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sr

sr

9.9
A unit for measuring how big an area on a sphere looks from its centre
  • noun
  • Specialized
: sr
  • The steradian, symbolized as sr, is used to measure solid angles in three-dimensional space.

Examples

  • When studying geometrical optics, the concept of sr is essential for understanding how light spreads.

  • Each point on a sphere subtends an angle measured in sr, helping calculate the area of the surface.

  • Sometimes I see a different set of hoppers, and my SR gets set back to 0.

    Blog text (29)
  • I think there is another place; I think the beginning of SR, that we jump between three POVs in one paragraph ...

    Blog text (9)
  • She's had 8 years of Reagan, 4 of Bush Sr, 8 of Clinton, and 8 of Junior.

    Blog text (31)
  • The total variance attributable to unique sources (sr) equals 40%, whereas the six independent variables combined would explain an additional 24% of the variance.

    Academic text (2006)
  • JOHNNY JONES SR:

  • Mobile phase A was used to elute 90Sr, 239Pu, and 90Y, while mobile phase B was used to elute 241Am; see PDF for image #.

    Academic text (2018)
  • OTIS SR.

Synonyms

steradian
vssr
  • Specialized
1 9.9

A unit for measuring the size of an area on a sphere from its centre

is the written symbol used to represent that unit

Surface Forms

sr singular
srs plural

Etymology

Sr stands for the unit steradian, which comes from Greek stere- meaning 'solid' and from radian (from radius) meaning 'ray'. A helpful image is a cone of rays from the centre of a ball: a steradian measures how wide that cone is in three dimensions, so sr is the unit for a 'solid' angle.