Showing posts with label Intellectual History. Show all posts
Showing posts with label Intellectual History. Show all posts

Monday, July 9, 2012

Newton After Einstein

Einstein did not disprove Newtonian Physics, rather he improved them. It is simplistic to think of Quantum Mechanics as a revolutionary force that disproved three hundred years of thought.  I have in the past indulged myself in this myth because of the glorious rush of the revolutionary feeling and the joy that concepts are not fixed and definite. It is as easy to say everyone in the past was wrong about practically everything, as it is easy to say that the past was far better than today.

To say Newton has been disproved or wrong is an error. For one thing in Newton's Principia he never claims to understand what gravity is or how it works.  He shows the mathematical principals behind gravity. Since he never claims to understand what gravity is there is nothing to disprove.  Einstein was only able to improve the equations, and through quantum mechanics physicists have been able to begin to understand what gravity is and how it works.

Einstein's Field Equation states:

R_{\mu \nu} - {1 \over 2}g_{\mu \nu}\,R + g_{\mu \nu} \Lambda = {8 \pi G \over c^4} T_{\mu \nu} \,.




This formula solved Mercury's seemingly erratic trajectory, and changed forever the way humans understand the universe. On a solar eclipse we can see light from stars bends around the sun. Newton's theory doesn't give us that possibility.
   
In his Principia, Newton states:

F = G \frac{m_1 m_2}{r^2}\

Through a long series of equations involving scalar curvature and tensors, and other calculus based jargon Newton's formula exists in the Einstein Field Equation. I don't fully understand what the entirety of the mathematics; so showing the full math would be useless, but you can look it up for yourself.

The main practical problem with Newton's Theory is that it is not truly universal. In fact Newton's Laws can still be used today, for ordinary earth bound applications. However, the lack of universality does not make his work untrue, and thus it does not mean that the Quantum Mechanics revolution disproved Newton. Newton's universe is only a stock image or a subset of a greater universe.

A bit of the defrocking of Newton comes from the Historical concept of Newton the man. How history came to define Newton as a rationalist, the father of calculus, and a brilliant scientist is wrapped up in the French Revolution.   The man Isaac Newton was born 1643 and died in 1727.  He was an alchemist and an empiricist, and his Christian theology was centered around disproving the great scourge of Spinozaism (or that is my sense from reading the Clarke-Leibniz letters.) During the French Revolution Newton's biography was scrubbed clean of all things non-rational. During this time he transformed into something more French and more Post-Enlightenment-Era appropriate: a deist, a naturalist, and a rationalist. The somewhat modern invention of Newton created by the Sorbonne placed Newton on a pedestal.  No longer is Newton a fallible man but a romanticized scientist.

After Einstein came along this once inescapable force, was turned on its head.  Time and space are one phenomenon which can be bent by matter via gravity.  It must have seemed so alien compared to "shit falls to the ground when dropped." And with Einstein, another god was seemingly disproved. But once again these two theories are not contradictory, but fit together.

It will be interesting to see in one hundred years how Newton is viewed.  It will be more interesting to see how Einstein is view in light of String Theory and other advancements Einstein only could have wished to theorize. With the discovery of the Higgs-boson it would appear we have pushed the era of Einstein to its outer limits. (Well science still needs to find the graviton.) It will be interesting to see whether another god falls to the history of time or if humanity has finally accepted a constantly changing universe. It doesn't look good for Einstein, as his name is synonymous with genius, and people have already forgotten that Einstein did not stand alone (Heisenberg, Bohr, David Hilbert).


As a child I had a mantra:

All ideas are simply waiting to be proven false.

Now as a man I realize that all concepts which appear true are awaiting a deeper nuance.



Liam '12

Freedom Just For Me