Question: There are five best-known potentials, what are they?
About the article "Thermodynamics", section "Potentials".

Candidate passages:
Thermodynamic potentials are different quantitative measures of the stored energy in a system.
Potentials are used to measure energy changes in systems as they evolve from an initial state to a final state.
The potential used depends on the constraints of the system, such as constant temperature or pressure.
For example, the Helmholtz and Gibbs energies are the energies available in a system to do useful work when the temperature and volume or the pressure and temperature are fixed, respectively.
The five most well known potentials are:where formula_1 is the temperature, formula_2 the entropy, formula_3 the pressure, formula_4 the volume, formula_5 the chemical potential, formula_6 the number of particles in the system, and formula_7 is the count of particles types in the system.
Thermodynamic potentials can be derived from the energy balance equation applied to a thermodynamic system.
Other thermodynamic potentials can also be obtained through Legendre transformation.
Sensory evoked potentials (SEP), are recorded from the central nervous system following stimulation of sense organs (for example, visual evoked potentials elicited by a flashing light or changing pattern on a monitor; auditory evoked potentials by a click or tone stimulus presented through earphones) or by tactile or somatosensory evoked potential (SSEP) elicited by tactile or electrical stimulation of a sensory or mixed nerve in the periphery.
They have been widely used in clinical diagnostic medicine since the 1970s, and also in intraoperative neurophysiology monitoring (IONM), also known as surgical neurophysiology.
There are three kinds of evoked potentials in widespread clinical use: auditory evoked potentials, usually recorded from the scalp but originating at brainstem level; visual evoked potentials, and somatosensory evoked potentials, which are elicited by electrical stimulation of peripheral nerve.
See below.
Long and Allen reported the abnormal brainstem auditory evoked potentials (BAEP) in an alcoholic woman who recovered from Ondine's curse.
These investigators hypothesized that their patient's brainstem was poisoned, but not destroyed, by her chronic alcoholism. 
Since gradients in potentials correspond to physical fields, it makes no difference if a constant is added on (it is erased by the gradient operator which includes partial differentiation).
This means there is no way to tell what the "absolute value" of the potential "is" - the zero value of potential is completely arbitrary and can be chosen anywhere by convenience (even "at infinity").
This idea also applies to vector potentials, and is exploited in classical field theory and also gauge field theory.
Absolute values of potentials are not physically observable, only gradients are.
However, the Aharonov–Bohm effect is a quantum mechanical effect which illustrates that non-zero electromagnetic potentials (even when the and fields are zero) lead to changes in the phase of the wavefunction of an electrically charged particle, so the potentials appear to have measurable significance. 
Synaptic noise refers to the constant bombardment of synaptic activity in neurons.
This occurs in the background of a cell when potentials are produced without the nerve stimulation of an action potential, and are due to the inherently random nature of synapses.
These random potentials have similar time courses as excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs), yet they lead to variable neuronal responses.
The variability is due to differences in the discharge times of action potentials. 
In general, in the presence of both a charge density ρ(r, "t") and current density J(r, "t"), there will be both an electric and a magnetic field, and both will vary in time.
They are determined by Maxwell's equations, a set of differential equations which directly relate E and B to ρ and J. Alternatively, one can describe the system in terms of its scalar and vector potentials "V" and A.
A set of integral equations known as "retarded potentials" allow one to calculate "V" and A from ρ and J, and from there the electric and magnetic fields are determined via the relations formula_11 formula_12