Earth & SkyGreek → English
Isobar
/ˈaɪsoʊbɑːr/noun
A line on a weather map joining points of equal atmospheric pressure.
The Greek roots
ἴσος
ísos
equal
βάρος
báros
weight
Literally: “equal weight”
The story of the word
Meteorologists began drawing these lines in the 1860s and named them for equal weight, which is literal: barometric pressure is the weight of the air column standing on you. Tightly packed isobars mean a steep pressure gradient, which is to say wind. Nuclear physicists later borrowed the same word for atoms of equal mass number, so isobar means two unrelated things depending on which room you are in.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 1860s
Same family
isotopebarometerbaritoneisosceles
In a sentence
The isobars over Iceland were stacked like contour lines on a cliff.