200. Heat

See also 90. COLD ; 162. FIRE

actinism

the ability of light and heat and other forms of radiant energy to cause chemical changes, as hormonal changes in birds causing them to migrate or brood. —actinic , adj.

adiathermancy

imperviousness to radiant heat or infrared radiation. Also called athermancy .

athermancy

adiathermancy.

calorimetry

the science of measuring heat. —calorimeter , n . —calorimetric , adj.

calorist

Rare. one who believed the caloric theory, that heat is a material substance. —caloristic , adj.

galvanothermy

the process of generating heat by means of an electric current.

geothermometry

the branch of geology that measures temperatures deep below the surface of the earth; geologic thermometry.

pyrogenesis

the production or generation of heat. —pyrogenetic , adj.

pyrolysis

the chemical process of decomposition under the effect of heat. —pyrolitic , adj.

pyrophotometer

a type of pyrometer that measures temperature optically or photometrically.

tepidity

a moderate warmth; lukewarmness. —tepid , adj.

thermatology

Medicine. the study of heat as a medical remedy or therapy. Also called thermotherapy .

thermionics

the science or study of the emission of electrons from substances at high temperatures. —thermionic , adj.

thermochemistry

the branch of chemistry that studies the relationship of heat to chemical changes, including the production of energy. —thermochemist , n . —thermochemical , adj.

thermodynamics

the branch of physics that studies the relationship of heat and mechanical energy and the conversion, in various materials, of one into the other. —thermodynamicist , n. —thermodynamic, thermodynamical , adj.

thermogenesis, thermogeny

the production of heat, especially in an animal body by physiological processes. —thermogenic, thermogenous , adj.

thermography

1. Engineering, a method of measuring surf ace temperatures by using luminescent materials.

2. a printing or photocopying process using infrared rays and heat.

3. a process of photography using far-infrared radiation; thermal photography. —thermographer , n. —thermographic , adj.

thermokinematics

the study of the movement of heat. —thermokinematic , adj.

thermology

Archaic. the science and study of heat. Also called thermotics .

thermoluminescence

Atomic Physics. any luminescence appearing in materials upon application of heat, caused by electron movement which increases as the temperature rises. —thermoluminescent , adj.

thermolysis

Physiology. the dispersion of heat from the body. —thermolytic , adj.

thermometry

the branch of physics that deals with the measurement of temperature. —thermometric , adj.

thermophobia

an abnormal fear of heat.

thermoscope

a device for giving an approximation of the temperature change of a substance by noting the accompanying change in its volume. —thermoscopic , adj.

thermostatics

the science or study of the equilibrium of heat.

thermotaxis

1. Biology. the movement of an organism toward or away from a source of heat.

2. Physiology. the regulation of body temperature by various physiological processes. —thermotactic, thermotaxic , adj.

thermotherapy

thermatology.

thermotics

thermology.

transcalency

the property or quality by which matter permits the passage of heat. —transcalent , adj.