Thursday, July 12, 2012

Evolving Particle Theory

Democritus, an ancient Greek philosopher, was sometimes called the father of modern science. This moniker was assigned to a number of historic figures. The 5th century BC ancient Greek philosopher developed a remarkable atomic theory without ability to support it empirically and evidentially. Nevertheless, his ideas were far ahead of their time. The citation of Democritus’s ancient ideas as we taught our introductory studies on chemistry was a fascinating tribute to the power of human reasoning and speculation harking back over two millennia.

Early atomists proposed a number of concepts, including the idea that there may be spaces between unseen tiny bits of matter, and that the tiny bits of matter could somehow be attached together or even change the shape or size of the sample. Democritus and his followers envisioned the changelessness of matter, imagining how tiny particles of matter become recycled and retain the same inherent, indivisible properties. The Apostle Paul’s familiar verse in Colossians cites a similar concept, the idea that by God “all things hold together.” Man was gifted with the ability to contemplate physical reality long before the development of formal scientific methods even if the early pagan thinkers did not share the Judeo-Christian worldview.

The Scientific Revolution of the last 400 years was bursting with discoveries on atomic theory. These inductive discoveries were founded on empirical and experimental methods and refined scientific thinking and knowledge. Unlike brilliant philosophers of the two millennia prior to the scientific revolution, science discovery by this time had taken a turn away from philosophical speculation. Now there were many brilliant minds uncovering answers concerning the nature of physical reality. For example, early atomic theorist John Dalton (1766-1844) was one of an army of early scientists who discovered the nature of atoms and how they combine with each other in a mathematically predictable way. He discovered laws relating to how atoms combine in constant proportions to form compounds. This was early affirmation that atoms were discrete particles and that all atoms of a specific element share certain common characteristics.

Many retired readers of this blog recall that in the youth of our grandparents and in the early adulthood of our parents, there were pioneering discoveries of fundamental particles which composed familiar elements and what these fundamental particles were like. Did hydrogen, oxygen, iron, and many other natural elements share fundamental particles in common? Did fundamental particles from one element to another even exist? Is there a commonality between fundamental particles of oxygen, iron, and dozens of other known elements even though their characteristics are very different from each other?

Contemporaries of our day might be surprised to learn that between 1897 and 1932 the electron, the proton, and the neutron respectively were discovered to be fundamental particles. In short, many of our grandparents and parents had not even heard of electrons, protons, and neutrons. Their familiarity with the basic characteristics of dozens of elements was remarkable -- nitrogen, carbon, calcium, and sodium, for example -- but they may not have been aware that all these elements shared only three basic fundamental particles. The eventual discovery of three famous discrete particles, the electron, the proton, and the neutron lent a measure of simplicity to our early chemistry courses. We found out how the particles were discovered, how large the particles were, what kind of charges they had, and enough other information to stoke our sense of pride. Could our lives be any simpler as students of chemistry? Yes, the best was yet to come.

Protons and neutrons are not considered elementary or fundamental particles any longer because they have substructure. Since 1960 scientists have gained a wealth of additional fundamental knowledge concerning subatomic particles. The protons and neutrons are now considered hadrons and have been found to be composed of up and down quarks, three of each. There are also six different leptons, of which the electron is only one. All told there are twelve quarks and leptons. In addition there are force carrying particles which are considered fundamental forces. We need to be aware that as our knowledge expands there are many more unanswered questions. The purported recent discovery of the Higgs boson is by no means the end of our quest.

As we search along the historical timeline going back 2500 years, and even thousands of years earlier, we realize God has enabled both discovery and application at each point in time. We might wonder why the keys to the bank of scientific knowledge have been kept locked for many thousands of years while the human intellect has flourished. Why have the secrets of subatomic particles been withheld until the 20th and 21st centuries, including the earlier identities and characteristics of the electron, proton, and neutron during the 19th and 20th?

These questions are appropriate for many more hours of sober reflection, including the words of Isaiah 40:26. His musings included the macro cosmos, “Who created all these?” Perhaps Isaiah, were he alive today, may also inquire of the wonders of the micro cosmos in sub-atomic beauty of matter surrounding us wherever we look!