A scientific survey at Gyanvapi, its limits”

Source: The post is based on the article “A scientific survey at Gyanvapi, its limits” published in “The Hindu” on 14th August 2023.

Syllabus: GS1- The salient aspects of Art Forms, Literature and Architecture from ancient to modern times.

News: The article discusses the Supreme Court of India’s order for a non-invasive survey of the Gyanvapi mosque to check if it’s built over a temple. It explains the science behind the methods used, their accuracy, and potential errors, emphasizing the sensitivity and significance of the findings due to the emotional and political implications involved.

What scientific methods are employed for a non-invasive survey of the Gyanvapi mosque?

Geophysical Mapping for Archaeological Prospecting: Techniques are adapted from geophysical mapping, which can be either:

Active Methods: Inject energy into the ground and measure the response. Examples include seismic and electromagnetic techniques.

Passive Methods: Measure existing physical properties like magnetometry and gravity surveying.

Ground-Penetrating Radar (GPR): ASI plans to use GPR to create a 3-D model of buried structures. It sends a radar impulse and records return signals from subsoil contrasts.

Data Analysis: Acquired data is processed to determine physical parameters. This requires a strong understanding of physical processes and advanced software.

Modeling: The archaeological object is simplified into a representative model with defined parameters for analysis.

What limitations exist in the scientific methods used for a non-invasive survey of the Gyanvapi mosque?

Ambiguity in Interpretation: Different earth materials can have similar physical properties, leading to uncertain results.

False Imaging with GPR: As the radar beam spreads in a cone shape, objects can reflect parts of the beam prematurely, creating incorrect images.

Data Limitations: Ideal methods expect infinite, error-free data. However, real data is limited and contains measurement errors.

Reconstruction Difficulties: Geophysical tools might not always perfectly reconstruct target images.

Contradictory Interpretations: Even sophisticated systems can have different interpretations, as seen with lunar penetrating radar systems.

Reliance on Supplementary Info: Due to data limitations, extra information is often added, which might lead to inaccurate results.