{"knowledge_schema": {"broad_category": "Astronomy \u2192 Cosmology \u2192 Redshift and Spectroscopy", "refinement": "This problem involves understanding the relationship between redshift and the observed wavelengths of light, particularly in relation to the Lyman alpha transition of neutral hydrogen.", "specific_scope": "The focus is on determining the minimum redshift necessary for the Lyman alpha wavelength (1216 Angstroms) to be shifted into the optical range detectable by ground-based telescopes.", "goal": "Calculate the minimum redshift required for the Lyman alpha line to be observed at a longer wavelength due to the expansion of the universe."}, "summary": "This problem pertains to the field of astronomy, specifically the concepts of redshift and spectroscopy. It requires understanding how the expansion of the universe affects the wavelengths of light emitted by neutral hydrogen. The task is to determine the minimum redshift needed for the Lyman alpha wavelength (1216 Angstroms) to be shifted into a range that can be observed by optical ground-based telescopes. The answer is found to be a redshift of 1.9, indicating the necessary shift for detection."}