Radiometric Dating Isn’t a New App

Radiometric Dating isn’t a new way to find someone to go to the movies with, or My Final Thoughts on Life on a Young Planet by Andrew H. Knoll.

Reading books like this reminds me how little I know about everything there is to know on this planet. You’d think I’d be bored, but the way Andrew H. Knoll writes about early life on this planet feels like you’re reading a mystery novel. And his analogies for science and references to literature make for a delicious read.

I feel like I know a little more about the subject, and I found some answers I’ve been looking for, but there is so much more to learn. Will I follow that rabbit trail? Probably not. I do wish I had the drive to deep dive and really learn all the details of a subject, but that’s just not the way I’m built and I’m learning to accept that.

I’m a shallow learning person. A little bit here, a little bit there. Just enough to get the taste of it and then I move on to something else. You can apply this to everything I do. I’m a butterfly person. The acceptance of that has changed how I interact with information and people. I’m open to hearing what people have to say about any subject they have specific knowledge about, instead of closing my eyes and assuming I already know.

That being said, here are the things I learned and some of my favorite analogies in this book.

“Note that there is no expectation that successively older members of our lineage should close in on chimp morphology. Humans didn’t descend from chimpanzees; humans and chimps both diverged from a common ancestor that was neither Homo nor Pan.”

This was an ah-ha moment, one that high school science could have given me if they had taught it better. Seriously. We really need to work on science classes not dumbing things down so much that they don’t make sense. Or… maybe I wasn’t listening all that closely? Honestly, I don’t remember anything about science classes other than having to dissect a frog and watching the girls next to me turn green when I made mine “talk.”

There was a lot about bacteria and respiration, something about genes being shared horizontally from one branch of the genetic tree to another by possibly a virus or DNA uptake from dead cells… I got lost a lot. Basically, I learned that bacteria make the world go round and that the evolution of some cells might have changed the atmosphere and then then that may have changed the cells, and round and round building on each other. Evolution wasn’t only biology but geology as well, one thing triggering another and so on. I learned the meaning of the words “earth system science,” a holistic view of earth science that include biology, geology, and a bunch more “-ologies.”

“The other main point is that life has not evolved on a static planetary surface. Rather, life and environments have evolved together throughout our planet’s history, inexorably linked by the biogeochemical cycles in which both participate.”

And then there was this:

“How do we know that North Pole rocks formed more than 3 billion years ago? Geologic time can be measured in two ways.”

That’s where I wrote, “YES! Now we’re talking!” in the margin. Understanding geologic time scales and how we decide how old things are is why I looked for a book like this in the first place, remember? And I finally got my answer in this chapter and a couple of YouTube videos I watched over dinner. My husband was very helpful in finding good ones! This one called “Dating Rock Layers” was good, even if it does have a funny title. You can take it so many ways: Who are these Layers of Rock and why would I want to Date them?”

Basically, there is relative time (where the rocks are under what layers) and quantitative time (radiometric dating). I’ve scoffed at the ages presented by scientists because I did not understand how you can measure the age of rock. This video about radiometric dating helped, along with this chapter in the book.

My biggest takeaway was learning that it’s not one system that dates everything. It’s more like a mystery book. Using absolute and relative dating together helps us get a clearer picture of time, and radiometric dating uses more than one element as a check and balance. Oh! And you can’t use radiometric dating on ANY rock you find.

Here was my favorite analogy, one I’ll take with me for the rest of my life.

“Beyond our distantmost candle of fact lies a seductive darkness. Scientists are drawn to this blackness because we know it hides more candles, as yet unlit. We strike matches of hypothesis in the hope that a new wick will catch fire. Hypotheses seek to explain what we know, but more important, they make predictions about what we don’t know – about experiments not yet run, or fossils not yet discovered. For this reason, hypotheses provide built-in criteria for evaluation: do they help us to light the next candle or not?”

Can’t you just see this image?! It’s inspiring and makes wish I had chosen a science major instead of theater, but then I’d have much different stories to tell and be a totally different person. THAT makes me hope that different timelines are real and that someday we’ll be able to jump between them and see what our different choices would have led to. Hmm… reminds me of The Midnight Library.

How in the world can a science book be a page-turner and leave me near tears by the last few pages? This guy is a genius. Read this one:

“As Hap McSween wrote in Fanfare for Earth, “we are stardust” is not just Woodstock bravado; it is literal truth. The carbon in my body was forged in a crucible of an early star, dispersed into space by a supernova, gathered along with dust and rock as our planet took shape, and then cycled repeatedly among air, oceans, and organisms, through cyanobacteria and dinosaurs, perhaps even through Darwin, before coming to rest, at least for the moment, in a paleontologist’s brain.”

…sigh… “It’s all connected.” We are all connected, for real, in every way, to everything else.

Last night, my husband once again proved himself the master of YouTube, and brought us this video called “The Whole History of Earth and Life – The Finished Edition.” The “finished” part made me giggle. I wonder…maybe he’s seen the future and this has not only theories about what has happened in the distant past, but what will happen in the next billion years! If you’re curious and not interested in spending so much time reading this book, this video is an hour long and has much of the same information, albeit not nearly as exciting as the book (typical). I especially enjoyed the last few minutes of it, speculating on the what the future holds. It was very sci-fi and sent me to bed dreaming about aliens coming across AI travelers sent by earth dwelling humans long extinct.


  1. I’m with you on with the butterfly consciousness. As for the rest of radio-whatever,, well, it’s beyond my willingness to dig in and learn. More power to you, though! 🙂

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