Cognitive Scaffold

Preparing your thinking workspace

arrow_back_ios_new
MENTAL MODEL · M4272

Earnshaw's Theorem

Earnshaw's Theorem
TechnicalHigh supportPhysics
Included
account_tree

Version 1.0.0 · Updated 2026-07-30

CORE DEFINITION

It is impossible to stably levitate a charged or magnetic body in mid-air using only static electric or magnetic fields. It will always find a direction to slip or flip.

SCAFFOLDING EFFECT

psychology

Reduce cognitive load

Reveals the impossibility of static equilibrium. To achieve levitation (or any highly difficult dynamic equilibrium), dynamic adjustments (such as rotation, feedback control) or special materials (such as diamagnetic materials) must be introduced. Static stability is often an illusion; dynamic adjustment is the norm.

anchor

Anchor fast decisions

Earnshaw's theorem: A system composed solely of inverse-square central forces such as electrostatic, gravitational, and magnetic dipole forces cannot form a stable static equilibrium in three-dimensional space (no minimum potential energy), so permanent magnet levitation is unstable.

MINIMUM ACTION

In progress 0/4

Practice this model in one real situation:

Check to track your progress (stored locally)
Learning progress0%
account_treeGenealogyexpand_more
menu_bookReferencesexpand_more

Source support: Explicit

  • link
    en.wikipedia.orghttps://en.wikipedia.org/wiki/Earnshaw%27s_theoremZH · Explicit
    verified

RELATED MODELS

Related model

Second Law of Thermodynamics

The second law of thermodynamics is one of the four fundamental laws of thermodynamics, stating the irreversibility of thermodynamic processes—isolated systems spontaneously evolve toward thermodynamic equilibrium, the state of maximum entropy. Similarly, a perpetual motion machine of the second kind is impossible. The history of this law can be traced back to Nicolas Carnot's research on the efficiency of heat engines and his Carnot theorem proposed in 1824.

arrow_forwardRelated model

Coherence

In physics, coherence (also called phase coherence) states the possibility of interference between two waves. Two monochromatic beams from the same single light source always interfere with each other. If two wave sources have the same frequency and waveform, they are coherent. The physical sources of coherent waves are not strictly monochromatic; they may be partially coherent. However, beams from different physical sources are mutually incoherent.

arrow_forwardRelated model

The Great Filter

The Great Filter theory is a hypothesis that attempts to explain the Fermi Paradox. It posits that in the development of life, from its early origins to the highest level on the Kardashev scale (Type III, capable of utilizing all resources of its galaxy), there exist certain developmental barriers (referred to as 'filters'). Consequently, extraterrestrial life detectable by humans is extremely rare. The concept was proposed by Robin Hanson: the absence of any extraterrestrial civilizations in the observable universe implies that the emergence of advanced intelligent life is very unlikely. This observation is conceptualized as the 'Great Filter'.

arrow_forward