• Webster's Revised Unabridged Dictionary
    • a Instable Not stable; not standing fast or firm; unstable; prone to change or recede from a purpose; mutable; inconstant.
    • ***
Century Dictionary and Cyclopedia
    • instable Not stable; unstable.
    • ***
Chambers's Twentieth Century Dictionary
    • adj Instable not stable: inconstant
    • ***


  • Seneca
    “Whatever has overstepped its due bounds is always in a state of instability.”


Webster's Revised Unabridged Dictionary
L. instabilis,: cf. F. instable,. See In- not, and Stable (a.), and cf. Unstable


In literature:

The instability thus variously illustrated becomes still more manifest if we consider its rationale.
"Essays: Scientific, Political, & Speculative, Vol. I" by Herbert Spencer
The criminality of immigrant populations increases in direct ratio to its instability.
"Criminal Man" by Gina Lombroso-Ferrero
You counsel me to reflect on the instability, on the insecurity of our existence, and on what there is beyond it.
"Pepita Ximenez" by Juan Valera
The main characteristic of adolescence is instability, physical, emotional, and intellectual.
"Religion & Sex" by Chapman Cohen
Various hypotheses have been postulated to account for the instability of the atom.
"A History of Science, Volume 5(of 5)" by Henry Smith Williams
It arouses such men to a sense of social instability but it offers no remedy.
"New Worlds For Old" by Herbert George Wells
The emotional instability of the pioneer grew out of his mixture of occupations.
"The Evolution of the Country Community" by Warren H. Wilson
Even to the qualified instability of a sea-going ship I have ever committed myself with resignation rather than confidence.
"The Works of Robert Louis Stevenson - Swanston Edition Vol. 20 (of 25)" by Robert Louis Stevenson
Do not think me unkind for such an exercise of my power, nor accuse me of instability without first hearing my reasons.
"The Complete Project Gutenberg Works of Jane Austen" by Jane Austen
The instability that had seized on the forms threatened the very principles of government.
"The History of Freedom" by John Emerich Edward Dalberg-Acton
There is an instability about him; every thing palls on him.
"Harper's New Monthly Magazine, Volume 1, No. 4, September, 1850" by Various
He said that your intellectual arrogance was only equaled by your spiritual instability.
"One-Act Plays" by Various
Man's greater impetuosity would lead to instability, unrest, and possible chaos.
"What a Young Husband Ought to Know" by Sylvanus Stall
Its only drawback was its instability.
"Just William" by Richmal Crompton
In running its canteens it conducted an immense retail business under all the disadvantages of instability.
"The Story of the Great War, Volume VIII (of VIII)" by various
The extreme instability of monarchical government showed itself afresh after Henry IV.
"Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 7" by Various
In his religious policy Francis showed the same instability.
"Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 8" by Various
We are then subjected to the illusion of instability or incongruity.
"Visual Illusions" by Matthew Luckiesh
We have had, within the last ten years, a severe lesson concerning the instability of wealth in some of its most trusted forms.
"Modern Society" by Julia Ward Howe
The instability of a deeply cambered surface.
"The Theory and Practice of Model Aeroplaning" by V. E. Johnson

In news:

Italy's return to political instability is a stark reminder for investors that Europe faces a long uphill battle to emerge from its economic crisis.
However, enough moisture and instability backed it's way westward from Kansas by evening, to develop severe storms.
But it has nothing to do with supply and demand or instability in the Middle East.
Growing financial instability seen for not-for-profit hospitals.
Romney singles out the rapid spread of instability and extremism in northern Mali — twice — in the opening minutes of the debate.
Japan's political instability continues as it faces another general election .
Metro hospital authority to explore options to fix financial instability .
The instability of the solar system.
News Local News Deputy resigns, cites Curry instability .
Syria instability leaves US at crossroads.
Atmospheric instability produces dramatic skies.
Family members tell NewsCenter 16 the man charged with killing his own sister in Cass County has a long history of mental instability .
Europe's economic instability remains focus at G-20 summit.
China's Alarming Risk Of Financial Instability .
As Egypt prepares to vote Saturday on a new constitution, a spiraling clash between supporters and foes of President Mohamed Morsi has sparked further instability.

In science:

However, probably the fastest growing instability for the case of our rising bubbles is the Richtmyer-Meshkov (RM) instability.
Constraining the Nature of X-ray Cavities in Clusters and Galaxies
However, the predicted growth time for RM and RT instabilities for 1/10th the bubble size is always over a factor of 10 lower than the rise time and such instabilities almost certainly should have developed (Figure 9).
Constraining the Nature of X-ray Cavities in Clusters and Galaxies
Fig. 9.— Adiabatic rise times for an assumed Γ = 4/3 against the instability time scales for the largest modes (λh = Rb ) of the Richtmyer-Meshkov (RM, red circles) and Rayleigh-Taylor instabilities (RT, blue squares).
Constraining the Nature of X-ray Cavities in Clusters and Galaxies
Note that NW, accounting for the cellular stabilization effect against instabilities, e.g., the LandauDarrieus instability, defined lG as the scale where the turbulent velocity exceeds the effective cellular flame speed.
The effect of turbulent intermittency on the deflagration to detonation transition in SN Ia explosions
The instability that occurs due to the resonance condition (17) in flows with the two-layer PWL profile of wind speed is quite similar to Miles’ resonance condition for the instability of flows with smooth velocity profiles (as is discussed in ), and the corresponding unstable mode is called Miles mode.
An asymptotic model for the Kelvin-Helmholtz and Miles mechanisms of water wave generation by wind
Since non-perturbative weak interaction instabilities are typically linked to exponentially small energy scales, tFLI−B will be large such that characteristic features of the instability are not observable for short times after the quench.
Real-time evolution for weak interaction quenches in quantum systems
In section 2 we recall the transmission coefficient approach to vacuum instability, and consider also how the instability affects thermal states in the framework of Thermofield Dynamics.
Pair-production of charged Dirac particles on charged Nariai and ultracold black hole manifolds
If real, the instability is immediate, while if imaginary, instability may still arise due to their collision with the phonon band, resulting in a Hamiltonian-Hopf bifurcation and eigenvalue quartets.
Stable structures with high topological charge in nonlinear photonic quasicrystals
However, due to the propagation of electrons along magnetic field lines, the conduction is essentially anisotropic leading to instabilities (such as the Heat flux Buoyancy Instability, HBI, see Quataert 2008; Parrish & Quataert 2008) in the cluster core.
Jet-regulated cooling catastrophe
The most likely driver of flux emergence into the lower corona is an ideal MHD instability driven by magnetic buoyancy (the magnetic buoyancy instability), a particular mode of which was first suggested by Shibata et al. (1989a,b) in 2D simulations using a crude model atmosphere and magnetic field configuration.
Tests of Dynamical Flux Emergence as a Mechanism for CME Initiation
The soft modes especially for transverse modes (shearing instability) lead to the instability of lattice.
Tc map and superconductivity of simple metals at high pressure
Instabilities caused by the viscous and non-adiabatic processes in disks may be classified into three types (Kato et al., 2008): thermal, secular instabilities and overstabilities of waves and oscillations.
Slim accretion disks around black holes
In the absence of the preemptive Ising-nematic instability, the magnetic instability would again occur at ¯r0 = 0.
Preemptive nematic order, pseudogap, and orbital order in the iron pnictides
The authors of argued that, under special conditions (which may or may not be satisfied in the iron pnictides), a SDW instability and a CDW instability in the form of orbital currents occur at almost the same temperature, with the orbital-current instability occurring first.
Preemptive nematic order, pseudogap, and orbital order in the iron pnictides
Stars are expected to pulsate in some specific areas of the HR-diagram, called instability strips, e.g. the “classical instability strip” is hosting Cepheids, RR Lyrae or δ Scuti stars.
Standard candles from the Gaia perspective