Richard Phillips Feynman

long time since I wrote a blog........I feel like writing a blog when I could easily relate something which I learnt to things that happen in daily life. I was not able to do something like that for quite sometime. Even now I dont have anything of that sort. The two major things which I like to do are to tell people what I have learnt and to listen to people who are ready to teach me what they have learnt. IISc is such a place where I can find people to express my thoughts and learn from them. It is very unfortunate that I am not able to share my views in person with my undergrad friends.But happy to share through blogs.Recently I saw an interview of Feynman.For my friends who still have the desire to learn physics it is a must watch.I don want to write about that interview here. I just want people to watch...... all the five parts
http://www.youtube.com/watch?v=Sk8TVopOBGE

THE HIDDEN TRUTHS OF NATURE alias GOD

Now its almost a century since the atomic theory was formulated and accepted. It states that every matter is made up of atoms. This theory had to go through hell lot of criticism before getting accepted. Now its a thing given for granted. The laws of thermodynamics were well established before the atomic hypothesis came into picture.Even though all the manifestations of any system is b'coz of the atomic interactions,the laws of thermodynamics were developed without this knowledge. Clasius was one of the first persons to view any system as being composed of atoms and he developed the subject of statistical mechanics. Since every macroscopic property of a system is b'coz of the atomic interactions averaged over a large number of atoms people tried to derive the laws of thermodynamics by assuming atoms to be rigid balls undergoing elastic collisions with the other atoms and by using the Newton's laws of motion.To their surprise they found that the second law of thermodynamics cannot be explained from this point of view,it has to be taken as a matter of experimental observation. The second law talks abt the direction in which a particular process can occur.First law is just a statement of conservation of energy. Hot coffee placed in a room eventually gets cooled but the reverse process never happens.The reverse process does not violate first law but it violates second.So second law is given by nature and it cannot be proved rigorously using statistical mechanics.Its an hidden truth.People just know this as an experimental fact.So every thing going around us cannot be explained.There are a few things which are beyond human brains.....this argument creates in me the belief that there is something beyond our perception and we are controlled by that.A few people call it the God and a few the hidden truths of nature........

Nonlinear world

When I had just a nodding acquaintance,even now I have only a nodding acquaintance with turbulence but at least I am aware that I have seen only the tip of the iceberg,I used to wonder what is so profound abt turbulence. When I formally attended a course ( actually preachings of Prof O N Ramesh ) I learned that there is a fundamental difficulty in understanding fluid dynamics b'coz these systems which we frequently encounter in nature are inherently nonlinear.....why nonlinear systems are difficult to understand????the major privilege enjoyed by a linear system is that the principle of superposition is applicable in a linear system!!!not so in a nonlinear system. . It is a well known fact the mathematics required to understand such systems is not yet known.Why???Right from our childhood we have been taught how to handle linear systems,even when everything happening around us are inherently nonlinear, by using the superposition principle which tells that the effects of causes are additive so that they can be treated separately and the effects can then be added. This is so not possible in a nonlinear system because the effects of a cause are very much interrelated. So a bias has been created in our minds to view any system as linear or to be precise we know only to look at the linear part of the problem........if u ve studied some fluid dynamics u will realize how we cleverly got rid of the nonlinear advection terms in Navier-Stokes equation!!!! N-S equations are just mathematical forms of expressing the most fundamental properties of any physical system namely conservation of mass,energy and balance of momentum(Newton's 2 nd law).....they completely describe turbulence,but they cannot be solved. God has made the problem so formidable that the system of PDE's is not closed that is to say that the number of equations are less than the number of unknowns. So we should get rid of the bias in our minds towards linear systems. The only way is to unlearn what all we have learned till now and start afresh.Start looking at the problem with a clean mind without any bias!!!!!!If I take a pessimistic view, we cannot solve the problem since we have come a long way carrying the bias......a new school of thought should come abt to carry forward the understanding of nonlinear systems........lets hope for a new kind of mathematics to take the problem of nonlinearity!!!!!!!!!!!!!!!!!