You are alone in a large, completely dark auditorium on Earth. What kind of telescope should I use from the other side of the auditorium to detect the electromagnetic radiation emitted by your body?
A) visible light
B) infra-red
C) ultra-violet
D) black light
E) no telescope will be effective if I am in a dark room

Question

Quizplus · Accepted Answer

In a completely dark environment, the only source of electromagnetic radiation would be the infrared radiation emitted by the human body. Using an infrared telescope would allow the observer to detect this radiation and locate the person in the auditorium.

You Are Alone in a Large, Completely Dark Auditorium on Earth