malus' law
very lowspecialist technical (physics, optics)
Definition
Meaning
The law stating that the intensity of light transmitted through a polarizer is proportional to the square of the cosine of the angle between the light's initial polarization direction and the polarizer's axis.
A fundamental principle in optics describing how polarized light intensity diminishes when passing through a polarizing filter, based on the angular orientation.
Linguistics
Semantic Notes
Always refers to a specific physical law. Commonly called "Malus's law" or "Malus law" (with or without the possessive). Not to be confused with 'Malus' as a genus of apple trees.
Dialectal Variation
British vs American Usage
Differences
No significant difference in meaning or application. The possessive form (Malus's) is slightly more common in American English, while both forms (Malus's/Malus') are accepted in British English.
Connotations
Purely technical, no cultural connotations.
Frequency
Extremely rare outside academic physics/engineering contexts. Frequency identical in both dialects within those fields.
Vocabulary
Collocations
Grammar
Valency Patterns
[Subject] obeys Malus's law.Malus's law states that [clause].According to Malus's law, [observation].The intensity is given by Malus's law.Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “N/A”
Usage
Context Usage
Business
Never used.
Academic
Used in physics and optical engineering textbooks, lectures, and research papers.
Everyday
Never used.
Technical
Core term in optics, photonics, and optical instrumentation design.
Examples
By Part of Speech
adjective
British English
- Malus's law analysis
- Malus's law experiment
American English
- Malus's law derivation
- Malus's law verification
Examples
By CEFR Level
- The scientist mentioned Malus's law in the lecture.
- To calculate the transmitted intensity, you must apply Malus's law.
- The experimental data for polarized light attenuation conformed precisely to the predictions of Malus's law, validating the theoretical model.
Learning
Memory Aids
Mnemonic
Malus Makes Light Lose Strength, squared by the cosine's measure.
Conceptual Metaphor
A filter that 'selects' alignment; light is 'accepted' based on how well its direction 'agrees' with the filter's orientation.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Direct translation 'закон Малюса' is correct. Trap: confusing with 'malus' as Latin for 'bad' or 'apple tree'. Ensure context is physics/optics.
Common Mistakes
- Misspelling as 'Mallus's law' or 'Malus law' without clarifying it's a person's name. Incorrectly applying it to unpolarized light.
Practice
Quiz
Malus's law is primarily concerned with which property of light?
FAQ
Frequently Asked Questions
It is named after the French physicist Étienne-Louis Malus, who discovered the law in 1808.
No, Malus's law specifically describes the intensity of already polarized light after it passes through a polarizer. For unpolarized light, the initial transmission through a polarizer reduces intensity by half, independent of angle.
It is typically written as I = I₀ cos²θ, where I is the transmitted intensity, I₀ is the initial intensity, and θ is the angle between the polarization direction of the light and the axis of the polarizer.
It is foundational in optics, optical engineering, photonics, and any field involving the manipulation or measurement of polarized light, such as lens design, photography filters, and liquid crystal displays (LCDs).