Chapter 23, Problem 1CC

To determine

When a “spiral nebula” is observed closer than some of our galaxy, would it be an evidence in favor of Shapley’s argument or Curti’s argument.

Answer to Problem 1CC

Solution:

The closeness of “spiral nebula” as compared to other stars in our galaxy will give evidence that supports Shapley’s argument.

Explanation of Solution

Introduction:

Spiral nebulae: Spiral nebulae are the clouds that are spiral in shape, which were later found to be galaxies themselves. These lie outside the region of the Milky Way.

Explanation:

The astronomical community was divided into two groups on the basis of nature of the spiral nebula. In April 1920 two different ideas were presented in front of the National academy of science in Washington D.C.

On one side there was a scientist named Harley Shapley, who was from the Mount Wilson Observatory. According to Shapley, the size of the spiral nebula was relatively small and the nearby objects scattered around our galaxy.

On the other hand, was Heber D. Curtis from the University of California Lick laboratory, who said that each of these spiral nebulae is a rotating system of stars similar to our galaxy.

Conclusion:

From the above observation, it can be concluded that if the spiral nebula is closer than some of the starts, then it would give evidence in favor of Harley Shapley’s argument.