Of diffusion and drift

Aug 29, 2010, 12.00am IST
G S Tripathi.

Diffusion is the law of nature. It takes place when there is inequality and non-uniformity. Since our world has plenty of the above traits, diffusion is bound to happen. However, it is not free from obstructions; it has to overcome barriers that oppose diffusion.

Consider the diffusion of knowledge. Knowledge developed at one place must diffuse to places devoid of it. This helps its spread and contributes to its growth. Similarly, wealth created at one place must also diffuse to places where it is absent. In the process, equilibrium is maintained, which contributes to stability of the system.

Society that jealously guards its wealth and knowledge, without making these available to others is bound to disintegrate. Strong isolated places of affluence do not serve the interest of humankind. Diffusion is a spontaneous process.

In the Bhagavad Gita, the cosmic form visualised by Arjuna of the Supreme Being seems infinite. It is the diffusion of an infinite energy. It is undiminished everywhere and all the time, hence is omnipresent and omnipotent because of its infinite power. Before assuming Vishwarupa, Krishna says: "All of the universes are pervaded by me in imperceptibly subtle manifestation." Thus, in the realm of spirituality, one could interpret the omnipresence of the Supreme Energy as being due to diffusion.

In real life, however, we experience limited diffusion. The spread of a flower's fragrance in the air and the dissolution of ink in water are examples of diffusion in gaseous and liquid states of matter. Diffusion takes place in gases and liquids due to their flexible nature. Diffusion does take place even in a solid matter, in spite of its rigidity. Diffusion takes place in the material world irrespective of its nature; however, the degree varies.

Unlike diffusion, drift is a driven process. There are both positive and negative drifts. If a person is swayed away by bad company or habits, it is a negative drift. If influenced by something good, it is a positive drift. It does well to both the doer and its recipient.

Good action done without attachment to results in sattvik drift. Drift resulted from a fruitful action may be termed as rajasik drift. However, its degree of positivity is much less than the former. Inaction is a tamasik drift, which is negative.


What is the sig nature of drift in inanimate matter? Electric current in a metallic wire is driven by a power source and is a drifted motion of conduction electrons, negatively charged subatomic particles, bound in an atom but free in a metal. There's a philosophical angle: The electron which conducts in a metal does not do so in an isolated atom.

Stretching it to life one would conclude that society makes one dynamic, whereas isolation does the opposite. Thus, if society does such a good thing for us, we should work more for it, rather than only for ourselves.

Diffusion and drift sometimes oppose each other. It is not bad. Together they create a balance in life. In matter, drift and diffusion together does wonders. Solid state electronics results from this joint action. In solid state, not only particles but also atoms, which are much heavier, diffuse. Hence no barrier is strong enough to stop spontaneity.
Life is a queer mixture of drift and diffusion. Both have their advantages and disadvantages. Roger Moore said: 'Teach love, generosity, good manners and some of that will drift from the classroom to the home and who knows, the children will be educating the parents."

(The writer teaches Physics and Materials Science at Berhampur University, Orissa)