Summary of Modern Physics and Scientific Philosophy

　　I would like to list what I have posted and give a brief introduction to each one.

1.Special Relativity(1905)(狹義相對論)

　　The most important principle is that the speed of light is a constant. This phenomenon cause time dilation(時間膨脹) and length contraction(長度收縮). Therefore, space plus time become spacetime(3+1 dimensions).

                                         

2.General Relativity(1915)(廣義相對論)

　　Newton’s theory of gravity is just an approximation. In fact, gravity is the curvature(曲率) of spacetime. Great physicist John Wheeler said: Spacetime tells matter how to move; matter tells spacetime how to curve”.

 

3.Quantum Mechanics(量子力學)

　　Quantum Mechanics is the description of microscopic world. All particles are dominated by Schrödinger’s equation, which is the statement of energy conservation. The most strange property is that all particles have wave-particle duality(波粒二象性).

                                    

4. Schrödinger’s Cat and Many-Worlds Interpretation(薛丁格的貓與多世界詮釋)

　　Schrödinger’s Cat showed how ridiculous and how strange quantum mechanics is. Many-Worlds interpretation is also a alternative interpretation of quantum mechanics. The idea of parellel universe is from this.

     

5.String theory and M-theory(These theories are not confirmed now)(弦論與M理論)

　　All the elementary particles(quarks and electrons) are different vibration modes of string. M-theory promote string to membrane. To make such theories realistic, they demand the world is 11 dimensions(10 space dimensions and 1 time dimension).

    

6.Scientific Philosophy:Popper and Kuhn(科學哲學:波普爾與孔恩)

　　Popper’s theory is called Falsificationism(否證論).Every scientific theory should provide testable statement or prediction. This is called falsifiability(可證偽性).

                        

　　Kuhn wrote a great book called《The Structure of Scientific Revolutions》. He divided the development of science into three parts. Paradigm shift(典範轉移) is a great idea.

7.Special topic: Higgs Boson

　　Nobel prize of physics this year is for the discovery of Higgs boson. Why we have mass? Higgs boson give the answer. Higgs mechanism is the origin of mass.

　　Hope you will feel that physics is interesting and share my happiness!

The Structure of Scientific Revolutions：Thomas‧Kuhn

　　I think Thomas‧Kuhn(1922-1996) may be the greatest scientific philosopher that I have ever known. His book《The Structure of Scientific Revolutions》(科學革命的結構)has been honored as the most influential book in post-20^th century.(I have a Chinese translation edition!)

 

                                            

　　The core of his theory is that he divide the development of science into three parts：Normal Science(常態科學)、Scientific Crisis(科學危機) and Scientific Revolution(科學革命).

            Normal Science→Scientific Crisis→Scientific Revolution→New Normal Science

　　In the period of Normal Science, paradigm(典範) was the highest guide of science and scientists. Scientists would not suspect whether the paradigm was correct or not. They were solving puzzles(解謎) under the guide of paradigm.The puzzles were provided by the paradigm.

　　Sometimes, some puzzles couldn’t be solved for a long time. Therefore, they became anomalies(異例) to that paradigm. They were crisises for the paradigm. Scientist

may want to seek new paradigms. A lot of new paradigms had been issued and compete with the original paradigm. If new paradigm replace old paradigm,this was called paradigm shift(典範轉移). The Scientific Revolution was completed and New Normal Science began.

　　Take Mechanics and Astronomy for examples as below：

   Aristotle’s Mechanics(亞里斯多德力學)→Descartes and Galileo(笛卡兒與伽利略)→Newton’s              Mechanics→Crisis Of Mechanics→Relativistic Mechanics(相對論性力學)

   Ptolemy’s Geocentric model(托勒密地心說)→Copernicus’s Heliocentrism(哥白尼日心說)→Newton’s    Theory→Relativistic Astronomy