how long has the sky been mapped out for?

Question

and why do the stars that are on the the map not changed by now?Also if the closest star is 4 light years away from earth the light we see is at least 4 years old therefore why has it not changed

Answer 1

Since the dawn of civilization, and possibly longer. The ancient Egyptians and Babylonians named and drew depictions of the constellations. The Egyptians knew the positions of some stars well enough to align features of their tombs to them. Some stone-age cave art appears to depict familiar asterisms.

The oldest star atlas in existence is that of Claudius Ptolemy, from the second century, but he referenced an older one from the second century BC, by Hipparchus.

As far as stars not changing, they do, but given that they burn for billions of years, most of them change very slowly. There are many variable stars, however, that change either cyclically or irregularly.

Because of how far away they are, the apparent motion of stars is very slow. None of them move fast enough to make a noticeable difference in position to the naked eye over the course of a lifetime. But many of the nearer stars move fast enough for the movement to be measurable over time (years, not hours) through a telescope. Come back in a hundred thousand years and you will notice some differences. Most of the stars we can see now will still be there, though Eta Carinae, Betelgeuse, and some of the other giant stars will probably be gone, and a few other stars will have evolved into giants. But you will also see that the familiar constellations have changed shape due to the motions of their stars.

Answer 2

The Greeks, Babylonians, and several other civilizations made the first maps.

As for Proxima Centauri. "Also if the closest star is 4 light years away from earth the light we see is at least 4 years old therefore why has it not changed". Your question is irrelevant because your question is based on false assumptions. We know Proxima Centauri changes a lot. It's classified as a flare star, a type of star that has very strong solar flares for it's size and type. It changes dynamically and without predictability.

Cheers ^_^

Answer 3

Some of the stars have moved from the positions shown on the early maps. Although most are too far away to show any movement, in 1718, Edmund Halley noticed that some of the stars plotted by Ptolemy in the 2nd century AD had moved. He was the first person to discover what's now called the "proper motion" of stars.

Answer 4

The sky has been crudely mapped since the time before the Mesopotamians, an stars change variables all the time as for the one that you refer to, I guess that you will have to wait another 4 years to find out.

Answer 5

in the book of Job (Job 38: 31-32) the constellations the pleiades, orion, and the big dipper(the bear) are mentioned. also, in Job 38: 7 it is mentioned that the stars sang----now science says that each star has it's own sound frequency. fascinating huh?