Newton was Theoretical Physicist … (a point of view)
Well, basically Newton was Natural Philosopher.
English Translation title of his Principlia Mathematica is “The Mathematical Principles of Natural Philosophy”.
Newton was not Theoretical Physicist. He was greatest Natural Philosopher however.
While every Science or Philosophy must have to start from a point, The unique sign or indication of Rationalism Philosophy is that starting point itself is boundary.
You have staring point. Now onward close your eyes … Now just ‘deduce in mind’ or ‘derive on blackboard’.
The idea is that since first principle was correct so only mind (logic) or mathematics can lead to all the details of reality.
Does Natural Philosophy of Newton follow this principle?
Newton does start from ‘axioms’ which are his three laws of motion. But he does not provide these three laws as a form of boundary. Now onward we should not close our eyes. The purpose of axioms was only to derive few theorems and not the whole of reality.
But Rationalism Philosophy intends to deduce or derive whole of reality only out of first principles.
Rationalism is a closed system of knowledge. There is no need to observe anything. Mind itself or somehow found the first principle. Rest of the reality will be found just out of logical deductions or mathematical derivations.
Now Theoretical Physics, being a form of Rationalism Philosophy, is also a closed system. Instead of emphasis on logical deductions, there is importance of only mathematical derivation. Since there is no essential difference between logical deduction and mathematical derivation, so to this extent Theoretical Physics completely follows the footsteps of Rationalism Philosophy.
There is however slight variation. Just like Rationalism Philosophy, your eyes are closed basically. You only open your eyes in order to celebrate that your ‘predictions’ have come true.
When, in year 1929, Edwin Hubble found a new observed fact, it was not even treated as a new observed fact. It was treated as ‘prediction coming true’. Eyes were closed … we already ‘knew’ this truth out of our ‘mathematical derivations’. We opened our eyes just for a while only to celebrate the success of our so-called earlier mathematical derivations. Similarly, finding of CMBR was not treated as a new observation. That was not a new thing at all as it was also already ‘mathematically derived’. That is how things are ‘observed’ in modern Theoretical Physics. When you already know the reality in your mind then you tend to observe the actual reality through your colored spectacles. This thing is true for Rationalism Philosophy and this thing is also true for Theoretical Physics or any ancient Mythology.
Natural Philosophy of Newton had started from axioms. But there is no requirement of keeping your eyes closed. You independently observe the reality and logically or mathematically conclude the things. In Theoretical Physics, the purpose of observations is not to see new things. Here, the purpose of observations is only to celebrate that ‘predictions have come true’. Within next few years NASA is going to launch James Webb Space Telescope that shall be 100x more powerful than Hubble Space Telescope. What is the purpose? Will this telescope show us some new things?
Not at all (for practical reasons). NASA already knows all the things through mathematical derivations. NASA already knows that no galaxy beyond this much distance will be seen and that after that distance there was a dark era and within this darkness was the time of creation of universe. So all the things are already known. Purpose of observations is only to celebrate the already known things.
Purpose of this blog post was to show that Theoretical Physics did not start from Newton. He was Natural Philosopher. And that Theoretical Physics of today is basically a form of Rationalism Philosophy.