The symbols Δt and ΔT (spoken as "delta T") are commonly used in a variety of contexts.
Time
*
ΔT (timekeeping)
In precise timekeeping, Δ''T'' (Delta ''T'', delta-''T'', delta''T'', or D''T'') is a measure of the cumulative effect of the departure of the Earth's rotation period from the fixed-length day of International Atomic Time (86,400 seconds). ...
the difference between two time scales, Universal Time and Terrestrial Time, which results from a drift in the length of a day
* The interval of time used in determining
velocity
Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity i ...
* The increment between
successive nerve impulses
Temperature
* to mean a difference in
temperature
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer.
Thermometers are calibrated in various Conversion of units of temperature, temp ...
including
thermodynamic temperature
Thermodynamic temperature is a quantity defined in thermodynamics as distinct from kinetic theory or statistical mechanics.
Historically, thermodynamic temperature was defined by Kelvin in terms of a macroscopic relation between thermodynamic ...
, may occur in
** Discussions of
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
** Discussions of
heat transfer
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, ...
** Discussions of the effects of
thermal gradients
See also
*
Delta time (disambiguation) Delta time can mean:
* ΔT (timekeeping), the time difference between Universal Time and Terrestrial Time.
* Delta timing, a technique used in graphics programming.
See also
* ΔT (disambiguation)
The symbols Δt and ΔT (spoken as "delta T") ...
*
Finite difference
A finite difference is a mathematical expression of the form . If a finite difference is divided by , one gets a difference quotient. The approximation of derivatives by finite differences plays a central role in finite difference methods for t ...
for the mathematics of the ''Δ'' operator
*
Δ for the Greek letter Delta
*
∂
The Character (symbol), character ∂ (Unicode: U+2202) is a stylized cursive ''d'' mainly used as a Table of mathematical symbols, mathematical symbol, usually to denote a partial derivative such as / (read as "the partial derivative of ''z'' wit ...
for the mathematical symbol used in the notation "∂T"
{{disambiguation