For over a century, astronomical consensus held that the solar corona was a quiescent, isothermal outer envelope of the Sun, observable only during total solar eclipses. This view was challenged in the late nineteenth century by George Ellery Hale’s development of the spectroheliograph, an instrument capable of imaging the Sun in monochromatic light. Early monochromatic photographs revealed dynamic, complex structures in the lower atmosphere, prompting Hale to hypothesize that solar activity was driven by strong localized magnetic fields rather than static thermal equilibrium. Critics initially dismissed Hale’s monochromatic features as instrumental artifacts caused by diffraction anomalies within the spectroheliometer's dual-slit apparatus. To counter this critique, Hale conducted comparative observations using independent spectroscopic techniques, ultimately demonstrating that the observed monochromatic vortex patterns correlated precisely with Zeeman splitting in sunspot spectra. This empirical convergence not only vindicated the spectroheliograph but also reoriented solar physics from passive coronal mapping toward the active electrodynamics of solar plasma.
Which of the following best describes the rhetorical function of the highlighted sentence ("To counter this critique...") in the passage?
- AIt presents the primary empirical evidence that initially led researchers to question the traditional isothermal model of the solar corona.
- BIt outlines a theoretical compromise proposed to reconcile the static thermal model with newly recorded magnetic phenomena.
- It describes a specific methodological procedure undertaken to neutralize a skeptical challenge to a novel observational finding.Cevap
- DIt demonstrates that the diffraction anomalies identified by critics were actually inherent features of all solar observations.
- EIt serves to qualify Hale's original hypothesis regarding localized magnetic fields by introducing an alternative explanation for sunspot spectra.