64th BPSC (Pre) 2018

Ancient Indian Science

Authentic Past Paper Standard Evaluation

Who among the following was the first to explain that the rotation of the earth on its own axis accounts for the daily rising and setting of the sun?

Solution & Analysis

Answer: A

Concept Ancient Indian astronomy reached a peak of scientific rationalism during the Gupta era, producing theories that predated similar European findings by over a millennium.

Explanation Aryabhatta was the first to state that the Earth is spherical and rotates on its own axis. He detailed this in his 5th-century treatise, the *Aryabhatiya*.

Logical Breakup
Logic 1: He explained that the apparent movement of the stars and sun is due to the Earth's rotation, much like trees seem to move for someone in a boat.
Logic 2: He also calculated the Earth's circumference and correctly identified the causes of lunar and solar eclipses as shadows.
Logic 3: While Brahmagupta (C) and Varahamihira (D) were great astronomers, they followed Aryabhatta's pioneering work in these specific rotational concepts.

Active Recall

Question

How did Aryabhatta explain the setting and rising of the sun?

Answer

He explained it as an optical illusion caused by the Earth rotating on its own axis toward the east.

Core Insight

Aryabhatta's ability to distinguish between apparent motion and actual motion marks him as a revolutionary thinker in global scientific history.