Have a deep view into what people are curious about.

🔗 Mathematics

Bellman's lost-in-a-forest problem is an unsolved minimization problem in geometry, originating in 1955 by the American applied mathematician Richard E. Bellman. The problem is often stated as follows: "A hiker is lost in a forest whose shape and dimensions are precisely known to him. What is the best path for him to follow to escape from the forest?" It is usually assumed that the hiker does not know the starting point or direction he is facing. The best path is taken to be the one that minimizes the worst-case distance to travel before reaching the edge of the forest. Other variations of the problem have been studied.

A proven solution is only known for a few shapes or classes of shape. A general solution would be in the form of a geometric algorithm which takes the shape of the forest as input and returns the optimal escape path as the output. Although real world applications are not apparent, the problem falls into a class of geometric optimization problems including search strategies that are of practical importance. A bigger motivation for study has been the connection to Moser's worm problem. It was included in a list of 12 problems described by the mathematician Scott W. Williams as "million buck problems" because he believed that the techniques involved in their resolution will be worth at least a million dollars to mathematics.

🔗 Internet culture 🔗 Television 🔗 The Simpsons

Flanderization is the process through which a fictional character's essential traits are exaggerated over the course of a serial work. The term flanderization was coined by TV Tropes in reference to Ned Flanders of The Simpsons, who was caricatured over the show's run from a good neighbor who was religious among other characteristics into an evangelical "bible-thumper". Flanderization has been analyzed as an aspect of serial works, especially television comedies, that shows a work's decline.

🔗 Years

The Alan Turing Year, 2012, marked the celebration of the life and scientific influence of Alan Turing during the centenary of his birth on 23 June 1912. Turing had an important influence on computing, computer science, artificial intelligence, developmental biology, and the mathematical theory of computability and made important contributions to code-breaking during the Second World War. The Alan Turing Centenary Advisory committee (TCAC) was originally set up by Professor Barry Cooper

The international impact of Turing's work is reflected in the list of countries in which Alan Turing Year was celebrated, including: Bolivia, Brazil, Canada, China, Czech Republic, France, Germany, India, Israel, Italy, Netherlands, Mexico, New Zealand, Norway, Philippines, Portugal, Spain, Switzerland, U.K. and the U.S.A. 41+ countries were involved.

🔗 Physics 🔗 History of Science

The ultraviolet catastrophe, also called the Rayleigh–Jeans catastrophe, was the prediction of late 19th century to early 20th century classical physics that an ideal black body at thermal equilibrium would emit an unbounded quantity of energy as wavelength decreased into the ultraviolet range.^: 6–7 The term "ultraviolet catastrophe" was first used in 1911 by Paul Ehrenfest, but the concept originated with the 1900 statistical derivation of the Rayleigh–Jeans law.

The phrase refers to the fact that the empirically derived Rayleigh–Jeans law, which accurately predicted experimental results at large wavelengths, failed to do so for short wavelengths. (See the image for further elaboration.) As the theory diverged from empirical observations when these frequencies reached the ultraviolet region of the electromagnetic spectrum, there was a problem. This problem was later found to be due to a property of quanta as proposed by Max Planck: There could be no fraction of a discrete energy package already carrying minimal energy.

Since the first use of this term, it has also been used for other predictions of a similar nature, as in quantum electrodynamics and such cases as ultraviolet divergence.

🔗 Philately 🔗 Netherlands

A postzegelcode is a hand-written method of franking in the Netherlands. It consists of a code containing nine numbers and letters that customers can purchase online from PostNL and write directly on their piece of mail within five days as proof-of-payment in place of a postage stamp.

For mail within the Netherlands the nine letters and numbers are written as a grid of 3x3. For international mail there is fourth additional row that contains P, N, L.

The system was started in 2013. Initially the postzegelcode was more expensive than a stamp because additional handling systems were required. Then for a while the postzegelcode was cheaper. Eventually the tariffs were set to the same price.

In December 2020, 590,000 people sent cards with postzegelcodes.

🔗 Mathematics

Gabriel's horn (also called Torricelli's trumpet) is a geometric figure which has infinite surface area but finite volume. The name refers to the Abrahamic tradition identifying the archangel Gabriel as the angel who blows the horn to announce Judgment Day, associating the divine, or infinite, with the finite. The properties of this figure were first studied by Italian physicist and mathematician Evangelista Torricelli in the 17th century.

🔗 Paranormal

The Eltanin Antenna is an object photographed on the sea floor by the Antarctic oceanographic research ship USNS Eltanin in 1964, while photographing the sea bottom west of Cape Horn.

Due to its regular antenna-like structure and upright position on the seafloor at a depth of 3,904 metres (12,808 ft), some proponents of fringe and UFO-related theories including Bruce Cathie have suggested that it might be an extraterrestrial artifact. Other authorities have suggested that the object photographed by the Eltanin was an unusual carnivorous sponge, Chondrocladia concrescens (formerly Cladorhiza concrescens).

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Business 🔗 Politics 🔗 Psychology 🔗 Marketing & Advertising

Serial-position effect is the tendency of a person to recall the first and last items in a series best, and the middle items worst. The term was coined by Hermann Ebbinghaus through studies he performed on himself, and refers to the finding that recall accuracy varies as a function of an item's position within a study list. When asked to recall a list of items in any order (free recall), people tend to begin recall with the end of the list, recalling those items best (the recency effect). Among earlier list items, the first few items are recalled more frequently than the middle items (the primacy effect).

One suggested reason for the primacy effect is that the initial items presented are most effectively stored in long-term memory because of the greater amount of processing devoted to them. (The first list item can be rehearsed by itself; the second must be rehearsed along with the first, the third along with the first and second, and so on.) The primacy effect is reduced when items are presented quickly and is enhanced when presented slowly (factors that reduce and enhance processing of each item and thus permanent storage). Longer presentation lists have been found to reduce the primacy effect.

One theorised reason for the recency effect is that these items are still present in working memory when recall is solicited. Items that benefit from neither (the middle items) are recalled most poorly. An additional explanation for the recency effect is related to temporal context: if tested immediately after rehearsal, the current temporal context can serve as a retrieval cue, which would predict more recent items to have a higher likelihood of recall than items that were studied in a different temporal context (earlier in the list). The recency effect is reduced when an interfering task is given. Intervening tasks involve working memory, as the distractor activity, if exceeding 15 to 30 seconds in duration, can cancel out the recency effect. Additionally, if recall comes immediately after the test, the recency effect is consistent regardless of the length of the studied list, or presentation rate.

Amnesiacs with poor ability to form permanent long-term memories do not show a primacy effect, but do show a recency effect if recall comes immediately after study. People with Alzheimer's disease exhibit a reduced primacy effect but do not produce a recency effect in recall.

🔗 Cryptography 🔗 Cryptography/Computer science

In cryptography, power analysis is a form of side channel attack in which the attacker studies the power consumption of a cryptographic hardware device (such as a smart card, tamper-resistant "black box", or integrated circuit). The attack can non-invasively extract cryptographic keys and other secret information from the device.

Simple power analysis (SPA) involves visually interpreting power traces, or graphs of electrical activity over time. Differential power analysis (DPA) is a more advanced form of power analysis, which can allow an attacker to compute the intermediate values within cryptographic computations through statistical analysis of data collected from multiple cryptographic operations. SPA and DPA were introduced to the open cryptology community in 1998 by Paul Kocher, Joshua Jaffe and Benjamin Jun.

🔗 Physics

On June 28, 2009, British astrophysicist Stephen Hawking hosted a party for time travelers in the University of Cambridge. The physicist arranged for balloons, champagne, and nibbles for his guests, but did not send out the invites until the following day, after the party was over.

The party was held at the Gonville and Caius College on Trinity Street (52° 12' 21" N, 0° 7' 4.7" E) at 12:00 UT on June 28, 2009. In preparing for the event, Hawking said he hoped that copies of the invite might survive for thousands of years, and that "one day someone living in the future will find the information and use a wormhole time machine to come back to my party, proving that time travel will one day be possible".

Hawking waited in the room for a few hours before leaving, and no visitors arrived. He regarded the event as "experimental evidence that time travel is not possible".