Question

If you were to divide the presentday universe into cubes whose sides are 10 million lightyears long, each cube would contain, on average, about one galaxy similar in size to the Milky Way. Now suppose you travel back in time, to an era when the average distance between galaxies is 0.26 of its current value, corresponding to a cosmological redshift z = 2.7. How many galaxies similar in size to the Milky Way would you expect to find, on average, in cubes of that same size?

Answer 1

Answer:

Explanation:

density of galaxies would be $\frac{1}{0.27^3}$ times higher which is equal to 50.81.

It means  in a cube that today contains one galaxy the size of the Milky Way, we would instead find 50.81 galaxies this size.

You can round this off to 52