apex predator: An animal at the top of the food chain. Such predators also have no predators themselves.
atomic: Having to do with atoms, the smallest possible unit that makes up a chemical element.
biologist: A scientist involved in the study of living things.
birds: Warm-blooded animals with wings that first showed up during the time of the dinosaurs. Birds are jacketed in feathers and produce young from the eggs they deposit in some sort of nest. Most birds fly, but throughout history there have been the occasional species that don’t.
dimension: Descriptive features of something that can be measured, such as length, width or time.
dinosaur: A term that means terrible lizard. These reptiles emerged around 243 million years ago. All descended from egg-laying reptiles known as archosaurs. Their descendants eventually split into two lines. For many decades, they have been distinguished by their hips. The lizard-hipped line are believed to have led to the saurischians, such as two-footed theropods like T. rex and the lumbering four-footed Apatosaurus. A second line of so-called bird-hipped, or ornithischian dinosaurs, appears to have led to a widely differing group of animals that included the stegosaurs and duckbilled dinosaurs. Many large dinosaurs died out around 66 million years ago. But some saurischians lived on. They are now the birds we see today (and who have now evolved that so-called “bird-hipped” pelvis).
fire: The burning of some fuel, creating a flame that releases light and heat. (in neuroscience) The activation of a nerve or neural pathway.
fuel: Any material that will release energy during a controlled chemical or nuclear reaction. Fossil fuels (coal, natural gas and petroleum) are a common type that liberate their energy through chemical reactions that take place when heated (usually to the point of burning).
gizzard: A thick-walled part of a bird’s stomach that is used for grinding food. It may contain grit or small stones to help the bird break down tough seeds.
gut: An informal term for the gastrointestinal tract, especially the intestines.
half-life: The time it takes for half of some quantity of a radioactive isotope to decay (transform) into a new isotope
laser: A device that generates an intense beam of coherent light of a single color. Lasers are used in drilling and cutting, alignment and guidance, in data storage and in surgery.
lizard: A type of reptile that typically walks on four legs, has a scaly body and a long tapering tail. Unlike most reptiles, lizards also typically have movable eyelids. Examples of lizards include the tuatara, chameleons, Komodo dragon, and Gila monster.
matter: Something that occupies space and has mass. Anything on Earth with matter will have a property described as “weight.”
metabolism: (adj. metabolic) The set of life-sustaining chemical reactions that take place inside cells and bigger structures, such as organs. These reactions enable organisms to grow, reproduce, move and otherwise respond to their environments.
organ: (in biology) Various parts of an organism that perform one or more particular functions. For instance, an ovary is an organ that makes eggs, the brain is an organ that makes sense of nerve signals and a plant’s roots are organs that take in nutrients and moisture.
particle: A minute amount of something.
planet: A large celestial object that orbits a star but unlike a star does not generate any visible light.
power plant: An industrial facility for generating electricity.
predator: (adjective: predatory) A creature that preys on other animals for most or all of its food.
prehistoric: An adjective for something that happened tens of thousands to millions of years ago, periods before people began deliberately recording events.
radiate: (in physics) To emit energy in the form of waves.
radiation: (in physics) One of the three major ways that energy is transferred. (The other two are conduction and convection.) In radiation, electromagnetic waves carry energy from one place to another. Unlike conduction and convection, which need material to help transfer the energy, radiation can transfer energy across empty space.
radioactive: An adjective that describes unstable elements, such as certain forms (isotopes) of uranium and plutonium. Such elements are said to be unstable because their nucleus sheds energy that is carried away by photons and/or and often one or more subatomic particles. This emission of energy is by a process known as radioactive decay.
random: Something that occurs haphazardly or without reason, based on no intention or purpose. Or an adjective that describes some thing that found itself selected for no particular reason, or even chaotically.
risk: The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. (For instance: Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.)
sea: An ocean (or region that is part of an ocean). Unlike lakes and streams, seawater — or ocean water — is salty.
technology: The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.
theory: (in science) A description of some aspect of the natural world based on extensive observations, tests and reason. A theory can also be a way of organizing a broad body of knowledge that applies in a broad range of circumstances to explain what will happen. Unlike the common definition of theory, a theory in science is not just a hunch. Ideas or conclusions that are based on a theory — and not yet on firm data or observations — are referred to as theoretical. Scientists who use mathematics and/or existing data to project what might happen in new situations are known as theorists.
toxin: A poison produced by living organisms, such as bacteria, algae and certain plants (such as poison ivy). Bees, spiders, snakes and other animals also produce toxins. These are referred to as venoms.
unique: Something that is unlike anything else; the only one of its kind.
uranium: The heaviest naturally occurring element known. It’s called element 92, which refers to the number of protons in its nucleus. Uranium atoms are radioactive, which means they decay into different atomic nuclei.
water vapor: Water in its gaseous state, capable of being suspended in the air.