The Flux

Flux: Describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications to physics. For transport phenomena, flux is a vector quantity, describing the magnitude and direction of the flow of a substance or property. In vector calculus flux is a scalar quantity, defined as the surface integral of the perpendicular component of a vector field over a surface.

The word flux comes from Latin: fluxus means "flow", and fluere is "to flow". As fluxion, this term was introduced into differential calculus by Isaac Newton.

Eight of the most common forms of flux from the transport phenomena literature are defined as follows:

Momentum Flux, the rate of transfer of momentum across a unit area (N·s·m−2·s−1). (Newton's law of viscosity)

Heat Flux, the rate of heat flow across a unit area (J·m−2·s−1). (Fourier's law of conduction)(This definition of heat flux fits Maxwell's original definition.

Diffusion Flux, the rate of movement of molecules across a unit area (mol·m−2·s−1). (Fick's law of diffusion)

Volumetric Flux, the rate of volume flow across a unit area (m3·m−2·s−1). (Darcy's law of groundwater flow)

Mass Flux, the rate of mass flow across a unit area (kg·m−2·s−1). (Either an alternate form of Fick's law that includes the molecular mass, or an alternate form of Darcy's law that includes the density.)

Radiative Flux, the amount of energy transferred in the form of photons at a certain distance from the source per unit area per second (J·m−2·s−1). Used in astronomy to determine the magnitude and spectral class of a star. Also acts as a generalization of heat flux, which is equal to the radiative flux when restricted to the electromagnetic spectrum.

Energy Flux, the rate of transfer of energy through a unit area (J·m−2·s−1). The radiative flux and heat flux are specific cases of energy flux.

Particle Flux, the rate of transfer of particles through a unit area ([number of particles] m−2·s−1)

These fluxes are vectors at each point in space, and have a definite magnitude and direction. Also, one can take the divergence of any of these fluxes to determine the accumulation rate of the quantity in a control volume around a given point in space.

In quantum field theory, a force carrier (also known as a messenger particle, intermediate particle, or exchange particle) is a type of particle that gives rise to forces between other particles. These particles serve as the quanta of a particular kind of physical field.

A force between two particles can be described either as the action of a force field generated by one particle on the other, or in terms of the exchange of virtual force carrier particles between them.

The Still Force is the natural opposite of the Speed Force, meaning that while the Speed Force is based around motion and moving forward, the Still Force is centered around stagnation, reversion and perpetuation.

Still Force users can use the Still Force to travel back in time; though differently. Unlike normal time travel, they instead send their consciousness back into an earlier version of themselves; it's unknown if this is a personal choice or limitation.

Spoiler:

The phrase "flux capacitor" has appeared in more serious contexts. U.S. Patent 6,084,285 describes a "lateral flux capacitor having fractal-shaped perimeters", the idea being to make a capacitor in an integrated circuit, some of whose capacitance exists between two conductors on a single layer (hence, "lateral"). The device is not a lateral flux-capacitor but a lateral-flux capacitor.

Flux is commonly used in electronics and electromagnetic theory and application, but rarely in the context of a capacitor. In general terms, flux simply means the rate at which some quantity (such as electric charge) passes through a surface (e.g. charge flux).