Chapter 34, Problem 3TS

To determine

Whether it is possible for two galaxies with stars evenly distributed to pass right through each other.

Answer to Problem 3TS

Yes, it is possible for two galaxies with stars evenly distributed to pass right through each other.

Explanation of Solution

A galaxy is the combination of various matters such as dust, gas and billions of stars. All the matters that are present in the galaxy are kept together by the force of gravity.

In previous questions, the surface area density of the star is $12.7\text{stars}/\text{light}{\text{year}}^{\text{2}}$. This value is very small. It shows that there is a lot of empty space that allow diffusion of stars of two different galaxies. Hence, two galaxies with this distribution can pass right through each other.

If the average amount of space around a single star is 1 star/312 million ${\text{AU}}^2$, then it is possible for two galaxies with stars evenly distributed to pass right through each other.

Conclusion:

Therefore, it is possible for two galaxies with stars evenly distributed to pass right through each other.