How is dust useful to us?

Most of the people think that dust is very harmful to us. But this is not true. Dust also is very useful to us.Before we go through the uses of dust, it is essential to know as to what dust is and how it is formed?

Every solid substance is composed of very small particles.
When these small particles of matter are scattered, they become dust particles. For example, if we go on breaking a brick or a stone into small pieces, they will turn into small particles. These particles get mixed with air and are called dust particles. The air carries dust particles from one place to another. There are different ways by which dust is formed. When solids break, dust is formed. Smoke generated by the burning of coal, wood, petrol etc. also produces dust. Dust particles also come from dead plant and animal matter, sea salt, desert, volcanic sand etc. The particles of the earth's surface also fly in air in the form of dust.
The biggest use of the dust particles is that they help in the formation of the rains. The water-vapour in the clouds condense on the dust particles in the form of water-drops. These drops fall on the earth as rains. The absence of dust particles can delay the rain. Likewise, mist, fog etc. are also formed due to the presence of dust particles.
The dust particles present in atmosphere reflect the sun-rays in all directions. Due to this reflection, even after the sun set, there is not complete darkness for one to two hours. The appearance of red colour at the sunrise and sunset is due to dust particles and water vapours. The beautiful rays of the sun seen in the twiligt is also due to dust particles. Thus we see that the dust particles which are regarded as useless by people are really very useful.