Claude Shannon. This model consists of circuits where several basic units are interconnected in order to compute some function. The GPAC can be implemented in practice through the use of mechanical devices or analog electronics. Although analog computers have fallen almost into oblivion due to emergence of the digital computer, the GPAC has recently been studied as a way to provide evidence for the physical Church–Turing thesis. This is because the GPAC is also known to model a large class of dynamical systems defined with ordinary differential equations, which appear frequently in the context of physics. In particular it was shown in 2007 that (a deterministic variant of) the GPAC is equivalent, in computability terms, to Turing machines, thereby proving the physical Church–Turing thesis for the class of systems modelled by the GPAC. This was recently strengthened to polynomial time equivalence.

🔗 Video games

In video games, grinding is performing repetitive tasks, usually for a gameplay advantage or loot but in some cases for purely aesthetic or cosmetic benefits. Many video games use different tactics to implement, or reduce, the amount of grinding in the gameplay. The general use of grinding is for "experience points", or to improve a character's level. In addition, the behavior is sometimes referred to as pushing the bar (leveling up), farming (acquiring loot repeatedly from one source), or catassing.

🔗 Canada 🔗 Minnesota 🔗 Canada/Geography of Canada 🔗 National Register of Historic Places

The northwesternmost point of the Lake of the Woods was a critical landmark for the boundary between U.S. territory and the British possessions to the north. This point was referred to in the Treaty of Paris in 1783 and in later treaties including the Treaty of 1818. This point lies at the corner of the Northwest Angle of Minnesota and is thus the northernmost point in the lower 48 United States. After Canadian Confederation, the point became the basis for the border between Manitoba and Ontario.

The "northwesternmost point" of the lake had not yet been identified when it was referenced in treaties defining the border between the US and Britain; it was simply an easily described abstraction based on a large landmark. The best maps at the time of the original negotiation depicted the lake as a simple oval. However, although the southern portion of the lake is easily mapped, to the north it becomes a complex tangle of bays, peninsulas, and islands, with many adjacent bodies of water separated or connected by narrow isthmuses or straits. An 1822 survey crew declared the referenced point impossible to determine. In 1824, British explorer David Thompson was hired to identify it. Thompson mapped the lake and found four possibilities, but did not conclusively declare one location.

In 1825, German astronomer in British service Dr. Johann Ludwig Tiarks surveyed the lake. Tiarks identified two possibilities for the northwesternmost point on the lake, based on Thompson's maps: the Angle Inlet and Rat Portage. To determine which point was the most northwestern, he drew a line from each point in the southwest-northeast direction. If the line intersected the lake at any point, it was not the most northwestern point, as shown in the example diagram here. Tiarks determined that the only such line that did not intersect the lake was at the edge of a pond on the Angle Inlet. (A 1940 academic study documents this point as being in the immediate vicinity of 49°23′51.324″N 95°9′12.20783″W (NAD83).)

Under the 1783 treaty, the international border would have run due west from this point to the Mississippi River. As this was determined to be geographically impossible (the Mississippi begins further south), under the 1818 treaty the international border instead ran from the point determined by Tiarks, to the 49th parallel. (It was not known at the time whether that was to the north or – in fact – the south.) From there it ran due west to the Rocky Mountains (and later, the Pacific coast).

Tiarks' point, however, created problems, because the 1818 treaty called for the border to run directly north–south from it. South of that point, the channel of the Northwest Angle Inlet meandered east and west, crossing the border five times, thereby creating two small enclaves of water areas totaling two and a half acres that belonged to the United States but were surrounded by Canadian waters. A 1925 treaty addressed this by adopting the southernmost of the points where the channel and the border intersected – approximately 5,000 ft (1,500 m) south of Tiarks' point – as the new "northwesternmost point". The new northwesternmost point thus became 49°23′4.14″N 95°9′11.34″W, based on the NAD27 datum, which is equivalent to 49°23′4.12373″N 95°9′12.20783″W under the modern NAD83 datum.