Why do black and white stripes turn?

What made the black and white stripes turn when we put a glass of water in front? The explanation for this phenomenon stems from what physical laws?

The change in speed has caused light waves to be diverted, or bent.

According to Popsci, when we look at the surrounding objects, light bounces off the object and goes to our eyes in a straight line. But when light waves have to travel through an environment thicker than air, they will move more slowly. In this case, the water in the glass cup obstructs the light wave.

The change in speed has caused light waves to be diverted, or bent. In physics, it is called light refraction . We have learned about this phenomenon in middle school. However, this is only half of the explanation. The glass is like a converging lens, in which all its surfaces are curved. When light passes through the cup, the curved shape forces the light to bend from all directions. The amount of "concentrated" water in the cup makes the curve become more curved.

Refractive light waves converge at a focal point, then they cross each other. This focus lies somewhere between our glass cup and our eyes. The image we see is created by light waves passing through each other. Because they travel in opposite directions, the reversal lines appear. Ignore the physical base, the image we see as being deceived. But remember that it is a real image.