The state of maintaining a stable internal environment regardless of changing external conditions is called
.

There are different types of observers. Casual observers differ from scientific observer. Seeing and observing are two different things. Not that everybody seeing is actually observing the thing.
A casual observer just sits back and watch for something to happen while a scientific observer comes up with some hypothesis to work on it.
You should always suppose to have safety goggles because you don't want to hurt your eyes