Context:
Suspended from the ceiling of the Central Foyer of India’s new Parliament building is a Foucault pendulum that all but touches the floor as it rotates on its axis. The pendulum hangs from a skylight at the top of the Constitution Hall, and signifies the “integration of the idea of India with the idea of the cosmos”.
Relevance:
GS III: Science and Technology
Dimensions of the Article:
- About Foucault’s Pendulum
- Pendulum Motion at Different Latitudes
- Educational Significance
About Foucault’s Pendulum
- Foucault’s pendulum is an experiment created by Leon Foucault in 1851.
- It provides direct visual evidence of the Earth’s rotation on its axis.
The Largest Foucault’s Pendulum in India:
- Created by the National Council of Science Museum (NCSM) in Kolkata.
- Stands 22 meters tall and weighs 36 kg.
- Installed at the new parliament building, it is the largest pendulum of its kind in India.
- A prototype was developed and tested at Science City, Kolkata, to ensure safety and functionality.
Experimental Setup:
- A heavy object is suspended from a height with a string, allowing it to swing freely.
- The pendulum’s initial motion can be in any direction, such as north-south.
- Over time, the pendulum changes its orientation gradually, e.g., shifting to east-west.
Ground Rotation, Not Pendulum:
- The apparent change in the pendulum’s motion is due to the rotation of the ground beneath it.
- Observers on the ground, rotating with the Earth, can observe the pendulum’s change in orientation.
Pendulum Motion at Different Latitudes:
At the north and south poles:
- When aligned with the Earth’s axis of rotation, the pendulum’s back-and-forth motion returns to its original plane in precisely 24 hours.
- It gradually shifts from north-south to northeast-southwest and east-west before returning to its original orientation.
At other latitudes:
- The pendulum takes longer to return to its original orientation.
- The pendulum is not aligned with the Earth’s axis, causing deviations in its swing.
At the equator:
- The pendulum remains perpendicular to the axis of rotation.
- It does not change its orientation, showing no deviation from its original course.
Educational Significance:
- Foucault’s pendulum is a common feature in science museums worldwide, designed to educate children about the Earth’s rotation.
- It helps people understand concepts such as the Earth’s spherical shape and its rotation on the axis.
- Experiments like Foucault’s pendulum embody the spirit of scientific inquiry and promote scientific temper.
-Source: Indian Express
