Have a deep view into what people are curious about.

🔗 Spaceflight 🔗 Astronomy 🔗 Astronomy/Solar System 🔗 Astronomy/Moon

On April 11, 2019, the Israeli spacecraft Beresheet crashed into the Moon during a failed landing attempt. Its payload included a few thousand tardigrades. Initial reports suggested they could have survived the crash landing. If any of them did survive, they would be the second animal species to reach the Moon, after humans.

We believe the chances of survival for the tardigrades... are extremely high.

🔗 Computing 🔗 Computing/Software 🔗 Computing/Free and open-source software

netcat (often abbreviated to nc) is a computer networking utility for reading from and writing to network connections using TCP or UDP. The command is designed to be a dependable back-end that can be used directly or easily driven by other programs and scripts. At the same time, it is a feature-rich network debugging and investigation tool, since it can produce almost any kind of connection its user could need and has a number of built-in capabilities.

Its list of features includes port scanning, transferring files, and port listening, and it can be used as a backdoor.

🔗 Video games

The Tetris effect (also known as Tetris syndrome) occurs when people devote so much time and attention to an activity that it begins to pattern their thoughts, mental images, and dreams. It takes its name from the video game Tetris.

People who have played Tetris for a prolonged amount of time can find themselves thinking about ways different shapes in the real world can fit together, such as the boxes on a supermarket shelf or the buildings on a street. They may see coloured images of pieces falling into place on an invisible layout at the edges of their visual fields or when they close their eyes.. They may see such coloured, moving images when they are falling asleep, a form of hypnagogic imagery.

The Tetris effect is a form of habit. Those experiencing the effect may feel they are unable to prevent the thoughts, images, or dreams from happening.

A broadening of the Tetris effect may be the Game Transfer Phenomena (GTP).

🔗 California 🔗 Skepticism 🔗 Geography 🔗 Alternative Views 🔗 Geology

Sailing stones (also known as sliding rocks, walking rocks, rolling stones, and moving rocks), are a geological phenomenon where rocks move and inscribe long tracks along a smooth valley floor without human or animal intervention. The movement of the rocks occurs when large ice sheets a few millimeters thick and floating in an ephemeral winter pond start to break up during sunny days. Frozen during cold winter nights, these thin floating ice panels are driven by wind and shove rocks at speeds up to 5 meters per minute.

Trails of sliding rocks have been observed and studied in various locations, including Little Bonnie Claire Playa in Nevada, and most famously at Racetrack Playa, Death Valley National Park, California, where the number and length of tracks are notable.

🔗 Technology 🔗 Environment 🔗 Science Fiction 🔗 Astronomy 🔗 Transhumanism 🔗 Futures studies 🔗 Energy

The Kardashev scale is a method of measuring a civilization's level of technological advancement based on the amount of energy they are able to use. The measure was proposed by Soviet astronomer Nikolai Kardashev in 1964. The scale has three designated categories:

• A Type I civilization, also called a planetary civilization—can use and store all of the energy available on its planet.
• A Type II civilization, also called a stellar civilization—can use and control energy at the scale of its stellar system.
• A Type III civilization, also called a galactic civilization—can control energy at the scale of its entire host galaxy.

🔗 Literature

The Thirty-Six Dramatic Situations is a descriptive list which was first proposed by Georges Polti in 1895 to categorize every dramatic situation that might occur in a story or performance. Polti analyzed classical Greek texts, plus classical and contemporaneous French works. He also analyzed a handful of non-French authors. In his introduction, Polti claims to be continuing the work of Carlo Gozzi, who also identified 36 situations.

🔗 Visual arts

Rhythm 0 was a six-hour work of performance art by Serbian artist Marina Abramović in Naples in 1974. The work involved Abramović standing still while the audience was invited to do to her whatever they wished, using one of 72 objects she had placed on a table. These included a rose, feather, perfume, honey, bread, grapes, wine, scissors, a scalpel, nails, a metal bar, a gun, and a bullet.

There were no separate stages. Abramović and the visitors stood in the same space, making it clear that the latter were part of the work. The purpose of the piece, she said, was to find out how far the public would go: "What is the public about and what are they going to do in this kind of situation?"

🔗 Sociology 🔗 Urban studies and planning

In sociology, the third place refers to the social surroundings that are separate from the two usual social environments of home ("first place") and the workplace ("second place"). Examples of third places include churches, cafes, clubs, public libraries, gyms, bookstores, stoops and parks. In his book The Great Good Place (1989), Ray Oldenburg argues that third places are important for civil society, democracy, civic engagement, and establishing feelings of a sense of place.

Robert Putnam addressed issues related to third place, but without using the term, in Bowling Alone: America's Declining Social Capital (1995, 2000).

🔗 Electronics

In signal processing, the Nyquist frequency (or folding frequency), named after Harry Nyquist, is a characteristic of a sampler, which converts a continuous function or signal into a discrete sequence. For a given sampling rate (samples per second), the Nyquist frequency (cycles per second) is the frequency whose cycle-length (or period) is twice the interval between samples, thus 0.5 cycle/sample. For example, audio CDs have a sampling rate of 44100 samples/second. At 0.5 cycle/sample, the corresponding Nyquist frequency is 22050 cycles/second (Hz). Conversely, the Nyquist rate for sampling a 22050 Hz signal is 44100 samples/second.

When the highest frequency (bandwidth) of a signal is less than the Nyquist frequency of the sampler, the resulting discrete-time sequence is said to be free of the distortion known as aliasing, and the corresponding sample rate is said to be above the Nyquist rate for that particular signal.

In a typical application of sampling, one first chooses the highest frequency to be preserved and recreated, based on the expected content (voice, music, etc.) and desired fidelity. Then one inserts an anti-aliasing filter ahead of the sampler. Its job is to attenuate the frequencies above that limit. Finally, based on the characteristics of the filter, one chooses a sample rate (and corresponding Nyquist frequency) that will provide an acceptably small amount of aliasing. In applications where the sample rate is pre-determined (such as the CD rate), the filter is chosen based on the Nyquist frequency, rather than vice versa.

🔗 Environment 🔗 Geology 🔗 Extinction

The Holocene extinction, otherwise referred to as the sixth mass extinction or Anthropocene extinction, is an ongoing extinction event of species during the present Holocene epoch (with the more recent time sometimes called Anthropocene) as a result of human activity. The included extinctions span numerous families of plants and animals, including mammals, birds, amphibians, reptiles and arthropods. With widespread degradation of highly biodiverse habitats such as coral reefs and rainforests, as well as other areas, the vast majority of these extinctions are thought to be undocumented, as the species are undiscovered at the time of their extinction, or no one has yet discovered their extinction. The current rate of extinction of species is estimated at 100 to 1,000 times higher than natural background rates.

The Holocene extinction includes the disappearance of large land animals known as megafauna, starting at the end of the last glacial period. Megafauna outside of the African mainland (thus excluding Madagascar), which did not evolve alongside humans, proved highly sensitive to the introduction of new predation, and many died out shortly after early humans began spreading and hunting across the Earth (many African species have also gone extinct in the Holocene, but – with few exceptions – megafauna of the mainland was largely unaffected until a few hundred years ago). These extinctions, occurring near the Pleistocene–Holocene boundary, are sometimes referred to as the Quaternary extinction event.

The most popular theory is that human overhunting of species added to existing stress conditions as the extinction coincides with human emergence. Although there is debate regarding how much human predation affected their decline, certain population declines have been directly correlated with human activity, such as the extinction events of New Zealand and Hawaii. Aside from humans, climate change may have been a driving factor in the megafaunal extinctions, especially at the end of the Pleistocene.

Ecologically, humanity has been noted as an unprecedented "global superpredator" that consistently preys on the adults of other apex predators, and has worldwide effects on food webs. There have been extinctions of species on every land mass and in every ocean: there are many famous examples within Africa, Asia, Europe, Australia, North and South America, and on smaller islands. Overall, the Holocene extinction can be linked to the human impact on the environment. The Holocene extinction continues into the 21st century, with meat consumption, overfishing, and ocean acidification and the decline in amphibian populations being a few broader examples of a cosmopolitan decline in biodiversity. Human population growth and increasing per capita consumption are considered to be the primary drivers of this decline.

The 2019 Global Assessment Report on Biodiversity and Ecosystem Services, published by the United Nations' Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, posits that roughly one million species of plants and animals face extinction within decades as the result of human actions.