The most active galactic nuclei are usually found at large distances from us; relatively few nearby galaxies have active galactic nuclei. What does this imply?.

This implies Active galactic nuclei tend to become less active as they age.This radiation is produced by the action of the central supermassive black hole. A typical quasar is very far away, allowing us to see how galaxies have evolved in the past. A very bright and compact core with a non-stellar spectrum can be brighter than the entire host galaxy.Hubble's law explains that the reason most galaxies are moving apart is that the universe as a whole is expanding. Astronomers can use what is known as a change in surface brightness along with the galaxy's color to calculate its distance from Earth. Most galaxies measured this way are millions of light years away. Active solar heating. A solar energy collection system in which a series of collectors collects solar energy and a pump or fan distributes the collected heat.Learn more about Active galactic nuclei here:-https://brainly.com/question/28476282#SPJ4