• Keeling, Charles
  • [person] American marine geochemist born in Scranton, Pennsylvania (1928-2005). Keeling researched the greenhouse effect and subsequent changes in Earth's atmosphere. Keeling helped establish a station on Mauna Loa in 1958 where monthly atmospheric CO2 measurements have been taken ever since. His dedication to producing a long-term record was critical to showing that atmospheric carbon dioxide levels have been increasing over time. His work resulted in a greater awareness of the human impact on global climate.

  • Kelvin, William
  • [person] Scottish physician and mathematician born in Belfast, Ireland (1824-1907). In 1867, Kelvin published Treatise on Natural Philosophy (later republished as Principles of Mechanics and Dynamics), which established the role of energy in the theory of mechanics. Kelvin also championed the idea that the entropy of the universe constantly increases, and will eventually reach a state of uniform temperature and maximum entropy, where no further work is possible: This uniform temperature will be absolute zero, or 0° Kelvin (-273°C).

  • Kepler, Johannes
  • [person] German mathematician and astronomer born in Weil der Stadt, Württemburg (now part of Stuttgart, Germany) (1571-1630). Kepler is best known for outlining his laws of planetary motion, which defined the paths of the planets as orbits that could be mathematically represented as an ellipse. He was a champion of the Copernican model of the universe, publishing the Mysterium Cosmographicum in defense of it.

  • kinetic
  • [adjective] Relating to the motion of objects.

  • kinetic energy
  • [noun] The energy an object possesses by virtue of its motion. An object of mass m moving at velocity v has a kinetic energy of ½m·v2.

  • kinetic molecular theory
  • [noun] The theory that molecules have kinetic energy (that is, energy of motion) and we interpret this energy as temperature. If the temperature increases then the molecules will gain more energy and move faster.

  • Knight, Thomas Andrew
  • [person] (1759-1838) An English horticulturalist and botanist. He conducted extensive breeding experiments with strawberries, cabbages, peas, and various kinds of fruit, with the goal of improving food plants by selectively breeding for better qualities. He also studied inheritance in peas and came to many of the same conclusions as Gregor Mendel, but did not formulate a theory to explain his observations. Knight served as president of the London Horticultural Society from 1811 to 1838. He is remembered for his devotion to improving the quality of food plants, and inspired generations of horticulturists to bend their efforts in that direction.

  • Krebs, Hans Adolf
  • [person] 1900–1981). One of thousands of scientists who fled Germany because of their Jewish heritage when the Nazis came to power, Krebs spent most of his career in England. He is best known for his discovery of the urea cycle and the citric acid cycle; the latter is also called the Krebs Cycle.