exclusion principle
C2Formal, Technical
Definition
Meaning
A rule stating that two identical particles with half-integer spin (fermions) cannot occupy the same quantum state simultaneously within a quantum system.
A general rule or concept in various fields (e.g., law, sociology) that prohibits two things from coexisting in the same space or under the same conditions, often to prevent conflict or maintain order.
Linguistics
Semantic Notes
In physics, it's a fundamental law of quantum mechanics (Pauli Exclusion Principle). In broader use, it denotes any rule designed to enforce separation or prevent overlap.
Dialectal Variation
British vs American Usage
Differences
No significant lexical differences; the term is identical in spelling and usage. Conceptual application in non-technical contexts (e.g., social policy) may vary by region but the term itself does not.
Connotations
Strongly technical/scientific primary connotation. In extended use, can carry connotations of elitism, segregation, or necessary regulation, depending on context.
Frequency
Much more frequent in academic (physics, chemistry) and technical legal contexts than in general discourse in both regions.
Vocabulary
Collocations
Grammar
Valency Patterns
The [exclusion principle] governs [quantum system].[Entity] operates under an [exclusion principle].This is a direct consequence of the [exclusion principle].Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Usage
Context Usage
Business
Rare. Might refer to a company policy prohibiting concurrent employment with a direct competitor (a 'non-compete' as an exclusion principle).
Academic
Primary context. Crucial in physics, chemistry (explaining periodic table), and quantum computing. Also used in logic, mathematics, and legal theory.
Everyday
Very rare. If used, it's in a metaphorical sense (e.g., 'In our house, the exclusion principle applies to my brother and I sharing a car').
Technical
The core domain. Precisely defined in quantum mechanics, quantum statistics (Fermi-Dirac statistics), and related engineering fields.
Examples
By Part of Speech
adjective
British English
- The exclusion-principle argument was central to the proof.
American English
- He gave an exclusion-principle-based explanation.
Examples
By CEFR Level
- The behaviour of electrons in an atom is explained by the exclusion principle.
- A simple exclusion principle prevents two companies from owning the same broadcast licence.
- The Pauli exclusion principle fundamentally differentiates fermions from bosons and underpins the structure of the periodic table.
- The treaty established an exclusion principle whereby military vessels of one signatory were barred from the other's territorial waters.
Learning
Memory Aids
Mnemonic
Think: 'EXclude' means to keep out. The 'exclusion principle' keeps two identical fermions out of the same quantum 'house' (state).
Conceptual Metaphor
QUANTUM STATES ARE SEATS; THE EXCLUSION PRINCIPLE IS A 'ONE PERSON PER SEAT' RULE FOR ELECTRON TWINS.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating as 'принцип исключения' in physics contexts; the standard term is 'принцип запрета Паули' (Pauli's prohibition principle). 'Принцип исключения' is a calque used only for the general concept.
- Do not confuse with 'exclusion zone' (зона отчуждения).
Common Mistakes
- Confusing it with the 'uncertainty principle'.
- Using it to refer to social exclusion without clarifying the metaphorical extension.
- Misspelling as 'exlusion principle'.
- Incorrectly applying it to bosons (which are not subject to it).
Practice
Quiz
In which field did the 'exclusion principle' originate?
FAQ
Frequently Asked Questions
Wolfgang Pauli in 1925 for the quantum mechanical version.
No, it applies only to fermions (e.g., electrons, protons, neutrons). Bosons (e.g., photons) are not subject to it.
In its fundamental quantum mechanical form, no. It is a law of nature. In its extended metaphorical uses, 'violation' means breaking a man-made rule.
It explains electron shell structure in atoms, leading to the diversity of chemical elements and the stability of matter.