perturbation of energy-level system
41Earth — This article is about the planet. For other uses, see Earth (disambiguation). Earth   …
42Climate change mitigation — Fossil fuel related CO2 emissions compared to five of IPCC s emissions scenarios. The dips are related to global recessions. Data from IPCC SRES scenarios; …
43Sun — This article is about the star. For other uses, see Sun (disambiguation). The Sun …
44Resilience (ecology) — For other uses, see Resilience (disambiguation). Lake and Mulga ecosystems with alternative stable states[1] In ecology, resilience is the capacity of an ecosyst …
45Antarctica — /ant ahrk ti keuh, ahr ti /, n. the continent surrounding the South Pole: almost entirely covered by an ice sheet. ab. 5,000,000 sq. mi. (12,950,000 sq. km). Also called Antarctic Continent. * * * Antarctica Introduction Antarctica Background:… …
46General relativity — For a generally accessible and less technical introduction to the topic, see Introduction to general relativity. General relativity Introduction Mathematical formulation Resources …
47Landau–Zener formula — The Landau–Zener formula is an analytic solution to the equations of motion governing the transition dynamics of a 2 level quantum mechanical system, with a time dependent Hamiltonian varying such that the energy separation of the two states is a …
48comet — cometary /kom i ter ee/, cometic /keuh met ik/, cometical, adj. cometlike, adj. /kom it/, n. Astron. a celestial body moving about the sun, usually in a highly eccentric orbit, consisting of a central mass surrounded by an envelope of dust and… …
49earthquake — /errth kwayk /, n. 1. a series of vibrations induced in the earth s crust by the abrupt rupture and rebound of rocks in which elastic strain has been slowly accumulating. 2. something that is severely disruptive; upheaval. [1300 50; ME erthequake …
50Mathematical formulation of quantum mechanics — Quantum mechanics Uncertainty principle …
