Why in the News?
NASA scientists have proposed using quantum technology to study gravitational changes on Earth by deploying a quantum gravity gradiometer (QGG) on a satellite in low-Earth orbit.
About Gravity Gradiometer & Quantum Gravity Gradiometer (QGG):
- A gravity gradiometer measures small variations in gravitational force over short distances.
- How It Works: It detects differences in the acceleration of falling objects, indicating the density of materials below the surface, such as hydrocarbon deposits or geological structures.
- Applications:
- Oil Exploration: Detects underground hydrocarbon deposits by measuring gravitational differences.
- Geological Studies: Used to explore subterranean features like minerals and fault lines.
- A Quantum Gravity Gradiometer (QGG) uses quantum technology to achieve much higher precision than traditional gravity gradiometers.
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- How It Works: Atoms are cooled to near absolute zero and manipulated with lasers. The phase shifts of these atoms, proportional to gravitational force, detect tiny changes in gravitational acceleration.
- It can detect changes as small as 10^-15 m/s² over just 1 meter, offering much finer measurements than traditional instruments.
- Specifications: Weighs 125 kg, has a volume like a 250-liter oil drum, and consumes 350 watts of power (comparable to an older Intel CPU).
Applications of QGG in Space:
- Studying Gravitational Variations: Measures small changes in Earth’s gravitational field, aiding climate change studies, such as melting ice caps and shifting water reserves.
- Earth’s Gravitational Field Mapping: Improves understanding of Earth’s internal structure and seismic activities.
- Dark Matter Research: Provides insights into dark matter by detecting gravitational anomalies.
- Satellite Navigation: Enhances space navigation and satellite positioning.
- Mapping Underground Features: Used to map structures like mineral deposits and fault lines.
- Security: Detects underground structures like military bunkers and natural disasters, offering valuable security information.
[UPSC 2003] If the radius of the Earth were to shrink by one per cent, its mass remaining the same, the value of ‘g’ on the Earth’s surface would:
Options: (a) Increase by 0.5% (b) Increase by 2% (c) Decrease by 0.5% (d) Decrease by 2% |
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