Chapter 13, Problem 36R

To determine

To Explain: It would be easier to make a concave mirror for a reflecting telescope than the objective lens for a refracting telescope.

Explanation of Solution

Introduction:

A reflector or a reflecting telescope is that which uses a single or a pair of spherical mirrors to create an image. While refracting microscope uses an objective lens and an eyepiece to form the image.

A refracting telescope consists of two lenses basically, which is used to generate the image of a distant object. Out of the two lenses, the larger one is the objective lens.

The failure of the lens to focus all colors at one point is called chromatic aberration which can only be caused in the lens so the concave mirrors are much more reliable and cheaper to build on a large scale. Also, the lens in the larger telescope can bulge downwards due to its own weight. Hence, it would be easier to make a concave mirror for a reflecting telescope.

Conclusion:

Hence, the concave mirrors are easier to build than the objective lens.