Visionlearning Glossary

The uppermost layer of the earth beneath the ocean basins. Oceanic crust is constantly forming at mid-ocean ridges and is constantly being destroyed at subduction zones, thus the oldest oceanic crust on the earth is about 160 million years old. Oceanic crust is composed of basalt and is 5-7 km thick.

Used in the following modules: Earth Structure, Plate Tectonics II

A principle that states that the explanation of any phenomenon should make as few assumptions as possible, eliminating those that make no difference in the observable predictions of the explanatory hypothesis or theory. Attributed to the 14^th-century English logician and Franciscan friar William of Ockham.

Danish physicist and chemist born in Langeland (1777-1851). He experimentally demonstrated the relationship between electricity and magnetism. For more information, see Hans Christian Oersted.

Used in the following modules: Light II

German natural philosopher and diplomat, born in Bremen (1619-1677). Oldenburg was an original fellow of the Royal Society, served as its first secretary, and was the founding editor of the Philosophical Transactions of the Royal Society. For further information see Henry Oldenburg.

Used in the following modules: Scientific Communication: Understanding Scientific Journals and Articles

Organic molecules are molecules that contain carbon bonded to hydrogen. Organic molecules may contain other elements as well, especially O, N, Cl, and others. Use of the term 'organic' dates to the 19th century, when it was believed that organic molecules could only be derived from living organisms.

Used in the following modules: Carbohydrates, Organic Chemistry

A living being.

Used in the following modules: Adaptation, Cells, Charles Darwin I, Charles Darwin II, Charles Darwin III, Data: Uncertainty, Error, and Confidence, DNA I, DNA II, Earth's Atmosphere, Genetics I, Genetics II, Light II, Organic Chemistry, Plate Tectonics I, Research Methods: Description, Research Methods: Experimentation, Research Methods: The Practice of Science, Scientists and the Scientific Community, Taxonomy I, The Carbon Cycle, The Nitrogen Cycle, The Rock Cycle

American geologist and paleontologist, born in Fairfield, Connecticut (1857-1935). In 1900, Osborne joined the US Geological Survey, and became the senior paleontologist in 1925. He participated in fossil-hunting expeditions to the American Southwest, and described and named several species, including Tyrannosaurus Rex in 1905 and Velociraptor in 1924. In 1918, he founded the Save the Redwoods League. For further information see Henry Fairfield Osborn.

Used in the following modules: Taxonomy II: Nomenclature

Gamete of a flowering plant, similar to egg cells in mammalian organisms.

Used in the following modules: Genetics I

The effective charge of an atom or element that indicates the extent or possibility of its oxidation.

Used in the following modules: The Nitrogen Cycle

A layer of higher than average concentrations of ozone within the stratosphere. Within the ozone layer, concentration are still in the range of 8-12 parts per million (ppm); concentrations outside of the ozone layer are around 0.02 ppm.

Used in the following modules: Earth's Atmosphere, Research Methods: The Practice of Science, The Nitrogen Cycle