Diffusion is the movement of a substance (majorly liquids and gases) from a region of high concentration to a region of low concentration. Liquid and gases excluding solids can undergo diffusion because of their ability to move randomly. Diffusion is driven by a gradient in concentration.
For example gases can easily diffuse quickly and easily into another gas, because of its ability to move randomly. The foul air from the back room (higher concentration) was able to quickly spread into the clean air at the front row (low concentration) by diffusion
the main idea is that bikes have a lot to do with society the problem is that most people don't think of the bicycles so they don't make the lanes for them and the solution is make more bike lanes because they are a main source of transportation
