pip and python(dot)org

[samsonite]

Title (re-written, for the fourth time): Is pip opensourced like Python(dot)org?

The following code, taken as an example, is running under the astropy library installable via (pip) and concerning a huge quantity of algorithms,well known all around the world by astronomy community. Nevertheless, nothing is said through its webpages on how the variables ut1,tt,mjd, etc.are computed, leaving the user thinking that he's dealing with a close software, despite Python(dot)org is clearly an opensourced organization.

# -------- tempo3.py ---------------
from astropy.time import Time 
t = Time('2006-01-15 21:24:37.5', format='iso', scale='utc', precision=6)
#
print (t.ut1.iso, t.ut1.mjd) 
print (t.ut1.jd1, t.ut1.jd2)
#
print (t.tt.iso, t.tt.mjd) 
print (t.tt.jd1, t.tt.jd2) 

#---------- OUTPUT ----------
# 2006-01-15 21:24:37.834136 53750.89210456175
# 2453751.0 0.3921045617535457
# 2006-01-15 21:25:42.684000 53750.89285513889
# 2453751.0 0.3928551388888888

In other words, pip seems only open accessible, far away from any open sourced status.
Thanks in advance for appreciated comments.