‘‘jyotish’’ shabd ‘‘jyoti’’ se bana hai. jyoti ka sidha-sada shabdik arth hai- dyuti, prakash, ujala, roshni, chamak, abha ityadi. ‘‘jyotish’’ ek vigyan hai. ‘‘jyotishan suryadigrahanan bodhkan shastram’’ arthat suryadi grah aur kal ka bodh karane vale shastra ko ‘‘jyotish shastra’’ kaha jata hai. akash mandal ke pradhan grah, nakshatra ham prithvivasiyon ko ‘‘jyoti’’ pradan karte hain. akashiya pindon se niklne vali ye ‘‘jyoti rashmiyan’’ apne bal v konatmak duri ya antar ke anusar ham prithvivasiyon ko bhinna-bhinn prakar se prabhavit karti hain. satyata yah hai ki janm ke samay ki ‘‘jyoti rashmiyan’’ hi manushya ke svabhav ka nirman karti hain.
ham manushyon ke jivan ke vibhinn pahluon par in ‘‘jyoti rashmiyon’’ ke prabhav ka adhyayan karne vale vishay ka nam hi ‘‘jyotirvigyan’’ ya ‘‘jyotish vigyan’’ hai. shiksha, kalp (sutra), vyakaran, nirukt, chand aur jyotish ved ke chah ang hain. isilie ved ko shadang ved kahte hain.’’ vedasya nirmalan chakshujryoti shastramnuttamama’’- narad sanhita ke anusar jyotish shastra ko vedon ka netra mana gaya hai. jyotish shastra ke mahatva ko rigved ka yah shlok siddh karta hai -‘‘viflanyanyashastrani vivad steshu kevalam. saflan jyotishan shastran chandrakaun yatra sakshinau..
yatha shikhamyuranan naganan manyon yatha. tadvadvedangshastratranan jyotishan murdhani sthitam.. maharaj chandragupt vikramaditya ke kal (i. san 380 se 414) men mahan khagolvid ganitagya evan jyotishvid aryabhatt pratham ne ganitiya akalan kar jyotish vigyan ki unnati men char chand lagae. aryabhatt ne prachin rishi-muniyon ki surya-chandra grahan ka samay janne ki prachin paddhati men sudhar kar sahi samay nikalne ki ganit vidhi taiyar ki aur prachin rishi-muniyon ka gaurav barhaya. vaidik kal ke rishiyon ke dvara ki jane vali shubhashubh ghatnaon ke sahi samay janne hetu 27 nakshatron par adharit ek samy-sarini taiyar ki. prithvi aur prithvivasiyon par parne vale grahon ke prabhav ka ek chart bhi taiyar kiya aur ‘aryabhattiya’ namak granth ki rachna ki. yah prachin bharat men ‘jyotish’ ka svarnim kal tha.
aj bhi uprokt vidhi sare vishva men apnai jati hai aur bharat men iska sarvadhik prachalan hai. purva madhya kal men jyotish vigyan men aur adhik unnati hui. ‘acharya varah mihir’ ne is vigyan ko kramabaddh kar ismen anek navin tathyon ka samavesh kiya aur ‘vrihajjatakam’ granth ki rachna ki. tatpashchat kalyan varma, brahmagupt, munjal, chandrasen, shripti, shridhar, bhattavosri, mallisain, ballalsain, narachandra, arddhadas, makarand mahenadrasuri, vaidyanath, keshav, ganesh, dhundiraj, nilkanth aur adhunik kal (19vin sadi) men munishvar, divakar, nityannad, ubhykushal baghjimuni, jasvantsagar, jagannath samrat, bapudev shastri, nilanbar jha, sudhakar dvivedi adi anekanek prasiddh rachnakaron/tikakaron/ samikshakaron ne jyotish par bahut kuch likha. in prachin rishi-muniyon, acharyon, lekhkon ki ‘gyan rashmiyon’ se nikle shabdon, vakyon, shlokon ka aj bhi ullekh kiya jata hai.
isi kal men takshashila, nalanda, magadh, kashi, ujjain, tanjaur, jaypur adi sthanon par jyotish ki uttam vedhshalaen sthapit ki gain. in vedhshalaon men bhartiya evan videshi vidyarthi jyotish vigyan ka gyanarjan kiya karte the. yadyapi ab inmen kai kendra nasht ho gaye hain. sansar ke prachin rashtron men jinhen ‘jyotish shastra’ ka purn gyan prapt hua. ve keval do rashtra hain, bharat tatha bharat ke pashchat grik. isvi san ke hajaron varsh purva bharatavarsh men ‘jyotish shastra’ ka vatvriksh itna uncha tha ki iski ghani chaya men dukh ke tikshn banon se trasit hue anya desh ke log vishranti paya karte the. manav jivan men jyotish ka mahatva v upyogita: manav ke samast karya jyotish ke dvara hi chalte hain.
vyavhar men atyant mahatvapurn evan upyogi divas, samay, tithi, var, saptah, paksh, mas, ritu, varsh, ayan, nakshatra, yog, karan, chandra sanchar, surya sthiti adi ka gyan jyotish se hi hota hai. is jankari ke lie pratyek varsh anekanek sthan v nam adharit panchangon ka nirman kiya jata hai. ismen dharmik utsav, divas, samajik tyauharon ke divas, mahapurushon ke janmadivas, rashtriya parva divas, mahatvapurn ghatnaon ke divas diye hote hain. sadharan manushya bhi sunakar ya parhakar unhen samay par mana sakte hain. isi prakar bahut si aitihasik tithiyon ka bhi pata lag jata hai. un par bhi ham mil baithakar vichar kar sakte hain aur sujhav de sakte hain tatha sahi nirnay le sakte hain. jalachar rashi ya jalachar nakshatron men achchi varsha ke asar hote hain.
anaparh dehati kisan akash mandal ki sthiti dekhakar iska asani se anuman laga lete hain. fasal bone ka samay bhanp lete hain taki achchi paidavar ho. samudri jahaj ke kaptan bhi samudri yatra ke dauran surya-chandra ki gati sthiti dekhakar samudri mausam ka andaj laga lete hain aur thik samay par samuchit evan nirapad marg ka anusaran karte hain. isse kshati ki sanbhavna samapt ho jati hai. jyotish ki shakha rekhagnit se parvaton-paharon ki unchai evan samudra ki gahrai mapi ja sakti hai. surya-chandra grahan ke adhar par prachinatam aitihasik tithiyon ki jankari ho jati hai. bhugarbh se prapt puratatva ki vastuon ke samay v unki ayu ka bhi pata lag jata hai. akshansh v rekhansh rekhayen disha gyan karati hai. is disha gyan ke adhar par vishva ke kisi bhi bhubhag ya sthan par pahunchna saral aur suvidhajanak ho jata hai.
srishti ke anekane rahasya tatha yugon ki jankari, surya-chandra grahan tithi v samay, jvar-bhate ki tivrata ki thik samay adi jyotish dvara jan lete hain. gunkari davaon ke banane ka sthan v samay ka gyan ho jata hai. rogon ke upchar hetu samyanusar uchit davai dene se avagat ho jate hain. vibhinn prakar ke shubh muhurton ka gyan hota hai. is prakar jyotish vigyan pratyaksh evan paroksh rup se ham prithvivasi manushyon, jivdhari pashuon, pakshiyon aur jar vastuon ke lie sarvatha upyogi evan labhkari hai, agyanta ke andhkar ko ghatane vala jyotirdip ‘jyotirvigyan’ hai.
isi jyotirvigyan ko sahastradhik varsh ke ghor prayatn dvara pashchatya vidvanon, jyotishagyaon v sanshodhkon ne apne gyan dvara pashchatya jyotish paddhati ko janm diya. falit jyotish par pashchatya desh ke tatvagyaon ko itni adhik shraddha ho gayi ki inglaind men is vishay par charcha karne hetu ek aisi sanstha sanghtit hui jismen pustak, bhashan, vyakhyan dvara lok samuday ko shastra shuddh gyan diya jata hai. amerika men is vishay par vishesh mahavidyalyon ki sthapna ki gai hai jinmen yogya vidyarthiyon ko pariksha utirn hone par padvi pradan ki jati hai.