サミュエル・ラングレー
The langley (symbol Ly) is used to measure solar radiation or insolation. It is equal to one thermochemical calorie per square centimetre (4.184 J/m2 or ≈3.684 BTU/sq ft) and was named after Samuel Pierpont Langley. Its symbol should not be confused with that for the light-year, ly.