missing mass: meaning, definition, pronunciation and examples
C1/C2 (specialized academic/scientific)Academic, Scientific, Technical
Quick answer
What does “missing mass” mean?
A discrepancy in astronomical observations where the amount of matter detected through its gravitational effects is far greater than the amount of visible matter.
Audio
Pronunciation
Definition
Meaning and Definition
A discrepancy in astronomical observations where the amount of matter detected through its gravitational effects is far greater than the amount of visible matter.
Refers to the hypothesized dark matter needed to account for gravitational forces observed in galaxies and galaxy clusters that cannot be explained by visible matter alone. In broader contexts, can metaphorically describe any significant gap between observed and expected quantities in a system.
Dialectal Variation
British vs American Usage
Differences
No significant difference in usage. Both use the term identically within scientific literature.
Connotations
Neutral, technical. May carry a slightly historical connotation, as it was more common in early-to-mid 20th century cosmology.
Frequency
Low frequency in general discourse; high frequency within specific astrophysics contexts. 'Dark matter' is now far more common.
Grammar
How to Use “missing mass” in a Sentence
The [scientist/observation] detected missing mass in [galaxy/cluster].The [theory/model] accounts for the missing mass by proposing [dark matter/MACHOs].[Rotation curves/Gravitational lensing] implies the presence of missing mass.Vocabulary
Collocations
Examples
Examples of “missing mass” in a Sentence
verb
British English
- The rotation curves of galaxies strongly suggest they are missing mass in their outer regions.
- Early models missed mass because they only counted visible stars.
American English
- The data indicates the cluster is missing about 90% of its expected mass.
- If our inventory of the cosmos is missing mass, our fundamental physics might be wrong.
adjective
British English
- The missing-mass problem has driven cosmology for decades.
- They studied the galaxy's missing-mass component through gravitational lensing.
American English
- Astronomers calculated a huge missing-mass fraction.
- The search for the missing-mass particles is a major experimental effort.
Usage
Meaning in Context
Business
Not used.
Academic
Primary context. Used in physics, astronomy, and cosmology papers, especially discussing historical development of the dark matter problem.
Everyday
Virtually never used. Would be replaced by 'dark matter' in popular science contexts.
Technical
Used in technical reports, conference presentations, and textbooks on astrophysics.
Vocabulary
Synonyms of “missing mass”
Strong
Neutral
Weak
Vocabulary
Antonyms of “missing mass”
Watch out
Common Mistakes When Using “missing mass”
- Using 'missing mass' and 'dark matter' as perfect, interchangeable synonyms (one is the problem, the other is the leading solution).
- Confusing 'missing mass' with 'lost mass' in nuclear reactions (binding energy).
- Using it in non-scientific contexts where 'shortfall' or 'discrepancy' is meant.
FAQ
Frequently Asked Questions
Not exactly. 'Missing mass' describes the observational *problem* – the discrepancy between observed gravitational effects and visible matter. 'Dark matter' is the leading theoretical *solution* – a proposed form of matter that explains the missing mass.
Because the focus has shifted from simply noting the mass is 'missing' to proposing what it is (dark matter). 'Dark matter' is the more specific, modern term for the hypothetical substance itself.
Only metaphorically. For example, 'The budget has a missing mass of several million pounds' would be a creative, technical metaphor for a large financial shortfall. It is not standard usage.
While not coined by a single person, it was brought to prominence by the work of astronomers like Fritz Zwicky (1933) on galaxy clusters and later Vera Rubin on galaxy rotation curves in the 1970s.
A discrepancy in astronomical observations where the amount of matter detected through its gravitational effects is far greater than the amount of visible matter.
Missing mass is usually academic, scientific, technical in register.
Missing mass: in British English it is pronounced /ˌmɪs.ɪŋ ˈmæs/, and in American English it is pronounced /ˌmɪs.ɪŋ ˈmæs/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “The hunt for the missing mass”
- “Closing the missing mass gap”
Learning
Memory Aids
Mnemonic
Think of a 'missing person' poster. The 'missing mass' is the matter that should be there based on gravity's 'wanted' poster, but is nowhere to be seen.
Conceptual Metaphor
A PUZZLE PIECE / ACCOUNTING ERROR. The universe's books don't balance; the mass we see doesn't add up to the gravitational effects we observe.
Practice
Quiz
What does the term 'missing mass' primarily refer to?