Scientific Glossary
- Carbon nanotubes: Hollow three dimensional tubes formed by interconnecting six-carbon rings; they are also known as "bucky tubes."
- Carrier: A mobile particle carrying an electric charge. In semiconductors, free electrons in the conduction band and traveling vacancies in valence-band electrons, or holes, are carriers.
- Carrier-envelope phase: An evolving phase shift between the peak of an ultrashort laser pulse's envelope function (superimposed on a continuous carrier wave) and the closest peak of that carrier wave.
- Cation: A positively charged ion, which has more protons than electrons.
- Cavity ringdown spectroscopy: Spectroscopic method using a high quality optical cavity that performs ultrasensitive absorption measurements on trace gases by tracking the exponential decay of light trapped in the cavity.
- Chaotic motion: Apparently random motion in a well-defined system sensitive to initial conditions.
- Chromosphere: Region between a star's photosphere and corona.
- Cluster ion: Ion formed by the combination of two or more identical ions or molecules in association with another atom, molecule, or ion.
- Coherence: Property of wavelike states of light (or atoms) that makes it possible for them to interfere with each other.
- Coherent control: The control of a chemical reaction with a shaped ultrashort laser pulse.
- Coherent spectroscopy: The of lasers to study the coherent interactions of excited atoms or molecules.
- Comb synthesizer: A stabilized mode-locked laser.
- Corona: Hot ionized plasmas in the outer atmospheres of most stars, including the Sun.
- Cosmic microwave background: Electromagnetic radiation (T = 2.725 K) that fills the entire universe; it is considered to be the best evidence for the origin of the Universe in a "big bang."
- Cyclopropyl radical: An important, but short-lived, reaction combustion intermediate consisting of a 3-carbon ring and five hydrogen atoms.
- Cytochrome c: Small heme protein in mitochondria that is an essential component of the electron transfer chain that transforms energy in food into the energy-rich molecule ATP.