spat (angular unit)

{{Short description|Unit of angle in solid geometry}}

{{Technical|date=March 2023}}

The spat (symbol sp{{cite book | title=The Ultimate Online Reference for Engineers | publisher=eFunda Inc. | location=Sunnyvale, California, USA | url=http://www.efunda.com/units/show_units.cfm?search_string=spat | accessdate=2015-10-19}}), from the Latin spatium ("space"), is a unit of solid angle.{{cite web | title=A Dictionary of Units of Measurement | first=Russ | last=Rowlett | date=2018 | publisher=University of North Carolina | location=Chapel Hill | url=https://www.ibiblio.org/units/dictS.html#spat | accessdate=2024-07-10}}{{cite book | title=Glossary » Units » Solid Angle » Spat | publisher=eFunda Inc. | location=Sunnyvale, California, USA | url=http://www.efunda.com/glossary/units/units--solid_angle--spat.cfm}} 1 spat is equal to 4{{pi}} steradians or approximately {{val|41253}} square degrees of solid angle {{OEIS|A125560}}. Thus it is the solid angle subtended by a complete sphere at its center.

The whole sphere contains ~148.510 million square arcminutes and ~534.638 billion square arcseconds.{{Citation needed|date=June 2025}}