MY GREATEST TOUCH EVER -- THE TOUCH BY EINSTEIN’S GENERAL THEORY OF RELATIVITY

The Newton’s law in classic mechanics for PARTICLES, i.e., the equation of motion, was originally written as

F = ma.

People usually do not say that Newton established or invented the laws of motion but say Newton DISCOVEREDD the laws of motion! In other words, Newton’s laws of motion were established on the basis of observations and experiments. Another example is the discovery of the gravitational law by Newton. Kepler DISCOVERED the laws of planetary motion such as the planets move in elliptic orbits with Sun located at their focal points, etc.. Based on the calculus invented by Newton himself, he found that the mathematical solution of F=ma satisfying Kepler’s laws led to a unique form of force between two bodies: F is inversely proportional to the square of distance between the two bodies, which led to the discovery of the gravitational law by Newton.

Later developments of classic mechanics showed that the same law could also be written in several different forms, such as the Lagrangian form based on the least action or the Hamilton’s equations based on canonical transformations. Though the principles and/or forms that led to the new sets of equations were more beautiful than Newton’s original form of F=ma, all the new developments (equations AND thus their principles) had to be tested by its correctness: the new forms of equations of motion should be identical, either trivially or non-trivially, to the original form of F=ma!

Why? This is because Newton’s law had been CORRECTLY tested by observations and experiments!!

The establishment of the general theory of relativity was a totally different story. The general theory of relativity was established on the basis of Nature’s beauty. In other words, the reason that the field equation for the general theory of relativity developed by Albert Einstein is in this form rather than in other different forms is: this form of the equation looks simply BEAUTIFUL!

WHEN I LEARNT EINSTEIN’S GENERALLY THEORY OF RELATIVITY, I WAS GREATLY TOUCHED BY ITS BEAUTY!!

(2004.05.28)