Giovanni was watching the night sky on a clear evening in November.He noticed that sometimes when he looked directly overhead he could detect a very faint star.A few minutes later,it seemed that the star had disappeared and then it "appeared" again.How would you describe the light from the star in this case

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Quizplus · Accepted Answer

The fact that Giovanni is able to detect the star at times and not others suggests that the light from the star is just at Giovanni's absolute threshold for light, meaning it is the minimum amount of light required for him to perceive it.

Giovanni Was Watching the Night Sky on a Clear Evening