When a Sparkler Is Twirled Rapidly, People Perceive a Circle

question 31

Multiple Choice

When a sparkler is twirled rapidly, people perceive a circle of light. This occurs because

• A) the trail you see is caused by sparks left behind from the sparkler.
• B) longer light wavelengths from the sparkler produce a visual echoic effect.
• C) the length of iconic memory is about a fraction of a second.
• D) Gestalt principles work to complete the circle in our minds.

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Definitions:

Secondary Alcohol

An organic compound where the hydroxyl (—OH) group is bonded to a carbon atom that is attached to exactly two other carbon atoms.

T-butyl Alcohol

A common name for tert-butyl alcohol, an organic compound with the formula (CH3)3COH, used as a solvent and in the production of other chemicals.

Ethanol

A two-carbon alcohol with the formula CH3CH2OH, commonly used as a solvent and in alcoholic beverages.

Cyclopentanol

An organic compound characterized by a five-membered ring structure bonded to a hydroxyl group, used in various chemical syntheses.