Do Sawaal Jo Bachpan Se Hain 🤔
Aasman neela kyun hai? Aur wahi aasman shaam ko laal-narangi kyun ho jaata hai?
Dono ka jawab ek hi cheez hai — aur wo itni sundar hai ki ise samajhne ke baad aap har shaam alag nazar se dekhoge.
📌 Scattering (prakeernan): jab roshni hawa ke bahut chhote kanon (molecules, dhool,
paani ki boondein) se takrati hai, toh wo har disha mein bikhar jaati hai. Isi
bikharne ko scattering kehte hain.
Aur sabse zaroori niyam: chhoti wavelength wali roshni ZYADA bikharti hai.
Yani neela aur violet sabse zyada, laal sabse kam.
"Neela bikharta hai, laal seedha nikal jaata hai."
Bas isi ek line se aap aasman ka neela rang, sunset ka laal rang, khatre ka laal signal, aur
hawai jahaz se dikhta gehra aasman — sab samjha sakte hain. Poora lesson isi ek line ka phailaav
hai.
🔬 Tyndall Effect — Bikhri Roshni Dikhti Hai
Roshni ka raasta hume tabhi dikhta hai jab wo kisi cheez se takra kar bikhar jaaye. Isi ko Tyndall effect kehte hain.
🔹 Khidki ki jhiri se aati dhoop ki patti jab kamre mein dikhti hai — kyunki hawa ki
dhool use bikhar rahi hai. Saaf hawa mein wo patti dikhti hi nahi!
🔹 Ghane jungle mein subah ki roshni ki rays dikhna — kohre ki boondon se
bikhraav.
🔹 Cinema hall mein projector se parde tak jaati roshni ki patti dikhna.
🔹 Raat mein kohre (fog) mein gaadi ki headlight ka poora beam dikhna.
🔹 Chai mein doodh daalte hi wo dhundhli ho jaati hai — doodh ke chhote kan roshni
bikhar dete hain.
📌 Tyndall effect tabhi dikhta hai jab kanon ka size roshni ki wavelength ke
lagbhag barabar ya usse thoda bada ho.
Isiliye ye colloid (jaise doodh, dhuaan, kohra) mein dikhta hai, par
saaf solution (jaise namak-paani, cheeni-paani) mein
nahi dikhta — wahan kan bahut chhote hote hain. Ye Class 9 ke Mixtures chapter se
juda hua hai!
💙 Aasman Neela Kyun Hai?
📌 Poori kahani 4 steps mein:
1️⃣ Sooraj ki safed roshni vaayumandal mein ghusti hai
2️⃣ Hawa ke molecules neeli roshni ko bahut zyada bikhar dete hain (chhoti
wavelength)
3️⃣ Laal roshni lagbhag seedhi nikal jaati hai (lambi wavelength)
4️⃣ Aap aasman mein kahin bhi dekho — aap tak bikhri hui neeli roshni hi pahunchti
hai
Isiliye aasman neela hai.
Bahut achha sawaal! Do wajahein hain:
1️⃣ Sooraj ki roshni mein violet, neele se kam hota hai
2️⃣ Aur zyada zaroori — hamari aankh ki cones neele ke prati zyada sanvedansheel
hain, violet ke prati kam
Yani aasman se violet bhi aa raha hai, par hamari aankh use theek se
pakad hi nahi paati. Ek machhli ya chidiya (jinki aankhein alag hain) shayad
aasman ka rang alag dekhti hogi!
Astronauts ki tasveeron mein aasman hamesha kaala dikhta hai — chaahe sooraj chamak
raha ho.
Kyun? Kyunki space mein hawa hai hi nahi — yani bikharne ke liye
koi molecule hi nahi! Roshni seedhi chalti rehti hai aur aapki aankh mein tabhi aati hai jab aap
seedhe sooraj ya kisi cheez ko dekho.
Isiliye chaand par khade astronaut ko ek saath tez sooraj
aur kaala aasman aur taare dikhte hain.
Isi wajah se hawai jahaz mein oonchai par jaate hi aasman gehra neela hone lagta
hai — kyunki upar hawa kam hai, toh bikhraav bhi kam.
🌅 Sunrise Aur Sunset Laal Kyun Hote Hain?
📌 Wajah ek line mein: sunrise aur sunset par sooraj
ufaq ke paas hota hai, isliye uski roshni ko hawa ki
bahut zyada moti parat paar karni padti hai (dopahar se lagbhag
40 guna zyada!).
Itne lambe raaste mein neela aur violet poori tarah bikhar kar khatam ho jaate
hain. Sirf laal aur narangi bach kar aap tak pahunchte hain.
Aur dopahar mein? Tab sooraj seedha upar hota hai, raasta sabse
chhota hai — isliye saare rang pahunch jaate hain aur sooraj
safed dikhta hai.
Jab hawa mein zyada kan hon — jaise baarish ke baad, ya dhool/dhuen wale din.
Zyada kan = zyada bikhraav = zyada gehra laal.
Isiliye bade jwalamukhi (volcano) phatne ke baad duniya bhar mein kai mahine tak
asaadharan laal sunset dikhte hain. 1883 mein Indonesia ka
Krakatoa phata tha — uske baad duniya bhar mein itne laal aasman dikhe ki kuch
jagah log aag lagne ki afwaah mein fire brigade bula baithe!
Par ek dukhad pahlu bhi hai: bade shehron mein aaj jo gehre laal sunset dikhte hain, unki wajah
aksar pradushan (pollution) hoti hai. Sundar dikhta hai, par
saans ke liye achha nahi.
🚦 Khatre Ka Signal Laal Hi Kyun?
📌 Kyunki laal roshni sabse kam bikharti hai — isliye wo
sabse door tak seedhi jaati hai, aur kohre, dhuen ya dhool mein bhi
saaf dikhti hai.
Isiliye:
🚦 Traffic ka rukne wala signal laal
🚂 Railway ka danger signal laal
🏗️ Ooncho building aur tower par laal batti (taaki hawai jahaz ko door se
dikhe)
🚑 Ambulance aur fire brigade par laal batti
Ye fashion nahi, seedha physics hai!
| Ghatna | Wajah |
|---|---|
| Aasman neela | Neeli roshni sabse zyada bikharti hai |
| Sunset/sunrise laal | Lamba raasta — neela raaste mein khatam, laal bach jaata hai |
| Dopahar ka sooraj safed | Chhota raasta — saare rang pahunch jaate hain |
| Space mein aasman kaala | Hawa nahi, isliye bikhraav nahi |
| Khatre ka signal laal | Laal sabse kam bikharta hai, door tak dikhta hai |
| Kohre mein headlight ka beam dikhna | Tyndall effect |
| Baadal safed | Boondein badi hain — wo saare rang barabar bikharti hain |
Baadal paani ki boondon se bane hote hain — aur ye boondein hawa ke molecules se
bahut badi hoti hain.
Aur badi boondein saare rangon ko lagbhag barabar bikharti hain — sirf neele ko
nahi. Saare rang barabar milte hain toh nateeja safed hota hai!
Aur baarish wale baadal kaale kyun dikhte hain? Kyunki wo itne
mote aur ghane ho jaate hain ki sooraj ki roshni unse
paar hi nahi ho paati. Neeche se dekhne par wo kaale lagte hain.
Scattering ka poora vigyan ek bharatiya vaigyanik se juda hai —
Sir C. V. Raman. 1921 mein wo jahaz se Europe ja rahe the aur unhone
Bhoomadhya Sagar (Mediterranean) ka gehra neela rang dekha.
Us waqt maana jaata tha ki samundar neela isliye dikhta hai kyunki wo
aasman ka pratibimb hai. Raman ne isse maanne se inkaar kar diya aur jahaz par hi
prayog shuru kar diye. Unhone sabit kiya ki paani khud neeli roshni bikharta
hai — samundar ka apna rang hai!
Isi disha mein aage badhte hue unhone 1928 mein wo khoj ki jise aaj
"Raman Effect" kehte hain — aur uske liye unhe 1930 mein
Nobel Prize mila. Wo vigyan mein Nobel paane wale pehle
eshiyai (Asian) vyakti the.
Aur ye khoj kisi mehnge videshi laboratory mein nahi, Kolkata ki ek chhoti si
laboratory mein hui thi — bahut hi saadharan upkaran ke saath. Isiliye har saal
28 February ko bharat "National Science Day" manata hai — usi din
Raman Effect ki ghoshna hui thi.
🧠 Apne Aap Ko Test Karo
🌇 Sky Explorer mein sooraj ko ghumao aur aasman ka rang badalte dekho!
Open Sky Explorer →