Carbon-14 Dating of a Fruitcake: A Holiday Chemistry Lesson From Hell

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Fruitcake aficionados, look away. It's holiday time and some of you will receive a re-gifted fruitcake that is ??? years old. How old? We'll show you how to figure it out in this Christmas Special Chemistry Lesson From Hell. We will also explore whether the fruitcake is the worst gift ever. And more!

Christmas is around the corner, and that means a bunch of bad gifts are heading your way. Some will be merely bad, like a calendar with a different cat hairball for every month. But even though you'd be hard-pressed to find anyone who actually wants a wall calendar, let alone one with hairballs, at least has the year on it, so it is unlikely that it was regifted – some misguided soul spent the time and money to purchase it. Other gifts are clearly regifted. Go ahead and try to convince me that you didn't regift a Chia Head back whenever those monstrosities first came out. 

Can't get much worse than this, right?



The Andrew Kolodny Chia Head. Coming to a rehab center near you! (Back-ordered - Supply chain issue)

It could be worse. At least when you throw the Chia Head out the window, it makes a satisfying sound when it hits the pavement. And if it lands on someone, it probably won't kill him. The same cannot be said for the truly hideous fruitcake, perhaps the most regifted gift of all.

In fact, on my list of research projects for next year, is to find supporting evidence that only a few dozen fruitcakes have ever been made and that they all circulate in random patterns during holiday time, resting for 12 months, only to be unleashed on the world a year later. 

(I'm aware of this because of a little-known fact: Bill Gates did not begin tracking vaccine victims with microchips. His pilot program started tracking fruitcakes. I mean real fruitcakes, not the vaccine conspiracy variety, just to show that the technology was reliable.) 

Let's leave that alone for a while and focus on the issue at hand: using chemistry to show how old these things really are. This means it's time for:

All elements have one or more isotopes, usually caused by extra neutron(s) in the nucleus. Some isotopes are stable, for example, 2H (deuterium) and 13C, and some are unstable, like 14C or all uranium isotopes. Unstable isotopes decay at specific rates, emitting a nuclear particle plus energy in the process. Measuring the ratio of 12C to 14C in a sample can tell you its age. Here's how (Figure 1).

Figure 1. A trace amount of 14C is formed in the atmosphere when nitrogen (14N) reacts with sunlight. Once formed, it immediately begins to decay back to 14N with a half-life of 5,730 years. The 14C, in the form of 14CO2, is taken up by plants, just like normal carbon dioxide. As the 14CO2 (or whatever the plant has converted it to) decays, it is replenished by more 14CO2 from the atmosphere. So the plant will always contain the same level of 14C as long as it remains alive. Likewise, as animals eat the plants, they will be taking in 14C at the same rate as it decays. This means that the ratio of 14C to 12C is the same in all living organisms. Diagram: Wikimedia Commons

But once an organism dies, it will no longer take in 14C, and whatever radioactive carbon it contains will steadily decay. So, the ratio of 14C to 12C in non-living material acts like an "atomic clock." The less 14C, the older the specimen. This ratio can be measured by a technique called mass spectrometry.

Image: Wikimedia Commons

Example: If a wood artifact has half the amount of 14C as that found in a living tree, then that wood is 5,730 years (one half-life) old. If it has only 25%, then the artifact must be 11,460 years old. After nine half-lives (51,000 years), only 0.0015% of the 14C remains, and it gets hard to measure; 14C is no longer helpful in dating specimens older than about 50,000 years. 

How Old is This Fruitcake?

In determining how many times a fruitcake has been regifted, its age may provide vital clues. Is the thing someone dumped on you five years old? 20? Let's do some math on fruitcake #17.

Fruitcake #17. Photo: Walmart

First, we tested that ear wax-looking thing marked #1. The mass spec indicated that 99.4% of the 14 C remained. If you plug that number into a handy dandy 14C dating calculator, it tells us that ear-wax thing #1 is 50 years old, putting it right in the middle of the disco era! This brings up the disturbing image of another fruitcake:

"Disco Joe" Mercola  Image:

Next, we tested thing #2, another culinary abomination – the Maraschino cherry. Although there is an ongoing debate about whether Maraschino cherries were ever living organisms, nonetheless, its age was measurable by the mass spec. The cherry was also 50 years old. 

Finally, just to be thorough, we took a core sample. This wasn't as easy as you might think.

First try. Image: Flickr

But with a bit of effort and a titanium drill bit, a sample was obtained. 

I must say that I was a bit surprised by the result: only 98.1% of 14C remained. The handy dandy 14C dating calculator revealed that the fruitcake was 158 years old, putting it right in the middle of the Civil War! Perhaps it was used in place of cannonballs.

The life of fruitcake #17

We can surmise the life of #17 by making certain assumptions. Fruitcake #17 was created and later underwent aftermarket modifications. The core sample tells us that the atrocity was first baked in 1861, perhaps as a gift to President Lincoln. A few years later, Andrew Johnson regifted it, probably to Robert E. Lee, to further rub in that he lost the Civil War. Then things become murky. During Reconstruction, life was hard, and people were starving, especially in the South, but #17 was not eaten. It is possible that starving Southerners regifted it during this time. 

At some time between the late 1860s and 1971, the stuff on top was scraped off, possibly for use as a rat poison, and the cake portion was used as insulation or maybe a punching bag. It is unclear whether a topless fruitcake gets regifted, but #17 reentered the regifting cycle when someone, perhaps Barry Gibb, added a new topping consisting of the unknown matter and Maraschino cherries. Now, 50 years later, it emerges as a lab specimen, which some unfortunate person will receive next year. Quite a journey indeed!

Others agree

I am hardly the only anti-fruiter out there. There are websites devoted to anti-fruitcakeism (See Burning Question: Why do so many people despise fruitcake?). I ran into some hilarious quotes. Here is my Christmas gift to all of you:

'The worst gift is a fruitcake. “There’s only one fruitcake in the world and people keep passing it around” (See that!)

Johnny Carson


“Airport screeners are now scanning holiday fruitcakes. Not even the scanners can tell what those little red things are.”

 David Letterman

Have you ever known anyone who bought a fruitcake for himself? Of course not. They are purchased as Christmas gifts, mostly for people you don't particularly like. 

Author: Phyllis Diller


 I would eat fruitcake if there'd been a nuclear war and I'd run out of canned goods. - Author: Deb Caletti

The easiest way to make a fruitcake is to buy a darkish cake, then pound some old, hard fruit into it with a mallet. Be sure to wear safety glasses. Author: Dave Barrett

Saving the best for last, here's some damn fine prose:

"For months they have lain in wait, dim shapes lurking in the forgotten corners of houses and factories all over the country and now they are upon us, sodden with alcohol, their massive bodies bulging with strange green protuberances, attacking us in our homes, at our friends’ homes, at our offices — there is no escape, it is the hour of the fruitcake."

Deborah Papier (a writer and editor)

(Actually, the worst/best quote by far was by Oscar Wilde, and it's in very poor taste. So much so that my colleagues yelled at me so I took it out. Look it up if you wish but don't shoot the messenger.)

I think I'll stop here and wish all of you a happy, virus-free holiday season, from all the fruitcakes at ACSH.