Well-defined Numbers That Are Not Precisely Known
Sagan's number is the number of stars in the observable universe. It is named in honor of Carl Sagan. This number is reasonably well defined, since we know what stars are and what the observable universe is, but its value is not known with any certainty (it is presently estimated to be approximately 70 sextillion (short scale)).
Sagan's number is unrelated to the bogus sagan unit or the humorous use of the term "sagan" to denote any large quantity.
Read more about this topic: Indefinite And Fictitious Large Numbers
Famous quotes containing the words numbers and/or precisely:
“Individually, museums are fine institutions, dedicated to the high values of preservation, education and truth; collectively, their growth in numbers points to the imaginative death of this country.”
—Robert Hewison (b. 1943)
“No group and no government can properly prescribe precisely what should constitute the body of knowledge with which true education is concerned.”
—Franklin D. Roosevelt (1882–1945)