Event Horizon

Light emitted from inside the horizon can never reach the observer, and anything that passes through the horizon from the observer's side is never seen again. A black hole is surrounded by an event horizon, for example.

Tachyons

To date, the existence of tachyons has been neither confirmed nor explicitly ruled out.

The Seikan Tunnel

It is a 53.85 km (33.49 mile) railway tunnel in Japan, with a 23.3 km (14.5 mile) portion under the seabed. It travels beneath the Tsugaru Strait — connecting the islands of Honshû and Hokkaidô. The Channel tunnel is 51.5kms (31 miles) long, but with an undersea section of 39kms (24 miles), it is the longest undersea tunnel in the world.

Equilibrioception

Some animals are better in this than humans, for example allowing a cat (as a quadruped using its inner ear and tail) to walk on a thin fence. All forms of equilibrioception can be described as the detection of acceleration. It is determined by the level of fluid properly called endolymph in the labyrinth - a complex set of tubing in the inner ear.

Bertrand Russell, in his autobiography

Russell's adolescence was very lonely and he remarked in his autobiography that his keenest interests were in sex, religion and mathematics. Russell is generally recognised as one of the founders of analytic philosophy, even of its several branches.

The act whereby an animal severs one of its own appendages, usually as a self-defense mechanism designed to elude a predator's grasp.

The animals that are captured by the tail will shed part of the tail structure and thus be able to flee. The detached tail will continue to wriggle, creating a deceptive sense of continued struggle and attracting the predator's attention away from the fleeing prey animal. The animal can partially regenerate its tail over a period of weeks. The new section will contain cartilage rather than bone and the skin will have different colouration, typically darker and with little or no pattern.

Boabab

Some are reputed to be many thousands of years old, though as the wood does not produce annual growth rings, this is impossible to verify; few botanists give any credence to these claims of extreme age. It is the national tree of Madagascar and is known colloquially as "upside-down tree" (from the Arabic legend which claims that the devil pulled out the tree and planted it upside down).

Seahorses and pipefishes

Seahorses reproduce in an unusual way: the male becomes pregnant. "The female inserts her ovipositor into the male’s brood pouch, where she deposits her eggs, which the male fertilizes. The fertilized eggs then embed in the pouch wall and become enveloped with tissues." New research indicates the male releases sperm into the surrounding sea water during fertilization, and not directly into the pouch as was previously thought. Most seahorse species' pregnancies lasts approximately two to three weeks.

Chilean Sea Bass

Illegal overfishing threatens the species in some areas, as it is slow-growing, reaching maturity between ten and twelve years of age. The longline fishery has also been criticised for drowning thousands of seabirds, including albatrosses.

The Astrolabe

(c)Brain, considered to be the first computer virus for the PC

(c)Brain was written by two brothers, Basit and Amjad Farooq Alvi, who lived in Lahore, Pakistan. The brothers told TIME magazine they had written it to protect their medical software from piracy and it was supposed to target copyright infringers only.

A facelift

Literally meaning 'surgical removal of wrinkles', it is a procedure used in plastic surgery to give a more youthful appearance. It usually involves the removal of excess facial skin, with or without the tightening of underlying tissues, and the redraping the skin on the patient's face and neck.

Quark

Quarks are the only fundamental particles that interact through all four of the fundamental forces. They come in six flavors, and their names (up, down, strange, charm, bottom, and top) were also chosen arbitrarily based on the need to name them something that could be easily remembered and used. Antiparticles of quarks are called antiquarks.

The Gaboon Viper

Their venom itself is not considered particularly toxic but their venom glands are enormous and produce the largest quantities of any venomous snake.

Arsenic

As the symptoms of arsenic poisoning were somewhat ill-defined, it was frequently used for murder until the advent of the Marsh test, a sensitive chemical test for its presence. (Another less sensitive but more general test is the Reinsch test.)

Butterfly effect

The phrase refers to the idea that a butterfly's wings might create tiny changes in the atmosphere that ultimately cause a tornado to appear (or prevent a tornado from appearing). The flapping wing represents a small change in the initial condition of the system, which causes a chain of events leading to large-scale phenomena. Had the butterfly not flapped its wings, the trajectory of the system might have been vastly different.

Western Redcedar

Pyrites

It is iron disulfide, FeS2, and is the most common of the sulfide minerals. The name pyrite is from the Greek word ðõñÜ (pura) meaning "fire". This is likely due to the sparks that result when pyrite is struck against steel. This capacity made it popular for use in early firearms such as the wheellock.

Cladistics

As the end result of a cladistic analysis, tree-like relationship-diagrams called "cladograms" are drawn up to show hypothesized relationships. A cladistic analysis can be based on as much or as little information as the researcher selects. Modern systematic research is likely to be based on a wide variety of information, including DNA-sequences (so-called "molecular data"), biochemical data and morphological data. In a cladogram, all organisms lie at the leaves, and each inner node is ideally binary (two-way).

The h index

By definition, a scholar with an index of h has published h papers with at least h citations each. Thus, the h-index is the result of the balance between the number of publications and the number of citations per publication. The index is designed to improve upon simpler measures such as the total number of citations or publications, to distinguish truly influential scientists from those who simply publish many papers. The index is also not affected by single papers that have many citations. The index works properly only for comparing scientists working in the same field; citation conventions differ widely among different fields.

The skin!

This applies to exterior surface, as it covers the body, appearing to have the largest surface area of all the organs. Moreover, it applies to weight, as it weighs more than any single internal organ, accounting for about 15 percent of body weight. For the average adult human, the skin has a surface area of between 1.5-2.0 square meters, most of it is between 2-3 mm thick.

Parthenogenesis

It is a form of asexual reproduction in which females produce eggs that develop without fertilization. It occurs naturally in some species, including lower plants, invertebrates (e.g. water fleas, aphids, some bees and parasitic wasps), and vertebrates (e.g. some reptiles, fish, and, very rarely, birds and sharks). It is sometimes also used to describe reproduction modes in hermaphroditic species which can self-fertilize.

Ganymede

It is Jupiter's moon, and the largest moon in the entire solar system.

Minamata disease

Symptoms include ataxia, numbness in the hands and feet, general muscle weakness, narrowing of the field of vision and damage to hearing and speech. In extreme cases, insanity, paralysis, coma and death follow within weeks of the onset of symptoms. It was caused by the release of methyl mercury in the industrial wastewater and this toxic chemical bioaccumulated in shellfish and fish in Minamata Bay and the Shiranui Sea, which when eaten by the local populace resulted in mercury poisoning.

Another name for the big toe

Zircons

Their oxygen isotopic composition has been interpreted to indicate that more than 4.4 billion years ago there was already water on the surface of the Earth. This spectacular interpretation has been published in top scientific journals, but is the subject of debate.

The Riemann hypothesis (also called the Riemann zeta-hypothesis), first formulated by Bernhard Riemann in 1859.

A $1,000,000 prize has been offered by the Clay Mathematics Institute for the first correct proof. Most mathematicians believe the Riemann hypothesis to be true.

Dialysis

It is a life support treatment and does not treat any kidney diseases. When healthy, the kidneys remove waste products (for example potassium, acid and urea) from the blood and also remove excess fluid in the form of urine. Dialysis treatments have to duplicate both of these functions as dialysis (waste removal) and ultrafiltration (fluid removal).

The Saltwater or Estuarine Crocodile

A healthy adult male saltwater crocodile is typically 4.8 to 7 metres (15.75 to 21.6 ft) long, and weighs up to 770 kg (1697 lb), with many exceptions being much larger than this.

Srinivasa Ramanujan (1887 - 1920)

A definitive example of an autodidact prodigy, Ramanujan compiled an estimated 3,900 theorems during his short lifetime. Although a small number of these results were actually false, most of his statements have now been proven to be correct. His deep intuition and uncanny algebraic manipulative ability enabled him to state results that were both original and highly unconventional, and these have inspired a vast amount of research.

He was the head Soviet rocket engineer and designer during the Space Race between the United States and the Soviet Union in the 1950s and 1960s.

Although trained as an aircraft designer, Korolyov's greatest strengths proved to be in design integration, organization and strategic planning. He oversaw the successes of the Sputnik and Vostok projects.

Klein bottle

Alice in Wonderland syndrome (AIWS), or Micropsia

The condition is in terms of perception only; the mechanics of the eye are not affected, only the brain's interpretation of information passed from the eyes. The syndrome is associated with, and perhaps in part caused by, the classical migraine headache. The disorder is named after Lewis Carroll's Alice's Adventures in Wonderland, where the title character experiences many situations similar to those of micropsia and macropsia. Because Lewis Carroll recorded at least one episode of classical migraine, scholars have speculated that he may have experienced this syndrome himself.

4-6 hrs

Only the transparent section of the eyes (called cornea) is taken out and not the full eye ball.

Polaroid photography

Among other things, he invented inexpensive filters for polarizing light, instant polaroid photography, and his retinex theory of color vision. At one time, he was listed in the Guinness Book of World Records as the world's richest scientist.

CERN (The European Organization for Nuclear Research)

The convention establishing CERN was signed on 29 September 1954. From the original 12 signatories of the CERN convention, membership has grown to the present 20 member states. Its main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research. As of 2007, about half of the world's particle physics community, work on experiments conducted at CERN. As an international facility, the CERN sites are not officially under Swiss or French jurisdiction, and some company vehicles have diplomatic number plates.

Vitamins

In humans there are 13 vitamins: 4 fat-soluble (A, D, E and K) and 9 water-soluble (8 B vitamins and vitamin C).

IQ

In 1912, the abbreviation of "intelligence quotient" or I.Q., a translation of the German Intelligenz-Quotient, was coined by the German psychologist William Stern.

Passenger Pigeons

Martha was frozen into a block of ice and sent to the Smithsonian Institution, where she was skinned and mounted. Martha is no longer on display, but is in the museum's archived collection.

Buckyball or Fullerene

The fullerenes, discovered in 1985 by researchers at Rice University, are a family of carbon allotropes named after Richard Buckminster Fuller and are sometimes called buckyballs. They are molecules composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube. Buckminsterfullerene is the smallest fullerene in which no two pentagons share an edge. It is also the most common in terms of natural occurrence, as it can often be found in soot.

The Okapi

Although it bears striped markings reminiscent of the zebra, the Okapi is most closely related to the giraffe. Native just to the Ituri forests situated in the north east of the Democratic Republic of the Congo, it was known only to the local people until 1901.

Messerschmitt Bf 109

It was one of the first true modern fighters of the era, including such features as an all-metal monocoque construction, a closed canopy, and retractable landing gear. The Bf 109 was the standard fighter of the Luftwaffe for the duration of World War II, although it began to be partially replaced by the Focke-Wulf Fw 190 starting in 1941. The Bf 109 scored more aircraft kills in World War II than any other aircraft. Although the Bf 109 had weaknesses, including a short range, and especially a sometimes difficult to handle narrow, outward-retracting undercarriage, it stayed competitive with Allied fighter aircraft until the end of the war.

Paul Erdos

Erdos (1913-1996) was an immensely prolific (and famously eccentric) Hungarian-born mathematician who, with hundreds of collaborators, worked on problems in combinatorics, graph theory, number theory, classical analysis, approximation theory, set theory, and probability theory.

Orange

Geber (Abu Musa Jabir ibn Hayyan, 721– c. 815)

His ethnic background is not clear; although most sources state he was an Arab, others describe him as Persian. He introduced many methods such as the syntheses of hydrochloric and nitric acids, distillation, and crystallisation.

Antoine-Laurent de Lavoisier (1743 – 1794)

He stated the first version of the Law of conservation of mass, co-discovered, recognized and named oxygen (1778) as well as hydrogen, disproved the phlogiston theory, introduced the Metric system, invented the first periodic table including 33 elements, and helped to reform chemical nomenclature.

Otzi (Frozen Fritz and Similaun Man are also used)

Seymour Cray (1925-1996), the architect of the Supercomputer

AIDS

Technically, it is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. It has also found applications in the food industry in detecting potential food allergens such as milk, peanuts, walnuts, almonds, and eggs.

Box jellyfish

Box jellyfish are found in Australia, the Philippines, and many other tropical areas.

Depleted Uranium

It is primarily composed of the isotope uranium-238. Since depleted uranium contains less than one third as much uranium-235 as natural uranium, it is weakly radioactive and an external radiation dose from depleted uranium is about 60% of that from the same mass of uranium with a natural isotopic ratio. Depleted uranium behaves in the body as does natural uranium.

Oxygen

Clouds. Stratus means 'layer' and cumulus means 'piled up'

These two cloud types are divided into four more groups that distinguish the cloud's altitude - High, Medium, Low and Vertical.

Menlo Park

It was in the Menlo Park Laboratory that Thomas Edison came up with his most famous inventions, including the phonograph and a commercially viable incandescent light bulb filament and he is sometimes referred to as "the Wizard of Menlo Park".

The spacecraft Pioneer 10

Pioneer 10 was the first spacecraft to travel through the asteroid belt, and was the first spacecraft to make direct observations of Jupiter. It was launched from Cape Canaveral on March 2, 1972. It is heading in the direction of the star Aldebaran in the constellation Taurus at roughly 2.6 AUs per year and if Aldebaran had zero relative velocity, it would take Pioneer about 2 million years to reach it.

Collagen

Collagen has been widely used in cosmetic surgery, as a healing aid for burn patients for reconstruction of bone and a wide variety of dental, orthopedic and surgical purposes. Collagens are widely employed in the construction of artificial skin substitutes used in the management of severe burns, as well as for a wide range of dental, orthopedic, and surgical purposes. These collagens may be derived from bovine, equine or porcine, and even human, sources and are sometimes used in combination with silicones, glycosaminoglycans, fibroblasts, growth factors and other substances.

Argentinosaurus, a herbivorous sauropod

Not much of Argentinosaurus has been recovered: just some back vertebrae, tibia, fragmentary ribs, and sacrum. One vertebra had a length of 1.3 metres and the tibia was about 155 centimetres (58 inches) However, the spectacular proportions of these bones and the familiarity of the species' sauropod relatives allows paleontologists to estimate that full-grown specimens reached some 35 metres (115 feet) in length. Weight was perhaps 80 to 100 tonnes. It is the largest dinosaur that there is good evidence for.

Leptons

There are three known flavors of lepton: the electron, the muon, and the tau.

An adverse effect associated with a medical practitioner or treatment.

Iatros means physician in Greek, and -genic, meaning induced by, is derived from the International Scientific Vocabulary. Combined, they become iatrogenic, meaning physician-induced.

One which inhabits or spends large amounts of time in trees or bushes.

Potassium

Apart from Potassium, Bananas are a valuable source of Vitamin A, Vitamin B6 and Vitamin C. The fruit averages 125g, of which approximately 75% is water and 25% dry matter content.

Cellulose

Cellulose was discovered and isolated in the mid-nineteenth century by the French chemist Anselme Payen. Cellulose is not digestible by humans and is often referred to as 'dietary fiber' or 'roughage'.

Isabelline penguins

This is possibly in reference to the legend that the archduchess Isabella of Austria vowed not to change her undergarments until her husband united the northern and southern Low Countries by taking the city of Ostend--which took three years to accomplish. Isabellinism is different from albinism, though the faded color of the plumage calls albinism to mind. Isabelline penguins tend to live shorter lives than normal specimens, since their backs aren't well camouflaged against the deep, and they are often passed over as mates, so the trait is selected against.

On Mars

The central edifice stands 27 kilometres (around 17 miles) high above the mean surface level of Mars (about three times the elevation of Mount Everest above sea level and 2.6 times the height of Mauna Kea above its base). It is 550 km (342 miles) in width.

Bioluminescence

5

The first orbiter, Enterprise, was not built for actual space flight, and was used only for testing purposes and is not considered an operational vehicle. Enterprise was followed by four operational space shuttles: Columbia, Challenger, Discovery and Atlantis. Challenger was destroyed on launch in 1986, and Endeavour was built as a replacement. Columbia was destroyed on re-entry in 2003.

Water

Blood is about 7% of the human body weight, so the average adult has a blood volume of about 5 litres, of which 2.7-3 litres is plasma.

Schrödinger's cat

The thought experiment serves to illustrate the strangeness of quantum mechanics and the mathematics necessary to describe quantum states. The idea of a particle existing in a superposition of possible states, while a fact of quantum mechanics, is a concept that does not scale to large systems (like cats), which are not indeterminably probabilistic in nature. Philosophically, these positions which emphasize either probability or determined outcomes are called (respectively) positivism and determinism.

pH scale

pH is a measure of the acidity or alkalinity of a solution. Solutions with a pH less than seven are considered acidic, while those with a pH greater than seven are considered basic (alkaline). pH 7 is considered neutral because it is the pH of pure water at 25 °C.

Extinct in the Wild

The other categories are Critically Endangered (CR), Endangered (EN), Vulnerable (VU), and Near Threatened (NT).

Amur (or Siberian) tiger is the largest and the Sumatran tiger is the smallest

Broca's area

Broca's area is named after the 19th century physician Paul Broca who discovered it. He arrived at this discovery by studying the brains of aphasic patients (persons with speech and language disorders resulting from brain injuries).

Superconductivity

At the temperature of 4.2 Kelvin, he observed that the resistance abruptly disappeared. In subsequent decades, superconductivity was found in several other materials. In 1913, lead was found to superconduct at 7 K, and in 1941 niobium nitride was found to superconduct at 16 K.

Monkey puzzle (X is monkey)

The proud owner of a young specimen in Cornwall was showing it to a group of friends, and one made the remark "It would puzzle a monkey to climb that"; as the tree species had no existing popular name, first 'monkey-puzzler', then 'monkey-puzzle' stuck. As a practical exercise, a monkey trying to climb one would not be so much puzzled as injured by the razor-sharp leaf edges.

Oleic acid

If a drop of oleic acid were to be added to a live bee, it would be dragged off, kicking and screaming, as if it were dead.

Ants

Ants have colonized almost every landmass on Earth. The only places lacking indigenous ant species are Antarctica, Greenland, Iceland, and the Hawaiian Islands. Individuals are divided into sub-fertile, and more commonly sterile, females ("workers"), fertile males ("drones"), and fertile females ("queens"). Colonies can occupy and use a wide area of land to support themselves. Ant colonies are sometimes described as superorganisms because the colony appears to operate as a single entity.

The Kakapo

Also called owl parrot, it is endemic to New Zealand and is currently listed as critically endangered.

Nikola Tesla

After his demonstration of wireless communication in 1893 and after being the victor in the "War of Currents", Tesla was widely respected as America's greatest electrical engineer. The SI unit measuring magnetic flux density or magnetic induction (commonly known as the magnetic field ), the tesla, was named in his honour. Aside from his work on electromagnetism and engineering, Tesla is said to have contributed in varying degrees to the establishment of robotics, remote control, radar and computer science and to the expansion of ballistics, nuclear physics and theoretical physics.

Fingerprints

There are also more complex classification systems that further break down patterns to plain arches or tented arches.

The Positron

The existence of positrons was first postulated in 1928 by Paul Dirac as a consequence of the Dirac equation. In 1932, positrons were discovered by Carl D. Anderson, who gave the positron its name. When a low-energy positron collides with a low-energy electron, annihilation occurs, resulting in the production of two gamma ray photons.

Portland cement

It is a fine powder produced by grinding Portland cement clinker (more than 90%), a maximum of about 5% gypsum which controls the set time, and up to 5% minor constituents (as allowed by various standards).

Unlike noble gases, an inert gas is not necessarily elemental and are often molecular gases.

Helium and neon are the only true elemental inert gases, because they do not form any (known) true chemical compounds, unlike the heavier noble gases (argon, krypton, xenon and radon).

The Galapagos tortoise

Adults of large species can weigh over 300 kilograms (660 lb) and measure 1.2 meters (3.9 ft) long. Although the maximum life expectancy of a wild tortoise is unknown, the average life expectancy is estimated to be 200 years.

Archimedes

The Fields Medal is a prize awarded to two, three, or four mathematicians not over 40 years of age at each International Congress of the International Mathematical Union, a meeting that takes place every four years. The Fields Medal is widely viewed as the top honor a mathematician can receive.

~ 13 times

The Moon makes a complete orbit about the Earth with respect to the fixed stars (its sidereal period) approximately once every 27.3 days. However, since the Earth is moving in its orbit about the Sun at the same time, it takes slightly longer for the Moon to show its same phase to Earth, which is about 29.5 days (its synodic period). Unlike most satellites of other planets, the Moon orbits near the ecliptic and not the Earth's equatorial plane.