Category: Dictionary

Pedestal: A base, a support or a foundation.

Pascal’s principle: States that: Pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid, as well as to the walls of the container.

Partial melting zone: The layer between the crust and the mantle of the earth. This layer consists of a molten rock ‘liquid’ with high viscosity and acts like a viscous ‘sea’ upon which the continents drift!

Papier-mâché: A substance made from paper pulp that can be moulded when wet and painted when dry.

Paper Chromatography: An analytical chemistry technique for separating and identifying mixtures that are or can be coloured, especially pigments. This can also be used in secondary or primary colours in ink experiments.

Pangaea: A hypothetical continent including all the landmass of the earth prior to the Triassic period when it split into Laurasia and Gondwanaland.

Oxygen: Oxygen, scientifically known as O2, occupies about 21 percent of the earth’s atmosphere and is also found in other substances including water. It can combine with many other elements and it is essential for plants & animals to breathe. Oxygen is also required for nearly all combustion.

Oxidation: The addition of oxygen to a compound accompanied with a loss of electrons

Osmosis: Osmosis is the diffusion of a liquid through a cell wall or membrane. Osmosis is the means by which water and nutrients move.

Oscilloscope: An electronic device with a screen, which displays a picture of the voltage of an electrical signal. When this device is connected to the output of an audio amplifier, it displays patterns related to the sound pressure coming out of the loudspeaker.

Oscillator: A tuned electronic circuit used to generate a continuous output repetitive variation, typically in time.

Optician: A specialist in fitting eyeglasses and making lenses to correct vision.

Optical illusion: An optical phenomenon that results in a false or deceptive visual impression.

Optic nerve: The optic nerve transmits visual information from the retina to the brain.

Oil: Any of a group of fats that is a liquid at room temperature that are obtained from plants.

Mycology: The branch of living sciences concerned with the study of fungi.

Ohm’s law: Ohm’s law states that the current through a conductor between two points is directly proportional to the potential difference or voltage across the two points, and in reverse proportional to the resistance between them.

Non-ferrous metals: Non-ferrous metals are those that have very little iron content. Non-ferrous metals are non-magnetic metals such as gold, silver or aluminium.

Nocturnal: Animals or insects that is active during the night and sleep during the day.

Natron: Natron is a natural salt, composed of sodium carbonate and sodium bicarbonate with traces of sodium chloride and sodium sulphate. It was used by the ancient Egyptians to dry out the bodies during mummification.

Mummification: The preserving of a dead body, by making it into a mummy.

Motion picture: Series of images on a strip of film usually projected at the rate of 24 frames per second, which make up a conceptually complete work. Also referred to as a film.

Morse Code: A telegraph code in which letters and numbers are represented by strings of dots and dashes (short and long signals)

Mordant: Any substance used to facilitate the fixing of a dye to a fibre

Momentum: Momentum is the product of the mass and velocity (speed) of an object (p = mv).

Mold: A fungus that produces a superficial growth on various kinds of damp or decaying organic matter.

Milliammeter: A sensitive ammeter for detecting small currents, graduated in milliamperes.

Microbes: Minute living organisms, including but not limited to bacteria, viruses and fungi.

Michael Faraday: Michael Faraday was a British physicist and chemist, best known for his discoveries of electromagnetic induction and of the laws of electrolysis. Born in 1791, Faraday was the son of a blacksmith and received little formal education. While working for a bookbinder in London, he read many scientific books and experimented with electricity. Faraday’s most important scientific contributions were in the fields of electricity and magnetism. In 1821 Faraday plotted the magnetic field around a conductor carrying an electric current, and in 1831 he followed this accomplishment with the discovery of electromagnetic induction.

Methylene blue: A blue dye used as a stain, an antiseptic, or a chemical indicator. Methylene blue has many uses in a range of different fields, such as biology and chemistry.

Metamorphic rock: Rocks formed from other rocks under pressure and extreme heat.

Metals: Any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets. Most metals also have magnetic properties.

Metabolism: The chemical reactions that allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually synonymous with energy production.

Meniscus: The curved top of a column of liquid, such as ‘water’ in a small tube. It is formed because the attractive forces between the tube and the water molecules (adhesive forces) are stronger than the cohesive forces between individual water molecules.

Membrane: A pliable sheet of tissue that covers or lines or connects the organs or cells of animals or plants.

Mealworms: Mealworms are the larva form of the mealworm beetle, ‘Tenebrio molitor’, a species of darkling beetle. Like all holo-metabolic insects, they go through four life-stages: egg, larva, pupa, and adult. Mealworms are a tasty treat for hamsters.

Matter: Matter is a general term for the “stuff” of which the world is made.

Mantle: Earth’s mantle is a rocky shell about 2,890 km thick that constitutes about 84 percent of Earth’s volume. It is predominantly solid and encloses the iron-rich hot core, which occupies about 15 percent of Earth’s volume.

Maltose: A white crystalline sugar formed during the digestion of starches.

Male ants: Male ants do not work and live only a few weeks or months. The only purpose of the male ant is to mate with the queens and they die shortly thereafter.

Magnification: A measurable increase in the apparent size of an object. This enlargement is quantified by a calculated number also called ‘magnification’. Magnification is the ratio between the apparent size and the true size of the viewed object behind the lens or other magnifier.

Magnetism: The force of attraction or repulsion of a magnetic material due to the arrangement of its atom. A magnet is a metal object that attracts pieces of ferrous (metal) objects.

Magnetic North: North according to the Earth’s magnetic poles rather than its geographic poles. Declination from true north is given in miles where one mile equals 1/6,400 of 360 degrees.

Magnetic field: A condition in the space around a magnet or electric current in which there is a detectable magnetic force and two magnetic poles are present.

Machine: Any mechanical or electrical device that transmits or modifies energy to perform or assist in the performance of human tasks. Also, a device that has parts to perform or assist in performing any type of work.

Lye: Lye is a strong alkaline substance, commonly ‘sodium hydroxide’ or ‘caustic soda’ (NaOH)

Lunar month: The average time between successive new or full moons. A lunar month is equal to 29 days 12 hours 44 minutes. Also called a ‘synodic’ month.

Lumens: The SI unit of luminous flux. It is a measure of the power of light that can be perceived by the human eye.

Logic gate: A computer circuit with several inputs but only one output that can be activated by particular combinations of inputs

Little dipper: A cluster of seven stars in the constellation Ursa Minor also called Little Bear. At the end of the dipper’s handle is ‘Polaris’, the North Star.

Litmus: A colouring material (obtained from lichens, a composite organism consisting of fungi) that turns red in acid solutions and blue in alkaline solutions. It is used as a very rough acid-base indicator.

Lignum: Wooden tissue. This may or may not contain the bark of the tree as well.

Lift: A fluid flowing past the surface of a body exerts a surface force on it. Lift is defined to be the component of this force that is perpendicular to the oncoming flow direction. Lift Take off or away by decreasing the air pressure.

Lever: A rigid bar used to apply pressure at one point along its length by applying a force (effort) at a second point and turning about a third point or fulcrum.

Leonardo da Vinci: Leonardo da Vinci, born in 1452, is considered as perhaps the most diversely talented person ever to have lived. Primarily known as an artist for his paintings and sculpting, he was also a scientist, mathematician, engineer, inventor, musician, writer and architect and was recognized in many more fields! It is even rumoured that he could paint with one hand and write with the other at the same time. Although relatively few of his designs were constructed or were even feasible during his lifetime, Leonardo is praised for his technological ingenuity. He conceptualised a helicopter, a tank, concentrated solar power, a calculator and many, many more during his lifetime!

Landslide: A rapid down slope mass movement where water in the soil and rock has accumulated to sufficiently increase stress and lubricate bedding planes.

Knee-jerk reaction: The involuntary contraction of the leg when the knee is tapped with a doctor’s mallet.

Kinetic energy: The energy possessed by an object by virtue of its motion is called kinetic energy.  The greater the mass or speed of the object, the greater is the kinetic energy.  Kinetic means active or moving.  Kinetic energy can be defined as energy in motion or the energy of a moving object.

Kilowatt hour: A kilowatt-hour (kWh) is a standard metric unit of measurement for electricity consumption for billing purposes. It can simply be described as 1000 watts of electricity used for one hour.

Kelvin: Kelvin is the fundamental unit of temperature adopted under the Systeme International d’Unites (SI).  It is not calibrated in terms of the freezing and boiling points of water, but in terms of energy itself.  The number 0 K is assigned to the lowest possible temperature, called ‘absolute zero’.

Kazoo: A toy wind instrument that has a membrane that makes a sound when you hum into the mouthpiece.

Kaleidoscope: A tubular instrument containing loose bits of coloured glass, plastic, etc. reflected by mirrors so that various symmetrical patterns appear when the tube is held to the eye and is rotated

Jean Foucault: Jean Bernard Léon Foucault (18 September 1819 – 11 February 1868) was a French physicist best known for the invention of the Foucault pendulum, a device demonstrating the effect of the Earth’s rotation.

Isaac Newton: Sir Isaac Newton (1642-1727), a mathematician and physicist were of the foremost scientific intellects of all time and who is famous for his ‘action-reaction law’ which states: ‘to every action there is an equal and opposite reaction’

Iron: A metallic chemical element with the symbol ‘Fe’ and atomic number 26.

Iris: A muscular diaphragm that controls the size of the pupil which in turn controls the amount of light that enters the eye. The iris forms the coloured portion of the eye.

Iodine: A non-metallic element belonging to the halogens. Iodine is used especially in medicine and photography and in dyes. It occurs naturally only in combination in small quantities as in sea water or rocks.

Invisible ink: A substance used for writing, which is invisible either on application or soon thereafter, and which can later on be made visible by some means.

Integrated circuit: A collection of active and passive electrical components such as transistors and resistors mounted on a single slice of silicon and packaged as a single component. An integrated circuit is also known as an IC, microcircuit, or microchip.

Insulator: A material such as glass or porcelain with a very tiny electrical or thermal conductivity.

Infra-red rays: Invisible radiation in the part of the electromagnetic spectrum characterized by wavelengths just longer than those of ordinary visible red light and shorter than those of microwaves or radio waves.

Inertia: The tendency of a body to maintain its state of rest or uniform motion unless acted upon by an external force.

Induction: An electrical phenomenon whereby an electrical current is generated in a closed circuit, by a stroking a magnet along a conductor.

Indicator: Any substance used to classify another, often by changing colour.

Indicator: Any substance used to classify another, often by changing colour.

Inclinometer: A measuring instrument for measuring the angle of magnetic dip. Airplane pilots make use of this device to show the angle that an aircraft makes with the horizon.

In series: Electrical components connected in a chain, instead of in parallel.

In Parallel: Connected at the same time. Electrical components connected side by side, instead of in series.

Immiscible liquids: Immiscibility is two or more liquids that are not mutually soluble or un-mixable, whereas miscibility is the property of liquids to mix in all proportions, forming a homogeneous solution.

Immiscible: The chemical property where two or more liquids or phases do not readily mix or dissolve in one another, such as oil and water.

Igneous rocks: Rocks that is produced under conditions involving intense heat

Ice: Water frozen in the solid state.

Hyphae: Small threads that are part of a fungus. These thin strands stretch out to gather food and nutrients to allow the fungus to grow.

Hygrometer: Measuring instrument for measuring the relative humidity of the atmosphere.

Hydroponics: A technique of growing plants (without soil) in water containing dissolved nutrients.

Hydrogen peroxide: An almost colourless, slightly pale blue liquid. H2O2 is soluble in water. Hydrogen peroxide is used as a mild antiseptic and is often found in bleaching agents, especially for bleaching hair.

Hydroelectric power: Hydroelectric power is electricity generated by hydropower, i.e., the production of electrical power through the use of the gravitational force of falling or flowing water.

Humidity: The relative humidity is a measure of the amount of water vapour in the air (at a specific temperature) compared to the maximum amount of water vapour air could hold at that temperature, and is given as a percentage value.

Hot-air balloon: Balloon for travel through the air in a basket suspended below a large bag or ‘envelope’ of heated air.

Horticulture: The science of caring for gardens or gardening; small scale agriculture.

Hormone: A chemical substance produced in a living organism which controls the rate of biochemical processes.

Hermann Grid Illusion: This is an optical illusion named by ‘Ludimar Hermann’ in the 1800’s. The illusion is characterised by blobs perceived at the intersections of a light-coloured grid between black squares.

Hering Illusion: This is an optical illusion named by Ewald Hering. The vertical or horizontal lines are all straight, but look as if they were bent. The distortion is produced by a lined pattern on the background that simulates a perspective design and creates a false impression of depth.

Helium: Helium is the chemical element with atomic number 2 and an atomic weight of 4.0026, which is represented by the symbol He. Helium is a colourless, odourless and tasteless gas. It also makes up a small amount of the air we breathe. It originates from the Greek word ‘helios’ meaning the sun. Helium is commonly used as a cooling agent in superconductors, cryogenics, inflating balloons as well as inflating airships.

Heat: A form of energy that is transferred by a difference in temperature.

Gyroscopic effect: Having the effect of a gyroscope – a rotating mechanism mounted so that its axis can turn freely in one or more directions. A spinning gyroscope tends to resist change in the direction of its axis.

Grounding: The process of connecting equipment to a common ground or ‘earth’. This is done as a safety mechanism in order to avoid the unsafe energizing of equipment.

Gravity: The force of attraction between all masses in the universe, especially the attraction of the earth’s mass for bodies near its surface. The farther a body from the earth’s surface, the less the gravitational force acting on it.

Grafting: A method of plant breeding widely used in agriculture and horticulture, where the tissues of one plant are encouraged to fuse with those of another.