luminosity
/,lu:mi'nɔsiti/
Học thuậtThân thiện
Definition
Noun: 1. The quality or state of being luminous; the property of emitting or reflecting light. This is the intrinsic brightness or radiance of an object, independent of its distance from an observer. 2. (In astronomy) The total amount of energy a star, galaxy, or other celestial object radiates per unit of time. It is an absolute measure of an object's true brightness.
Usage
- Luminosity is primarily a scientific and technical term used in physics, astronomy, and photography.
- It describes an inherent property, not a subjective perception of brightness.
- It is often measured and compared quantitatively (e.g., "The luminosity of the star is 10 times that of the Sun").
Examples
- The luminosity of a light bulb depends on its wattage and efficiency.
- Astronomers calculate a star's luminosity based on its apparent brightness and its distance from Earth.
- The screen's high luminosity makes it easily readable in direct sunlight.
- Its luminosity is measured relative to that of our sun.
Advanced Usage
- Photometric Luminosity: In technical contexts, luminosity can refer to a specific photometric quantity measured in lumens, representing the total visible light emitted by a source.
- In Figurative Language: While less common, "luminosity" can be used figuratively to describe intellectual brilliance or spiritual radiance.
- Example: The luminosity of her ideas illuminated the entire discussion.
Variants and Related Words
- Luminous (Adjective): Emitting or reflecting light; shining.
- Example: The watch has luminous hands.
- Luminance (Noun): The intensity of light emitted from a surface per unit area in a given direction (a more specific technical term in photometry and display technology).
- Illuminance (Noun): The amount of luminous flux per unit area (how much light falls on a surface).
Synonyms
- Brightness
- Radiance
- Brilliance
- Luminousness
- (In astronomy) Absolute Magnitude
Antonyms
- Darkness
- Dimness
- Dullness
- Opacity
Noun
- the quality of being luminous; emitting or reflecting light
- its luminosity is measured relative to that of our sun