Friday, 22 May 2015

Gravity, Newton and Einstein

On a recent holiday in North Norfolk I had a conversation with a local person who held interesting theories regarding Quantum Mechanics ability to influence understanding. Now I have a more scientific background and his was more philosophical. Anyway this led to a discussion on gravity and he sent me the following link to a Youtube.

Gravity Newton to Einstein

This was my reply.

Just watched video. I have seen most of this before but the new bit was his 'thought experiment' of explaining why the planets do not fly off instantaneously if the sun was to suddenly vanish. Let's hope it remains a 'thought experiment'.

There is a lot of coincidences between Einstein and Newton, both studied light, motion and gravity. Both appear to have eccentric behaviours, Newton spent years studying Cabalism. However for Newton to develop his Laws Of Motion he developed a whole new field of mathematics, now known as Calculus, which is used by pretty well all of Physics to this day, including Einstein. Now no doubt Calculus would have been developed by someone else if he had not written his Principia Mathematica, in fact it was being developed on the continent at the same time by Leibniz. 

The origins of Quantum Mechanics as taught to me all those 50 years ago was the discrete energy levels of light being released from atoms. Why discrete and not continuous as expected form Newtonian physics applied to atoms. This specific energy level was called quantum. Einstein's Nobel Prize for Physics was in recognition of his work on  photo-electric effect related to this new science.

I find it interesting that Newton's theory of light was built on a corpuscular model, he believed the eye emitted small particles that were reflected back into the eye. However the alternative wave theory of light gained prominence as it explained diffraction and the dual slit patterns, and Newton rings, the interference patterns you can see if you place a convex lens on a mirror. The wave theory culminated in Maxwell's Equations of Electro-magnetic waves in the 19th century, at which point some bright spark said 'Pretty well all that is to be found out about physics has been completed'.

Then at the start of the 20th century things started to change. They could not find the ether in the universe the media through which light was suppose to travel. They could not explain the quanta levels of emission. This led to new theories about light and again 50 years ago they (academia) were beginning to think of light as a duality of particles and wave lengths, say particles that were bundles of light waves. It was at this point in my education I began to get disappointed in the loss of elegance of the solutions compared to the more classical physics so I concentrated on other areas to specialise in where I could understand and so enjoy the maths and learn enough to pass the exams.

Anyway having discussed these things with you have inspired me to look again at General Relativity and Quantum Physics, because half a century has gone by and who knows what has been happening. So I have googled around and found a reasonable book on line, but there were a couple of math techniques I have to learn first, but now maths is written all different so I am having to do a crash revision on Set Theory! I am expecting it will take a good year to do all this considering it is only going to be a background activity.

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