Why Is the Rainbow Curved ? ā§°āĻžāĻŽāϧ⧇āύ⧁ āĻ•āĻŋāϝāĻŧ āĻŦ⧇āρāĻ•āĻž āĻĻ⧇āĻ–āĻž āϝāĻžāϝāĻŧ ? : hysics (Light / Optics) : āĻĒāĻĻāĻžā§°ā§āĻĨāĻŦāĻŋāĻœā§āĻžāĻžāύ (āĻĒā§‹āĻšā§° / āĻ…āĻĒā§āϟāĻŋāĻ•ā§āϏ)


A rainbow is a natural spectrum of seven colors seen in the sky after rain. It forms when sunlight passes through raindrops. The light bends (refraction), reflects inside the drop, and splits into different colors (dispersion). These colors appear as a curved arc in the sky.


ā§°āĻžāĻŽāϧ⧇āύ⧁ āĻšā§ˆāϛ⧇ āĻŦā§°āώ⧁āĻŖā§° āĻĒāĻŋāĻ›āϤ āφāĻ•āĻžāĻļāϤ āĻĻ⧇āĻ–āĻž āĻĒā§‹ā§ąāĻž āϏāĻžāϤāϟāĻž ā§°āϙ⧰ āĻĒā§ā§°āĻžāĻ•ā§ƒāϤāĻŋāĻ• āĻŦā§°ā§āĻŖāĻžāϞ⧀āĨ¤ āĻ¸ā§‚ā§°ā§āϝ⧰ āĻĒā§‹āĻšā§° āĻĒāĻžāύ⧀⧰ āĻŦāĻŋāĻ¨ā§āĻĻ⧁āϤ āĻĒā§ā§°ā§ąā§‡āĻļ āϕ⧰āĻŋ āĻŦ⧇āρāĻ•āĻžāχ āϝāĻžāϝāĻŧ, āĻĒā§ā§°āϤāĻŋāĻĢāϞāĻŋāϤ āĻšāϝāĻŧ āφ⧰⧁ āĻŦāĻŋāĻ­āĻŋāĻ¨ā§āύ ā§°āĻ™āϤ āĻŦāĻŋāĻ­āĻ•ā§āϤ āĻšāϝāĻŧ, āϝāĻžā§° āĻĢāϞāϤ āφāĻ•āĻžāĻļāϤ āĻŦ⧇āρāĻ•āĻž āϧāύ⧁āϕ⧰ āĻĻ⧰⧇ āĻĻ⧇āĻ–āĻž āϝāĻžāϝāĻŧāĨ¤


• A rainbow forms when sunlight enters raindrops. : āϝ⧇āϤāĻŋāϝāĻŧāĻž āĻ¸ā§‚ā§°ā§āϝ⧰ āĻĒā§‹āĻšā§° āĻŦā§°āώ⧁āĻŖā§° āĻĒāĻžāύ⧀⧰ āĻŦāĻŋāĻ¨ā§āĻĻ⧁āϤ āĻĒā§ā§°ā§ąā§‡āĻļ āϕ⧰⧇, āϤ⧇āϤāĻŋāϝāĻŧāĻž ā§°āĻžāĻŽāϧ⧇āύ⧁ āϏ⧃āĻˇā§āϟāĻŋ āĻšāϝāĻŧāĨ¤



• The light bends inside the raindrop (refraction). : āĻĒā§‹āĻšā§° āĻĒāĻžāύ⧀⧰ āĻŦāĻŋāĻ¨ā§āĻĻ⧁⧰ āĻ­āĻŋāϤ⧰āϤ āĻŦ⧇āρāĻ•āĻžāχ āϝāĻžāϝāĻŧ (refraction)āĨ¤


• The light then reflects inside the drop. : āϤāĻžā§° āĻĒāĻŋāĻ›āϤ āĻĒā§‹āĻšā§° āĻŦāĻŋāĻ¨ā§āĻĻ⧁⧰ āĻ­āĻŋāϤ⧰āϤ āĻĒā§ā§°āϤāĻŋāĻĢāϞāĻŋāϤ āĻšāϝāĻŧ (reflection)āĨ¤


• The light splits into seven colours (dispersion). : āĻĒā§‹āĻšā§° āϏāĻžāϤāϟāĻž ā§°āĻ™āϤ āĻŦāĻŋāĻ­āĻ•ā§āϤ āĻšāϝāĻŧ (dispersion)āĨ¤


Raindrops are round in shape. : āĻŦā§°āώ⧁āĻŖā§° āĻĒāĻžāύ⧀⧰ āĻŦāĻŋāĻ¨ā§āĻĻ⧁āĻŦā§‹ā§° āĻ—ā§‹āϞāĻžāĻ•āĻžā§° āĻšāϝāĻŧāĨ¤


• Because light leaves many round drops at different angles, we see a curved arc. : āĻ—ā§‹āϞāĻžāĻ•āĻžā§° āĻŦāĻŋāĻ¨ā§āĻĻ⧁⧰ āĻĒā§°āĻž āĻĒā§‹āĻšā§° āĻŦāĻŋāĻ­āĻŋāĻ¨ā§āύ āϕ⧋āĻŖāϤ āĻ“āϞāĻžāχ āφāĻšā§‡, āϏ⧇āϝāĻŧ⧇ ā§°āĻžāĻŽāϧ⧇āύ⧁ āĻŦ⧇āρāĻ•āĻž āĻĻ⧇āĻ–āĻž āϝāĻžāϝāĻŧāĨ¤


Key Point: Rainbow appears curved because light leaves round raindrops in an arc.


āĻŽā§‚āϞ āĻ•āĻĨāĻž: ā§°āĻžāĻŽāϧ⧇āύ⧁ āĻŦ⧇āρāĻ•āĻž āĻĻ⧇āĻ–āĻž āϝāĻžāϝāĻŧ āĻ•āĻžā§°āĻŖ āĻĒā§‹āĻšā§° āĻ—ā§‹āϞāĻžāĻ•āĻžā§° āĻĒāĻžāύ⧀⧰ āĻŦāĻŋāĻ¨ā§āĻĻ⧁⧰ āĻĒā§°āĻž āϧāύ⧁āĻ• āφāĻ•āĻžā§°āϤ āĻ“āϞāĻžāχ āφāĻšā§‡āĨ¤