[person - light & optics, matter, research methods, science & decision making, science communication, scientific concepts] English statesman and philosopher born in London (1561-1626). In 1620, Bacon published the Novum Organum, in which he argued for a method of scientific inquiry based on inductive reasoning in which the only way to discover the truth was to gather evidence from the real world. He is often referred to as the catalyst for the Scientific Revolution. In 1618, Bacon was appointed Lord Chancellor, and in 1621, he was made viscount St. Albans.

• Appears in modules:

• Scientific Institutions and Societies
• The Phosphorus Cycle
• The Practice of Science

[noun - organisms] (plural of bacterium) A large group of one-celled organisms that are found almost everywhere.

• Appears in modules:

• Biodiversity I
• Carbohydrates
• Cell Division I
• Cell Division II
• Cellular Organelles I
• Composition of Earth's Atmosphere
• Data Analysis and Interpretation
• David Ho
• Discovery and Structure of Cells
• DNA I
• DNA III
• Energy Metabolism I
• Energy Metabolism II
• Experimentation in Scientific Research
• Exponential Equations in Science II
• Future of Human Evolution
• History of Earth's Atmosphere II
• Lipids
• Meselson and Stahl
• Photosynthesis I
• Santiago Ramón y Cajal and Camillo Golgi
• The Nitrogen Cycle
• The Phosphorus Cycle
• Theories, Hypotheses, and Laws
• Y-Chromsome and Mitochondrial DNA Haplotypes

[noun - medicine, organisms, toxicology & pharmacology] Any of a group of viruses that infect and reproduce in specific bacteria, usually causing their disintegration or dissolution. After the bacterium is destroyed, the bacteriophage is released and can invade surrounding bacteria.

• Appears in modules:

• DNA I

[noun - rocks & minerals] A dark, fine-grained igneous rock formed by cooling of iron- and magnesium-rich lava above the surface of the earth. Basalt is the main component of the oceanic crust of the Earth.

• Appears in modules:

• Defining Minerals
• Earth Structure
• Origins of Plate Tectonic Theory
• The Rock Cycle

[noun - acids, bases & pH] Generally, a substance that reacts with acids to form a salt, several different definitions of bases have been proposed by different scientists (listed in parentheses). 1) (Arrhenius) a compound that releases hydroxide ions (OH-) in solution; 2) (Brønsted-Lowry) a molecule or ion that accepts hydrogen ions from solution; 3) (Lewis) a molecule or ion that donates an electron pair to an acid.

• Appears in modules:

• Acids and Bases I
• Acids and Bases II
• Animal Behavior
• Atomic Theory I
• Atomic Theory II
• Barbara McClintock
• Biodiversity I
• Cell Division II
• Cellular Organelles I
• César Milstein
• Chemical Bonding
• Chemical Equations
• Chemical Reactions
• Composition of Earth's Atmosphere
• Confidence Intervals
• Data Analysis and Interpretation
• Defining Minerals
• Description in Scientific Research
• Diffusion I
• Discovery and Structure of Cells
• DNA I
• DNA II
• DNA III
• Early Ideas about Matter
• Earth Structure
• Ellen Ochoa
• Exponential Equations in Science I
• Exponential Equations in Science II
• France Anne-Dominic Córdova
• Franklin Chang Díaz
• Gravity
• Introduction to Inferential Statistics
• Kinetic-Molecular Theory
• Light and Electromagnetism
• Linear Equations in Science
• Mario Molina
• Measurement
• Membranes II
• Mendel and Independent Assortment
• Nuclear Chemistry
• Origins of Life I
• Origins of Plate Tectonic Theory
• Photosynthesis I
• Plates, Plate Boundaries, and Driving Forces
• Properties of Minerals
• Ruth Benerito
• Scientific Notation and Order of Magnitude
• Sergio Avila
• Taxonomy I
• Taxonomy II
• Temperature
• The Carbon Cycle
• The Metric System
• The Mole and Atomic Mass
• The Phosphorus Cycle
• The Practice of Science
• Thermodynamics I
• Uncertainty, Error, and Confidence
• Utilizing the Scientific Literature
• Waves and Wave Motion

[person - anatomy & physiology] (August 8, 1861 - February 8, 1926) A British geneticist who was the first person to use the term genetics to describe the study of biological inheritance and heredity. In addition, he was largely responsible for popularizing the ideas of Gregor Mendel following their rediscovery in 1900 by Hugo de Vries, Erich Tschermak von Seysenegg, and Carl Correns. Bateson's most famous work, Materials for the study of variation, was published in 1894. In it, he cataloged physical variations in animal specimens, such as bees with legs instead of antenna, and humans with polydactylism (extra fingers) or extra ribs.

• Appears in modules:

• Mendel and Independent Assortment

[noun - time periods] An abbreviation for Before the Common Era, which is a designation for the years prior to year 1 of the Gregorian calendar. BCE is an alternative to the abbreviation BC, and the numbering of years is identical to the Before Christ system. Compare with CE.

• Appears in modules:

• Biodiversity I
• Density
• Description in Scientific Research
• Diffusion I
• Early Ideas about Matter
• Experimentation in Scientific Research
• Exponential Equations in Science I
• Exponential Equations in Science II
• Factors that Control Earth's Temperature
• Factors that Control Regional Climate
• Measurement
• Taxonomy I
• The Hydrologic Cycle
• The Nature of Scientific Knowledge
• The Practice of Science
• Theories, Hypotheses, and Laws
• Understanding Scientific Journals and Articles
• Utilizing the Scientific Literature
• Waves and Wave Motion

[noun - light & optics] A ray or shaft of light from a source.

• Appears in modules:

• Atomic Theory I
• Atomic Theory IV
• Experimentation in Scientific Research
• Gravity
• Light I
• Luis Walter Alvarez

[person - atoms & subatomic particles, materials science, physical & chemical properties] French physicist, born in Paris (1852-1908). Becquerel's most famous work is his study of uranium salts, which he discovered produced rays that caused gas to ionize. This type of radiation was termed Becquerel radiation. In 1903, he was awarded half a Nobel Prize for his discovery of radiation; the other half was awarded to Pierre and Marie Curie for their work on Becquerel radiation.

• Appears in modules:

• Nuclear Chemistry

[noun - equations, statistics] See normal distribution.

• Appears in modules:

• Introduction to Descriptive Statistics

[person - fluid mechanics & hydraulics, scientific concepts] Swiss medical doctor and mathematician born in Groningen (1700-1782). His work Hydrodynamica contains the first correct analysis of the dynamics of water flowing through a hole, based on the principle of the conservation of energy. He was a prolific researcher and won the Grand Prize of the Paris Academy four times, for topics in astronomy and nautical topics.

• Appears in modules:

• Early Ideas about Matter
• Kinetic-Molecular Theory
• Solutions, Solubility, and Colligative Properties

[person - atoms & subatomic particles, chemical reactions] Swedish chemist and medical doctor born in Väversunda, Ostergötland (1779-1848). While studying for his medical degree, Berzelius experimented with the use of electric shock to treat patients with various diseases. He is most famous for a series of experiments that proved that elements in inorganic compounds are bound together in definite proportions. In studying compounds, he discovered cerium, selenium, and thorium. With his experimental results, he was able to determine the atomic weights of nearly all elements then known.

• Appears in modules:

• The Silicate Minerals

[noun - astrophysics, cosmology, planetary science, scientific concepts] A theory proposed by Georges Lemaitre (originally known as the "hypothesis of the primeval atom") describing the origin of the universe. It was based on the idea that if the space between galaxy clusters is continuing to increase, then there had to be a time when these same bodies were closer together. The term "Big Bang" was coined by Fred Hoyle in 1949 to describe an event 13.7 million years ago involving the rapid expansion of matter and energy from a single hot, dense point. This expansion and cooling provided a foundation for the creation of the Universe.

[noun - anatomy & physiology, cells, evolution & adaptation, genetics & inheritance] A form of asexual reproduction where a cell divides itself into two identical daughter cells.

• Appears in modules:

• Cell Division II
• Discovery and Structure of Cells

[noun - astrophysics, stellar and galactic astronomy] A term coined by Sir William Herschel in 1802 to describe a pair of stars that revolve around a common mass and are unaffected by the mass of other stars, creating their own system.

• Appears in modules:

• The Nature of Scientific Knowledge

[noun - organisms, taxonomy & systematics] [adjective] A formal two-word name given to each species, based on the combination of a genus name and a species name.

• Appears in modules:

• Taxonomy II

[noun - biodiversity & ecological relationships] The variety and abundance of life and its ecological context, including the different kinds of organisms, the numbers of species, the variations in their genes, and the complexity of their ecological conditions.

• Appears in modules:

• Biodiversity I
• Charles Darwin III
• Craig Lee
• Sergio Avila
• Taxonomy I
• Taxonomy II

[noun - biomolecules, organisms, chemical reactions, energy, organic & biochemistry, landforms & geologic formations, physical & chemical properties, seismology & plate tectonics] Of or relating to the partitioning and cycling of chemical elements and compounds between the living and nonliving parts of an ecosystem.

• Appears in modules:

• Composition of Earth's Atmosphere
• Kevin Arrigo
• The Carbon Cycle
• The Nitrogen Cycle
• The Phosphorus Cycle

[noun - cells, organisms] The combined mass of living or once-living organisms in a given area.

• Appears in modules:

• Biodiversity I
• The Nitrogen Cycle

[noun - bioregions, biomes & ecosystems] A large, distinct biological community characterized by vegetation and wildlife adapted to particular environmental conditions, such as climate and soil type. Examples include desert, grassland, and tundra.

• Appears in modules:

• Biodiversity I
• Sergio Avila

[noun - bioregions, biomes & ecosystems] (Also known as ecoregion) A large area of land or water defined by its natural features, rather than political boundaries like state lines or international borders. A bioregion is an area with similar ecosystems and natural resources, sharing features like soil types, currents, climate, geological features, vegetation, and wildlife.

For example, the Commission for Environmental Cooperation of North America lists 181 terrestrial ecoregions and 86 marine ecoregions. These include areas like the Ozark Highlands and the Sonoran Desert on land and the Puget Sound Estuarine Area and Central Hudson Bay in the water. Classification systems vary, and not all scientists agree on the exact number or boundaries of Earth's bioregions. But the concept is useful for managing large numbers of wildlife and natural resources.

• Appears in modules:

• Sergio Avila

[noun - bioregions, biomes & ecosystems] All of the living organisms on Earth.

• Appears in modules:

• Kevin Arrigo
• The Carbon Cycle
• The Nitrogen Cycle
• The Phosphorus Cycle

[person - atmospheric science, weather & climate] Norwegian mathematician, physicist and meteorologist born in Christiana, Norway (now Oslo) (1862-1951). Bjerknes proposed the concept of numerical weather prediction, developed by later scientists as a means of weather forecasting through the use of mathematical modeling. Bjerknes also made fundamental contributions to our understanding of air masses, fronts, and circulation in the atmosphere. He received many honors during his life, and posthumously was honored by a stamp with his image.

• Appears in modules:

• Modeling in Scientific Research
• Scientific Controversy

[noun - atoms & subatomic particles, energy, matter, atoms & subatomic particles, energy, matter, thermodynamics] Radiation emitted by a black-body held at constant temperature and in thermodynamic equilibrium with its surroundings. The specific nature and intensity of the radiation is dependent only upon temperature.

• Appears in modules:

• Atomic Theory II

[noun - scientific tools & techniques] A detailed outline or plan of action. The word technically refers to a process of photographic printing, used chiefly in copying architectural and mechanical drawings, which produces a white line on a blue background.

• Appears in modules:

• Cell Division I
• Charles Darwin III
• DNA I
• DNA II
• Introduction to Paleoanthropology
• The Phosphorus Cycle

[noun - stellar and galactic astronomy, scientific concepts] Occurs when the observed light from an object appears to be of a shorter wavelength (bluer) than what is actually emitted. Blueshift is caused by the Doppler Effect, when a source of light moves toward an observer. See also redshift.

[person - atoms & subatomic particles, atoms & subatomic particles, modern physics] Danish physicist born in Copenhagen (1885-1962). Bohr's research was mainly theoretical in nature, including an investigation into the absorption of alpha rays and the structure of atoms. He combined Rutherford's atomic model with concepts from the Quantum Theory, developing the model of the atom that is still used today. He was awarded the Nobel Prize in Physics in 1922 for his work on atomic structure.

• Appears in modules:

• Atomic Theory I
• Atomic Theory II
• Atomic Theory III

[noun - atoms & subatomic particles, compounds, matter] The force that holds together units such as atoms or molecules.
[verb] To hold or fasten units such as atoms or molecules together.

• Appears in modules:

• Atomic Theory II
• Carbon Chemistry
• César Milstein
• Chemical Bonding
• Chemical Equations
• Composition of Earth's Atmosphere
• Creativity in Science
• Defining Minerals
• DNA II
• DNA III
• Energy
• Energy Metabolism I
• Lipids
• Membranes II
• Meselson and Stahl
• Origins of Life I
• Origins of Life II
• Percy Lavon Julian
• Photosynthesis I
• Properties of Liquids
• Properties of Minerals
• Properties of Solids
• Ruth Benerito
• Solutions, Solubility, and Colligative Properties
• States of Matter
• The Nitrogen Cycle
• The Silicate Minerals
• Water

[noun - atoms & subatomic particles, matter] The distance between atoms where their electrostatic forces are reduced to a minimum. This minimum represents the most stable position.

• Appears in modules:

• Chemical Bonding

[noun - atoms & subatomic particles, chemical reactions, compounds, elements, matter, organic & biochemistry, physical & chemical properties] The act of fastening two atoms together.

• Appears in modules:

• Acids and Bases II
• Atomic Theory IV
• Carbon Chemistry
• Chemical Bonding
• Early Ideas about Matter
• Energy
• Lipids
• Properties of Liquids
• Properties of Solids
• Solutions, Solubility, and Colligative Properties
• The Phosphorus Cycle
• The Silicate Minerals
• Water

[person - atoms & subatomic particles, modern physics] German physicist instrumental in the development of quantum mechanics for which he won the Nobel Prize in physics in 1954 for, "fundamental research in Quantum Mechanics, especially in the statistical interpretation of the wave function."

• Appears in modules:

• Atomic Theory III

[person - statistics, modern physics] Indian Bengali mathematician born in Calcutta (1894-1974). Bose developed an interest in physics and mathematics in high school. He later worked on quantum theory, particularly Planck's law of black-body radiation. His 1924 paper Planck's Law and the Hypothesis of Light Quanta was strongly endorsed by Einstein, and helped to form the foundation for Bose-Einstein statistics and the theory of Bose-Einstein condensates. The boson, a subatomic particle with integer spin, is named in his honor.

• Appears in modules:

• States of Matter

[noun - cells, landforms & geologic formations] A line or limit that divides one area from another.

• Appears in modules:

• Biodiversity I
• Chemical Bonding
• Composition of Earth's Atmosphere
• Earth Structure
• Factors that Control Regional Climate
• Light I
• Linear Equations in Science
• Luis Walter Alvarez
• Origins of Life I
• Plates, Plate Boundaries, and Driving Forces
• The Phosphorus Cycle
• The Rock Cycle

[noun - matter, physical & chemical properties, matter, thermodynamics] The relationship between a gas’s volume (V) and pressure (P), which was first observed by Robert Boyle and Robert Hooke. Boyle’s Law states that for a fixed amount of gas at a stable temperature, the gas’s volume is inversely proportional to its pressure.

• Appears in modules:

• Scientific Institutions and Societies

[person - physical & chemical properties, matter, thermodynamics] English chemist and theologian, born at Lismore Castle, Munster, Ireland (1627-1691). Boyle published on a broad array of topics, including chemistry, physics, medicine, and theology. He is best known for Boyle's Law, from which the ideal gas law is derived. In 1661, Boyle published The Sceptical Schymist or Chymico-Physical Doubts and paradoxes, which is considered a cornerstone in the field of modern chemistry. Boyle was also one of the founding members of the Royal Society of London.

• Appears in modules:

• Acids and Bases I
• Early Ideas about Matter
• Kinetic-Molecular Theory
• Properties of Gases
• Scientific Institutions and Societies
• The Phosphorus Cycle
• Waves and Wave Motion

[person - planetary science] Danish astronomer, born in Knutstorp Castle (1546-1601). He is famous for his geocentric theory of the solar system, as well as for his meticulous astronomical observations concerning the positions of planets. He made his observations over 20 years, from the island of Hven. He later was appointed Imperial Mathematician to the Holy Roman Emperor, Rudolph II, in Prague.

• Appears in modules:

• Gravity
• Introduction to Descriptive Statistics

[noun - genetics & inheritance, organisms] The production of offspring; the propagation of plants or animals by sexual means.

• Appears in modules:

• Adaptation
• Animal Behavior
• Barbara McClintock
• Carlos J. Finlay
• Creativity in Science
• Mendel and Independent Assortment
• Mendel and Inheritance
• Scientists and the Scientific Community
• Sergio Avila

[noun - evolution & adaptation, biodiversity & ecological relationships, human impacts on the environment] A group of animals of a particular species that is large enough and close enough together to successfully produce offspring. Larger breeding populations tend to have higher genetic diversity, which can help a species withstand natural or human-driven changes in the environment. Species that have large geographic ranges may have multiple breeding populations in different locations that do not interbreed with one another. A small breeding population may also be assembled in captivity, such as at a zoo, in order to help boost the population of a species that is threatened in the wild.

[person - biomolecules, atoms & subatomic particles, matter, atoms & subatomic particles, matter] Scottish botanist born in Montrose (1773-1858). Brown discovered that pollen granules suspended in water moved in a random manner. This "random walk" of particles was later termed Brownian Motion in his honor and was mathematically proven by Albert Einstein.

• Appears in modules:

• Diffusion I

[noun - biomolecules, atoms & subatomic particles, matter, atoms & subatomic particles, matter] The random movement of particles suspended in a fluid medium. Named in honor of Robert Brown (1773-1858), Brownian motion is a result of particles bumping into molecules and environmental barriers.

• Appears in modules:

• Diffusion I
• Photosynthesis I

[person - acids, bases & pH, physical & chemical properties] Danish physical chemist born in Varde (1879-1947). In 1906, Brønsted published his first paper on electron affinity. In 1923, he suggested the protonic theory of acid-base reactions, and later became an authority on catalysis by acids and bases. The Brønsted catalysis equation is named for him. He also developed the theory of proton donors during ionization.

• Appears in modules:

• Acids and Bases I

[noun - acids, bases & pH, compounds] An aqueous solution containing a weak acid and its conjugate base that moderates pH changes when acid or base is added. For example, in a solution containing both carbonic acid (H2CO3) and carbonate ions (HCO3-), the carbonate ions that can absorb excess H+ if an acid is added, stabilizing the pH.

• Appears in modules:

• Biodiversity I

[adjective - physical & chemical properties, matter] The ability of an object to rise and stay afloat in a liquid or gas.

• Appears in modules:

• Adaptation
• Density
• Plates, Plate Boundaries, and Driving Forces

[noun - forces] The upward pressure exerted on an object by a fluid in which the object rests.

[person - computers & programming, scientific tools & techniques, research methods, science & decision making, science communication] American scientist and statesman, born in Everett, Massachusetts (1890-1974). Bush did seminal work in analog computing, and founded the American Appliance Company, later renamed Raytheon. In 1939 he was appointed chairman of the National Advisory Committee for Aeronautics and began advocating for the establishment of a federal agency to coordinate scientific research, especially as related to military and defense needs. The effort would eventually lead to the creation of the National Science Foundation in 1950.

• Appears in modules:

• Scientific Institutions and Societies
• Utilizing the Scientific Literature