A125560 - OEIS

A125560

Full solid angle of 4*Pi steradians (sr) in square degrees (degree^2).

4, 1, 2, 5, 2, 9, 6, 1, 2, 4, 9, 4, 1, 9, 2, 7, 1, 0, 3, 1, 2, 9, 4, 6, 7, 1, 4, 6, 6, 1, 5, 5, 7, 2, 2, 6, 3, 9, 3, 3, 1, 9, 4, 0, 1, 7, 5, 9, 2, 6, 3, 1, 1, 5, 1, 5, 3, 9, 5, 3, 7, 5, 5, 8, 0, 0, 6, 6, 0, 4, 9, 9, 4, 6, 7, 9, 1, 5, 1, 7, 8, 9, 5, 3, 5, 7, 4, 9, 7, 6, 7, 7, 0, 1, 2, 7, 9, 9, 8, 7, 9, 8, 1, 4, 0

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OFFSET

5,1

COMMENTS

"A 35 mm camera with a standard 50 mm lens covers an area some 38 degrees x 27 degrees. Theoretically, one can cover the sky with about 40 photographs." [A Field Guide]

One sphere = 4*Pi steradians, a spherical right angle = 1/4 hemisphere = 1/8 sphere = Pi/2 steradian.

REFERENCES

John A. Adam, Mathematics in Nature, Modeling Pattern in the Natural World, Princeton University Press, Princeton & Oxford, 2003, page 78.

Patrick Kelly, Editor, Observer's Handbook 2007, The Royal Astronomical Society of Canada, page 32.

Donald H. Menzel, A Field Guide to the Stars and Planets, Houghton Mifflin Co., Boston, MA, 1964, page 317.

LINKS

Table of n, a(n) for n=5..109.

Rod Pierce, MathIsFun: Steradian, 2012.

Eric Weisstein's World of Mathematics, Solid Angle.

Wikipedia, Solid Angle.

FORMULA

4Pi*(180/Pi)^2 = 10*A019694*A072097^2 = 129600/Pi = 129600*A049541.