In thermodynamics, a state of thermodynamic equilibrium of a substance, the physical properties of which differ from those of other equilibrium states-that is, other phases-of the same substance ( see EQUILIBRIUM, THERMODYNAMIC). In this case, the fractional part of the period is usually expressed in terms of angular measure, with one period being equal to 360° or 2π radians. In comparing the phase relationships at a given instant between two time-varying quantities, the phase of one is usually assumed to be zero, and the phase of the other is described, with respect to the first, as the fractional part of a period through which the second quantity must vary to achieve a zero of its own (see illustration).

In the case of a sinusoidally varying quantity, the time origin is usually assumed to be the last point at which the quantity passed through a zero position from a negative to a positive direction. The fractional part of a period through which the time variable of a periodic quantity (alternating electric current, vibration) has moved, as measured at any point in time from an arbitrary time origin. The Columbia Electronic Encyclopedia™ Copyright © 2022, Columbia University Press. Of the planets, only Mercury and Venus, whose orbits pass between the earth and sun, show all the phases that the moon shows the other planets are always either gibbous or full. Between the first quarter and the full moon and between the full moon and the last quarter we see more than half the lighted side this phase is called gibbous. The half-moon between the new moon and the full moon is known as the first quarter and that between the full moon and new moon is known as the last quarter. When the moon is at quadrature with the sun, having completed either one quarter or three quarters of its orbit from new moon to new moon, half the lighted side is visible this phase is called the half-moon. When the moon has completed half its orbit from new moon to new moon, it is on the opposite side of the earth from the sun and we see the entire lighted half this phase is called the full moon.

For a few days before and after the new moon we can see a small part of the lighted half, which appears as a crescent with the horns, or cusps, pointing away from the sun. When the moon is between the earth and the sun, we cannot see the lighted half at all, and the moon is said to be new.

txt file is free by clicking on the export iconĬite as source (bibliography): Period of a Function on dCode.Phase, in astronomy, the measure of how much of the illuminated surface of a planet or satellite can be seen from a point at a distance from that body the term is most often used to describe the moon as seen from the earth. The copy-paste of the page 'Period of a Function' or any of its results, is allowed (even for commercial purposes) as long as you cite dCode!Įxporting results as a. Except explicit open source licence (indicated Creative Commons / free), the 'Period of a Function' algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, breaker, translator), or the 'Period of a Function' functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and all data download, script, or API access for 'Period of a Function' are not public, same for offline use on PC, mobile, tablet, iPhone or Android app! The most common periodic functions are trigonometric functions based on sine and cosine functions (which have a period of 2 Pi).ĭCode retains ownership of the 'Period of a Function' source code.

Periodic phenomena definition