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| -rw-r--r-- | info/blueshift.texinfo | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/info/blueshift.texinfo b/info/blueshift.texinfo index 4b3dce1..89c7bde 100644 --- a/info/blueshift.texinfo +++ b/info/blueshift.texinfo @@ -1509,6 +1509,17 @@ The Sun's lowest and highest elevation during astronomical twilight, measured in degrees. @end table +Blueshift provides a constant for the apparent +size of the Sun: @code{SOLAR_APPARENT_RADIUS}. +This constant can for example be used to get a +more accurate time when the night begins: rather +than simply saying that the night begins when +the Sun's apparent elevation is zero, you can say +that it begins when the Sun is no longer visible +at all, which is when the Sun's apparent elevation +is minus @code{SOLAR_APPARENT_RADIUS}. This value +is approximate. + @node Weather @section Weather |