Answer:
You are basically moving your hand. Moving your hand muscle.
Explanation:
Refraction is the change in the direction of the wave passing from one medium to another.
The change in the direction of the propagation of any wave is due to the different speed at different points.
A far away object appears closer and a small object appears larger.
Take an example. Suppose, an object lies in water.
A far away object appears closer. The angle from which the rays of light reach the observer is larger than the angle that it makes in air.
This makes the angular size larger to the observer's eye which makes the object look larger relative what it looks in air. Similar but vice versa condition occurs in the case when a small object appears larger.
In archaeology, rock art is human-made markings placed on natural stone; it is largely synonymous with parietal art. A global phenomenon, rock art is found in many culturally diverse regions of the world. It has been produced in many contexts throughout human history, although the majority of rock art that has been ethnographically recorded has been produced as a part of ritual. Such artworks are often divided into three forms: petroglyphs, which are carved into the rock surface, pictographs, which are painted onto the surface, and earth figures, formed on the ground. The oldest known rock art dates from the Upper Palaeolithic period, having been found in Europe, Australia, Asia and Africa. Archaeologists studying these artworks believe that they likely had magico-religious significance.