Though scientific discoveries in the past 50 or 60 years have been phenomenal, the preceding century changed the way we view the universe and our place in it like no other time in history.
The public may not like what science finds, but modern society is dependent upon it and, as its fundamental ideas become fleshed out, its discoveries become compelling. Science isn’t a democracy, it is driven by the search for non-contradictory truths.
Let me chronicle just a few of the advances in physics, cosmology, geology and biology to illustrate how these ideas revolutionized our world-view and made possible most of our technology today. Some laid the foundation for entire fields of study.
This golden age began with publications from two giants of science, Charles Darwin and James Maxwell. Darwin’s “Origin of Species” was released in 1859 and laid the foundation for all modern biology.
In Theodosius Dobzhansky’s characterization, “Nothing in biology makes sense except in the light of evolution”.
James Maxwell published “A Dynamical Theory of the Electromagnetic Field” in 1865. It provided, in four elegant equations, a unified explanation of all the electrical and magnetic phenomena that had been observed.
It was essential to all future developments in electronics, including exploitation of radio- and micro-waves. Being the first unification of “forces”, it inspired later generations of physicists in a quest to unify the yet to be discovered strong nuclear force (introduced by Hideki Yukawa in 1934) and weak nuclear force (proposed in 1935 by Enrico Fermi).
Our concept of matter would change dramatically. Throughout the 19th century the concept that matter was composed of irreducible elements had gained traction.
That each element had a unique atomic structure which was itself composed of more fundamental parts wasn’t appreciated until the first few decades of the 20th century.
Around the turn of the century, J. J. Thompson suggested data supported the idea that atoms had a massive core with a positive electrical charge while negatively charged electrons surrounding the core.
Between 1910 and 1920 Ernst Rutherford refined this atomic model. He introduced first protons and later neutrons as the constituents of the nucleus. These particles accounted for the bulk of an atom’s mass.
Many problems existed in these early atomic models. They were eventually resolved by the Theory of Quantum Mechanics. Its roots lay in Max Planck’s 1900 explanation for a host of phenomena that had stymied classical physics.
Over the first three decades of the 20th century physicist Max Born, Werner Heisenberg, Wolfgang Pauli, Paul Dirac and Albert Einstein made critical contributions to advance our understanding of the atomic and subatomic realm.
By mid-century we had sufficient command of nuclear and quantum theory to develop the atomic bomb and nuclear power. Quantum mechanics eventually lead to such developments as transistors, microelectronics and lasers. These items drive much of today’s economy.
By the late 1800’s naturalists had worked out a complete relative geologic time scale. The absolute depth in time associated with the various stratigraphic layers would, however, await radiometric dating, introduced by Ernest Rutherford in 1905.
This was a great boon to fossil study in paleontology and anthropology. The first half of the 20th century saw acceleration in fossil excavation requiring the building and expansion of natural history museums around the world.
Though the first neanderthal fossil was discovered in 1859 and the first homo erectus in 1891, it wasn’t until Raymond Dart’s discovery of the first Australopithecus africanus fossil in southern Africa in 1924 that we began fully appreciating the very long history of human lineage. These were just the start of an ever accelerating rate of discovery.
Before Alfred Wegener introduced plate tectonics concepts in 1920 there was no all-encompassing explanation for the shape and arrangement of Earth’s continents and oceans, volcanos, earthquakes or mountain range formation. By the late ’50s and early ’60s his proposed explanation had been confirmed.
In just six decades, cosmology advanced from little understanding of the size, dynamics or origins of the universe to the coherent model accepted today.
It began with Einstein’s introductions of his Special and General Theories of Relativity in 1905 and 1915.
By 1923 Edwin Hubble had measured the distances to nearby galaxies, showing they were far beyond our own Milky Way. In 1929 he discovered the red-shift, used to establish that the universe was expanding.
George Gamow predicted the existence of cosmic background radiation in 1948. Its conformation in 1965 was important to developing the Big Bang model proposed in 1950 by Fred Hoyle. This has given us insight into the beginnings and structure of the universe.
The robust state of biology today is attributable to discoveries during this period in genetics and molecular biology and improvements in microscopy.
Though Gregor Mendel published his seminal work on what was to become genetics in 1865, it wasn’t until the first half of the 20th century that advances in molecular biology made genetics a pillar of biology.
The DNA-era of genetics began in 1944 with isolation and identification of DNA as the genetic material. This was followed by discovery of the double helix structure of the DNA molecule by Francis Crick, James Watson and Rosalind Franklin. By the mid ’60s the DNA code had been cracked.
In the 1930s molecular biologists unraveled the workings of the Krebs cycle. The importance of this discovery for understanding cell metabolism is emblematic of the many other, non-genetic, aspects of the chemistry of life revealed during this period.
This sweeping overview of roughly 100 years of discovery is offered in the hope readers will appreciate transformations that occurred in our perspectives on the workings of the universe.
The pace of discovery is greater today, but this period has no peers for its revolutionary impact.
Steve Luckstead is a medical physicist living in Walla Walla. He can be reached at firstname.lastname@example.org.