This article does not deal with types of bicycle

Bicycle

A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist....

s, for that see Bicycle#Types and :Category:Cycle types.

This is a list of recurring cycle

Cycle

Cycle, and in some cases cyclic, may refer to:* A process that returns to its beginning and repeats itself in the same sequence. Such processes are seen in many fields, such as physics, mathematics, biology, astronomy, economics, audio frequency, etc....

s. See also list of wave topics, time

Time

Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....

, and pattern

Pattern

A pattern, from the French patron, is a type of theme of recurring events or objects, sometimes referred to as elements of a set of objects.These elements repeat in a predictable manner...

.

Time and calendar cycles

Atomic clock

Atomic clock

An atomic clock is a clock that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element...

 - Calendar

Calendar

A calendar is a system of organizing days for social, religious, commercial, or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. The name given to each day is known as a date. Periods in a calendar are usually, though not...

 - Chinese calendar

Chinese calendar

The Chinese calendar is a lunisolar calendar, incorporating elements of a lunar calendar with those of a solar calendar. It is not exclusive to China, but followed by many other Asian cultures as well...

 - Computus

Computus

Computus is the calculation of the date of Easter in the Christian calendar. The name has been used for this procedure since the early Middle Ages, as it was one of the most important computations of the age....

 - Deepavali - Ephemeris Time

Ephemeris time

The term ephemeris time can in principle refer to time in connection with any astronomical ephemeris. In practice it has been used more specifically to refer to:...

 - Hertz

Hertz

The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....

 - Intellectual history of time - Julian date - Season

Season

A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...

 

Astronomical cycles

Astronomy

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 - CNO cycle

CNO cycle

The CNO cycle is one of two sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain. Unlike the proton–proton chain reaction, the CNO cycle is a catalytic cycle. Theoretical models show that the CNO cycle is the dominant source of energy in stars...

 - Eclipse cycle

Eclipse cycle

Eclipses may occur repeatedly, separated by certain intervals of time: these intervals are called eclipse cycles. The series of eclipses separated by a repeat of one of these intervals is called an eclipse series.- Eclipse conditions :...

 - Eclipse

Eclipse

An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer...

 - Full moon cycle

Full moon cycle

The full moon cycle is a cycle of about 14 lunations over which full moons vary in apparent size and age . The sequence is*Full moon big - *Full moon young -...

 - Galactic year

Galactic year

The galactic year, also known as a cosmic year, is the duration of time required for the Solar System to orbit once around the center of the Milky Way Galaxy. Estimates of the length of one orbit range from 225 to 250 million "terrestrial" years....

 - Great year

Great year

The Great Year is an archaic cosmological conception, found in different cultures, which acquired new interpretations with the development of astronomical knowledge In the Western tradition Plato has been the main source for the idea, so it was also frequently called 'Platonic year'...

 - Lunar phase

Lunar phase

A lunar phase or phase of the moon is the appearance of the illuminated portion of the Moon as seen by an observer, usually on Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the changing relative positions of the Earth, Moon, and Sun...

 - Mesoamerican calendars

Mesoamerican calendars

Mesoamerican calendars are the calendrical systems devised and used by the pre-Columbian cultures of Mesoamerica. In addition to the basic function of a calendar—defining and organizing periods of time in a way that allows events to be fixed, ordered and noted relative to each other and some...

 - Metonic cycle

Metonic cycle

In astronomy and calendar studies, the Metonic cycle or Enneadecaeteris is a period of very close to 19 years which is remarkable for being very nearly a common multiple of the solar year and the synodic month...

 - Milankovitch cycles

Milankovitch cycles

Milankovitch theory describes the collective effects of changes in the Earth's movements upon its climate, named after Serbian civil engineer and mathematician Milutin Milanković, who worked on it during First World War internment...

 - Mira

Mira

Mira also known as Omicron Ceti , is a red giant star estimated 200-400 light years away in the constellation Cetus. Mira is a binary star, consisting of the red giant Mira A along with Mira B. Mira A is also an oscillating variable star and was the first non-supernova variable star discovered,...

 - Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 - Nutation

Nutation

Nutation is a rocking, swaying, or nodding motion in the axis of rotation of a largely axially symmetric object, such as a gyroscope, planet, or bullet in flight, or as an intended behavior of a mechanism...

 - Orbit

Orbit

In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...

 - Orbital period

Orbital period

The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...

 - Saros cycle

Saros cycle

The saros is a period of 223 synodic months , that can be used to predict eclipses of the Sun and Moon. One saros after an eclipse, the Sun, Earth, and Moon return to approximately the same relative geometry, and a nearly identical eclipse will occur, in what is referred to as an eclipse cycle...

 - Sothic cycle

Sothic cycle

The Sothic cycle or Canicular period is a period of 1,461 ancient Egyptian years or 1,460 Julian years...

 - Secularity

Secular phenomena

In astronomy, secular phenomena are contrasted with phenomena observed to repeat periodically. In particular, astronomical ephemerides use secular to label the longest-lasting or non-oscillatory perturbations in the motion of planets, as opposed to periodic perturbations which exhibit repetition...

 - Sunspots - Tides

Climate and weather cycles

Animal migration

Animal migration

Animal migration is the relatively long-distance movement of individuals, usually on a seasonal basis. It is a ubiquitous phenomenon, found in all major animal groups, including birds, mammals, fish, reptiles, amphibians, insects, and crustaceans. The trigger for the migration may be local...

 - Avalanche

Avalanche

An avalanche is a sudden rapid flow of snow down a slope, occurring when either natural triggers or human activity causes a critical escalating transition from the slow equilibrium evolution of the snow pack. Typically occurring in mountainous terrain, an avalanche can mix air and water with the...

 - Carbon cycle

Carbon cycle

The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth...

 - Climate change

Climate change

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

 - Climate model

Climate model

Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface, and ice. They are used for a variety of purposes from study of the dynamics of the climate system to projections of future climate...

 - Clock of the Long Now

Clock of the Long Now

The Clock of the Long Now, also called the 10,000-year clock, is a proposed mechanical clock designed to keep time for 10,000 years. The project to build it is part of the Long Now Foundation....

 - Ecology

Ecology

Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

 - Endometrium

Endometrium

-Function:The endometrium is the innermost glandular layer and functions as a lining for the uterus, preventing adhesions between the opposed walls of the myometrium, thereby maintaining the patency of the uterine cavity. During the menstrual cycle or estrous cycle, the endometrium grows to a...

 - Environmental geography

Environmental geography

Integrated geography is the branch of geography that describes the spatial aspects of interactions between humans and the natural world. It requires an understanding of the dynamics of geology, meteorology, hydrology, biogeography, ecology, and geomorphology, as well as the ways in which human...

 - Global cooling

Global cooling

Global cooling was a conjecture during the 1970s of imminent cooling of the Earth's surface and atmosphere along with a posited commencement of glaciation...

 - Global warming and agriculture - Global warming

Global warming

Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

 - Historical temperature record - Ice age

Ice age

An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...

 - Mars Polar Lander

Mars Polar Lander

The Mars Polar Lander, also referred to as the Mars Surveyor '98 Lander, was a 290-kilogram robotic spacecraft lander, launched by NASA on January 3, 1999, to study the soil and climate of Planum Australe, a region near the south pole on Mars, as part of the Mars Surveyor '98 mission...

- Transhumance

Transhumance

Transhumance is the seasonal movement of people with their livestock between fixed summer and winter pastures. In montane regions it implies movement between higher pastures in summer and to lower valleys in winter. Herders have a permanent home, typically in valleys. Only the herds travel, with...

 - Milankovitch cycles

Milankovitch cycles

Milankovitch theory describes the collective effects of changes in the Earth's movements upon its climate, named after Serbian civil engineer and mathematician Milutin Milanković, who worked on it during First World War internment...

 - Monsoon

Monsoon

Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea...

 - Pleistocene

Pleistocene

The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 - Season

Season

A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...

 - Sunspot

Sunspot

Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature....

 - Tides - Timeline of meteorology

Timeline of meteorology

The Timeline of Meteorology contains events of scientific and technological advancements in the area of atmospheric sciences. The most notable advancements in observational meteorology, weather forecasting, climatology, atmospheric chemistry, and atmospheric physics are listed chronologically...

 - 1500-year climate cycle

Geological cycles

Age of the Earth

Age of the Earth

The age of the Earth is 4.54 billion years This age is based on evidence from radiometric age dating of meteorite material and is consistent with the ages of the oldest-known terrestrial and lunar samples...

 - Mass extinction cycles - Climate change

Climate change

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

 - Earthquake cycles

Agricultural cycles

Agricultural cycle

Agricultural cycle

The Agricultural cycle is the annual cycle of activitites related to the growth and harvest of a crop. These activities include loosening the soil, seeding, special watering, moving plants when they grow bigger, and harvesting, among others....

 - Crop rotation

Crop rotation

Crop rotation is the practice of growing a series of dissimilar types of crops in the same area in sequential seasons.Crop rotation confers various benefits to the soil. A traditional element of crop rotation is the replenishment of nitrogen through the use of green manure in sequence with cereals...

 - Fertile Crescent

Fertile Crescent

The Fertile Crescent, nicknamed "The Cradle of Civilization" for the fact the first civilizations started there, is a crescent-shaped region containing the comparatively moist and fertile land of otherwise arid and semi-arid Western Asia. The term was first used by University of Chicago...

 - Global warming and agriculture - Harvest

Harvest

Harvest is the process of gathering mature crops from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper...

 - Organic farming

Organic farming

Organic farming is the form of agriculture that relies on techniques such as crop rotation, green manure, compost and biological pest control to maintain soil productivity and control pests on a farm...

 - Season

Season

A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...

 - Soil degradation - Sustainable industries

Sustainable industries

The earliest mention of the phrase sustainable industries appeared in 1990 in a story about a Japanese group reforesting a tropical forest to help create sustainable industries for the local populace. The earliest mention of the phrase sustainable industries appeared in 1990 in a story about a...

Biological and medical cycles

Alternation of generations

Alternation of generations

Alternation of generations is a term primarily used in describing the life cycle of plants . A multicellular sporophyte, which is diploid with 2N paired chromosomes , alternates with a multicellular gametophyte, which is haploid with N unpaired chromosomes...

 - Bioelectricity - Biological pest control

Biological pest control

Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...

 - Biorhythm

Biorhythm

Biorhythm is an attempt to predict various aspects of a person's life through simple mathematical cycles. Most scientists believe that the idea has no more predictive power than raw chance, and consider the concept an example of pseudoscience.-Beliefs:...

 - Bipolar disorder

Bipolar disorder

Bipolar disorder or bipolar affective disorder, historically known as manic–depressive disorder, is a psychiatric diagnosis that describes a category of mood disorders defined by the presence of one or more episodes of abnormally elevated energy levels, cognition, and mood with or without one or...

 - Cardiopulmonary resuscitation

Cardiopulmonary resuscitation

Cardiopulmonary resuscitation is an emergency procedure which is performed in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person in cardiac arrest. It is indicated in those who are unresponsive...

 - Calvin cycle

Calvin cycle

The Calvin cycle or Calvin–Benson-Bassham cycle or reductive pentose phosphate cycle or C3 cycle or CBB cycle is a series of biochemical redox reactions that take place in the stroma of chloroplasts in photosynthetic organisms...

 - Cell cycle

Cell cycle

The cell cycle, or cell-division cycle, is the series of events that takes place in a cell leading to its division and duplication . In cells without a nucleus , the cell cycle occurs via a process termed binary fission...

 - Chronobiology

Chronobiology

Chronobiology is a field of biology that examines periodic phenomena in living organisms and their adaptation to solar- and lunar-related rhythms. These cycles are known as biological rhythms. Chronobiology comes from the ancient Greek χρόνος , and biology, which pertains to the study, or science,...

 - Citric acid cycle

Citric acid cycle

The citric acid cycle — also known as the tricarboxylic acid cycle , the Krebs cycle, or the Szent-Györgyi-Krebs cycle — is a series of chemical reactions which is used by all aerobic living organisms to generate energy through the oxidization of acetate derived from carbohydrates, fats and...

 - Circadian rhythm

Circadian rhythm

A circadian rhythm, popularly referred to as body clock, is an endogenously driven , roughly 24-hour cycle in biochemical, physiological, or behavioural processes. Circadian rhythms have been widely observed in plants, animals, fungi and cyanobacteria...

 - Clinical depression

Clinical depression

Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...

 - Digestion

Digestion

Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....

 - Ecology

Ecology

Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

 - Feedback

Feedback

Feedback describes the situation when output from an event or phenomenon in the past will influence an occurrence or occurrences of the same Feedback describes the situation when output from (or information about the result of) an event or phenomenon in the past will influence an occurrence or...

 - Life cycle

Biological life cycle

A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...

 - List of biochemistry topics - Marine biology

Marine biology

Marine biology is the scientific study of organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather...

 - Menstrual cycle

Menstrual cycle

The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....

 - Neurofeedback

Neurofeedback

Neurofeedback , also called neurotherapy, neurobiofeedback or EEG biofeedback is a type of biofeedback that uses realtime displays of electroencephalography or functional magnetic resonance imaging to illustrate brain activity, often with a goal of controlling central nervous system activity...

 - Non-Hodgkin's lymphoma - Organic farming

Organic farming

Organic farming is the form of agriculture that relies on techniques such as crop rotation, green manure, compost and biological pest control to maintain soil productivity and control pests on a farm...

 - Polymerase chain reaction

Polymerase chain reaction

The polymerase chain reaction is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence....

 - Soil degradation - Stomach cancer

Stomach cancer

Gastric cancer, commonly referred to as stomach cancer, can develop in any part of the stomach and may spread throughout the stomach and to other organs; particularly the esophagus, lungs, lymph nodes, and the liver...

 - Triage

Triage

Triage or ) is the process of determining the priority of patients' treatments based on the severity of their condition. This rations patient treatment efficiently when resources are insufficient for all to be treated immediately. The term comes from the French verb trier, meaning to separate,...

 - Zygote

Zygote

A zygote , or zygocyte, is the initial cell formed when two gamete cells are joined by means of sexual reproduction. In multicellular organisms, it is the earliest developmental stage of the embryo...

Brain waves and cycles

Bioelectricity - Circadian rhythm

Circadian rhythm

A circadian rhythm, popularly referred to as body clock, is an endogenously driven , roughly 24-hour cycle in biochemical, physiological, or behavioural processes. Circadian rhythms have been widely observed in plants, animals, fungi and cyanobacteria...

 - Consciousness

Consciousness

Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...

 - Electroencephalography

Electroencephalography

Electroencephalography is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain...

 - Neurofeedback

Neurofeedback

Neurofeedback , also called neurotherapy, neurobiofeedback or EEG biofeedback is a type of biofeedback that uses realtime displays of electroencephalography or functional magnetic resonance imaging to illustrate brain activity, often with a goal of controlling central nervous system activity...

 - Persistent vegetative state

Persistent vegetative state

A persistent vegetative state is a disorder of consciousness in which patients with severe brain damage are in a state of partial arousal rather than true awareness. It is a diagnosis of some uncertainty in that it deals with a syndrome. After four weeks in a vegetative state , the patient is...

 - Sjögren's syndrome

Sjögren's syndrome

Sjögren's syndrome , also known as "Mikulicz disease" and "Sicca syndrome", is a systemic autoimmune disease in which immune cells attack and destroy the exocrine glands that produce tears and saliva....

 - Sleep

Sleep

Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than...

Physics cycles

Cyclic process - Double-slit experiment

Double-slit experiment

The double-slit experiment, sometimes called Young's experiment, is a demonstration that matter and energy can display characteristics of both waves and particles...

 - Dynamic theory of gravity - Physics of music - Resonance

Resonance

In physics, resonance is the tendency of a system to oscillate at a greater amplitude at some frequencies than at others. These are known as the system's resonant frequencies...

 - Sonoluminescence

Sonoluminescence

Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound.-History:The effect was first discovered at the University of Cologne in 1934 as a result of work on sonar. H. Frenzel and H. Schultes put an ultrasound transducer in a tank of...

 - Speed of light

Speed of light

The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...

 - Sunspot

Sunspot

Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature....

Mathematics of waves and cycles

Almost periodic function

Almost periodic function

In mathematics, an almost periodic function is, loosely speaking, a function of a real number that is periodic to within any desired level of accuracy, given suitably long, well-distributed "almost-periods". The concept was first studied by Harald Bohr and later generalized by Vyacheslav Stepanov,...

 - Amplitude modulation

Amplitude modulation

Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...

 - Amplitude

Amplitude

Amplitude is the magnitude of change in the oscillating variable with each oscillation within an oscillating system. For example, sound waves in air are oscillations in atmospheric pressure and their amplitudes are proportional to the change in pressure during one oscillation...

 - Beat

Beat (acoustics)

In acoustics, a beat is an interference between two sounds of slightly different frequencies, perceived as periodic variations in volume whose rate is the difference between the two frequencies....

 - Chaos theory

Chaos theory

Chaos theory is a field of study in mathematics, with applications in several disciplines including physics, economics, biology, and philosophy. Chaos theory studies the behavior of dynamical systems that are highly sensitive to initial conditions, an effect which is popularly referred to as the...

 - Cyclic group

Cyclic group

In group theory, a cyclic group is a group that can be generated by a single element, in the sense that the group has an element g such that, when written multiplicatively, every element of the group is a power of g .-Definition:A group G is called cyclic if there exists an element g...

 - Diffraction

Diffraction

Diffraction refers to various phenomena which occur when a wave encounters an obstacle. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record accurate observations of the phenomenon in 1665...

 - Doppler effect

Doppler effect

The Doppler effect , named after Austrian physicist Christian Doppler who proposed it in 1842 in Prague, is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from...

 - Eigenstate - Eigenvalue - Fourier series

Fourier series

In mathematics, a Fourier series decomposes periodic functions or periodic signals into the sum of a set of simple oscillating functions, namely sines and cosines...

 - Frequency domain

Frequency domain

In electronics, control systems engineering, and statistics, frequency domain is a term used to describe the domain for analysis of mathematical functions or signals with respect to frequency, rather than time....

 - Frequency spectrum

Frequency spectrum

The frequency spectrum of a time-domain signal is a representation of that signal in the frequency domain. The frequency spectrum can be generated via a Fourier transform of the signal, and the resulting values are usually presented as amplitude and phase, both plotted versus frequency.Any signal...

 - Hamiltonian (quantum mechanics)

Hamiltonian (quantum mechanics)

In quantum mechanics, the Hamiltonian H, also Ȟ or Ĥ, is the operator corresponding to the total energy of the system. Its spectrum is the set of possible outcomes when one measures the total energy of a system...

 - Harmonic oscillator

Harmonic oscillator

In classical mechanics, a harmonic oscillator is a system that, when displaced from its equilibrium position, experiences a restoring force, F, proportional to the displacement, x: \vec F = -k \vec x \, where k is a positive constant....

 - Huygens' principle - Longitudinal wave

Longitudinal wave

Longitudinal waves, as known as "l-waves", are waves that have the same direction of vibration as their direction of travel, which means that the movement of the medium is in the same direction as or the opposite direction to the motion of the wave. Mechanical longitudinal waves have been also...

 - Mechanical wave

Mechanical wave

A mechanical or material wave is a wave that needs a medium to travel. The oscillating material does not move far from its initial equilibrium position, as only the energy is transferred by connected particles. Ocean waves and sound are examples of this phenomenon.A mechanical wave requires an...

 - Navier–Stokes equations - Partial differential equation

Partial differential equation

In mathematics, partial differential equations are a type of differential equation, i.e., a relation involving an unknown function of several independent variables and their partial derivatives with respect to those variables...

 - Periodic function

Periodic function

In mathematics, a periodic function is a function that repeats its values in regular intervals or periods. The most important examples are the trigonometric functions, which repeat over intervals of length 2π radians. Periodic functions are used throughout science to describe oscillations,...

 - Permutation

Permutation

In mathematics, the notion of permutation is used with several slightly different meanings, all related to the act of permuting objects or values. Informally, a permutation of a set of objects is an arrangement of those objects into a particular order...

 - Phase (waves)

Phase (waves)

Phase in waves is the fraction of a wave cycle which has elapsed relative to an arbitrary point.-Formula:The phase of an oscillation or wave refers to a sinusoidal function such as the following:...

 - Physics of music - Power spectrum - Signal - Sine-wave - Spectrum of an operator - Translational symmetry

Translational symmetry

In geometry, a translation "slides" an object by a a: Ta = p + a.In physics and mathematics, continuous translational symmetry is the invariance of a system of equations under any translation...

 - Transverse wave

Transverse wave

A transverse wave is a moving wave that consists of oscillations occurring perpendicular to the direction of energy transfer...

 - Wave equation

Wave equation

The wave equation is an important second-order linear partial differential equation for the description of waves – as they occur in physics – such as sound waves, light waves and water waves. It arises in fields like acoustics, electromagnetics, and fluid dynamics...

 - Wave–particle duality

Wave–particle duality

Wave–particle duality postulates that all particles exhibit both wave and particle properties. A central concept of quantum mechanics, this duality addresses the inability of classical concepts like "particle" and "wave" to fully describe the behavior of quantum-scale objects...

 - Wave

Wave

In physics, a wave is a disturbance that travels through space and time, accompanied by the transfer of energy.Waves travel and the wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium—that is, with little or no associated mass...

 - Waveform

Waveform

Waveform means the shape and form of a signal such as a wave moving in a physical medium or an abstract representation.In many cases the medium in which the wave is being propagated does not permit a direct visual image of the form. In these cases, the term 'waveform' refers to the shape of a graph...

Electromagnetic spectrum

Absorption spectroscopy

Absorption spectroscopy

Absorption spectroscopy refers to spectroscopic techniques that measure the absorption of radiation, as a function of frequency or wavelength, due to its interaction with a sample. The sample absorbs energy, i.e., photons, from the radiating field. The intensity of the absorption varies as a...

 - Anders Jonas Ångström

Anders Jonas Ångström

Anders Jonas Ångström was a Swedish physicist and one of the founders of the science of spectroscopy.-Biography:...

 - Astronomy

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 - Black body

Black body

A black body is an idealized physical body that absorbs all incident electromagnetic radiation. Because of this perfect absorptivity at all wavelengths, a black body is also the best possible emitter of thermal radiation, which it radiates incandescently in a characteristic, continuous spectrum...

 - Blazar

Blazar

A blazar is a very compact quasar associated with a presumed supermassive black hole at the center of an active, giant elliptical galaxy...

 - Bremsstrahlung

Bremsstrahlung

Bremsstrahlung is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus. The moving particle loses kinetic energy, which is converted into a photon because energy is conserved. The term is...

 - Caesium

Caesium

Caesium or cesium is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C , which makes it one of only five elemental metals that are liquid at room temperature...

 - Cherenkov radiation

Cherenkov radiation

Cherenkov radiation is electromagnetic radiation emitted when a charged particle passes through a dielectric medium at a speed greater than the phase velocity of light in that medium...

 - Color

Color

Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...

 - Colors - Diffraction

Diffraction

Diffraction refers to various phenomena which occur when a wave encounters an obstacle. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record accurate observations of the phenomenon in 1665...

 - Digital signal processing

Digital signal processing

Digital signal processing is concerned with the representation of discrete time signals by a sequence of numbers or symbols and the processing of these signals. Digital signal processing and analog signal processing are subfields of signal processing...

 - Direct-sequence spread spectrum

Direct-sequence spread spectrum

In telecommunications, direct-sequence spread spectrum is a modulation technique. As with other spread spectrum technologies, the transmitted signal takes up more bandwidth than the information signal that is being modulated. The name 'spread spectrum' comes from the fact that the carrier signals...

 - Dispersion (optics)

Dispersion (optics)

In optics, dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency, or alternatively when the group velocity depends on the frequency.Media having such a property are termed dispersive media...

 - Eigenstate - Eigenvalue - Electromagnetic radiation

Electromagnetic radiation

Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...

 - Electromagnetic spectroscopy - Electromagnetic spectrum

Electromagnetic spectrum

The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....

 - Electromagnetism

Electromagnetism

Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...

 - Emission line - Emission spectrum

Emission spectrum

The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted by the element's atoms or the compound's molecules when they are returned to a lower energy state....

 - FM broadcast radio - Frequency domain

Frequency domain

In electronics, control systems engineering, and statistics, frequency domain is a term used to describe the domain for analysis of mathematical functions or signals with respect to frequency, rather than time....

 - Frequency hopping - Frequency spectrum

Frequency spectrum

The frequency spectrum of a time-domain signal is a representation of that signal in the frequency domain. The frequency spectrum can be generated via a Fourier transform of the signal, and the resulting values are usually presented as amplitude and phase, both plotted versus frequency.Any signal...

 - Gamma ray burster - Hamiltonian (quantum mechanics)

Hamiltonian (quantum mechanics)

In quantum mechanics, the Hamiltonian H, also Ȟ or Ĥ, is the operator corresponding to the total energy of the system. Its spectrum is the set of possible outcomes when one measures the total energy of a system...

 - History of radio

History of radio

The early history of radio is the history of technology that produced radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy"...

 - Hue

Hue

Hue is one of the main properties of a color, defined technically , as "the degree to which a stimulus can be describedas similar to or different from stimuli that are described as red, green, blue, and yellow,"...

 - Isotope

Isotope

Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...

 - Light

Light

Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...

 - Optical brightener

Optical brightener

Optical brighteners, optical brightening agents , fluorescent brightening agents or fluorescent whitening agents are dyes that absorb light in the ultraviolet and violet region of the electromagnetic spectrum, and re-emit light in the blue region...

 - Optical spectrum - Particle in a spherically symmetric potential - Piezoelectricity

Piezoelectricity

Piezoelectricity is the charge which accumulates in certain solid materials in response to applied mechanical stress. The word piezoelectricity means electricity resulting from pressure...

 - Power spectrum - RADAR

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 - Radio frequency

Radio frequency

Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...

 - Radio

Radio

Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...

 - Radiocommunications Agency - Redshift

Redshift

In physics , redshift happens when light seen coming from an object is proportionally increased in wavelength, or shifted to the red end of the spectrum...

 - SETI

SETI

The search for extraterrestrial intelligence is the collective name for a number of activities people undertake to search for intelligent extraterrestrial life. Some of the most well known projects are run by the SETI Institute. SETI projects use scientific methods to search for intelligent life...

 - Spectrogram

Spectrogram

A spectrogram is a time-varying spectral representation that shows how the spectral density of a signal varies with time. Also known as spectral waterfalls, sonograms, voiceprints, or voicegrams, spectrograms are used to identify phonetic sounds, to analyse the cries of animals; they were also...

 - Spectrometer

Spectrometer

A spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization...

 - Spectroscopy

Spectroscopy

Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...

 - Spectrum analyser - Stellar spectroscopy - Sunyaev-Zel'dovich effect

Sunyaev-Zel'dovich effect

The Sunyaev–Zel'dovich effect is the result of high energy electrons distorting the cosmic microwave background radiation through inverse Compton scattering, in which the low energy CMB photons receive energy boost during collision with the high energy cluster electrons...

 - Supernova

Supernova

A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...

 - Telecommunication

Telecommunication

Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

 - Timbre

Timbre

In music, timbre is the quality of a musical note or sound or tone that distinguishes different types of sound production, such as voices and musical instruments, such as string instruments, wind instruments, and percussion instruments. The physical characteristics of sound that determine the...

 - Very high frequency

Very high frequency

Very high frequency is the radio frequency range from 30 MHz to 300 MHz. Frequencies immediately below VHF are denoted High frequency , and the next higher frequencies are known as Ultra high frequency...

 - Visible light - White noise

White noise

White noise is a random signal with a flat power spectral density. In other words, the signal contains equal power within a fixed bandwidth at any center frequency...

Sound waves

Acoustic theory

Acoustic theory

Acoustic theory is the field relating to mathematical description of sound waves. It is derived from fluid dynamics. See acoustics for the engineering approach....

 - Acoustics

Acoustics

Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics...

 - Aerodynamics

Aerodynamics

Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

 - Amplitude

Amplitude

Amplitude is the magnitude of change in the oscillating variable with each oscillation within an oscillating system. For example, sound waves in air are oscillations in atmospheric pressure and their amplitudes are proportional to the change in pressure during one oscillation...

 - Anemometer

Anemometer

An anemometer is a device for measuring wind speed, and is a common weather station instrument. The term is derived from the Greek word anemos, meaning wind, and is used to describe any airspeed measurement instrument used in meteorology or aerodynamics...

 - Beat (acoustics)

Beat (acoustics)

In acoustics, a beat is an interference between two sounds of slightly different frequencies, perceived as periodic variations in volume whose rate is the difference between the two frequencies....

 - Bugging - Cherenkov radiation

Cherenkov radiation

Cherenkov radiation is electromagnetic radiation emitted when a charged particle passes through a dielectric medium at a speed greater than the phase velocity of light in that medium...

 - Cold fusion

Cold fusion

Cold fusion, also called low-energy nuclear reaction , refers to the hypothesis that nuclear fusion might explain the results of a group of experiments conducted at ordinary temperatures . Both the experimental results and the hypothesis are disputed...

 - Compressibility - Delay line memory

Delay line memory

Delay line memory was a form of computer memory used on some of the earliest digital computers. Like many modern forms of electronic computer memory, delay line memory was a refreshable memory, but as opposed to modern random-access memory, delay line memory was serial-access...

 - Diffraction

Diffraction

Diffraction refers to various phenomena which occur when a wave encounters an obstacle. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record accurate observations of the phenomenon in 1665...

 - Doppler effect

Doppler effect

The Doppler effect , named after Austrian physicist Christian Doppler who proposed it in 1842 in Prague, is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from...

 - Echo sounding

Echo sounding

Echo sounding is the technique of using sound pulses directed from the surface or from a submarine vertically down to measure the distance to the bottom by means of sound waves. This information is then typically used for navigation purposes or in order to obtain depths for charting purposes...

 - Electronic filter

Electronic filter

Electronic filters are electronic circuits which perform signal processing functions, specifically to remove unwanted frequency components from the signal, to enhance wanted ones, or both...

 - FTIR - Krakatau - Loudspeaker

Loudspeaker

A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...

 - Mach number

Mach number

Mach number is the speed of an object moving through air, or any other fluid substance, divided by the speed of sound as it is in that substance for its particular physical conditions, including those of temperature and pressure...

 - Microphone

Microphone

A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1877, Emile Berliner invented the first microphone used as a telephone voice transmitter...

 - Ossicles

Ossicles

The ossicles are the three smallest bones in the human body. They are contained within the middle ear space and serve to transmit sounds from the air to the fluid-filled labyrinth . The absence of the auditory ossicles would constitute a moderate-to-severe hearing loss...

 - Pan pipes - Parabolic microphone

Parabolic microphone

A parabolic microphone is a microphone that uses a parabolic reflector to collect and focus sound waves onto a receiver, in much the same way that a parabolic antenna does with radio waves...

 - Phonetics

Phonetics

Phonetics is a branch of linguistics that comprises the study of the sounds of human speech, or—in the case of sign languages—the equivalent aspects of sign. It is concerned with the physical properties of speech sounds or signs : their physiological production, acoustic properties, auditory...

 - Phonons - Piezoelectricity

Piezoelectricity

Piezoelectricity is the charge which accumulates in certain solid materials in response to applied mechanical stress. The word piezoelectricity means electricity resulting from pressure...

 - Psychoacoustics

Psychoacoustics

Psychoacoustics is the scientific study of sound perception. More specifically, it is the branch of science studying the psychological and physiological responses associated with sound...

 - Sawtooth wave

Sawtooth wave

The sawtooth wave is a kind of non-sinusoidal waveform. It is named a sawtooth based on its resemblance to the teeth on the blade of a saw....

 - Shock wave

Shock wave

A shock wave is a type of propagating disturbance. Like an ordinary wave, it carries energy and can propagate through a medium or in some cases in the absence of a material medium, through a field such as the electromagnetic field...

 - SID

MOS Technology SID

The MOS Technology 6581/8580 SID is the built-in Programmable Sound Generator chip of Commodore's CBM-II, Commodore 64, Commodore 128 and Commodore MAX Machine home computers...

 - Sonar

Sonar

Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

 - Sonic boom

Sonic boom

A sonic boom is the sound associated with the shock waves created by an object traveling through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding much like an explosion...

 - Sonoluminescence

Sonoluminescence

Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound.-History:The effect was first discovered at the University of Cologne in 1934 as a result of work on sonar. H. Frenzel and H. Schultes put an ultrasound transducer in a tank of...

 - Sound proofing - Sound recording - Sound

Sound

Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...

 - Speech signal processing

Speech signal processing

Speech signal processing refers to the acquisition, manipulation, storage, transfer and output of vocal utterances by a computer. The main applications are the recognition, synthesis and compression of human speech:...

 - Speed of sound

Speed of sound

The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at , the speed of sound is . This is , or about one kilometer in three seconds or approximately one mile in five seconds....

 - Sperm Whale

Sperm Whale

The sperm whale, Physeter macrocephalus, is a marine mammal species, order Cetacea, a toothed whale having the largest brain of any animal. The name comes from the milky-white waxy substance, spermaceti, found in the animal's head. The sperm whale is the only living member of genus Physeter...

 - Square wave

Square wave

A square wave is a kind of non-sinusoidal waveform, most typically encountered in electronics and signal processing. An ideal square wave alternates regularly and instantaneously between two levels...

 - Subsonic

Speed of sound

The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at , the speed of sound is . This is , or about one kilometer in three seconds or approximately one mile in five seconds....

 - Subtractive synthesis

Subtractive synthesis

Subtractive synthesis is a method of sound synthesis in which partials of an audio signal are attenuated by a filter to alter the timbre of the sound...

 - Synthesizer

Synthesizer

A synthesizer is an electronic instrument capable of producing sounds by generating electrical signals of different frequencies. These electrical signals are played through a loudspeaker or set of headphones...

 - Telephone

Telephone

The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...

 - Transmission line

Transmission line

In communications and electronic engineering, a transmission line is a specialized cable designed to carry alternating current of radio frequency, that is, currents with a frequency high enough that its wave nature must be taken into account...

 - Triangle wave

Triangle wave

A triangle wave is a non-sinusoidal waveform named for its triangular shape.Like a square wave, the triangle wave contains only odd harmonics...

 - Wave drag

Wave drag

In aeronautics, wave drag is a component of the drag on aircraft, blade tips and projectiles moving at transonic and supersonic speeds, due to the presence of shock waves. Wave drag is independent of viscous effects.- Overview :...

 - Waveform

Waveform

Waveform means the shape and form of a signal such as a wave moving in a physical medium or an abstract representation.In many cases the medium in which the wave is being propagated does not permit a direct visual image of the form. In these cases, the term 'waveform' refers to the shape of a graph...

Economic and business cycles

Business cycle

Business cycle

The term business cycle refers to economy-wide fluctuations in production or economic activity over several months or years...

 - Inflation

Inflation

In economics, inflation is a rise in the general level of prices of goods and services in an economy over a period of time.When the general price level rises, each unit of currency buys fewer goods and services. Consequently, inflation also reflects an erosion in the purchasing power of money – a...

 / Recession

Recession

In economics, a recession is a business cycle contraction, a general slowdown in economic activity. During recessions, many macroeconomic indicators vary in a similar way...

 - Monetary policy

Monetary policy

Monetary policy is the process by which the monetary authority of a country controls the supply of money, often targeting a rate of interest for the purpose of promoting economic growth and stability. The official goals usually include relatively stable prices and low unemployment...

 - Virtuous circle and vicious circle

Virtuous circle and vicious circle

A virtuous circle and a vicious circle are economic terms. They refer to a complex of events that reinforces itself through a feedback loop. A virtuous circle has favorable results, while a vicious circle has detrimental results...

 - Kitchin cycle

Kitchin cycle

Kitchin cycle is a short business cycle of about 40 months discovered in the 1920s by Joseph Kitchin.This cycle is believed to be accounted for by time lags in information movements affecting the decision making of commercial firms. Firms react to the improvement of commercial situation through the...

 - Juglar cycle

Juglar cycle

Juglar cycle is a fixed investment cycle of 7 to 11 years identified in 1862 by Clement Juglar. Within the Juglar cycle one can observe oscillations of investments into fixed capital and not just changes in the level of employment of the fixed capital , as is observed with respect to Kitchin cycles...

 - Kuznets swing

Kuznets swing

Kuznets swing is a claimed medium-range economic wave with a period of 15–25 years found in 1930 by Simon Kuznets. Kuznets connected these waves with demographic processes, in particular with immigrant inflows/outflows and the changes in construction intensity that they caused, that is why he...

Music and rhythm cycles

Harmonics - Interval cycle

Interval cycle

In music, an interval cycle is a collection of pitch classes created from a sequence of the same interval class. In other words a collection of pitches by starting with a certain note and going up by a certain interval until the original note is reached In music, an interval cycle is a collection...

 - Musica universalis

Musica universalis

Musica universalis is an ancient philosophical concept that regards proportions in the movements of celestial bodies—the Sun, Moon, and planets—as a form of musica . This 'music' is not usually thought to be literally audible, but a harmonic and/or mathematical and/or religious concept...

 - Music theory

Music theory

Music theory is the study of how music works. It examines the language and notation of music. It seeks to identify patterns and structures in composers' techniques across or within genres, styles, or historical periods...

 - Physics of music - Ring cycle

Der Ring des Nibelungen

Der Ring des Nibelungen is a cycle of four epic operas by the German composer Richard Wagner . The works are based loosely on characters from the Norse sagas and the Nibelungenlied...

 - Rhythm

Rhythm

Rhythm may be generally defined as a "movement marked by the regulated succession of strong and weak elements, or of opposite or different conditions." This general meaning of regular recurrence or pattern in time may be applied to a wide variety of cyclical natural phenomena having a periodicity or...

 - Song cycle

Song cycle

A song cycle is a group of songs designed to be performed in a sequence as a single entity. As a rule, all of the songs are by the same composer and often use words from the same poet or lyricist. Unification can be achieved by a narrative or a persona common to the songs, or even, as in Schumann's...

Religious, mythological, and spiritual cycles

Astrology

Astrology

Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...

 - Mantra

Mantra

A mantra is a sound, syllable, word, or group of words that is considered capable of "creating transformation"...

 - Numerology

Numerology

Numerology is any study of the purported mystical relationship between a count or measurement and life. It has many systems and traditions and beliefs...

 - Pratitya-samutpada

Pratitya-samutpada

Dependent origination or dependent arising is a cardinal doctrine of Buddhism, and arguably the only thing that holds every Buddhist teaching together from Theravada to Dzogchen to the extinct schools. As a concept and a doctrine it has a general and a specific application, both being integral to...

 - Samhain

Samhain

Samhain is a Gaelic harvest festival held on October 31–November 1. It was linked to festivals held around the same time in other Celtic cultures, and was popularised as the "Celtic New Year" from the late 19th century, following Sir John Rhys and Sir James Frazer...

 - Sexagenary cycle

Sexagenary cycle

The Chinese sexagenary cycle , also known as the Stems-and-Branches , is a cycle of sixty terms used for recording days or years. It appears, as a means of recording days, in the first Chinese written texts, the Shang dynasty oracle bones from the late second millennium BC. Its use to record years...

 - Surya

Surya

Surya Suraya or Phra Athit is the chief solar deity in Hinduism, one of the Adityas, son of Kasyapa and one of his wives, Aditi; of Indra; or of Dyaus Pitar . The term Surya also refers to the Sun, in general. Surya has hair and arms of gold...