Observers in the Nineteenth Century Reported Seeing Many Straight-Line Features

question 60

Multiple Choice

Observers in the nineteenth century reported seeing many straight-line features crisscrossing the surface of Mars and interpreted them to be canals constructed by intelligent beings. What is the MOST likely present-day explanation for these observations?

• A) The lines were rifts in the Martian surface at the boundaries of geological tectonic plates.
• B) The lines were linear, stationary cloud formations (mountain lee wave clouds) and weather fronts moving around with the planet.
• C) The lines were optical illusions caused by vague shadings on the planet's surface.
• D) The lines were groups of dark volcanoes similar to those of the Hawaiian Islands on Earth.

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Definitions:

Dependent Populations

Populations in which the members of one sample are related or matched to the members of the other samples.

Matched Pairs Experiment

An experimental design in which participants are paired based on certain criteria, and each pair is split between control and treatment groups for comparison.

Matched Samples

Pairs of samples that are intentionally matched or paired based on certain characteristics before conducting an experiment or analysis.

Independent Samples

Samples drawn from populations in such a way that the sample values selected from one population are not influenced by those selected from the other population.