By Thomas

As many, I was fascinated with dinosaurs as a kid. My childhood memory is filled with pictures of (featherless!) monsters as in Figure 1. For quite a while I wanted to become a “dinosaur-explorer”, after all, it seemed to be quite an easy job (Figure 2) and fun. What fascinated me the most though, were not the creatures themselves but how they came to an end:

A silent killer, stalking through the endless darkness of space, approaching Earth and then – WHAM!!!

From one second to the other – Death and Destruction.

Trex2
Figure 1: Unfeathered (and slightly obese?) T-Rex: Cool! But maybe also feeling a bit cold? Feathered or not, those creatures stay fascinating.
From: chasmosaurs.blogspot.com.au

That at least, is the main theory that explains the last of the five (known) major extinction events in the history of life on Earth. I didn`t knew it at that time, but this theory was only a bit older then myself and was born in 1980 [1-5]. Despite the childhood fascination, I didn`t became a palaeontologist1 but ventured into chemistry and mineralogy for my studies. A few years later I was working on my master thesis, trying to determine how fast natural occurring glasses cool down. The glasses in question were Impactites – Glasses formed from rocks that are molten during an asteroid or comet impact on Earth.

History
Figure 2: Find some bones. Draw some sketches. Give it a name.
Science in the good old days.
From: chasmosaurs.blogspot.com.au

There I was, by coincidence, working on samples, formed by events like the one that obliterated around 75% of all species some 66 Million years ago. And while the problem I had to solve for my thesis was more of a technical nature2, the old fascination with impacts of extra-terrestrial bodies crept out of some corner of my brain, where it had slept for years. I started reading more about the processes and effects of impacts3, and in doing so, came across the early literature that linked the dinosaur’s extinction to a massive impact event. While it was fascinating to read through the original papers that gave rise to the impact theory, I couldn`t help but notice, that the description given therein, were (compared to my imagination) a bit dull:

In brief, our hypothesis suggests that an asteroid struck the earth, formed an impact crater, and some of the dust-sized material ejected from the crater reached the stratosphere and was spread around the globe. This dust effectively prevented sunlight from reaching the surface for a period of several years, until the dust settled to earth. Loss of sunlight suppressed photosynthesis, and as a result most food chains collapsed and the extinctions resulted.” [1]

When writing a scientific paper, one is bound to some degree of “dullness”, as a paper gets its credibility from carefully chosen and precise wording. Unfortunately this leads many people to see science as a rather technical or even boring affaire. The problem is, that they only see the “end product” of a very long and creative thought process.

Luckily, from time to time, we can get a glimpse on the imaginative power, that stands behind a scientific theory, when distinguished scientists find the time to write popular science books. As it so happens, Walter Alvarez, one of the “fathers” of the “dinosaurs got whacked by impact” theory [1], did exactly this.
In “T. rex and the Crater of Doom” he gives an account about how the whole impact could have happened. Assuming the impactor was a comet, he describes it as follows:

“It was a ball of dirty ice, spewing out gases boiled off by the heat of the Sun, and it announced impending doom with a shimmering head and a brilliant tail splashed across half the sky, illuminating the night, and finally visible even in the daytime as Armageddon approached.”

Such difference in wording, compared to the scientific account further above. A depiction which paints a vivid picture in our minds. I don`t know why exactly, probably because it is a story of a world coming to an end, but I felt reminded of another “End-of-the-World” description: Namely, Ragnarök, the destruction and end of the world in Norse mythology. It is described in the poem “Völuspá” in the Poetic Edda (a collection of poems) from Iceland. There the approaching doom is depicted in form of the fire giant Surt:

“Surt comes from the south, and fire he brings.
Branches and twigs to ravage;
From his sword light blazes to be a sun
To all the gods of carnage.”

Note, that I do not want to draw any connections in regards to the content of both descriptions (e.g. that Ragnarök is inspired by an impact event). It`s the similarity in verbalism:
Both accounts are depictions of looming doom that trigger the label “epic” when I read them. Of course, that might not be the case for you, “epic” is a pretty subjective label. So let me compare the two accounts a bit more.

Alvarez describes the world after the big impact as follows:

“Where only the day before there had been fertile landscapes, full of animals and plants of all kinds, now there was a vast, smoldering netherworld, mercifully hidden from view by black clouds of roiling smoke.”

While the Vikings thought, after gods, giants and men had their last fight:

“The sun grows black, earth sinks in the sea,
The bright stars fade from the sky;
Fires and fumes are raging; to heaven itself
The flickering heat leaps high.”

In both cases, the world (or at least life) seems to have come to an end. But as we know, life on Earth didn`t ended with the impact, and so Alvarez finishes with:

“Our nostalgia for the lost world of the Cretaceous is tempered when we realize that it was a world that held no place for us — for large mammals. Our horror at the destruction caused by the impact that ended the Cretaceous is eased by the understanding that only because of this catastrophe did evolution embark on a course which, 65 million years later, has led to us. We are the beneficiaries of Armageddon.”

And of course in Norse mythology the world makes a comeback after the “End of the World”, with a similar optimistic tone to it:

“Yet I see earth rise from the waves again,
Green now for evermore:
The waterfalls flow, and the eagle flies
Hunting fish along the shore.”

So we see, what goes on in a scientists imagination, when thinking about a theory, is likely much more powerful than what he brings to paper later. And it even might be as good a story as we find in other literature. And those kind of stories are the ones which our brain soaks up like a sponge.

dinosvsaliens
Figure 3: Definetly an epic story! The scrap metal from the Alien-machinery even would account for the Iridium anomaly. Still not a very feasable theory.
From: Imgur

But for a scientific text these stories have to be told with neutral and technical terms. Remember though, when we read those texts, nothing stops us from reversing this process and adding some “epicness” to the story, to give our brain something to hold on to.

We just need to let our imagination a bit loose. Not tooooo much (Figure 3) though!

 


1 A more fancy way of saying “dinosaur-explorer” that I learned while growing older.
2 Basically: Can this particular method be adapted to impactites, and if yes, how fast did these glasses cool down? It didn`t worked out for all samples, but we finally could apply the method to an impactite from the El`gygytgyn crater in Russia [6].
3 The book that really got me hooked was Traces of Catastrophe. Even though a few years old by now, it gives a very good introduction into the field of impact cratering.


Literature:

1. Alvarez, L.W., et al., Extraterrestrial Cause for the Cretaceous-Tertiary Extinction – Experimental Results and Theoretical Interpretation. Science, 1980. 208(4448): p. 1095-1108.
2. Smit, J. and J. Hertogen, An Extraterrestrial Event at the Cretaceous-Tertiary Boundary. Nature, 1980. 285(5762): p. 198-200.
3. Hsu, K.J., Terrestrial Catastrophe Caused by Cometary Impact at the End of Cretaceous. Nature, 1980. 285(5762): p. 201-203.
4. Ganapathy, R., A Major Meteorite Impact on the Earth 65 Million Years Ago – Evidence from the Cretaceous-Tertiary Boundary Clay. Science, 1980. 209(4459): p. 921-923.
5. Kyte, F.T., Z. Zhou, and J.T. Wasson, Siderophile-Enriched Sediments from the Cretaceous-Tertiary Boundary. Nature, 1980. 288(5792): p. 651-656.
6. Rantzsch, U., et al., The cooling rate of El`gygytgyn impact glass. Meteoritics & Planetary Science, 2013. 48(7): p. 1351-1358.