One of the "Quiet" Bands in the Electromagnetic Spectrum Used

question 16

Multiple Choice

One of the "quiet" bands in the electromagnetic spectrum used for SETI is the so-called "water hole" between about 10³ and 10⁴ MHz. What is the principal source of the natural signals in this frequency band?

• A) emissions from the water molecule
• B) emissions from oxygen molecules
• C) cosmic microwave background radiation
• D) radio emission from terrestrial sources

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Definitions:

Truth Values

The valuation in logic assigned to statements indicating whether they are true or false.

Short Form Truth Table

A method used for checking the validity of logical expressions more efficiently by focusing only on the rows of a truth table that could potentially falsify the expression.

Atomic Sentences

Simple statements that do not contain any other statements as parts and express a complete thought.

Truth Values

The attribution of truth to the propositions in logic, typically categorized as either true or false.