When a Sparkler Is Twirled Rapidly, People Perceive a Circle

question 10

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) due to its high intensity, we see the light from the sparkler for about a second after it goes out.
• C) the length of iconic memory (the persistence of vision) is about one-third of a second.
• D) Gestalt principles work to complete the circle in our minds.

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Definitions:

Expected Values

The mean of a probability distribution, representing the average outcome one can expect to see.

Null Hypothesis

A statement used in statistics that suggests there is no significant difference or effect, serving as the default assumption to be tested.

Chi-Squared Test

A statistical test used to determine whether there is a significant difference between the expected frequencies and the observed frequencies in one or more categories.

P-Value

A statistical measure that helps scientists determine the significance of their research results; a low p-value indicates strong evidence against the null hypothesis.