ScientificIrfan

          Atmospheric Electricity: The earth's surface has a surface charge density of about 1nCm^-2.There is a corresponding electric field of about 100V/m in the atmosphere above the earth's surface (in the downward direction).So,the electric potential increases by about 100V as one move up by 1m.But the magnitude of the electric field gradually decreases as one move up. At about 50km above the earth's surface,the field is negligible.Thus, the potential difference between the earth's surface and the top of the atmosphere is about 400kV.  The atmosphere contains a large number of positive and negative ions. Their main sources are cosmic rays which come from the solar system and the interstellar bodies like stars and galaxies. The cosmic rays contains lots of protons,neutrons, electrons, neutrino and other particles and radiation as well. Dust particles also become charged due to friction when they move through the air. Because of the electric field in the a

Brownian Motion:  The  nature is full of beauty and elegance. From your daily life experiences, you are perhaps most familiar with 'motion'. The motion of your bicycle 🚲, the motion of the earth 🌎, the Sun,stars, galaxies, vehicles, aeroplane,etc. is the eternal part of nature that makes the universe exist. Everything is eternally in motion. A basic question that may arise in your mind is that what constitutes this eternal movement of these stuff in nature around us? That's what I have been fascinated to write this article!      Brownian Motion: In 19th century,there were enough experimental data to validate the kinetic theory of gases but the existence of atoms or molecules were still a mystery for physicists because there were no any direct experimental evidence for them. Most physicists thought that the molecules are alive and hence they have ability to move and perform various movements.But this idea had no any experimental support. In 1827,a botanist name