Question

Telescopes that observe nonvisible types of light work on the same principles as visible telescopes, but they might require different technologies. For instance, instead of lenses or mirrors, a radio telescope (such as the one in the figure) uses technology similar to the television satellite dish you might install on your roof. As with visible light telescopes, bigger radio telescopes yield greater light-gathering power and better angular resolution.

However, the angular resolution (θ) of a telescope also depends on the wavelength of light (λ) based on the following equation, where D is the diameter of the telescope, and the resolution is in units of arcseconds (when D and λ have the same units).
θ=2.06×105(λD)

If there were two telescopes with the same diameter, but one is a visible light telescope and the other a radio telescope, how would the resolution of the images from each telescope compare? The wavelength of visible light is several hundred nanometers (1 nanometer = 10^–9 meters), and radio can be several centimeters (1 cm = 10^–2 meters) or several meters.

Select one:

a. There is not enough information to answer this question.

b. The radio telescope would have a much better angular resolution.

c. The radio telescope would have a much worse angular resolution.

d. The angular resolution of the two telescopes would be about the same.

Answer 1