In Science
- The atomic number of protactinium, an actinide.
- McCarthy 91 function, a recursive function in discrete mathematics
In astronomy,
- Messier object M91, a magnitude 11.5 spiral galaxy in the constellation Coma Berenices
- The New General Catalogue object NGC 91, a single star in the constellation Andromeda
- The Saros number of the solar eclipse series which began on August 6, 159 BC and ended on 1175 October. The duration of Saros series 91 was 1334.2 years, and it contained 75 solar eclipses.
- The Saros number of the lunar eclipse series which began on 161 May and ended on 1459 July. The duration of Saros series 91 was 1298.1 years, and it contained 73 lunar eclipses.
Read more about this topic: 91 (number)
Famous quotes containing the word science:
“We are living now, not in the delicious intoxication induced by the early successes of science, but in a rather grisly morning-after, when it has become apparent that what triumphant science has done hitherto is to improve the means for achieving unimproved or actually deteriorated ends.”
—Aldous Huxley (1894–1963)
“Democracy is the art and science of running the circus from the monkey-cage.”
—H.L. (Henry Lewis)