Question

We can study how galaxies evolve because ______.A) Galaxies are transparent to visible light.B) We are really smart astronomers.C) We can watch as they interact in real time.D) The farther away we look, the further back in time we see.

Answer 1

Galaxies evolve in a manner that can be studied because looking at more distant galaxies equates to looking further back in time due to the finite speed of light. Modern telescopes allow us to observe very young galaxies and analyze their redshifts, reconstructing their developmental history.

Step-by-step explanation:

We can study how galaxies evolve because the farther away we look, the further back in time we see. This is due to the finite speed of light and the vast size of the universe acting as a cosmic time machine, allowing us to observe distant galaxies as they were billions of years ago. With sophisticated tools like large telescopes and sensitive detectors, astronomers today can obtain images and spectra of very distant, faint galaxies. By studying these galaxies at various cosmic distances and look-back times, we can piece together the evolutionary timeline of galaxies from their 'infancy' to 'adulthood' in the 13.8-billion-year-old universe.

Advanced technologies and long exposure imaging from observatories such as the Hubble, Spitzer, and giant ground-based telescopes enable us to detect very faint and young galaxies. The redshift of the light from these galaxies offers further information on their movement and distance, which is integral in estimating the age of the universe and understanding galactic evolution.

Answer 2

We can study how galaxies evolve because the farther away we look, the further back in time we see.

Answer: Option D

Step-by-step explanation:

As the galaxies are located far away from us and also as per the broad band theory, these galaxies are spreading as the time goes. So as time passes, the galaxies are moving further light years away.

So depending upon the time taken for the light waves to reach Earth from these galaxies will state the time they have evolved. So the farther or more lately the light reaches the earth surface, the further time back we can see its evolution. Thus option d is correct choice.