I like making ‘top ten’ lists of my favourite things which can be movies, books, songs, food items, cities, actors, heroes, scientists, cars, football teams – almost anything.  It is a good way to pass idle time and provides an avenue for introspection.  I try to analyse why certain items appeal to me more than others.

Being a physicist by education I wondered one day what my top ten favourite laws of physics are!  First, I had to decide the criterion for liking a certain law; is it the complexity and abstractness or is it the simplicity and practical usefulness? Or is it something more profound?

After some thought, I decided to base my list on the spiritual implications of the laws. Such associations suggest that these laws (applicable to inert objects in physics) are perhaps special cases of more far-reaching principles applicable to our entire existence.

 I also took liberty with the word ‘law’ and generalised it to include ‘principle’, ‘postulate’, ‘equation’ etc. Without further ado, here is my list.

Maxwell’s equations: This set of equations represents not just one law but combines four different laws viz. Gauss’ law for electrical field, Gauss’ law for magnetostatic field, Ampere’s circuital law and Faraday’s law.  Together this set is probably the most beautiful set of equations in physics in the way the electric field E and the magnetic field B appear in an almost symmetrical fashion.  It is the closest thing to being a mathematical representation of God himself: omnipresent electromagnetic fields symbolising God and the E and B fields symbolising Yin and Yang (or Radha and Krishna).

The second law of thermodynamics:  It is amazing that while both the concept of entropy and the idea in the second law of thermodynamics that entropy of the universe never decreases are so abstract that they are almost meaningless to most people, they have such a profound impact on our daily life.  A consequence of the second law is that heat energy cannot be converted one hundred per cent into mechanical work.  For example, the moment we turn the ignition in our cars there must be exhaust gases with huge ramifications in the destruction of the ozone layer and global warming. One interpretation of entropy is that it is a measure of disorder in a system; ‘the disorder in the universe is never decreasing’ seems to suggest more generalised concepts like ‘it is easier to create clutter than order’, ‘it is easier to destroy than create’, ‘it is easier to hate than love’.

Newton’s third law: Every action has an equal but opposite reaction.  One can easily extend this statement to well beyond inert objects.  One cannot kiss without being kissed. A friend of mine once told me ‘I treat other people exactly in the same way as they treat me’. The same can be said about all other intimate physical and emotional interactions between human beings. This is the essence of collective existence.

Hubble’s law: The law states that the speed of a galaxy away from the Earth is directly proportional to its distance from the Earth.  It is astounding that there are galaxies millions of miles away which probably obey laws that we may not even know about, but all follow such a simple linear relationship.  This almost suggests that the universe may be a lot simpler than cosmologists and astrophysicists have led us to believe.

Third law of thermodynamics: The absolute zero of temperature cannot be attained. It was probably the first time that even physicists realised that the ability of human beings is limited. We cannot reach or even simulate certain physical conditions on this earth no matter how hard we try and no matter how much technology has advanced!

Law of conservation of mass/energy: We, human beings, cannot create anything which has mass or contains energy nor truly destroy them.  We can only convert from one form to another. There is only one creator and destroyer of everything in this universe.  There is a similar principle involving wealth. We cannot create or destroy wealth; we can  only convert from one form to another (from gold to stocks, for example).  So, whenever someone is getting richer some other person (or persons) is getting poorer.

E = Mc^2 or energy released by converting mass into energy is equal to mass times the square of the speed of light. The theory of relativity and the ensuing quantum mechanics revolutionised our understanding of properties of matter; in particular, it explained how solar energy is generated at the expense of the mass of the sun and of course, it is the sun that sustains all life on this earth. Unfortunately, it also led to the invention of atomic and nuclear bombs and divided the world into two groups: the ones who have nuclear bombs and the ones who do not. The former group tried to exert their influence throughout the world using their nuclear capability as a veiled threat, resulting in resentment if not violent backlash from other countries. Much of the misery and turmoil in the world today is related to this destructive use of mass-energy equivalence.

The second postulate of Einstein’s special theory of relativity: The speed of light in free space appears the same to all observers regardless of both the motion of the source of light and of the observer. The implication that comes to mind is that light and God may be one and the same entity! Can God travel at a speed faster than what we measure to be the speed of light? Of course, He can. The theory of relativity is His way of showing us our limitations. We cannot go faster than Him.

Heisenberg’s uncertainty principle: This principle describes the essence of quantum mechanics in a basic simplistic language: all elementary entities sometimes behave like a wave and sometimes as a particle and as a result we cannot simultaneously determine both its position and velocity. Every prediction in quantum mechanics is probabilistic and probabilities exhibit a wave-like behaviour. Similar duality is present in every aspect of our belief system; nothing can be pure binary whether it is our political view, sense of right or wrong, sexual identity or intellect versus intuition.

Navier-Stokes equation: Strictly speaking it is not an independent law; it can be derived by combining Newton’s second law and fluid properties. However, unlike almost all other equations representing laws of physics, this equation is a nonlinear one.  Nonlinearities are almost always ignored in other applications of Newton’s second law.  If such nonlinearities, representing friction and other dissipative forces were included, predictions of classical mechanics could have been entirely different as described in the ‘chaos’ theory.  This equation makes me wonder if physicists live in a ‘dream world’ where all equations are linear and have analytical solutions, but which are detached from reality!

The writer, a physicist who worked in industry and academia, is a Bengali settled in America