Have a deep view into what people are curious about.

🔗 Computing 🔗 Computing/Computer hardware 🔗 Computing/Software

On the x86 computer architecture, a triple fault is a special kind of exception generated by the CPU when an exception occurs while the CPU is trying to invoke the double fault exception handler, which itself handles exceptions occurring while trying to invoke a regular exception handler.

x86 processors beginning with the 80286 will cause a shutdown cycle to occur when a triple fault is encountered. This typically causes the motherboard hardware to initiate a CPU reset, which, in turn, causes the whole computer to reboot.

🔗 Horticulture and Gardening 🔗 Animals 🔗 Sanitation

The nematodes ( NEM-ə-tohdz or NEEM-; Greek: Νηματώδη; Latin: Nematoda) roundworms or eelworms, constitute the phylum Nematoda. They are a diverse animal phylum inhabiting a broad range of environments. Most species are free-living, feeding on microorganisms, but there are many that are parasitic. The parasitic worms (helminths) are the cause of soil-transmitted helminthiases.

They are taxonomically classified along with arthropods, tardigrades and other moulting animals in the clade Ecdysozoa. Unlike the vaguely similar flatworms, nematodes have a tubular digestive system, with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum.

Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species are uncertain. A 2013 survey of animal biodiversity published in the mega journal Zootaxa puts this figure at over 25,000. Estimates of the total number of extant species are subject to even greater variation. A widely referenced article published in 1993 estimated there may be over 1 million species of nematode. A subsequent publication challenged this claim, estimating the figure to be at least 40,000 species. Although the highest estimates (up to 100 million species) have since been deprecated, estimates supported by rarefaction curves, together with the use of DNA barcoding and the increasing acknowledgment of widespread cryptic species among nematodes, have placed the figure closer to 1 million species.

Nematodes have successfully adapted to nearly every ecosystem: from marine (salt) to fresh water, soils, from the polar regions to the tropics, as well as the highest to the lowest of elevations. They are ubiquitous in freshwater, marine, and terrestrial environments, where they often outnumber other animals in both individual and species counts, and are found in locations as diverse as mountains, deserts, and oceanic trenches. They are found in every part of the earth's lithosphere, even at great depths, 0.9–3.6 km (3,000–12,000 ft) below the surface of the Earth in gold mines in South Africa. They represent 90% of all animals on the ocean floor. In total, 4.4 × 10²⁰ nematodes inhabit the Earth's topsoil, or approximately 60 billion for each human, with the highest densities observed in tundra and boreal forests. Their numerical dominance, often exceeding a million individuals per square meter and accounting for about 80% of all individual animals on earth, their diversity of lifecycles, and their presence at various trophic levels point to an important role in many ecosystems. They have been shown to play crucial roles in polar ecosystems. The roughly 2,271 genera are placed in 256 families. The many parasitic forms include pathogens in most plants and animals. A third of the genera occur as parasites of vertebrates; about 35 nematode species occur in humans.

Nathan Cobb, a nematologist, described the ubiquity of nematodes on Earth thus:

In short, if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes. The location of towns would be decipherable since, for every massing of human beings, there would be a corresponding massing of certain nematodes. Trees would still stand in ghostly rows representing our streets and highways. The location of the various plants and animals would still be decipherable, and, had we sufficient knowledge, in many cases even their species could be determined by an examination of their erstwhile nematode parasites.^(p 472)

🔗 Astronomy 🔗 Central Asia 🔗 Museums 🔗 Central Asia/Uzbekistan

The Ulugh Beg Observatory is an observatory in Samarkand, Uzbekistan. Built in the 1420s by the Timurid astronomer Ulugh Beg. Islamic astronomers who worked at the observatory include Al-Kashi, Ali Qushji, and Ulugh Beg himself. The observatory was destroyed in 1449 and rediscovered in 1908.

🔗 Computing 🔗 Computing/Software

dwm is a dynamic, minimalist tiling window manager for the X Window System that has influenced the development of several other X window managers, including xmonad and awesome. It is externally similar to wmii, but internally much simpler. dwm is written purely in C for performance and security in addition to simplicity, and lacks any configuration interface besides editing the source code. One of the project's guidelines is that the source code is intended to never exceed 2000 SLOC, and options meant to be user-configurable are all contained in a single header file.

🔗 Systems 🔗 Systems/Chaos theory

In mathematics, the Menger sponge (also known as the Menger cube, Menger universal curve, Sierpinski cube, or Sierpinski sponge) is a fractal curve. It is a three-dimensional generalization of the one-dimensional Cantor set and two-dimensional Sierpinski carpet. It was first described by Karl Menger in 1926, in his studies of the concept of topological dimension.

🔗 United States 🔗 Mathematics 🔗 Law 🔗 History of Science 🔗 United States/Indiana

The Indiana Pi Bill is the popular name for bill #246 of the 1897 sitting of the Indiana General Assembly, one of the most notorious attempts to establish mathematical truth by legislative fiat. Despite its name, the main result claimed by the bill is a method to square the circle, rather than to establish a certain value for the mathematical constant π, the ratio of the circumference of a circle to its diameter. The bill, written by the crank Edward J. Goodwin, does imply various incorrect values of π, such as 3.2. The bill never became law, due to the intervention of Professor C. A. Waldo of Purdue University, who happened to be present in the legislature on the day it went up for a vote.

The impossibility of squaring the circle using only compass and straightedge constructions, suspected since ancient times, was rigorously proven in 1882 by Ferdinand von Lindemann. Better approximations of π than those implied by the bill have been known since ancient times.

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Business 🔗 Philosophy/Philosophy of science 🔗 Science

Wronger than wrong is a statement that equates two errors when one of the errors is clearly more wrong than the other. It was described by Michael Shermer as Asimov's axiom. The mistake was discussed in Isaac Asimov's book of essays The Relativity of Wrong as well as in a 1989 article of the same name in the Fall 1989 issue of the Skeptical Inquirer:

When people thought the Earth was flat, they were wrong. When people thought the Earth was spherical, they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together.

Asimov explained that science is both progressive and cumulative. Even though scientific theories are later proven wrong, the degree of their wrongness attenuates with time as they are modified in response to the mistakes of the past. For example, data collected from satellite measurements show, to a high level of precision, how the Earth's shape differs from a perfect sphere or even an oblate spheroid or a geoid.

Shermer stated that being wronger than wrong is actually worse than being not even wrong (that is, being unfalsifiable).

According to John Jenkins, who reviewed The Relativity of Wrong, the title essay of Asimov's book is the one "which I think is important both for understanding Asimov's thinking about science and for arming oneself against the inevitable anti-science attack that one often hears – [that] theories are always preliminary and science really doesn't 'know' anything."

🔗 Taxation

A comparison of tax rates by countries is difficult and somewhat subjective, as tax laws in most countries are extremely complex and the tax burden falls differently on different groups in each country and sub-national unit. The list focuses on the main indicative types of taxes: corporate tax, individual income tax, and sales tax, including VAT and GST, but does not list capital gains tax.

Some other taxes (for instance property tax, substantial in many countries, such as the United States) and payroll tax are not shown here. The table is not exhaustive in representing the true tax burden to either the corporation or the individual in the listed country. The tax rates displayed are marginal and do not account for deductions, exemptions or rebates. The effective rate is usually lower than the marginal rate. The tax rates given for federations (such as the United States and Canada) are averages and vary depending on the state or province. Territories that have different rates to their respective nation are in italics.

🔗 Color

International orange is a color used in the aerospace industry to set objects apart from their surroundings, similar to safety orange, but deeper and with a more reddish tone.

🔗 Psychology

Transactive memory is a psychological hypothesis first proposed by Daniel Wegner in 1985 as a response to earlier theories of "group mind" such as groupthink. A transactive memory system is a mechanism through which groups collectively encode, store, and retrieve knowledge. Transactive memory was initially studied in couples and families where individuals had close relationships but was later extended to teams, larger groups, and organizations to explain how they develop a "group mind", a memory system that is more complex and potentially more effective than that of any of its individual constituents. A transactive memory system includes memory stored in each individual, the interactions between memory within the individuals, as well as the processes that update this memory. Transactive memory, then, is the shared store of knowledge.

According to Wegner, a transactive memory system consists of the knowledge stored in each individual's memory combined with metamemory containing information regarding the different teammate's domains of expertise. The transactive memory system works similarly to external memory, where other members of the group are the external memory aid. Just as an individual's metamemory allows them to be aware of what information is available for retrieval, so does the transactive memory system provide teammates with information regarding the knowledge they have access to within the group. Group members learn who knowledge experts are and how to access expertise through communicative processes. In this way, a transactive memory system can provide the group members with more and better knowledge than any individual could access on their own.