Archaeology/Ancient buildings and cities
I love watching shows where they are exploring ancient cities es-pecially Aztec and Inca sites. But as the narrator wanders through it, they will point out buildings and say, "this was a palace", "this was the temple of the sun, etc. What Id like to know is how can they be sure WHAT it was used for? I am sure that a lot of modern buildings in ruins would look like palaces or even accidentally line up with the sun or moon. I am just wondering how and who decides this?
You are fundamentally right. How can we interpret these things with any kind of certainty. Well, there are several factors that allow us to make good educated guesses. First of all, if it is the largest "house" in the community then chances are, it was occupied by someone important. If the other structures were made of wood, and this one of stone, then again, a whole lot more work went into its construction then the wooden ones and probably was occupied by someone important. If all of the houses were built of brick and stone, then again the largest would probably belong to the head "person" who can demand the assistance of the people to build such a grand structure. When it comes to a religious structure, then chances are, you will want your people to be able to join in on the ceremonials all at one time thus large interior spaces would have been important, thus dictating the size yet again.
Alignment to the sun, moon, stars etc.. can be easily seen and "studied" by observation. Even churches today are alined astronomically and, like ancient ceremonial sites are built of stone and can "contain" many people. In most of the world, the palace of the king or queen or emperor are large stone structures when the subjects live in wooden homes or smaller stone structures.... So it is part of a pattern of how we live. These kinds of human patterns can be traced back with great certainty to the time of the Romans, Chinese and others so, it makes some amount of sense that it goes back to much earlier times.
But, we can and do make mistakes. We can interpret things incorrectly but through excavation, study of the remains found during excavation and understanding as much as possible, we can often come to the recognition that what we first thought was the case is wrong and we now need to rethink and reevaluate our previous conclusions. This is happening at Stone Henge currently as we learn that it is only a part of a much larger complex and system.
There is a wonderful book that I use when I teach. I use it as a way of warning my archaeology students that making assumptions is a dangerous thing to do and that in doing so, it can lead one down the wrong road to interpretation. The book is the Motel of the Mysteries. It is quite humorous but carries an important message.
I hope this explanation is of help and value. If you have more questions, please don't hesitate to ask.