Over Time

It’s time for us talk about time again. Also time to review another science book: Earth’s Deep History by Martin J.S. Rudwick, 2014.

How old is the earth? It’s a question to which we now have an answer: 4.6 billion years. But for nearly all of human history people either did not think about how old the earth was (people have a long history of not thinking too much), or just held mistaken ideas about how old the earth was. Until quite recently, five or six thousand years was the standard, “scholarly” estimate for the age of the earth. Biblical reckonings and an assortment of folk legends and Creation stories sufficed for most people. Furthermore, the history of the earth began with the creation of people. Apparently, nothing much had happened until man and woman appeared on the scene. Well, perhaps there had been a brief “heroic” period, an age of titans and demi-gods. And supposedly, there had been a great Flood, etc., etc. But the vast extent of pre-human history remained unknown. As they say, the “story was hidden in the rocks”.

As Rudwick tells us in this excellent book, ancient fossils, dinosaur bones, and remains of the great Ice-Age megafauna – most of which were buried in the New World – remained undiscovered or just ignored for many years. It was only in the late 18th century and early 19th century that “prehistoric” fossils began to be uncovered. Similarly, geologists, such as Hutton in Scotland, Buffon and Cuvier in France, and many other European geologists, began to scientifically examine their local rock formations, and came to realize that these various cliffs, seashores, and river valleys etc had been formed over many, many years. According to Hutton’s Uniformitarianism doctrine, the earth was shaped by the same physical forces that we see operating today. “Actualism”or the principle that “what happens today happened back then too”, became a guiding principle in geology – and still is. The laws of physics are universal.

As “savants” in France, England, and other countries around the world learned to look at the morphology of fossils and to appreciate the processes of stratigraphy and the physical forces involved in the geological record, it soon became obvious that the earth was very, very, very ancient. Early scientists ventured bold estimates of the earth’s age. The physicist Lord Kelvin applied the recently-formulated laws of thermodynamics to calculated the time it would take for a molten earth to cool to present temperatures and came up with an estimate of a bit over 200 million years. As fossil discoveries accumulated and scientific information was exchanged within the small, but growing, 19th century, international scientific community, the absence of human fossils remained hard to explain.

Apparently, “natural history” didn’t start with Adam and Eve, and apparently the world was not static. Rather, the earth and life on it was constantly, albeit slowly, changing, or evolving. Mountains rose and fell, continents shifted. Interestingly, many of the early geologists were devout Christians, including Darwin and Lyell. Rudwick makes the point that in most countries, there was little conflict between religious and scientific thinkers. Indeed many of the early efforts in geology were guided and driven by efforts to confirm Biblical accounts such as Noah’s flood. But 19th century fossil discoveries revealed a previous era, or eras, of great sea monsters and extincted species – and rocks further down pointed to even vaster periods of time where there were no fossils at all.

Recent geological research – aided by modern, computerized, methods such as electron microscopy, isotope dating, seismography, as well as astronomical data – now provide a wonderfully rich picture of earth’s 4.6 billion year history – all explainable by the laws of physics operating over vast periods of time. Wow.


A Geo-Paleontological Poem

Hail the paleontologist

Picking at rocks

Searching for marvels in the chalky cliffs

Happy Lincoln’s Birthday Day, and Happy Charles Darwin’s Birthday Day!

17 thoughts on “Over Time

  1. Books like this are awesome, not only do they entertain and educate but let us marvel at how we had no idea for thousands of years just what we were living on. This is being added to the list.

  2. Excellent post, Bumba! Still, it drives me nuts thinking about what caused the beginning of earth (big bang?) perhaps, but what caused the cause… ad infinitum?
    I lose sleep over this! Sigh!

    1. Don’t worry so much. We personally have at least a couple more million years to figure it out. And then we’ll be able to get on the bus for $1.75.

  3. I think the 209th birthday … The Creation Museum is a bit less than an hour from me … nope … I’ve never attended …. Never thought about going … and odds are never will.

  4. Great blog, Bumba! I too smiled at, “people have a long history of not thinking too much.” I’ve recently been watching this on You Tube: “The Big Bang was not the origin of the universe …” Sir Roger Penrose, in which he talks about how there has been more than this particular universe. When asked about evidence he says that there is evidence right now and I said out loud, “microwaves!” And indeed, he believes there is evidence in the cosmic microwave background of a prior universe to this one.

  5. 4.6 billions years – that’s fascinating.

    I suppose in the early days the powers-that-be, aka priests, dictated what was and what was not. Those who disagreed were probably drowned, quartered or burned as heretics.

  6. Isn’t geology wonderful! Though much like quantum mechanics a lot of it is hard to grasp – or at least the language is hard to penetrate – a bit like the rocks then.
    ‘But for nearly all of human history people either did not think about how old the earth was (people have a long history of not thinking too much)’ This made me laugh 🙂

    1. … the radiometry and accelerators and sensors etc are very tough, but it’s good to get ones feet wet. And to laugh! Cheers. Keep digging in Wenlock!

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