Eta

Greek Letter Eta (Ήτα - Η)

In Semitic "η" a consonant, but the Greeks used it as their "long a" sound. On the continent, e often takes what we call the "long a" sound. The letter moved into Latin as the "H", which was needed because the Greek reverse apostrophe wouldn't do.

"H" Letter in mathematics and in science

η represents:

• the partial regression coefficient in statistics.
• elasticities in economics.
• the absolute vertical vorticity (relative vertical vorticity + Coriolis effect) in fluid dynamics
• an index of refraction
• a type of meson
• viscosity
• efficiency

Greek words with "η"

ησυχία, κήπος