natural materials that are used by humans; they can be classified as renewable or nonrenewable.
an undesirable change in the natural environment that is caused by the introduction of substances that are harmful to living organisms or by excessive wastes, heat, noise, or radiation.
the condition in which human needs are met in such a way that a human population can survive indefinitely.
the study of the interactions of living organisms with one another and with their environment.
people who obtained food by collecting plants and by hunting wild animals or scavenging their remains.
a time period which involved the practice of growing, breeding, and caring for plants and animals that are used for food, clothing, housing, transportation, and other purposes that had a dramatic impact on human societies and their environment.
countries that have lower average incomes, simple and agriculture-based economies, and rapid population growth.
the study of the air, water, and land surrounding an organism or a community; it includes the study of the impact of humans on the environment.
a calculation that shows the productive area of Earth needed to support one person in a particular country.
law of supply and demand
a law of economics that states that as the demand for a good or service increases, the value of the good or service also increases.
countries that have higher average incomes, slower population growth, diverse industrial economies, and stronger social support systems.
a time period which involved a shift from energy sources such as animal muscle and running water to fossil fuels, such as coal and oil.
this model includes one or more equations that represents the way a system or process works.
association between two or more events; what scientists use to test a prediction when an experiment is unethical or impossible.
a series of steps that scientists worldwide use to identify and answer questions.
this model is a verbal or graphical explanation of how a system works or is organized.
A diagram in which the numerical values of variables are represented by the height or length of lines or rectangles of equal width.
A procedure that is carried out under controlled conditions to discover, demonstrate, or test a fact, theory, or general truth.
Not believing everything you're told. Being open minded about how the world works and being open to new ideas.
is a piece of information we gather using our senses - our sight, hearing, smell, and touch.
Earth's thinnest layer, composed almost entirely of light elements, makes up less than 1% of the Earth's mass.
the pieces of lithosphere that are divided and glide across the underlying asthenosphere.
an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
The force that attracts a body toward the center of the earth, or toward any other physical body having mass.
Big Bang Theory
theory that states all matter and energy were once compressed into a single point, 13.7 billion years ago, and expanded to form our universe.
a shift in the light spectra of very distant galaxies toward longer wavelengths (toward the red end of the spectrum); generally interpreted as evidence that the universe is expanding.
cosmic background radiation
the radiation emitted from the Big Bang that is left behind by the expansion of the Universe. Its detectable today as radio-wavelength radiation, and we can see it on a fuzzy channel of our TV screens.
elements (hydrogen, helium, lithium) that were formed during the first million years of our Universe, and continue to be formed through nucleosynthesis.
elements (heavier than Iron (Fe)) that continue to be formed through supernovas, and death of large stars via nucleosynthesis
the process by which nuclei of small atoms combine to form a new, more massive nucleus thereby releasing energy.
a system of millions of billions of stars, together with gas and dust, held together by gravitational attraction.
the theory that explains how solar systems are created from nebulae, going through the protostar/protoplanet phase, and ending up with a main sequence star orbited by planets and other bodies.
a high-temperature, disk-shaped cloud of gas and dust in space that has grown from a nebula to near the point of beginning nuclear fusion and becoming a star.
the main cycle of a star's life, undergoing nuclear fusion, with gravity and pressure in a delicate balance.
the result of a red supergiant shrinking and exploding that releases massive amounts of energy, dust and gas.
second generation star
a star produced from supernovas of previous stars, as evidenced by presence of heavier elements.
a small body that orbits the sun, collecting dust and gas, to become a larger planetary body.
lithosphere that is mainly comprised of basalt; it is more dense that is why it sits lower in the asthenosphere.
lithosphere that is mainly comprised of granite; not as dense as basalt that's why it sits higher up in the asthenosphere.
the time period when volcanic eruptions went on continuously, releasing gases such as water vapor, carbon dioxide, and sulfur, forming our early atmosphere.
early atmosphere formation
formation of the early envelope of gases around the earth, composed of carbon dioxide, water vapor, sulfur gases.
early ocean formation
formation of the early water bodies around the Earth, created by water vapor that cooled enough to condense and precipitate onto Earth.
early life formation
thought to have begun in the oceans, evolved in the absence of oxygen as simple structured bacteria.
layered form of rock formed in shallow water by the trapping, binding and cementation of cyanobacteria, which show some of the most ancient records of life on Earth.
Earth's twin, theorized to have crashed into Earth, increasing its mass, and remnants forming the Earth's Moon.
the relative arrangement of the members of a statistical population; usually shown in a graph.
the number obtained by adding up the data for a given characteristic and dividing this sum by the number of individuals.
the raising of crops and livestock for food or for other products that are useful to humans.
the mostly solid, rocky part of Earth; extends from the center of the core to the surface of the crust.
the solid, outer layer of the Earth that consists of the crust and the rigid upper part of the mantle.
the solid, plastic layer of the mantle beneath the lithosphere; made of mantle rock that flows very slowly, which allows tectonic plates to move on top of it.
a pattern, plan, representation, or description designed to show the structure or workings of an object, system, or concept.
The lowest layer of the atmosphere, in which temperature drops at a constant rate as altitude increases; the part of the atmosphere where weather conditions exist.
The layer of the atmosphere that lies between the troposphere and the mesosphere and in which temperature increases as altitude increases; contains the ozone layer.
The energy that is transferred as electromagnetic waves, such as visible light and infrared waves.
The warming of the surface and lower atmosphere of Earth that occurs when carbon dioxide, water vapor, and other gases in the air absorb and reradiate infrared radiation.
Any form of water that falls to the Earth's surface from the clouds; includes rain, snow, sleet, and hail.
a nonrenewable energy resource formed from the remains of organisms that lived long ago; examples include oil, coal, and natural gas.
oil deposits that can be extracted profitably at current prices using current technology.
the energy released by a fission or fusion reaction; the binding energy of the atomic nucleus.
The process by which nuclei of small atoms combine to form a new, more massive nucleus; the process releases energy.
The process by which the nucleus of a heavy atom splits into two or more fragments; the process releases neutrons and energy.
active solar heating
energy from the sun can be gathered by collectors and used to heat water or to heat a building.
when warm surface water is used to boil cold deep sea water, this is possible because deep sea water boils easily. This proses creates steam to turn a turbine and generate electricity.
hydrogen fuel cell
produces electricity chemically, by combining hydrogen fuel with oxygen from the air. When hydrogen and oxygen are combined, electrical energy is produced and water is the only byproduct.
the percentage of energy put into a system that does useful work. It can be determined using this simple equation: energy efficiency (in %) = useful energy out/energy in X 100.