Prof. Ranjith Padinhateeri, IIT Bombay
Why Physics, Chemistry, Mathematics, and Engineering are important to understand the secret of “life”? To understand that we should know what biology is. It is the science of living beings. But what are these living beings?
They are some machines that take energy from outside (sunlight, food), create some “order”, and do some work. They are essentially machines working far away from thermal equilibrium. But they are not simple machines like a computer or a car!
While thinking about computers with Alan Turing, a super-brilliant scientist of the 20th century, Professor Von Neumann came up with this idea of a self-replicating machine! A machine that would make copies of itself. Since then, we have made computers and robots; but we have not yet artificially made such self-replicating machines. We are familiar with them as biological cells or living beings. Can we make them? These machines are so complex that to even understand them, we might need to use all the knowledge that we have gained so far — knowledge in physics, chemistry, mathematics, and engineering!
After all, living beings are physical objects in this world — molecules having positive and negative charges; a sack of material living in a fluid (water) at a narrow range of temperature; objects that use light for “seeing” and also as an energy source. They must obey the laws of physics and chemistry that exist in this physical world. They must obey the laws of electrostatics; they cannot violate the principles of fluid mechanics; they must obey the laws of thermodynamics. They must figure out how to deal with light. What does this imply? If we want to understand this living world, we have to use ideas from physics and chemistry. It turns out that mathematics is the language in which ideas of physics and chemistry are written! Hence mathematics is equally necessary to understand the living world.
How do we understand the living world? We study them using tools like microscopes, X-ray machines, MRI machines, etc. To study bio-molecules like proteins and DNA, we use spectroscopy, electron microscopy, magnetic/optical tweezers, and so on. Without knowing relevant physics, one cannot use these machines effectively.
The living beings — cells for example – are also molecular computers of some sort. They gather information about the environment around them, do some computations, and make decisions! How do they do that? We do not understand this fully, yet! It will take young physicists, chemists, mathematicians, and engineers to come forward and learn about these amazing machines and understand them!