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Glossary

A glossary of science-related words.

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S-waves

Seismic waves that travel though side to side movements. They can travel through solid only. They are also called shear waves.

saccule

1. In mammals, a small sensory structure in the inner ear that monitors up and down head movements by sending nerve impulses to the brain for interpretation. 2. In fish, a structure found in the head region that allows fish to sense sound and gravity.

salinity

The amount of chemicals dissolved in water. In seawater, the main chemical is sodium chloride (salt), but there are many others in smaller quantities.

saliva

A watery fluid produced by the salivary glands in the mouth. It is made up of water, mucus, amylase, lipase and sodium bicarbonate.

salivary glands

Structures found in and around the mouth and throat that produce saliva. The major salivary glands are the parotid, submandibular and sublingual.

sandstone

A sedimentary rock formed from grains of sand (0.1–2.0 mm in size) held together by a natural cement. Sandstone can be formed under water or from wind-blown sand on land.

sapropel

A dark sediment layer with a high proportion of organic matter that can be found at the bottom of lakes and oceans.

sarcomere

One unit of a myofibril made up of a set of overlapping thick and thin protein filaments.

satellite

Any object that orbits around another object.

satiation

The feeling of fullness achieved during food consumption that promotes the termination of eating during a meal.

satiety

The lack of appetite or hunger for a period of time following a meal.

saturated fat

The fatty acids present in this type of fat have only single bonds present between each of the carbon atoms in the molecule.

scale insects

A family of insects that generally feed directly on the sap produced by plants.

scanning tunnelling microscope

A microscope that uses a tiny tip and electric current to provide a 3D image of atoms on a surface.

scientific community

The total body of scientists, their relationships and interactions.

scientific journal

A periodical publication intended to further the progress of science, usually by reporting new research.

scientific method

The notion that there is a unique standard method central to scientific progress. There is no such unique standard method.

scientific theory

To scientists, a theory provides a coherent explanation that holds true for a large number of facts and observations about the natural world. It has to be internally consistent, based upon evidence, tested against a wide range of phenomena and demonstrate problem solving.

scoria

A type of volcanic rock (igneous rock) that can be found in Auckland and also Mount Tarawera. Generally associated with basaltic or andesitic volcanoes. It is dark in appearance and often contains holes formed by escaping gases.

scurvy

A disease resulting from a deficiency of vitamin C. Symptoms includes fatigue, painful joints, bleeding gums and slow healing of wounds.

SDO

The Solar Dynamics Observatory (SDO) is a satellite launched by NASA in 2010. Its main aim is to understand the mechanisms responsible for solar variations that influence life on Earth.

sea pens

Sea pens are a type of colonial marine animal that belong to the order Pennatulacea.

secretin

A hormone that is released in response to acid in the small intestine. It stimulates the pancreas and gall bladder to release pancreatic juice and bile to neutralise the acid.

sedimentary

A type of rock formed after the deposition, compaction and cementation of sedimentary material produced by either the weathering and erosion of the Earth’s surface, biological organisms (shells) or chemical precipitation (ooids). Examples of sedimentary rocks are sandstone, mudstone, limestone and coal.

sedimentary geologist or sedimentologist

A scientist who studies the Earth with a special interest in rocks that have formed from compacting sediments.

sedimentation

The process of depositing sediment. Sedimentation rates can change by altering land use, e.g. deforestation tends to increase sedimentation, and exposed sediments can be carried along by wind and surface water and into rivers for eventual deposition in the sea.

sediments

In geology, it describes the solid fragments of inorganic or organic material that come from the weathering of rock and are carried and deposited by wind, water or ice.

seed

Part of the sexual reproduction of angiosperms (flowering plants) and gymnosperms (cone plants). Contains an embryo and its food store, which creates a new plant when conditions are right.

seepage

The slow movement of a liquid or gas through small holes or cracks in a porous material.

seine net

A fishing net that hangs vertically in the water with its bottom edge held down by weights and its top edge buoyed by floats. A seine net is used to form a barrier, weir or enclosure to prevent the escape of fish caught in the net.

seismic velocity

The speed at which seismic waves travel.

seismograph

An instrument that measures ground movement, including that caused by earthquakes and scientifically controlled underground explosions.

seismologists

People who study earthquakes.

seismology

The study of earthquakes.

seizure

A sudden episode of symptoms such as involuntary muscle movements, sensory disturbances and altered consciousness. A seizure is caused by abnormal electrical activity in the brain.

self-pollination

The transfer of pollen from the male to the female part of the same flower or another flower on the same plant.

self-sustaining population

When a population of animals has sufficient numbers to maintain the population level without human intervention.

semiconductor

A substance that can be made to conduct or block electricity. Silicon is a semiconductor that forms the basis of computer chips and many electronics components.

sentinel node

The first lymph node that a tumour drains into through the lymphatic system.

septuagenarian

A person aged 70–79 years old.

sequestration

The act of capturing and storing carbon dioxide so that it is no longer available for release into the atmosphere.
In chemistry, sequestration also means forming a chelate or other stable compound with ions, atoms or molecules so they can no longer react with other elements (effectively capturing and storing them).
In biology, sequestration also means the storage of toxins as butterfly larvae move through metamorphosis.

series

An electrical circuit layout where components are connected one after the other so that the current passes in a single path through the components.

serum

The clear liquid that can be separated from clotted blood. Serum differs from plasma – the unclotted blood containing the red and white cells and platelets.

sessile

An organism that is permanently attached to a substrate or surface.

setae

(Also written as chaetae.) In earthworms, bristly hairs found on each body segment. Earthworms use setae to grip the soil when they move or to anchor themselves in their burrows.

sexual reproduction

The formation of a new individual after the joining of male and female sex cells (gametes) from different parents. In some plants, sexual reproduction can involve gametes from the same parent.

sferic

A radio emission generated as part of the electromagnetic radiation produced in a lightning discharge.

shear stress

A stress state that will cause shearing when it exceeds a material's shear strength. The direction of the stress is parallel or tangential to the slip plane.

shield volcano

A type of volcano that is associated with volcanic fields such as the one in Auckland. Formed by relatively hot fluid lava, they have shallow sides. Often formed from basaltic lava. Includes scoria cone volcanoes.

short-chain fatty acids (SCFAs)

In digestion, the products of fermentation of undigested carbohydrate by bacteria in the large intestine.

SI

A measurement system used worldwide in the scientific community. SI stands for Système International d’Unités.

sial

The material of the Earth’s continental crust. The name is derived from silica and aluminia – the two main chemical constituents.

sialon

Any of a group of advanced ceramic materials based on the elements silicon, aluminium, oxygen and nitrogen.

sidereal time

Time kept with respect to distant stars. For example, a solar day is based on the Earth’s revolution, whereas a sidereal day is based on the Earth’s revolution in relation to a distant star.

silage pit

A silage pit (or silo) is a place to store silage. Silage is fermented, high-moisture plant material used to feed animals (usually cows or sheep).

silica

Informal name for the chemical silicon dioxide (SiO2). A component of rocks that can make them look white in appearance, for example, pumice has high silica content.

silicate

The chief rock-forming minerals, which contain silicon and oxygen.

silicon

A semimetal – symbol Si, atomic number 14.

silt

A granular material of a size somewhere between sand and clay. Its mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in water. It may also exist at the bottom of a water body.

silver

A transition metal in Group 11 of the periodic table – symbol Ag, atomic number 47.

silverfish

A 5 cm long fish that is especially common in the Ross Sea.

sima

The material of the Earth’s oceanic crust. The name is derived from silica and magnesia – the two main chemical constituents.

sintering

A method for making objects from powder that involves heating to a high temperature. The powder particles can fuse together, forming very strong bonds, making the final product hard, tough and durable.

skeletal muscles

The muscles attached to bones by tendons. One of the three different kinds of muscle in the human body, it is also called striated or striped muscle. Skeletal muscles are attached to the skeleton and are used to cause skeletal movement and to maintain posture. Skeletal muscles respond to conscious control.

skin friction

The opposing force caused as particles of air (or another fluid) move over the surface of an object. Collisions cause the air particles to change speed.

slaked lime

The common name for calcium hydroxide. When water is added to lime (calcium oxide), a chemical reaction occurs converting it into slaked lime (calcium hydroxide).

slow twitch

Slow, muscles that develop force slowly, maintain contractions longer and contract without needing oxygen.

small intestine

That part of the gastrointestinal tract that connects the stomach to the large intestine. It consists of three parts: the duodenum, the jejunum and the ileum.

smallpox

A disease believed to have originated over 3000 years ago in India or Egypt. It was one of the most devastating diseases to ever occur and is the only known disease that has been completely eradicated.

smectites

A family of clay minerals that includes montmorillonite and bentonite.

smooth muscles

The muscle tissue that makes up internal organs in the body. One of the three different kinds of muscle in the human body. A smooth muscle fibre has only one nucleus, and contracts more slowly and rhythmically than a skeletal fibre. Smooth muscle is found in the walls of the blood vessels, digestive system (e.g. the stomach and intestines) and other internal organs.

SMS

Short message service. A system that enables cell phone users to send and receive text messages.

Snell’s law

Snell’s Law of Refraction is expressed as n 1sinθ1 = n 2sinθ2 . The law states that, for waves passing from one medium to another, the ratio of the sine of the angle of incidence and the sine of the angle of refraction is constant.

socio-scientific

Combining social and scientific factors.

SOHO

The Solar and Heliospheric Observatory (SOHO) is a satellite launched by NASA in 1995 to study the Sun from its core to the outer atmosphere as well as the solar wind.

soil pore

Any open space within the soil framework. Water or air usually occupies this space.

soil porosity

Refers to the open spaces in soil between mineral particles or organic matter. Water or air usually occupies these spaces.

soil scientist

A scientist who studies soil, looking at a variety of aspects from the chemistry and form of soil to environmental protection and resource planning.

soil structure

The way that soil particles are arranged together.

soil texture

The relative proportion of the various sizes of sand, silt and clay particles that make up a soil.

solar cell

Any device that directly converts the energy in light into electrical energy through the process of photovoltaics.

solar collector

A device that absorbs and accumulates solar radiation for use as a source of energy.

solar energy

The energy received by the Earth and from the Sun. Also called solar power.

solar flare

A surface of the Sun event that is seen as an intense variation in brightness on or near its surface. It occurs as a result of the sudden release of magnetic energy that has built up in the solar atmosphere.

solar panel

A device that collects and converts solar energy into electricity or heat.

solar power

The energy received by the Earth from the Sun. Also called solar energy.

solar power plants

These indirectly generate electricity when the heat from solar thermal collectors is used to heat a fluid, which produces steam that is used to power generator. There are no solar power plants in New Zealand.

solar radiation

Radiant energy emitted by the Sun as a result of nuclear fusion reactions.

Solar System

The Sun and objects in orbit around it, including the planets and their moons, asteroids and comets. The Sun is a star like many others in the galaxy.

solar wind

A stream of high-speed charged particles that is ejected from the upper atmosphere of the Sun into the solar system. It is rapidly moving plasma.

solid state physics

The study of rigid matter or solids.

solstice

An astronomical event that occurs as the Sun reaches its highest or lowest excursion relative to the celestial equator on the celestial sphere. This occurs twice a year, defining our summer and winter seasons.

solvent

A liquid that dissolves another substance to form a solution. For example, water is a solvent for sugar – when sugar is dissolved in water, it becomes a sugar solution.

sonar

A method of detecting, locating, and determining the speed of objects through the use of reflected sound waves. A sound signal is produced, and the time it takes for the signal to reach an object and for its echo to return is used to calculate the object's distance.

sori

(Singular: sorus) Clusters of sporangia on the back of a fertile fern frond.

sounding rocket

A rocket designed to take measurements of the atmosphere or to perform microgravity experiments as it travels up through the atmosphere and then fall back to Earth.

source rock

The rock material of origin from which, in the case of oil formation, hydrocarbons like oil will form.

space shuttle

A reusable NASA spacecraft that carries astronauts, space station material and satellites into a low orbit around Earth.

spat

Juvenile mussels that have recently settled onto seaweed and other surfaces. Spat is also used to describe juveniles of other bivalves, such as oysters.

spatial resolution

The ability to sharply and clearly define the extent or shape of features within an image.

species

(Abbreviation sp. or spp.) A division used in the Linnean system of classification or taxonomy.

specimen

An item held in a collection that is preserved to allow study. The item is selected to represent a particular species and is generally a typical individual of that species.

spectrometer

An instrument that collects information about the different parts of the electromagnetic spectrum coming from a light source.

spectroscopy

The branch of science devoted to discovering the chemical composition of materials by looking at the light (and other kinds of electromagnetic radiation) they emit.

specular reflection

The reflection of light from a smooth surface in which the incident light rays are reflected from the surface such that the angle of reflection equals the angle of incidence.

spicule

Small usually needle-like structure made of silicate or calcium carbonate, which supports the soft tissue of some invertebrates, especially sponges.

spina bifida

A type of neural tube defect (NTD) that occurs as a foetus develops its spinal cord. It is the incomplete closure of the embryonic neural tube, where some vertebrae overlying the spinal cord are not fully formed and remain unfused and open. Sometimes if the hole is too big, a portion of the spinal cord can stick out, causing a noticeable external bubble on the baby’s back. The term is from the Latin spina (spine) and bifida (split).

spindle shaped

Shaped like a very elongated (stretched out) rugby ball.

spinneret

A jointed organ on the abdomen of spiders, which they use to spin their webs. Most spiders have three pairs of spinnerets. The silk thread of the spider is made of several smaller threads spun together as they leave the spinnerets.

splat

A term used to describe the ‘cow-pat’ shaped disc that a molten droplet forms on high-speed collision with the surface of a given substrate.

sporangia

(Singular: sporangium) The reproductive structures on the underside of the frond in which spores are produced.

spores

Small structures produced by many plants such as ferns, fungi, algae and some protozoans for reproduction. The spores help disperse the genetic information to allow the organisms to spread to new areas. Spores are similar to seeds but they do not contain any stored foods or sugar.

sporophyte

The spore-producing individual or phase in the life cycle of a plant that has alternation of generations. The diploid generation of the life cycle.

squamous cells

Flat cells, which look like fish scales, that make up most of the cells in the outer layer of the skin (the epidermis) as well as the linings of the hollow organs of the body.

stalactite

A cylindrical or conical structure made of calcium carbonate that hangs from the ceiling of a limestone cave. There is usually a hollow tube at the centre of the structure.

stalagmite

A conical structure that is formed by upward growth from a limestone cave floor due to dripwater falling from the roof of the cave or a stalactite.

stamen

Male reproductive part of flower. Made of an anther, where pollen is made, and a filament which attaches the anther to the flower.

stand-off pad

In agriculture, a stand-off pad is a firm surface, purpose-built as a resting place where stock can be held for long periods of time to minimise damage to paddocks.

star

A self-luminous celestial body consisting of a mass of gas held together by its own gravity.

starch

A complex carbohydrate found chiefly in seeds, fruits, tubers, roots and stem pith of plants.

states of matter

The classical states of matter are solid, liquid and gas. Several other states, such as plasma, do exist. Plasma is the most common form of matter in the universe.

statocyst

The balance organ found in some species of fish and invertebrates such as crabs and shrimp.

stem cell

A cell that has the potential to become any of the specialised cell types that makes up an organism.

stepped leader

A faint luminous light that branches down from a thunderstorm cloud base towards the ground before a lightning flash. It is seen to rapidly grow towards the ground in 50 m steps, and as it nears the ground, a positively charged streamer fires upwards to connect with it.

steroid hormone

A type of hormone with a lipid structure. Natural steroid hormones are produced in the body from cholesterol. The sex hormones testosterone and oestrogen are typical examples.

sterols

A type of chemical that is involved in sending chemical messages in the body.

stigma

Part of the carpel – the female reproductive organ of a flower. During pollination, pollen from a male flower part (anther) is transferred to the sticky female stigma.

stipe

The section of the stalk from the base of the frond to the lamina.

stolon

A special plant stem for asexual reproduction. It grows out sideways along the surface of the ground, and new plants grow up along it or just at the end.

stomach

An organ of digestion with a sac-like shape located between the oesophagus and the small intestine. It temporarily stores food, mixes and churns it with gastric juice and allows digestion of some of the protein content of food to take place.

stomata

The pores on the epidermis of a plant

stoneware

A type of pottery that is non-porous and opaque. Stoneware clay is fired at a high temperature (about 1200 °C) until made glass-like (vitrified). It is a sturdy, chip-resistant and durable material suitable for use in the kitchen for cooking, baking, storing liquids and as serving dishes.

STP

Standard temperature and pressure is taken as a temperature of 0°C (273 K) and a pressure of 101.3 kPa.

stratosphere

A layer in the atmosphere between 10 to 40 kilometres above the Earth’s surface where the temperature gradually rises from approximately -55 °C to 0 °C. The ozone layer is found in the stratosphere.

stratovolcano

A type of cone volcano that is built up layer by layer over subsequent eruptions. Generally steep sided and formed by moderately hot lava. Often form andesite rocks. An example is Mt Ngāuruhoe in the North Island.

streak

The colour of a crushed mineral’s powder, which may be different from the colour of the mineral. For example, calcite has a white streak even though the mineral has various coloured forms.

streamer

An upwardly propagating positively charged channel that meets a stepped leader to form a lightning bolt.

stress

A force applied to a body.

striated

A type of muscle that looks striped and is under voluntary control.

strike slip fault

Blocks of earth shift past each other in a horizontal movement.

strobe

To give the appearance of stopped or slowed motion by lighting something intermittently.

stromatolite

A mound-shaped structure formed in shallow water by alternating layers of carbonate or silicate sediment (mud that becomes trapped in the algae) and algal mats that become fossilised over time. Mounds over a metre high have been found. Stromatolites are widely distributed and contain some of the oldest recorded forms of life from over 2–3 billion years ago. They continue to form today, especially in Australia.

structural formula

A graphical representation of the molecular structure of a compound that shows how the atoms are arranged relative to one another.

style

A stalk that connects the stigma to the ovary in the female reproductive part of a flower.

stylet

A specialised mouthpart on an insect adapted for piercing.

Subantarctic Front (SAF) and Antarctic Polar Front (APF)

The two main water fronts in the Southern Ocean that make up most of the transport in the Antarctic Circumpolar Current.

subatomic particles

Particles that make up atoms – the building blocks of matter. The three basic ones are protons, neutrons and electrons. Protons and neutrons are themselves made of even smaller particles called quarks.

subduction

When tectonic plates with differing material densities collide and the denser plate is forced down under (subducts) the less dense one.

suborbital

A flight trajectory in which an object moves up and then returns to the ground. It does not have enough speed to go into orbit around the Earth.

substrate

1. In ecology, the surface or sediment where an organism lives and grows. 2. In biochemistry, the substance on which an enzyme works.

subtidal

Marine habitats that are always submerged.

succus entericus

The clear to pale yellow watery secretions from the glands lining the small intestine walls. It contains hormones, digestive enzymes, mucus and bicarbonate.

sucrase

An enzyme that catalyses the hydrolysis of sucrose into glucose and fructose.

sunscreen

A product applied to the skin to protect it from the effects of the Sun's rays. Sunscreens act by absorbing or reflecting ultraviolet radiation.

superconducting magnet

The phenomenon of almost perfect conductivity shown by certain substances at temperatures approaching absolute zero.

superconductivity

The ability of certain substances to conduct electric current with almost no resistance at very low temperatures.

superconductor

A type of solid material whose electrical resistance drops to zero when cooled below a certain temperature.

supernova

A rare celestial event involving the explosion of most of the material in a star, resulting in an extremely bright, short-lived object that emits vast amounts of energy.

superoxide

A free radical produced in mitochondria as a result of electron leakage from the electron transport chain. It can damage biological molecules such as proteins and nucleic acids.

superphosphate

New Zealand’s premium fertiliser. Superphosphate provides the essential nutrient phosphorus and first went on sale in England in 1843. It is produced by treating rock phosphate with sulfuric acid.

supersaturated

A description of a solution that has become more concentrated than is normally possible under given conditions of temperature and pressure.

supersonic

Anything travelling faster than the speed of sound (about 330 m/s or 1200 km/h).

surface area

The total area of the surface of a three-dimensional object.

surface tension

A property of liquids caused by intermolecular forces near the surface causing an elastic-like force or the apparent presence of a surface film.

surfactant

A chemical wetting agent that reduces the surface tension between oil and water. Detergents and soaps are surfactants.

swallowing reflex

Swallowing, also known as deglutition, is the process that makes something pass from the mouth, to the pharynx, into the oesophagus and then to the stomach. It is a complex neuromuscular process involving voluntary actions (mouth) followed by involuntary actions (pharynx) and peristalsis (oesophagus).

switch

An electrical component that can make or break an electrical circuit, connecting or interrupting the current or diverting it from one conductor to another.

symbionts

Organisms that live together for their mutual benefit.

symbiosis

A close association of two different species. The relationship could be commensalistic, mutualistic or parasitic.

symbiotic

A relationship between two species that benefits both species. For example, lichen results from a mutually beneficial partnership between fungi and algae.

synchrotron

A type of particle accelerator in which particles move at accelerating speed around a hollow ring – sometimes several kilometres in circumference. The ion beam or particle path is very precisely focused by the magnetic field of a continuous ring of electromagnets.

synergy

The working together of two things (food components, for example) to produce an effect greater than the sum of their individual effects.

synodic period

The time required for a body within the solar system, such as a planet, the Moon or an artificial Earth satellite, to return to the same position relative to the Sun as seen by an observer on the Earth. The Moon’s synodic period is the time between successive recurrences of the same phase, for example, between full moon and full moon.

synthetic molecules

In immunity, a molecule specially developed to resemble another molecule. Its role is to trigger a response from the immune system by mimicking other pathogenic molecules (such as those from bacteria).