Why Is It That We Rely Upon the 21-Cm Line

question 180

Multiple Choice

Why is it that we rely upon the 21-cm line associated with the spin flip in hydrogen and not the more familiar hydrogen Balmer lines to gather information from the far side of the galactic plane?

• A) The Balmer lines are associated with neutral hydrogen, and most of the hydrogen we need to observe is molecular hydrogen.
• B) The Balmer lines are associated with molecular hydrogen, and most of the hydrogen we need to observe is neutral hydrogen.
• C) The Balmer lines are in the visible and ultraviolet regions of the spectrum, and these do not penetrate the gas and dust clouds easily.
• D) Photons released in the spin flip transition have much more energy than those that come from the Balmer transitions.

Grasp the basic principles of molecular self-organization and its role in the formation of cellular structures.

Recognize the importance of catalysts in the early history of life and modern cellular metabolism.

Comprehend the central role of RNA in the origin and evolution of life.

Identify the conditions that might have favored the polymerization of biomolecules on early Earth.

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Definitions:

Cause

The reason or motive behind an action or situation, often examined in legal contexts to establish causality or justification.

Disparate Impact

A theory in employment law where practices may be considered discriminatory if they have a disproportionate adverse effect on members of a minority group, even if unintentional.

Civil Rights Act

A landmark piece of legislation in the United States that outlaws discrimination based on race, color, religion, sex, or national origin.

Business Necessity

A justification for implementing certain policies or actions as essential for the operation of a business.