fluorescence

flor-ESS-unss /flɔːˈrɛs.əns/
nounC1GRETOEFL
academicscientific

The emission of light by a substance that has absorbed light or electromagnetic radiation, stopping immediately when the excitation source ceases.

Unlike phosphorescence, fluorescence stops almost instantly (within nanoseconds) after the stimulating light is cut off.

The story behind the word. Coined in 1852 by British physicist Sir George Gabriel Stokes. He named the phenomenon after fluorite, a mineral that emits striking blue light when exposed to ultraviolet radiation.

Word relationships

  • luminescence: Luminescence is the general term for cold light emission; fluorescence is a rapid specific subtype.

Commonly confused with

  • phosphorescence: Phosphorescence glows continuously long after excitation stops; fluorescence ceases immediately.

Word family

  • fluorescent (adjective): Exhibiting or relating to fluorescence.
  • fluoresce (verb): To emit light via fluorescence.

Collocations

  • fluorescence microscopy
  • ultraviolet fluorescence
  • exhibit fluorescence
  • fluorescence resonance

Example sentences

  • "Geologists examine rock samples under ultraviolet light to detect the bright green fluorescence of uranium minerals." Geological survey
  • "Fluorescence microscopy allows biological researchers to tag cellular structures with glowing protein markers." Microbiology research

Memory hook

FLUORite mineral inspired FLUORESCENCE under UV light. Instant light emission under UV excitation.

When not to use

Do not use for glow-in-the-dark novelties that remain lit for hours in the dark without light input.

Fun facts

  • Tonic water glows bright neon blue under blacklight fluorescence because it contains the natural compound quinine.
LangBlitz
Take your vocabulary further with LangBlitz

Our English vocabulary app: FSRS spaced repetition, 5,000+ curated words across 119 topic groups, CEFR A1 to C2. Explore your mastery with the beautiful Vocabulary World feature.