Air is certainly the most important thing in our life. In fact that’s what keeps us alive. With air, we maintain certain pressure in the tires of our vehicles to keep ourselves moving. We fill our birthday balloons with air. We fly airplanes in air using aerodynamic principles. It helps us burning various fuels for numerous uses such as for cooking and generating electricity. Needless to say, air has countless uses in our daily life.
Yet air is something that we cannot see. Let’s understand why we cannot see?
In order for us to see something, it must emit or reflect visible light.
Air is a mixture of gases. It consists of 78% nitrogen, 21% Oxygen and 1% of other traces of gases.
Since the molecules of these gases are much smaller than the wavelength of visible light which is between 380-700 nm hence they do not reflect or scatter light.
Furthermore since air exists in gaseous form and in which the molecules are widely separated from each other. That means air is not dense enough to block or scatter the light significantly.
It is due to these reasons we don’t see air.