Importance ratings

Wikenigma assigns 'Importance Ratings' to some pages.

The idea is to separate articles which are considered (by the editors) to cover exceptionally important unknown issues from those which (although also unknown) are probably not so important. For example, the fact that no-one knows how Yardangsplugin-autotooltip__plain plugin-autotooltip_bigYardangs

Yardangs are enigmatic wind-parallel ridges found in arid environments. They often form downwind of rocks in sandy environments. They can be unusually stable structures, given their sandy / dusty composition (and the fact that the wind which forms them can al… form wouldn't normally be considered as important as the fact that no-one understands what causes Diabetesplugin-autotooltip__plain plugin-autotooltip_bigDiabetes (type 1)

Type 1 Diabetes is a chronic autoimmune disease that occurs either when the pancreas does not produce enough insulin, or when the body cannot effectively use the insulin it produces. Insulin is a crucial hormone required for the body to regulate and u….

If a page doesn't have a rating, that doesn't mean it's unimportant - but that some other articles may be more important (or, it hasn't been rated yet).

Note: As with the rest of the content, the ratings are available for editing, and may change over time.

The tables below show links to examples of articles which have been given Importance Ratings (alphabetical order)

4 Stars

Ageingplugin-autotooltip__plain plugin-autotooltip_bigEvolution of ageing

Evolutionary scientists have been trying to form a consolidated theory of ageing since the 1890's.

"Enquiry into the evolution of ageing aims to explain why a detrimental process such as ageing would evolve, and why there is so much variability in…
Alcoholplugin-autotooltip__plain plugin-autotooltip_bigAlcohol intoxication

"Despite the fact that alcohol has been used and misused for hundreds of years, the mechanism of action of this simple molecule remains the subject of study. Alcohol use results in diverse behavioral effects, including intoxication, cognitive impa…
Antimatterplugin-autotooltip__plain plugin-autotooltip_bigThe Antimatter Problem

According to Big Bang Theory, matter and anti-matter should have been created in equal amounts at the 'beginning' of the Universe. And, in experiments with high-energy particle accelerators, that is exactly what happens. Baryons (i.e. 'heavy' par…
Antimatter Gravityplugin-autotooltip__plain plugin-autotooltip_bigAntimatter and gravity

resolved

The 'Resolved' category archives questions which have been answered since they were added to the site.

As of Sep. 2023, this entry is now moved to the 'Resolved' section.

A recent set of experiments at CERN, which created thousands o…
Cell Organellesplugin-autotooltip__plain plugin-autotooltip_bigCellular organelles

Eukaryotic cells are cells which have a nucleus. Within that nucleus are various discrete structures with very specific functions that are, as a group, called 'organelles'.

In the 1970s a book by professor Lynn Margulis (titled Origin of Eukaryotic…
Cfeplugin-autotooltip__plain plugin-autotooltip_bigCO2 fertilization effect ( CFE )

The CO2 Fertilization Effect refers to the fact that increased atmospheric CO2 levels can encourage plant growth. This is a well known effect, and is exploited in farms which grow crops in greenhouses with artificially elevated CO
Cognitionplugin-autotooltip__plain plugin-autotooltip_bigCognition

Cognition has been defined as “the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses” source

It's currently thought that all animate and inanimate objects are composed entirely of quarks, gluons, an…
Consciousnessplugin-autotooltip__plain plugin-autotooltip_bigConsciousness

Does an ant carrying a piece of leaf across the forest floor ‘know’ it’s doing so? Is it conscious? If science could construct a machine as complex as the human brain, would it ‘know’ it existed? Will it oneday be possible to explain consciousness via the…
Constantsplugin-autotooltip__plain plugin-autotooltip_bigPhysical constants

Constants variability :

Many physics calculations rely on the assumption that the ‘physical constants’ e.g. light-speed, gravity, etc etc are, in fact, constant. Extremely accurate experimental procedures strongly suggest that they (mostly) are. But…
Covid19plugin-autotooltip__plain plugin-autotooltip_bigCovid-19

Editor's note : Because of the intense, ongoing, global research efforts related to Covid-19, it's difficult to get an accurate picture of the unknown factors. Here are some of the many as-yet-unanswered questions Why does the virus have much more serious eff…
Dark Energyplugin-autotooltip__plain plugin-autotooltip_bigDark Energy

"The observational results of the latest 15 to 20 years have established a standard model for the cosmology which has some amazing consequences. A mysterious entity, the dark energy, has been confirmed as the dominant component of the Universe, and is also…
Dark Matterplugin-autotooltip__plain plugin-autotooltip_bigDark Matter

"The nature of the dominant component of galaxies and clusters remains unknown.“

Source : Measuring the dark matter equation of state (Mon. Not. R. Astron. Soc. 415, L74–L77)"

In the 1930s, astronomical observations of galaxy rotations showed that the ou…
Electron Quark Balenceplugin-autotooltip__plain plugin-autotooltip_bigElectron / Quark charge balance

It's known that all atoms are based on a structure where the 'negative' electric charge of the electron(s) (conventionally known as '-1') exactly balances the 'positive' charge of the corresponding proton(s) in the atom's nucleus.
Entanglementplugin-autotooltip__plain plugin-autotooltip_bigQuantum entanglement

Quantun Entanglement was first predicted by Albert Einstein, Boris Podolsky, and Nathan Rosen in 1935.

It has now been (unequivocally) experimentally demonstrated with photons, neutrinos, electrons, and even molecules and crystals :

In 2019, it …
Enzyme Catalysisplugin-autotooltip__plain plugin-autotooltip_bigEnzyme catalysis

Almost all metabolic processes in living cells need enzyme catalysis in order to proceed at rates fast enough to sustain life. Although enzyme processes have been investigated for many decades, and more than 5000 have been identified, the extreme compl…
Gamma Ray Burstsplugin-autotooltip__plain plugin-autotooltip_bigGamma-ray bursts

Gamma-Ray Bursts (GRBs) were first discovered by satellites originally intended to scan for nuclear weapon detonations.They range from bursts of ten milliseconds to several hours, and also have differing energy levels. They are generally unexplained.
Gen Anaestheticsplugin-autotooltip__plain plugin-autotooltip_bigGeneral Anaesthetics

A general anaesthetic is a drug that brings about a reversible loss of consciousness.

In formal use since 1842 - the first public demonstration used Diethyl ether to carry out surgery. (Though it's likely that alcohol, another chemical classed as…
Gravityplugin-autotooltip__plain plugin-autotooltip_bigGravity

Although three of the four (known) fundamental forces have been unified by one paradigm called the Standard Model (SM) Gravity remains outside.

This doesn't necessarily mean that Standard Model has failed in some way. Perhaps Gravity is independent from and i…
Great Depressionplugin-autotooltip__plain plugin-autotooltip_bigThe Great Depression (causes)

"The Great Depression was a severe worldwide economic depression that took place mostly during the 1930s, beginning in the United States. The timing of the Great Depression varied across the world; in most countries, it started in 1929 an…
Homochiralityplugin-autotooltip__plain plugin-autotooltip_bigHomochirality

"Symmetry is a fundamental aspect of nature. For example, certain molecules exist in two forms which are symmetrical mirror images of each other. They are called chiral molecules. Common chemical synthesis generally produces equal amounts of the two form…
Ht Superconductivityplugin-autotooltip__plain plugin-autotooltip_bigHigh Temperature Superconductivity

functionality_unexplained

The first 'high-temperature' (defined as above --196.2°C) superconductor was discovered in 1986 by IBM researchers Karl Müller and Johannes Bednorz - for which they were awarded the Nobel Prize in Physics in…
Inflationplugin-autotooltip__plain plugin-autotooltip_bigCosmological inflation

Using calculations constrained by the ‘Standard Model’ (the laws of particle and fundamenta-force physics as currently understood) it’s not possible to create coherent mathematical solutions which account for the evolution of the universe – from …
Intelligenceplugin-autotooltip__plain plugin-autotooltip_bigIntelligence

"Numerous definitions of and hypotheses about intelligence have been proposed since before the twentieth century, with no consensus reached by scholars.“

Source wikipedia"

Despite the lack of an agreed definition, tests of IQ (Intelligence Quotients) …
Life-definitionplugin-autotooltip__plain plugin-autotooltip_bigDefining Life

There isn’t, as yet, any definition of a 'lifeform' which can withstand logical scrutiny.

Exceptions can easily be found for any definition so far presented. For example (from The American Heritage Dictionary of the English Language
Massplugin-autotooltip__plain plugin-autotooltip_bigMass

All physical objects have ‘mass’. The mass is (largely) a consequence of the additions of the masses of the atomic and subatomic particles from which the objects are comprised. Theorists currently support the idea of mass-creation via the
Memoryplugin-autotooltip__plain plugin-autotooltip_bigMemory

"Although it is commonly accepted that learning and memory occur via enduring changes in neuronal properties such as synaptic strength within a network of neurons, many details of these processes remain unknown, including the mechanisms responsible for the pers…
Metallic Catalystsplugin-autotooltip__plain plugin-autotooltip_bigMetallic catalysts

The history of using metallic catalysts to speed up chemical reactions goes back to the mid 1800s. They typically make reaction rates many thousands of times faster.

Without metallic catalysts, many current-day commercial reaction processes would be…
Methane Cycleplugin-autotooltip__plain plugin-autotooltip_bigGlobal Atmospheric Methane Cycle

Methane is roughly 80 times more potent as a Greenhouse Gas (GG) than CO2. Over the last 30 years, the measured levels in the atmosphere have been steadily rising, - maintaining a clearly-defined seasonal cycle.

"Methane is an importa…
Numerical Cognitionplugin-autotooltip__plain plugin-autotooltip_bigNumerical cognition

Many animals have demonstrated abilities to count numbers - a.k.a Numerical Cognition. This fits in with evolutionary theory in the sense that it could be advantageous for an animal to understand (small) numbers when involved in feeding, threat sit…
Oxygen Processplugin-autotooltip__plain plugin-autotooltip_bigOxygen Evolving Process (EVP)

"Photosynthetic oxygen evolution is the fundamental process by which oxygen is generated in earth's biosphere. The reaction is part of the light-dependent reactions of photosynthesis in cyanobacteria and the chloroplasts of green algae an…
Photosynthesisplugin-autotooltip__plain plugin-autotooltip_bigPhotosynthesis

"Photosynthetic water splitting (or oxygen evolution) is one of the most important reactions on the planet, since it is the source of nearly all the atmosphere's oxygen [...] The mechanism of water oxidation is still not fully elucidated,
Prime Numbersplugin-autotooltip__plain plugin-autotooltip_bigPrime Numbers

Since all other whole numbers (except 0) can be produced by multiplying together primes – they must be considered fundamental.

(1), 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31 &etc

There are an infinite number of primes - as proved by Euclid around 300B.C. (…
Primordial Soupplugin-autotooltip__plain plugin-autotooltip_bigPrimordial Soup

"In 1953 an iconic set of experiments showed that some of the chemical building blocks of life, such as amino acids, could form spontaneously in the atmospheric conditions thought to prevail on the primordial Earth. This gave rise to the idea that the …
Proton Hoppingplugin-autotooltip__plain plugin-autotooltip_bigProton Hopping

Proton hopping - a.k.a. the Grotthuss Mechanism has been said to be “the fastest known chemical reaction”. The effects of which were first noted by Theodor Grotthuss in 1805, who was investigating the decomposition of water under electrolysis.

In the pr…
Quantum Mechanicsplugin-autotooltip__plain plugin-autotooltip_bigQuantum mechanics

This is a general note about the yet-to-be-understood complexities of quantum theory

Here are some 20th century quotes from eminent scientists regarding its extreme counter-intuitiveness :

"• “Those who are not shocked when they first come across q…
Quarksplugin-autotooltip__plain plugin-autotooltip_bigQuarks

Following theoretical calculations, particle accelerator experiments in the 1970s confirmed that quarks are responsible for the internal structure of protons and neutrons. ( 3 quarks each, in different configurations, see :Electron / Quark charge balance).

Agai…
Random Numbersplugin-autotooltip__plain plugin-autotooltip_bigRandom numbers

unknowable

"We can never decide for sure that a number is random, but what we can do is apply an increasing number of tests and treat our sequence of numbers as innocent until proved guilty.“

Source Colva Roney-Dougal, Senior Lecturer in Pure Mathemat…
Schrodinger Equationplugin-autotooltip__plain plugin-autotooltip_bigSchrödinger equation paradox

Quote from Professor Roger Penrose speaking on BBC Radio 4 'Start the week - A Theory of Everything? 20th June 2016.

"There is a deep paradox in quantum mechanics, it's a contradiction, and it's hardly ever pointed out as a contradiction.…
Sea Level Risesplugin-autotooltip__plain plugin-autotooltip_bigSea level rises

Climate change, along with the associated ice-shelf melting, contributes to sea level rise. However, the calculations linking the temperature records with ice melt leave an unexplained 12 cm/century rise in the actual levels - as measured around the wor…
Thoughtplugin-autotooltip__plain plugin-autotooltip_bigThought

It seems clear that thoughts involve brain-neurones, because damage to (or a reduction in the number of) neurones makes rational thought more difficult. But, likememory, the exact physical and/or biological micro-mechanisms which lead to the formation of ‘thou…
Time Awarenessplugin-autotooltip__plain plugin-autotooltip_bigTime Awareness

"Anticipating events that will happen in the future is among the most important functions the brain performs. Indeed, it has been increasingly stressed that learning and memory are prospective brain functions; that is, they are only adaptive to the exte…
Times Arrowplugin-autotooltip__plain plugin-autotooltip_bigArrow of Time

A term coined in 1927 by the British astronomer Arthur Eddington to describe the “one-way direction” or “asymmetry” of time.

For most people, the notion that time passes only in one direction is a given. There are multiple reasons for taking this point o…
Universe Shapeplugin-autotooltip__plain plugin-autotooltip_bigUniverse shape and size

The 'Observable Universe' is limited by the speed of light and the length of time that it has been in existence. It's possible that the 'Observable Universe' is the real size, or, because light has a finite speed, there may be more of the univer…
Vacuum Energyplugin-autotooltip__plain plugin-autotooltip_bigVacuum energy

Quantum physics, and the widely accepted and experimentally tested Heisenberg Uncertainty Principle implies that no 'vacuum' can be truly empty. At all times, innumerable quantised 'virtual particles' must be coming into existence and then disappearing.…
Waterplugin-autotooltip__plain plugin-autotooltip_bigWater - its origin

One obvious difference between Earth and other planets in the Solar System is that it's 70% covered in liquid water. There are at least five major (and very different) theories proposing the origins of such a large volume of water (estimated at aroun…
Water Clustersplugin-autotooltip__plain plugin-autotooltip_bigWater clusters

Water has a long list of 'anomalous' physical (and chemical) properties (list here, archived from London Southbank University). Most are now fairly well understood - but there is currently no overall model to explain all of its unusual properties

3 Stars

Adsorptionplugin-autotooltip__plain plugin-autotooltip_bigAdsorption

[ Note : Not to be confused with 'Absorption' whereby molecules, atoms or ions of a substance 'soak' into other materials. E.g. water / sponge ]

In adsorption, atoms, ions or molecules from a gas, liquid (or dissolved solid) adhere to a surface, and can dra…
Alzheimersplugin-autotooltip__plain plugin-autotooltip_bigAlzheimer's disease

"Alzheimer’s disease is a chronic progressive neuro-degenerative disorder characterised by three primary groups of symptoms. The first group (cognitive dysfunction) includes memory loss, language difficulties, and executive dysfunction (that is, lo…
Appetiteplugin-autotooltip__plain plugin-autotooltip_bigAppetite Regulation

Very extensive research, over many decades, has identified a number of biochemical routes that can influence appetite in humans.

For an overview, see: Mechanisms of Appetite Regulation

In particular, the so called 'hunger hormones' leptin and ghre…
Avian Kt Survivalplugin-autotooltip__plain plugin-autotooltip_bigAvian K-T survival

It's now widely accepted that the Cretaceous–Tertiary (K–T) extinction event (also known as the The Cretaceous–Paleogene (K–Pg) extinction event) played a large part in the extinction of the non-avian dinosaurs. (see : Dinosaur extinction )

The bra…
Aviation Contrailsplugin-autotooltip__plain plugin-autotooltip_bigAviation contrails (climate impact)

Jet engines used in commercial and military aircraft typically burn carbon-based fuels (e.g. kerosene). When the fuel burns, a by-product is CO2, which is a potent greenhouse gas and contributes towards global warming.
Bondingplugin-autotooltip__plain plugin-autotooltip_bigChemical bonding

Chemistry textbooks normally describe three types of chemical bonds - the strong attraction between atoms, ions or molecules that enables the formation of all chemical compounds.

* The Ionic bond * The Covalent bond * The Metallic bond
Cable Bacteriaplugin-autotooltip__plain plugin-autotooltip_bigCable Bacteria

Cable bacteria are filamentous bacteria, found in aqueous sediments, which form chains that conduct electricity. They transfer electrons across distances over 1cm (possibly more) in sediment and groundwater aquifers. They enable the reduction of oxygen a…
Carotid Bodyplugin-autotooltip__plain plugin-autotooltip_bigCarotid Body Mechanism

The level of oxygen present in mammalian blood - critical for survival - is controlled by a complex feedback system triggering increased or decreased breathing, and alterations in blood pressure etc.. It's dependent on 'sensors', one primary sens…
Cell Proliferationplugin-autotooltip__plain plugin-autotooltip_bigCell proliferation

When organic 'tissue' grows (either during embryonic development, post-natal growth, or tissue regeneration) there are two processes in operation which determine the final size of the tissue or organ. The first is the size of the cells themselves - w…
Chaos Theoryplugin-autotooltip__plain plugin-autotooltip_bigChaos Theory

unknowable

Chaos Theory is the concept that the behaviour of some complex dynamical systems (e.g. global weather patterns) can be extremely sensitive to tiny changes in initial conditions.

Any large-scale system which has a complex set of interacting fee…
Chillsplugin-autotooltip__plain plugin-autotooltip_bigChills

Note: This item refers to the emotionally or imaginatively triggered sensation of 'Frisson' rather than shiver reactions caused by cold or fever etc.

Chills, 'goosebumps' etc can be induced in a number of ways: musical, scenic, tactile, and even taste sensation…
Cloud Ice Formationplugin-autotooltip__plain plugin-autotooltip_bigCloud ice formation

The formation of ice crystals have important implications for stratospheric ozone chemistry, cloud dynamics, rock weathering, and hydrate formation etc., however the exact mechanisms by which microscopic particulate matter 'seeds' ice-crystals are u…
Core Clockplugin-autotooltip__plain plugin-autotooltip_bigCore Clock

In humans, mammals, fish, insects, and very many other organisms, the 'Core Clock' which regulates variations in body functions is set to (approximately) 24 hours. This is the so-called Circadian Rhythm. - which in many organisms, is synchronised via dayligh…
Cosmic Raysplugin-autotooltip__plain plugin-autotooltip_bigCosmic rays

"Cosmic rays are typically protons or atomic nuclei of elements such as helium, carbon, or iron. The most energetic have energies more than 10 million times greater than those in the world’s most powerful atom smasher, the Large Hadron Collider.
Cosmological Constantplugin-autotooltip__plain plugin-autotooltip_bigCosmological Constant Problem

The cosmological constant problem is the disagreement in 'measured' values of the cosmological constant and theoretical calculations of its value.

The cosmological constant was first proposed by Einstein as a mathematical necessity to rat…
Cryingplugin-autotooltip__plain plugin-autotooltip_bigCrying

Crying is the shedding of tears (or welling of tears in the eyes) in response to an emotional state - as distinct from non-emotional 'lacrimation' which is the medical term for non-emotional shedding of tears (e.g. in response to peeling onions).
Crystallizationplugin-autotooltip__plain plugin-autotooltip_bigCrystallization

Crystallization is the (natural or artificial) process by which a solid forms from solution, where the atoms or molecules are highly organized into a structure. Some aspects of the process, particularly nucleation have still not been completely describe…
Depressionplugin-autotooltip__plain plugin-autotooltip_bigMajor Depressive Disorder

Major Depressive Disorder (MDD), also known simply as 'depression', is a mental disorder characterized by at least two weeks of pervasive low mood.

Current estimates are that severe depression affects around 2% of the global population at any…
Diabetesplugin-autotooltip__plain plugin-autotooltip_bigDiabetes (type 1)

Type 1 Diabetes is a chronic autoimmune disease that occurs either when the pancreas does not produce enough insulin, or when the body cannot effectively use the insulin it produces. Insulin is a crucial hormone required for the body to regulate and u…
Dna Rnaplugin-autotooltip__plain plugin-autotooltip_bigDNA / RNA

The vast majority of human DNA lies outside of the genes within the cells. Of this, recent work has discovered that 85% of these stretches of DNA appear to make RNA - which, for the most part, has yet-to-be-determined functions.

A study published in the onli…
Endophytesplugin-autotooltip__plain plugin-autotooltip_bigEndophytes

Endophytes (literally “inside plants”) were first found in 1809 by examining plant sections under the microscope. They are fungal, or bacterial, or viral inclusions in plant tissues – 'foreign' materials, found in very large numbers. They're permanent fixtur…
Environmental Plasticsplugin-autotooltip__plain plugin-autotooltip_bigEnvironmental plastic degradation

Of the (estimated) 300 - 400 million tonnes of plastic produced worldwide every year, only around 20% is currently recycled or incinerated. Much of the remaining 80% eventually ends up in the environment.

In the environment, plastics …
Fine Structure Constantplugin-autotooltip__plain plugin-autotooltip_bigThe Fine Structure Constant

The Fine Structure Constant, identified by the Greek letter α is a fundamental number used in quantum physics calculations. The current estimate is that it's around 0.00729735256 - or roughly 1/137.

It has been called the
Flagellaplugin-autotooltip__plain plugin-autotooltip_bigFlagella

A flagellum is a lash-like movable appendage - often used as a means of propulsion - which is attached to the cell body of many bacteria and some eukaryotic cells. There are some notable examples in plants (e.g. fern spores) and even mammals (e.g. sperm cells)…
Fluoxetineplugin-autotooltip__plain plugin-autotooltip_bigFluoxetine

Fluoxetine is a Selective Serotonin Reuptake Inhibitor (SSRI) used in the treatment of Major Depressive Disorderand Obsessive-Compulsive disorder etc.. It's marketed under the trade names Prozac, Sarafem, Fontex and many others.

SSRIs are believed to act by…
Foetal Immunityplugin-autotooltip__plain plugin-autotooltip_bigImmune tolerance in pregnancy

Why doesn't an expectant mother's immune system damage her growing baby - since it has 'foreign' DNA?

This fundamental phenomenon has yet to be fully explained.

"During pregnancy, the maternal immune system is exposed to a major challe…
Fogettingplugin-autotooltip__plain plugin-autotooltip_bigForgetting

"Although it is commonly accepted that learning and memory occur via enduring changes in neuronal properties such as synaptic strength within a network of neurons, many details of these processes remain unknown, including the mechanisms responsible for the …
Galaxy Rotationplugin-autotooltip__plain plugin-autotooltip_bigGalaxy Rotation Problem

"The rotation curve of a disc galaxy (also called a velocity curve) is a plot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy's centre. It is typically rendered graphically as a plot, a…
Geomagnetic Fieldplugin-autotooltip__plain plugin-autotooltip_bigEarth’s magnetic field

Without the magnetic field, high energy radiation from space would affect the Earth's upper atmosphere much more dramatically – and high-energy radiation reaching the surface would be far higher. The levels of radiation without
Gravitotropismplugin-autotooltip__plain plugin-autotooltip_bigGravity sensing in plants

Specialist cells (Statocytes) in plants are able to sense gravity. Thus shooting tips grow upwards, against the Earth's gravitational field, while roots grow downwards. Statocytes are located in the starch parenchyma cells near vascular tissue…
Heavy Elementsplugin-autotooltip__plain plugin-autotooltip_bigOrigin of the heavier elements

Since theBig Bang Theory doesn't provide an explanation for the origin of the heavier elements which make up most of the Earth and the life on it, many cosmological theorists contend that they may have instead formed in supernovae explosi…
Heritable Primingplugin-autotooltip__plain plugin-autotooltip_bigHeritable priming

Heritable Priming is the name given to the process in which organisms are able to pass on stress-protection from the parent generation to the siblings.

The 'stress' can be physical (one of the original studies investigated how plants' lack of water c…
Hgtplugin-autotooltip__plain plugin-autotooltip_bigHorizontal gene transfer (HGT)

Horizontal Gene Transfer (HGT) - a.k.a. Lateral Gene Transfer (LGT) - is the transfer of genetic material (i.e. DNA) from one organism to another, but via routes other than the normal inheritance from parent to offspring.
Hypertensionplugin-autotooltip__plain plugin-autotooltip_bigHypertension

Only 5 -10% of cases of hypertension (high blood pressure) have causes which can be clearly identified - e.g. due to narrowing of the arteries. Put another way, of those patients who have been identified as having abnormally high blood pressure, physician…
Ibsplugin-autotooltip__plain plugin-autotooltip_bigIrritable bowel syndrome (IBS)

"The most common condition seen in gastrointestinal outpatient clinics is irritable bowel syndrome (IBS), which has a prevalence rate of 14-24% in women and 5-19% in men. [...] There is no known structural or anatomical explanation that …
Immunological Toleranceplugin-autotooltip__plain plugin-autotooltip_bigImmunological tolerance

Immunological tolerance is the ability of an individual's immune system to ignore “self” while reacting to “non-self” organisms and substances.

The system is extremely complex, and needs to somehow set a balance between being able to accurately…
Insect Declineplugin-autotooltip__plain plugin-autotooltip_bigInsect population decline

Various scientific studies have shown that the global terrestrial* insect population is in sharp decline.

The declines are primarily found in 'developed' nations. Estimates for the rate of decline vary wildly. One review study, which compiled…
Insect Flightplugin-autotooltip__plain plugin-autotooltip_bigInsect flight evolution

"Sometime in the Carboniferous Period, some 350 to 400 million years ago, when there were only two major land masses, insects began flying. How and why insect wings developed is not well understood, largely due to the scarcity of appropriate fo…
Instinctplugin-autotooltip__plain plugin-autotooltip_bigInstinct and Inheritance

Complex behaviour patterns can be learned, but they can also be inherited.

Example 1 The female Common Cuckoo (Cuculus canorus) is a so-called 'brood parasite' - in that it lays its eggs in the nests of other birds. This can't be a 'learned' …
Intergalactic Starsplugin-autotooltip__plain plugin-autotooltip_bigIntergalactic stars

Until 1997 (ref.NASA) it was assumed that all stars belonged to galaxy clusters. In other words 'bound' by the gravitational field of a galaxy.

It is now confirmed that there are very many stars which are totally independent of any galaxy. More tha…
Jupiter Heatingplugin-autotooltip__plain plugin-autotooltip_bigJupiter - atmospheric heating

The low to mid-latitudes of Jupiter's atmosphere have been found to have a temperature of around 800ºK - which is 600ºK warmer than can be accounted for by solar heating. The apparent anomaly was discovered in the mid 1970's (See:
Life On Earthplugin-autotooltip__plain plugin-autotooltip_bigLife on Earth (timespan)

There is currently no scientific agreement as to how long ago life on Earth evolved. Estimates, based on geological evidence, vary by about 200 million years - from between 3.85 billion years ago (Ga), and 3.65 Ga..

To date, the oldest undispu…
Magnetic Monopolesplugin-autotooltip__plain plugin-autotooltip_bigMagnetic monopoles

A magnetic monopole is a (possibly hypothetical) elementary particle in the form of an isolated magnet with only one magnetic pole (a North pole without a South pole or vice versa). In other words, a particle with a 'magnetic charge' somewhat analog…
Marine Calcium Balanceplugin-autotooltip__plain plugin-autotooltip_bigMarine calcium carbonate balance

"The chemistry of the oceans has varied significantly over the past several billion years, and it is changing at an unprecedented rate today in response to anthropogenic burning of fossil fuels. [...] Calcium carbonates are among the …
Meissner Corpusclesplugin-autotooltip__plain plugin-autotooltip_bigMeissner corpuscles

"The Meissner corpuscle, a mechanosensory end organ, was discovered more than 165 years ago and has since been found in the glabrous skin of all mammals, including that on human fingertips. Although prominently featured in textbooks, the function o…
Memory Declineplugin-autotooltip__plain plugin-autotooltip_bigAge-related memory decline

"Normal aging is associated with a decline in various memory abilities in many cognitive tasks; the phenomenon is known as age-related memory impairment (AMI) or age-associated memory impairment (AAMI). The ability to encode new memories of …
Menopauseplugin-autotooltip__plain plugin-autotooltip_bigMenopause

The decline in the number viable ovarian follicles, which leads to the menopause, is well documented (see Wikipedia), but, from an evolutionary perspective the reasons for its prevalence in humans are unknown.

Only a few other mammals* are known to exhibit m…
Microbiome Interactionsplugin-autotooltip__plain plugin-autotooltip_bigMicrobiome interactions

"The human gut harbors trillions of invisible microbial inhabitants, referred to as the microbiota, that collectively produce thousands of unique small molecules. The sources and biological functions of the vast majority of these molecules are …
Microplastic Pollutionplugin-autotooltip__plain plugin-autotooltip_bigMicroplastic pollution

"Plastic waste is currently generated at a rate approaching 400 Mt [mega-tonnes] / year. The amount of plastics accumulating in the environment is growing rapidly, yet our understanding of its persistence is very limited.“
Microplasticsplugin-autotooltip__plain plugin-autotooltip_bigMicroplastics and human health implications

Note: Microplastic pollution is so widespread that it's now been found contaminating almost all multicellular lifeforms which have been tested. This article is only related to possible risks to human health.
Migraineplugin-autotooltip__plain plugin-autotooltip_bigMigraine

"Chronic migraine has a great detrimental influence on a patient’s life, with a severe impact on socioeconomic functioning and quality of life. Chronic migraine affects 1–2% of the general population, and about 8% of patients with migraine; it usually develop…
Musical Appreciationplugin-autotooltip__plain plugin-autotooltip_bigMusical appreciation

Music psychologists are trying to understand the processes that support musical behaviours - including perception, comprehension, memory, attention, emotional effects, and performance.

"Music is more mysterious than language because its
Neural Networksplugin-autotooltip__plain plugin-autotooltip_bigNeural Networks

functionality_unexplained

"“Multilayer neural networks are among the most powerful models in machine learning, yet the fundamental reasons for this success defy mathematical understanding.”

Source : Proceedings of the National Academy of Sciences …
Neuropathic Painplugin-autotooltip__plain plugin-autotooltip_bigNeuropathic pain

Neuropathic pain is caused by damage or disease in the nervous system. It's estimated that more than 5% of the global population is affected, often severely.

"Central neuropathic pain is found in spinal cord injury, multiple sclerosis, and some strok…
Neutrino Massplugin-autotooltip__plain plugin-autotooltip_bigNeutrino mass

New research has found that the neutrino has a non-zero mass - but this requires a modification to the Standard Model of particle physics. The non-zero mass also means that neutrinos cannot travel at light-speed as photons do.

"Although neutrinos were l…
Neutron Decayplugin-autotooltip__plain plugin-autotooltip_bigNeutron decay

When part of an atomic nucleus, neutrons are extremely stable, but 'free' neutrons (i.e. those outside of a nucleus) decay into a proton, an electron and an electron-antineutrino in about 15 minutes.

Two different methods have been used to measure the ne…
Number Of Speciesplugin-autotooltip__plain plugin-autotooltip_bigNumber of species

"We demonstrate that after more than six decades, estimates of global species richness have failed to converge, remain highly uncertain, and in many cases, are logically inconsistent.“

Source : Global species richness estimates have not converged…
Oceanic C02plugin-autotooltip__plain plugin-autotooltip_bigOceanic CO2 absorption

Estimates for the amount of man-made CO2 absorbed by the oceans is estimated at around 30 > 40%. The processes which govern the rate of absorption are extremely complex and poorly understood.

Examples:

• As the ocean warms, its capacity to abso…
Osteoarthritisplugin-autotooltip__plain plugin-autotooltip_bigOsteoarthritis

"Osteoarthritis (OA) is considered a complex multifactorial disease of weight-bearing joints, with extensive psychosocial impact. The etiology of primary OA remains unknown and the molecular and cellular mechanisms of OA initiation and progression are n…
Ozone Depletionplugin-autotooltip__plain plugin-autotooltip_bigOzone Depletion Events

The Earth's Troposphere regularly experiences (naturally occurring *) ozone depletion events. The presence of atmospheric ozone is of extreme importance to organic life, as it substantially 'filters out' a large proportion of dangerous UV radiati…
Parkinsonsplugin-autotooltip__plain plugin-autotooltip_bigParkinson's disease

Also known as Parkinson disease, Parkinson's, idiopathic Parkinsonism, primary Parkinsonism, PD, or paralysis agitans - is a degenerative disorder of the central nervous system resulting from the death of dopamine-containing cells in the
Photoisomerizationplugin-autotooltip__plain plugin-autotooltip_bigPhotoisomerization

Photo-isomerization is the name given to the structural re-arrangement of asymmetric chemical compound molecules from one 'isomer' (e.g. 'left-handed' or 'right handed') to another, when illuminated.

The process is normally reversible, is dependent …
Placeboplugin-autotooltip__plain plugin-autotooltip_bigPlacebo effect

Placebos are faux medications - typically lactose or microcrystalline cellulose - designed to act as inert, non-functional 'controls' in medical experiments. (There are also faux medical procedures, see section below)

From the beginnings of their use i…
Pollen Tubesplugin-autotooltip__plain plugin-autotooltip_bigPollen Tubes

"A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. Pollen tube elongation is an integral stage in the plant life cycle. The pollen tube acts as a conduit to transport the male gamete cells from the po…
Protein Structuringplugin-autotooltip__plain plugin-autotooltip_bigProtein structuring

Genes set the order that amino acids (the chemical building blocks of proteins) appear in the proteins which they code for. But, working from the gene, the form which the protein's 3-D structure will take cannot as yet be predicted. The extremely co…
Proton Spinplugin-autotooltip__plain plugin-autotooltip_bigThe Proton Spin Crisis

'Spin' is an intrinsic property of many subatomic particles - it's been likened in some ways to the 'angular momentum' of a spinning ball, - but more accurately is a mathematical 'vector' or 'property'.

After the discovery that protons are compo…
Proton Structureplugin-autotooltip__plain plugin-autotooltip_bigProton structure

The 'textbook' explanation for the structure of the proton is that it's a 'state' of two up quarks and one down quark bound by gluons, But it has been known for 40 years or so that this is an over-simplification. According to accepted quantum theory, t…
Radioactive Decayplugin-autotooltip__plain plugin-autotooltip_bigRadioactive decay

Note: This item is one example of a special case - Known Unknowables

unknowable

Radioactive decay is the process by which the nucleus of an unstable atom loses energy by emitting 'radiation' - which can be in the form of alpha particles (two neutro…
Raindropsplugin-autotooltip__plain plugin-autotooltip_bigRaindrop formation

"When [an] ascending parcel of moist air reaches the condensation level, the initial mist of small, micron-size water droplets is formed, which are suspended in the air. In the super-saturated environment water droplets grow due to condensation of w…
Redshift Quantizationplugin-autotooltip__plain plugin-autotooltip_bigRedshift quantisation

'Cosmological Redshift' (with regard to cosmological luminous objects such as galaxies, quasars etc) refers to the observed lowering of spectral frequencies caused by the high speed motion of astronomical objects away from an observer.
Respiratory Rhythmplugin-autotooltip__plain plugin-autotooltip_bigRespiratory rhythm

The neural regulators and feedback mechanisms which control the rhythmic nature of breathing in mammals (and many other organisms) are currently the subject of intense research.

"Mammalian central pattern generators producing rhythmic movements exh…
Rheumatoid Arthritisplugin-autotooltip__plain plugin-autotooltip_bigRheumatoid Arthritis

Rheumatoid Arthritis (RA) is a chronic severe inflammatory disease believed to affect around 1% of the global population. It primarily affects joints, typically resulting in warm, swollen, painful joints. Pain and stiffness often worsen following r…
Rubisco Anomalyplugin-autotooltip__plain plugin-autotooltip_bigRuBisCO anomaly

RuBisCO (full name : Ribulose-1,5-bisphosphate carboxylase-oxygenase) is a crucial enzyme involved in the conversion of CO2 into sugars during photosynthesis. Without it, photosynthesising plants (and all other organisms which depend on plants, or requi…
Schizophreniaplugin-autotooltip__plain plugin-autotooltip_bigSchizophrenia

"Schizophrenia is a mental disorder characterized by abnormal social behavior and failure to understand what is real. Common symptoms include false beliefs, unclear or confused thinking, auditory and visual hallucinations, reduced social engagement and e…
Self-organized Criticalityplugin-autotooltip__plain plugin-autotooltip_bigSelf-Organized Criticality

The term Self-Organized Criticality (SOC) was introduced in a 1987 paper for Physical Review Letters. The groundbreaking research by Per Bak, Chao Tang and Kurt Wiesenfeld (now known as 'BTW') described how complex systems can feature 'critic…
Sexual Reproductionplugin-autotooltip__plain plugin-autotooltip_bigSexual reproduction

"The maintenance of sexual reproduction in a highly competitive world has long been one of the major mysteries of biology given that asexual reproduction can reproduce much more quickly as 50% of offspring in sexual reproduction are males, unable t…
Singlet Fissionplugin-autotooltip__plain plugin-autotooltip_bigSinglet fission (photo-voltaics)

Current photo-voltaic (PV) cells - e.g. solar panels for 'green' energy generation - have a quite low efficiency limit. If a high energy (that's to say high frequency, or short wavelength) photon falls onto a PV cell, it generates the …
Sleepplugin-autotooltip__plain plugin-autotooltip_bigSleep

"The purposes and mechanisms of sleep are only partially clear and are the subject of intense research“

Source Wikipedia"

Although extensive research in humans and animals has shown unequivocally that sleep is essential, the reasons why it's required are as y…
Solar Cycleplugin-autotooltip__plain plugin-autotooltip_bigSolar Cycle

Scientists started to make records of sunspot activity in the mid 18th century, and by the mid 19th it was discovered that the number of spots (which are lower-temperature entry-and-exit points for magnetic flux lines penetrating the Sun's surface) varies o…
Static Electricityplugin-autotooltip__plain plugin-autotooltip_bigStatic electricity

Static electricity has been investigated for more than 2 thousand years. The earliest written scientific accounts of 'static electricity' are believed to be those of Thales of Miletus at around 600BC. He thought (correctly, but for the wrong reasons)…
Supersymmetryplugin-autotooltip__plain plugin-autotooltip_bigSupersymmetry (SUSY)

Supersymmetry (colloquially known as SUSY) is a principle that proposes that every boson atomic particle (an example boson is the photon) has a corresponding fermion particle (an example fermion is the electron), and vice versa. If such 'paired' p…
Thermoregulationplugin-autotooltip__plain plugin-autotooltip_bigThermoregulation

"The core temperature of a human is regulated and stabilized primarily by the hypothalamus, a region of the brain linking the endocrine system to the nervous system, and more specifically by the anterior hypothalamic nucleus and the adjacent preoptic …
Tornadosplugin-autotooltip__plain plugin-autotooltip_bigTornados

Descriptions of the atmospheric mechanisms which cause tornados to form ('tornadogenesis') are currently unclear. Similar problems exist with full explanations of dust-devils, waterspouts, landspouts and hurricanes.

Currently available computer models (such a…
Toxoplasmosisplugin-autotooltip__plain plugin-autotooltip_bigToxoplasmosis

Toxoplasmosis is a parasitic disease caused by infections of the protozoan parasite Toxoplasma gondii.

It is extremely widespread in the human population. Infection rates vary in various regions of the world - but it's currently estimated that about 40 -…
Travelling Salesmanplugin-autotooltip__plain plugin-autotooltip_bigThe travelling salesman problem

Given a list of cities and the distances between each pair of cities, what is the shortest possible route that visits each city exactly once and returns to the origin city?

Computing algorithms (using so-called 'Monte Carlo' processes) …
Turbulenceplugin-autotooltip__plain plugin-autotooltip_bigTurbulence

Due to lack of understanding of precise underlying mechanisms, turbulent flow in liquids, gases and powders (etc) cannot be exactly described.

This can be very significant when attempting to predict the behaviour of complex natural phenomena - weather syste…
Ultratrace Elementsplugin-autotooltip__plain plugin-autotooltip_bigUltratrace elements

Ultratrace elements are chemical elements, derived from diet, which appear to play significant - and sometimes essential - biological roles in animals, including humans.

They typically comprise less than one microgram per gram of a given organism (…
Universe Expansionplugin-autotooltip__plain plugin-autotooltip_bigExpansion of the universe

Note: This item belongs to a special case - Known Unknowables

unknowable

Current cosmological theory, backed up by many diverse observations, suggests that the universe is not only expanding, but that the speed of expansion is accelerating
Virus Originsplugin-autotooltip__plain plugin-autotooltip_bigThe origins of viruses

The evolutionary origins of viruses is disputed. Although they don't leave a fossil record it's known that they are ancient (at around 4.5 billion years old).

It's not known, however, whether they evolved from cellular lifeforms, or
Water Bondingplugin-autotooltip__plain plugin-autotooltip_bigWater molecule chemical bonding

Debates about an exact model of the chemical bonding of the H20 molecule have been running for more than 50 years.

There are two main models, the Molecular Orbital Theory and the Valence Bond Theory (described at Wikipedia).

Neither th…

2 Stars

Amoeboid Movementplugin-autotooltip__plain plugin-autotooltip_bigAmoeboid movement

Amoeboid locomotion is the usual mode of movement in adherent (i.e. sticky) eukaryotic cells - e.g. amoebas, slime moulds, leukocytes and sarcomas etc etc. It also features in biological processes such as embryonic development, wound healing, and canc…
Bicycle Dynamicsplugin-autotooltip__plain plugin-autotooltip_bigBicycle dynamics

Riderless bicycles (hand launched) tend to self-stabilise whilst in forward motion.

The phenomenon has been extensively studied at the Delft University of Technology (NL) in collaboration with Cornell University (US) (videos here)

The physics behind …
Ciss Theoryplugin-autotooltip__plain plugin-autotooltip_bigCISS theory

The Chirality-Induced Spin Selectivity ( CISS ) effect was first discovered over two decades ago in the field of optical polarization. (ref.)

It was found that a fundamental quantum property of electrons - known as 'spin' - is strongly influenced by the 'c…
Coronal Heatingplugin-autotooltip__plain plugin-autotooltip_bigSun's coronal heating problem

The Sun's outer corona - stretching millions of kilometers out into space from the surface - reaches temperatures of up to 4 million °C.. This contrasts sharply with the surface of the sun which has been measured at around 6 thousand °C.…
Deep Carbonplugin-autotooltip__plain plugin-autotooltip_bigDeep Carbon life-forms

Ongoing research into the prevalence of life-forms (predominantly bacteria and archaea) living deep in the Earth's crust is revealing them in previously unimagined quantities. Some researchers suggest that the biological diversity of deep-carbon …
Earthquake Predictionplugin-autotooltip__plain plugin-autotooltip_bigEarthquake prediction

"In the 1970s, scientists were optimistic that a practical method for predicting earthquakes would soon be found, but by the 1990s continuing failure led many to question whether it was even possible. Demonstrably successful predictions of large …
Extracellular Vesiclesplugin-autotooltip__plain plugin-autotooltip_bigExtracellular vesicles

Extracellular vesicles (EVs) (a.k.a.Exosomes ) are small protected packets of extracellular RNA that are produced on the cell membrane of most eukaryotic cells. They can separate from the cell wall and travel freely in any bodily fluid.
Hypofrontalityplugin-autotooltip__plain plugin-autotooltip_bigHypofrontality

Hypofrontality refers to a decreased blood flow in the frontal cortex of the human brain. Some studies rate the decease at round 5%. (example ref.) It was first discovered in 1974, and was initially assumed to be due to anti-psychotic drugs which patien…
Jupiter Radio Auroraplugin-autotooltip__plain plugin-autotooltip_bigJupiter - radio aurora

Chance observations in 1955 logged strong radio frequency oscillations from Jupiter between the Kilometric (1000s metres) and Decametric (10s metres) wavebands. NASA's Juno spacecraft scanned Jupiter in late 2016 and made recordings of the emissi…
Macrophagesplugin-autotooltip__plain plugin-autotooltip_bigMacrophages

Macrophages are a type of white blood cell which are a crucial component of the immune system. They engulf and 'digest' microbes and cancer cells etc. (See Wikipedia)

"Although the overall role of macrophages has been known for over 100 years, we understa…
Melanin Protectionplugin-autotooltip__plain plugin-autotooltip_bigMelanin and UV protection

In general, people with darker skin tones (i.e. with more melanin) are less likely to suffer from skin cancers triggered by exposure to high energy photons in sunlight.

"It has been traditionally believed that skin pigmentation is the most i…
Metallic Whiskersplugin-autotooltip__plain plugin-autotooltip_bigMetallic whiskers

From the early days of electronics, it was found that some metallic components, especially the lead-based (Pb) and tin-based (Sn) soldered connections, tend to slowly grow conductive 'metal whiskers' (MWs) which can cause short-circuits and severely a…
Moral Superiority Illusionplugin-autotooltip__plain plugin-autotooltip_bigThe Moral Superiority Illusion

"Most people strongly believe they are just, virtuous, and moral; yet regard the average person as distinctly less so.“

Source : The Illusion of Moral Superiority [Open Access]Social Psychological and Personality Science, Volume: 8 iss…
Oil And Coalplugin-autotooltip__plain plugin-autotooltip_bigOrigins of Oil, Gas, and Coal

"[...] it is now generally accepted, but not conclusively proven, that petroleum formation predominantly arises from the decay of organic matter in the earth. [...] alternative theories should not be dismissed until it can be conclusively…
Paracetamolplugin-autotooltip__plain plugin-autotooltip_bigParacetamol

"Acetaminophen (INN Paracetamol) is one of the most widely used over-the-counter antipyretic and analgesic drugs worldwide. [...] Although discovered more than 100 years ago, and used extensively for ~ 50 years, its mode of action is still unclear
Plasmodesmataplugin-autotooltip__plain plugin-autotooltip_bigPlasmodesmata

Plasmodesmata are controllable openings in plant cell walls which allow chemicals and small molecules to pass in both directions from a cell to its neighbours.

Every plant so far examined has plasmodesmata, suggesting that they must be crucial cellular c…
Protein Knottingplugin-autotooltip__plain plugin-autotooltip_bigProtein Knotting

Note: This article is an extension of the Protein Folding Problem

"Knotting in proteins was once considered exceedingly rare. However, systematic analyses of solved protein structures over the last two decades have demonstrated the existence of many…
Psychedelic Drugsplugin-autotooltip__plain plugin-autotooltip_bigPsychedelic drugs

Psychedelic drugs currently have a circular definition. Classed as hallucinogenic psychoactive drugs which have the primary effect of triggering non-ordinary states of consciousness - termed 'psychedelic' experiences.

Many of the known psychedelic s…
Psychobioticsplugin-autotooltip__plain plugin-autotooltip_bigPsychobiotics

It's been known for many years that the microbiome (the bacterial and viral components of gut contents) can affect the physical wellbeing of mammals, including humans.

It's recently been suggested that the micro-organisms might also be able to affect hum…
Radiotrophic Fungiplugin-autotooltip__plain plugin-autotooltip_bigRadiotrophic Fungi

Radiotrophic fungi were first discovered in 2000 as black moulds growing inside and around the damaged Chernobyl Nuclear Power Plant in Ukraine. Subsequent research at the Albert Einstein College of Medicine showed that three melanin-containing fungi…
Rhythm Perceptionplugin-autotooltip__plain plugin-autotooltip_bigRhythm perception

Humans (and some other animals*) have an innate sense of 'rhythm', i.e. the ability to detect and react with 'beats' in musical compositions. Professional drummers and percussionists can 'beat time' with accuracies of just a few milliseconds per beat…
Snowflakesplugin-autotooltip__plain plugin-autotooltip_bigSnowflake formation

Snowflakes mostly form in two different types - plate-like and column-like - but there are many others, including needle-like, prism-like and star-like etc.. Although the many types have been extensively documented, and have been found to be tempera…
Solar Flaresplugin-autotooltip__plain plugin-autotooltip_bigSolar flares

The first solar flare to be formally documented was recorded by astronomer Richard Carrington, who observed a 'white light' flare in September 1859 - projecting the image produced by an optical telescope, without filters. See: Wikipedia

However, the mecha…
Sonoluminescenceplugin-autotooltip__plain plugin-autotooltip_bigSonoluminescence

Sonoluminescence is the emission of very short (pico-second) pulses of light from imploding bubbles in a liquid when it's subjected to strong sound waves. It was discovered in 1934 during sonar experiments at the University of Cologne.
Tectonic Subductionplugin-autotooltip__plain plugin-autotooltip_bigTectonic subduction

Movements of the 'Tectonic Plates' are believed to have formed almost all of the Earth's current-day crust - relying on a process called 'Subduction'.

In that process, the oceanic lithosphere of a tectonic plate collides with the less dense lithosp…
Vascular Dementiaplugin-autotooltip__plain plugin-autotooltip_bigVascular dementia

"Vascular dementia (VD) is the second most common cause of dementia following Alzheimer’s disease (AD). The major symptoms of VD including memory loss, language deficits and impairment of executive functions. Its specific etiology and pathogenesis re…
Visual Accommodationplugin-autotooltip__plain plugin-autotooltip_bigVisual Accommodation

Accommodation is the process by which the eye changes optical focus (from distant to near and vice versa) due to muscular re-shaping of the eye's lens. It can either be automatic or under voluntary control.

The mechanism involves a smooth muscle g…
Vitamin Cplugin-autotooltip__plain plugin-autotooltip_bigVitamin C deficits

Humans, some non-human primates, guinea pigs, bats, capybara and some birds and fish have lost the ability to synthesize vitamin C - apparently due to an as-yet-unexplained gene mutation defect. Because vitamin C is required for a range of essential …
Xerophthalmiaplugin-autotooltip__plain plugin-autotooltip_bigXerophthalmia

Xerophthalmia is one of the most common causes of blindness worldwide.

It predominantly affects children, and is estimated to cause vision loss in more than 500,000 people each year.

It leads to a gradual loss of transparency of the cornea, and is know…

1 Star

Assortive Matingplugin-autotooltip__plain plugin-autotooltip_bigAssortative mating

Assortative mating refers to the tendency of (some) animals to mate with individuals that share similar traits. For example, having the same fur colour, or size. The effect is particularly strong in fishes, less so in birds. It also seems to apply, i…
Bee Colony Collapseplugin-autotooltip__plain plugin-autotooltip_bigBee Colony Collapse Disorder [ CCD ]

"Colony collapse disorder (CCD) is the phenomenon that occurs when the majority of worker bees in a colony disappear and leave behind a queen, plenty of food and a few nurse bees to care for the remaining immature bees and the quee…
Cell Sizeplugin-autotooltip__plain plugin-autotooltip_bigCell size

A detailed explanation of the factors which regulate cell size (i.e. the size to which cells grow) has not yet been found. Since (most) cells stop growing when they reach a specific size, it's suggested that there must be some feedback mechanism to restrict g…
Cetacean Strandingsplugin-autotooltip__plain plugin-autotooltip_bigCetacean strandings

It's currently estimated that around 2,000 whales and dolphins are 'stranded' (i.e. run aground) each year. The majority of strandings result in death. About 10 cetacean species frequently display mass beachings, and another 10 do so occasionally.
Cmb Excessplugin-autotooltip__plain plugin-autotooltip_bigCosmic Microwave Background excess

"The cosmic microwave background (CMB) is currently our most precise window on the physics of the early universe. Measurements of the frequency spectrum of the CMB can rule out alternative cosmologies and place limits on physical pro…
Domsplugin-autotooltip__plain plugin-autotooltip_bigDelayed onset muscle soreness

Delayed onset muscle soreness (DOMS) is the pain and stiffness felt in muscles some time after unaccustomed or strenuous exercise. The soreness usually increases in intensity in the first 24 hours after exercise, and peaks from 24 to 72 ho…
Electrostatic Pollinationplugin-autotooltip__plain plugin-autotooltip_bigElectrostatic pollination

The idea that flying insects might be electrically charged during flight bystatic electricity was suggested almost 100 years ago. (Heuschmann, O. (1929). Über die elektrischen Eigenschaften der Insekten Haare, Journal of Comparative Physiology…
Geobatteriesplugin-autotooltip__plain plugin-autotooltip_bigGeobatteries

Geobatteries (also known as 'Self Potential' (SP) anomalies), are widespread measurable electrical differences in naturally-occurring geological formations.

There have been several proposals to explain how they might come about - it's likely that there a…
Hair Greyingplugin-autotooltip__plain plugin-autotooltip_bigHair greying (canities)

"Hair greying (referred to during ageing as ‘canities’) is one of the earliest and most visible indicators of ageing in humans. The social significance of greying persists across cultures, geographical locations, and ethnicities, alongside a no…
Laughterplugin-autotooltip__plain plugin-autotooltip_bigLaughter

"...laughter is more often prompted by banal comments than amusing jokes. That makes it even more mysterious.”

Source : New Scientist August 2009."

Laughter, or something very similar, has been observed in various different species – including (but probabl…
Lignin Synthesisplugin-autotooltip__plain plugin-autotooltip_bigLignin synthesis

"Lignin is, after cellulose, the second most abundant terrestrial biopolymer, accounting for approximately 30% of the organic carbon in the biosphere. The ability to synthesize lignin has been essential in the evolutionary adaptation of plants from an…
Persistent Luminescenceplugin-autotooltip__plain plugin-autotooltip_bigPersistent luminescence

Persistent luminescence is the name given to the phenomenon found in materials which glow in the dark after the end of an excitation with UV or visible light - mainly phosphors such as silver-activated zinc sulphide or doped strontium aluminate…
Pyramids Constructionplugin-autotooltip__plain plugin-autotooltip_bigThe Pyramids - construction

Construction engineers and archaeologists have not been able to agree on ways in which the Great Pyramids of Giza (and others) might have been constructed - at around 2580–2560 BC.

"The logistics involved in the construction of this pyrami…
Staebler Wronskiplugin-autotooltip__plain plugin-autotooltip_bigStaebler–Wronski effect

The Staebler–Wronski effect was first described in 1977. It refers to the unexplained drop-off in the efficiency of silicon-based photovoltaic cells - as used in solar panels etc - after a few hundred hours of light exposure (So-called 'Light S…
Triboluminescent Tapeplugin-autotooltip__plain plugin-autotooltip_bigTriboluminescent tape

When rolls of transparent adhesive tape are peeled, the relative motion between the two separating surfaces can produce electromagnetic radiation - an example of triboluminescence.

It can be seen as visible light, but the peeling action can also …
Venous Thrombosisplugin-autotooltip__plain plugin-autotooltip_bigVenous Thrombosis

Venous Thrombosis - blood clots which from in veins (as opposed to arteries) - are relatively common and potentially very dangerous (e.g. DVT).

Although it's firmly established that three factors (hypercoagulability, hemodynamic changes and endothe…

Wikenigma

Dear reader : Do you have any suggestions for the site's content?

Ideas for new topics, and suggested additions / corrections for older ones, are always welcome.

If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !

Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.

( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)

Automatic Translation

You are currently viewing an auto-translated version of Wikenigma

Please be aware that no automatic translation engines are 100% accurate, and so the auto-translated content will very probably feature errors and omissions.

Nevertheless, Wikenigma hopes that the translated content will help to attract a wider global audience.

Further resources :

Main Menu : categories & index etc.

Wikenigma - an Encyclopedia of Unknowns Wikenigma - an Encyclopedia of the Unknown

Importance ratings

4 Stars

3 Stars

2 Stars

1 Star

Dear reader : Do you have any suggestions for the site's content?

Automatic Translation

User Tools

Main Menu : categories & index etc.

Wikenigma - an Encyclopedia of Unknowns Wikenigma - an Encyclopedia of the Unknown

Importance ratings

4 Stars

3 Stars

2 Stars

1 Star

Dear reader : Do you have any suggestions for the site's content?

Automatic Translation

Page Tools