In 1964, radio astronomers Arno Penzias and Robert Wilson were using a sensitive horn antenna at Bell Labs to detect faint radio waves bounced off Echo balloon satellites. To their frustration, they encountered a persistent, low-frequency background noise that interfered with their measurements. This uniform static, which did not vary regardless of where they pointed the antenna or the time of day, was far more intense than expected. Suspecting the interference was terrestrial in origin, they meticulously cleaned the horn, even removing nesting pigeons and their debris. However, the signal remained unchanged. Only after consulting with theoretical physicists at Princeton did they realize that this ubiquitous hiss was not equipment malfunction, but rather the cosmic microwave background radiation, the residual heat left over from the early universe's rapid expansion.
According to the passage, the text indicates that the background static detected by Penzias and Wilson had which of the following characteristics?
- constant level that remained unaffected by the antenna's direction or the hour of the day.Cevap
- Btendency to fluctuate in strength depending on whether the antenna was aimed at Echo satellites.
- Cterrestrial origin, which was confirmed when cleaning the antenna failed to change the signal.
- Dsudden increase in intensity when the antenna was directed toward Princeton University.