Science & TechnologyGreek → English
Bolometer
/boʊˈlɒmɪtər/noun
An instrument that measures radiant energy by the heat it deposits in an absorbing element.
The Greek roots
βολή
bolḗ
a throw, a ray
μέτρον
métron
measure
Literally: “ray measurer”
The story of the word
Langley built the first in 1878: two blackened platinum strips in a bridge circuit, one shielded, one exposed, sensitive to temperature differences around a hundred-thousandth of a degree. βολή is a throw, used of a ray thrown out by a source, so the name means the thing that measures what the sun flings at you. He hauled it up Mount Whitney to work out how much of that the atmosphere eats before it reaches the ground. Cooled bolometers now map the microwave background.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 19th century
Same family
symbolparabolaproblemthermometer
In a sentence
The bolometer runs at a fraction of a degree above absolute zero.
Langley's bolometer pushed the solar spectrum far into the infrared.