4.6 Billion Years Ago..

My random numbers today were 3, 8, 12 and direction R. It’s usually floor 3 or 1, which is fine, because that is where most of our stacks are.  I’m always kind of silently hoping somebody will send me to 4 since that is we have all of our old periodicals, and those are really fun. So it’s up the stairs over and around and I find myself smack dab in the middle of… Brace yourselves… The geology section?

I’m starting to realize more and more as I do this that I actually know very little about many things. But I guess that is why we have libraries, and available information. There were so many small pamphlets and reports, I did see a title called Geology for non-geologists (which in retrospect I should have grabbed) but something else ultimately caught my eye.

Today I have picked: Meditations at 10,000 Feet: A Scientist in the Mountains. By James S. Trefil.


Yes, I picked it solely because it had the word meditation in the title, although I think it’s used in a different way than I thought it would be. I did my random flip through and landed on this passage:

All the other radiometric dating techniques follow the same principle, although they don’t all use exactly the same logical sequence to arrive at an answer. All, however, share certain limitations. In the first place, it is essential to the accuracy of the method that none of the product nuclei escape. Argon, as we have noted, is a gas, so if a rock is heated in the normal course of the geological cycle, some of the argon may be driven off. In effect, such an event resets the geological clock. When the rock is analyzed, the date determined by the radiometric techniques will be that of the heating even, not the formation of the rock. Sometimes this problem can be dealt with by analyzing an entire rock rather than just certain minerals in it, since the decay nuclei may well be in the rock even when they’re no longer locked into the mineral structure. This sort of error leads to an age that is too small; it always underestimates the true age. (Trefil, 1986, p.109)

So he’s discussing one of the pitfalls of radiometric dating for rocks? I think? I have no idea what radiometric dating consists of, I have a feeling it has changed since 1986, but let’s look shall we?

Radiometric dating became a possibility with Becquerel’s discovery in 1896 of natural radioactivity. Rutherford postulated that radioactivity could be used to determine the age of the Earth. His and Soddy’s discovery (1902) of the transmutation of the atom became the basis for understanding exponential decay and the evolution of decay products (“daughter” elements). Age estimates for the Earth that had been determined by rate of heat loss (Lord Kelvin) now had to make allowances for the heat energy associated with radioactive decay. Thus, scholars were able to argue for great antiquity of the rocks on Earth. It was really with the advent of data collection technologies after World War II that the radiometric dating field began to develop with rapidity.

Radiometric dating must be viewed as having two forms: (1) techniques that rely on the decay of an isotope of an element, the production and decay of daughter decay products (radiocarbon dating, potassium-argon, argon-argon, and uranium-lead, uranium series) and (2) the techniques that rely on the crystal damage that is generated by the ionizing radiation generated by the decay of radioactive elements (thermoluminescence, electron spin resonance, and fission track) (Pavish, 2006.)

So without the big words, it’s a fancy way of telling how old the rocks on the earth are by the amount of the decay of the elements inside that rock. I’m going to assume the excerpt is talking about argon-argon series of dating, but I really can’t be sure really.

So why is it important to date the rocks on the earth? Does it matter how long we have been around? (I mean not US, but the actual floating sphere in space that we reside on) Sure it does. Well I think it does, but for me I see this post as something more philosophical than scientific because, well I guess I’m just more right brained. I did a quick google search “Why do we need to know how old the earth is?” and really all I’m getting is How do we know how old the earth is? I went through about 10 pages of this and saw no why.

I guess maybe it’s implied that more knowledge is better. To figure things out scientifically is what makes us advanced as humans. There is an innate need to figure out the world and universe around us and how it works. The two most famous ways are faith and science, and by nature seem to conflict. What’s funny is as I’m sifting through the basic google results a lot of biblical stuff is coming up. Maybe the purpose of radiometric dating is to scientifically refute the bible, or at least point out the loopholes in its plots. I’m also seeing a lot of weird political stuff out there too. Man the internet really is full of lots and lots of opinions.

I’m going to assume most of the literature published on the subject of radiometric dating may use lots of jargon and ideas that may be a bit over my head and would take far too long to decipher and explain than we have in our short period of time here. A quick easy search of “radiometric dating” AND accuracy AND rocks actually only afforded me one hit, the Funk & Wagnall’s New World Encyclopedia, this should be more readable, oh and it gives a general reason too. That’s good.

Dating Methods, in earth science, methods used to date the age of rocks and minerals. By applying this information, geologists are able to decipher the 4.6-billion-year history of the earth. The events of the geologic past—uplift of mountain ranges, opening and closing of seas, flooding of continental interiors, changes in climate—are all recorded in the strata of the earth’s crust (Funk & Wagnall’s, 2016).

Scientific dating methods prove that the rocks and minerals found on the earth range back to 4.6 billion years ago. They can also track geological events such as flooding, mountain range shifts and climate changes. This is important. It’s nice to be able to track a history of something, and I see how it’s beneficial for the future to know these things.  I can’t help but think of how different things have become today with all the awful stuff we do to the planet and it’s atmosphere and ecosystems with the products, waste and emissions we have as humans. I know that recycling has become big in the course of my life, that’s a step. Now public transport is gaining speed, as well as re-using things to reduce waste. I try as much as I can to reduce my footprint and I feel like many people are doing the same which is a great step too. I mean do you ever really think of where all your trash goes? What that looks like? The amount of square feet or acres of just pure trash that you throw out in your one little life? I often think of this when I’m cataloging DVDs. There’s a box, then plastic shrink-wrap, then a sticker, then like 5 pieces of paper for ads inside. (So much that’s doing so little).

According to Nat Geo:

Americans generated 251 million tons of trash in 2006, the most recent year for which the Environmental Protection Agency (EPA) has data. Our per capita trash disposal rate was 4.6 pounds per person, per day. Sixty-five percent came from residences, while 35 percent came from schools and commercial locations such as hospitals and businesses. (National Geographic, 2017).

The EPA has it at about the same, give or take. Look at that jump from 1980 to 2000. I wonder what the deal is there. I want to say at LEAST we are kind of leveling off, it would be nice to see it go down, but taking population growth into consideration it doesn’t seem like we are spiraling.


I can’t even fathom how long 4.6 billion years is, nobody can. But I think it’s safe to say that the earth is something that is much older and wiser than us as humans. So we better respect it. From scientific jargon, to philosophical ranting, to standing up for environmental causes. Another Sunday, another random library book.

Dating Methods. (2016). Funk & Wagnall’s New World Encyclopedia, 1p. 1.

Environmental Protection Agency. (n.d.). U.S. municipal solid waste generation from 1960 to 2014 (in million tons). In Statista – The Statistics Portal. Retrieved February 12, 2017, from https://www.statista.com/statistics/186256/us-municipal-solid-waste-generation-since-1960/.

Kulpinski, D. (2017). Where does it all go? Retrieved from: http://channel.nationalgeographic.com/channel/human-footprint/trash-talk.html

Pavlish, L. (2006). Dating techniques, radiometric. In H. J. Birx (Ed.), Encyclopedia of anthropology (Vol. 5, pp. 707-707). Thousand Oaks, CA: SAGE Publications Ltd. doi: 10.4135/9781412952453.n238


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