Visibility of Luna and Lunar Crescent

Tlrc'€ seE 6 c66 when thc ag. of M@n @ bciwen 24 hou's dnd 30 hous
ed rhe crescenl w4 not seen. Thus, ihis srudy also suppons th. idea that age is not a
depcndablc l&to. for any pEdiction crildion.
Anodier inrporbnt pdMeler concened is rhe noonFt-sun*l LAG. There are 22
occasions *hen the crescenr of lag 60 minures or less was Fen. Oul of rhese only two
*ft wnh lag less rhan 50 hinules, Nov. l], 2004 with lag ]5 mi.ur€s a.d Aprit t0,
2005 Nith lsg .l,l minut€s. In ihe *co.d of thcse c6es rhe prediclion c (ia a o$€d
naked ele lisibility. There wer€ 15 cases when the tag sas b€lveen 40 and 50 minules
and bolh dic pEdic on crileria did nor altov crcscent
visibility *ilhoui optic.l aid, Tbls lh. n@Mr-sN4lag alone is also not a dependabte
parametef for any prediclioh criterion. Out of 95 new Moons rhe predic on crileria difer
from $e Babylonian clnerion (Faroonhi et al, 1999) only g tines when Dabylonian
crnerion (ARCL + l"Ac(in deg.ect < 22) alto$ nalcd eye visibility but ,{luc dd
lhe s-laluc cnteria do tur Howld, on rhese nine ccas
I'r view of tn6c fads we conclude rhat bod q-vatue ed r-value cilcda arc N€I
suilcd predicrior cireria with r !.tue clireion delcloped in $is work has mdginalty
be cr success percenrage ibr posnive ob$ralions (chapter 4). porricutarly in viewofrh€
facl dar $cs fire.ia do not march acrual cr.senr visibitiry onty in one ou 95 cas
(1.057q).nd thal @casion Ns conkoversial in liew ofrhe above discussioD. Thc nve
cases Nhcn the cEscent $as seen hler tan prcdicrd aE not conside!€d as an ero! 0s thc
probl€n occun d d!. lo ore(sr skies. TtrGfoF, tor lhe tomulaion oa turue
obenarional IuMrqlendar $ese Fediction dreia de nidly dependable_
TIE € has ben only o.e occasion whd lherc mrc three co.*curivc nonrhs of
29 dars elcb (during June, July and Aususl 2ooo). This is rhe ndinum fo. Fpelnion of
29 days lund nondrs anticipoied s e&ly a loricentury AD by Muslims ( yas, 1994a).
The li6t (Rabi ul Awal, I42l) of$is lriphr ofnonthsbeema day talerrhan p!.dicled
196