laws principals and theories

(geology) the principle that in a series of stratified sedimentary rocks the lowest stratum is the oldest

the displacement of any point due to the superposition of wave systems is equal to the sum of the displacements of the individual waves at that point

prescribed guide for conduct or action

a generalization that describes recurring facts or events in nature

(neurology) the principle that the cortex of the brain operates as a coordinated system with large masses of neural tissue involved in all complex functioning

the principle that if any change is imposed on a system that is in equilibrium then the system tends to adjust to a new equilibrium counteracting the change

(physics) the principle that an observer has no way of distinguishing whether his laboratory is in a uniform gravitational field or is in an accelerated frame of reference

the principle that entities should not be multiplied needlessly; the simplest of two competing theories is to be preferred

the principle that entities should not be multiplied needlessly; the simplest of two competing theories is to be preferred

(physiology) the principle that specific functions have relatively circumscribed locations in some particular part or organ of the body

(physiology) the principle that specific functions have relatively circumscribed locations in some particular part or organ of the body

a determination of the place where something is

(economics) the principle that when two kinds of money having the same denominational value are in circulation the intrinsically more valuable money will be hoarded and the money of lower intrinsic value will circulate more freely until the intrinsically more valuable money is driven out of circulation; bad money drives out good; credited to Sir Thomas Gresham

a principle of Gestalt psychology that identifies factors leading to particular forms of perceptual organization

(hydrostatics) the apparent loss in weight of a body immersed in a fluid is equal to the weight of the displaced fluid

(chemistry) the total energy in an assembly of molecules is not distributed equally but is distributed around an average value according to a statistical distribution

the principle that equal volumes of all gases (given the same temperature and pressure) contain equal numbers of molecules

(statistics) law stating that a large number of items taken at random from a population will (on the average) have the population statistics

(chemistry) law stating that when two elements can combine to form more than one compound the amounts of one of them that combines with a fixed amount of the other will exhibit a simple multiple relation

(chemistry) law stating that when two elements can combine to form more than one compound the amounts of one of them that combines with a fixed amount of the other will exhibit a simple multiple relation

law formulated by the English chemist William Henry

(astronomy) the generalization that the speed of recession of distant galaxies (the red shift) is proportional to their distance from the observer

(physics) the principle that (within the elastic limit) the stress applied to a solid is proportional to the strain produced

(psychophysics) the concept that the magnitude of a subjective sensation increases proportional to a power of the stimulus intensity

(physics) an equation that expresses the distribution of energy in the radiated spectrum of an ideal black body

(psychophysics) the concept that the magnitude of a subjective sensation increases proportional to the logarithm of the stimulus intensity; based on early work by E. H. Weber

(physics) a universal law that states that the laws of mechanics are not affected by a uniform rectilinear motion of the system of coordinates to which they are referred

the pressure of an ideal gas at constant temperature varies inversely with the volume

the pressure of an ideal gas at constant temperature varies inversely with the volume

(astronomy) one of three empirical laws of planetary motion stated by Johannes Kepler

a law affirming that to continue after a certain level of performance has been reached will result in a decline in effectiveness

(chemistry) law stating that every pure substance always contains the same elements combined in the same proportions by weight

a law affirming that in the long run probabilities will determine performance

(physics) law obeyed by a systems of particles whose wave function changes when two particles are interchanged (the Pauli exclusion principle applies)

a fundamental principle of electrostatics

(psychology) the principle that behaviors are selected by their consequences; behavior having good consequences tends to be repeated whereas behavior that leads to bad consequences is not repeated

(physics) statistical law obeyed by a system of particles whose wave function is not changed when two particles are interchanged (the Pauli exclusion principle does not apply)

(physics) a law governing the relations between states of energy in a closed system

(chemistry) law stating that the proportions in which two elements separately combine with a third element are also the proportions in which they combine together

(chemistry) law stating that the proportions in which two elements separately combine with a third element are also the proportions in which they combine together

(chemistry) law stating that every pure substance always contains the same elements combined in the same proportions by weight

(neurophysiology) a nerve impulse resulting from a weak stimulus is just as strong as a nerve impulse resulting from a strong stimulus

(chemistry and physics) law stating that the pressure exerted by a mixture of gases equals the sum of the partial pressures of the gases in the mixture; the pressure of a gas in a mixture equals the pressure it would exert if it occupied the same volume alone at the same temperature

(astronomy) one of three empirical laws of planetary motion stated by Johannes Kepler

(psychophysics) the concept that the magnitude of a subjective sensation increases proportional to a power of the stimulus intensity

one of three basic laws of classical mechanics

(physics) the law that states any two bodies attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them

(physics) the law that states any two bodies attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them

(chemistry) the principle that (at chemical equilibrium) in a reversible reaction the ratio of the rate of the forward reaction to the rate of the reverse reaction is a constant for that reaction

(physics) the density of an ideal gas at constant pressure varies inversely with the temperature

(physics) the density of an ideal gas at constant pressure varies inversely with the temperature

(statistics) law stating that a large number of items taken at random from a population will (on the average) have the population statistics

(psychophysics) the concept that the magnitude of a subjective sensation increases proportional to the logarithm of the stimulus intensity; based on early work by E. H. Weber

(psychophysics) the concept that a just-noticeable difference in a stimulus is proportional to the magnitude of the original stimulus

a body remains at rest or in motion with a constant velocity unless acted upon by an external force

action and reaction are equal and opposite

the rate of change of momentum is proportional to the imposed force and goes in the direction of the force

action and reaction are equal and opposite

the basis of quantum theory

(chemistry) the principle that chemical properties of the elements are periodic functions of their atomic numbers

(chemistry) the principle that chemical properties of the elements are periodic functions of their atomic numbers

electric current is directly proportional to voltage and inversely proportional to resistance; I = E/R

(chemistry) the law that states the following principle: the rate of a chemical reaction is directly proportional to the molecular concentrations of the reacting substances

no two electrons or protons or neutrons in a given system can be in states characterized by the same set of quantum numbers

pressure applied anywhere to a body of fluid causes a force to be transmitted equally in all directions; the force acts at right angles to any surface in contact with the fluid

each member of a pair of homologous chromosomes separates independently of the members of other pairs so the results are random

members of a pair of homologous chromosomes separate during the formation of gametes and are distributed to different gametes so that every gamete receives only one member of the pair

(genetics) one of two principles of heredity formulated by Gregor Mendel on the basis of his experiments with plants; the principles were limited and modified by subsequent genetic research

a Gestalt principle of organization holding that aspects of perceptual field that move or function in a similar manner will be perceived as a unit

a Gestalt principle of organization holding that aspects of perceptual field that move or function in a similar manner will be perceived as a unit

a Gestalt principle of organization holding that there is an innate tendency to perceive incomplete objects as complete and to close or fill gaps and to perceive asymmetric stimuli as symmetric

a Gestalt principle of organization holding that there is an innate tendency to perceive a line as continuing its established direction

a Gestalt principle of organization holding that there is an innate tendency to perceive a line as continuing its established direction

a Gestalt principle of organization holding that (other things being equal) objects or events that are near to one another (in space or time) are perceived as belonging together as a unit

a Gestalt principle of organization holding that (other things being equal) parts of a stimulus field that are similar to each other tend to be perceived as belonging together as a unit