Why Do Closer Objects Seem to Move Faster?

Have you ever noticed that objects moving towards or away from you seem to speed up as they get closer? Scientists have long known that the speed at which we perceive things moving on a flat plane can be affected by how fast they appear to be moving at our eyes and where they start from. But what about objects moving in depth? That's what researchers wanted to find out. They set up a special experiment with two tasks and five different moving objects. These objects moved towards or away from the participants, starting from different distances. Some started 20 centimeters away, others 60 centimeters, and so on. The participants had to choose which object they thought was moving faster. Guess what? They found that objects starting from 20 centimeters away seemed to move faster than those starting from 40 centimeters. And objects starting from 60 centimeters away seemed to move slower. This suggests that how fast we think something is moving in depth depends on how much it changes in size as it moves. The closer it starts, the faster it seems to move!