I LOVE Science - seeing the moment of extinction

 

You know when you re-imagine your life, in particular when you re-imagine what you would have studied at university if you knew then what you knew now? Well I sometimes think 'what if I had studied Chinese, or Mathematics, or one of the Sciences? (instead of English Language and Literature, since you ask)

The Chinese is from later life interests, but the Science is from pure admiration for the scientific process. I just love that pure commitment to establishing what you can know and test, to try to understand the nature of things. And I know that people have all sorts of silly ideas about what science is and how it works, and I also know that sometimes it doesn't work as purely as it should. But at root it is a very simple process. How can I know these facts and I how can I prove them?

I also know that some scientists will spend their entire lives researching and testing and theorising about one small element of a large process that will help someone else eventually to prove something much bigger. Which brings me to today's little paean.

It was clear to paleontologists as early as the 18th century that there were major extinction events in the history of our planet; times at which large percentages of previous species had suddenly disappeared from the fossil record. Admittedly, that 'suddenly' might have been a few million years, but that still counts as sudden in a 3.5 billion year record. 

And one of the best-known extinction events was the one that killed off all the non-avian dinosaurs, about 65 million years ago, from what you could see from the geology and timelines. Various theories gave explanations, and in the 1970s there was a lot of interest in the idea that an impact from a large extraplanetary body such as a meteorite or comet, could have triggered it. 

Anyway, through a lot of work by several scientists, it was eventually established that there was a smoking gun, a previously undiscovered impact crater on the coast of Mexico, which was evidence of an asteroid impact by a 10-km wide object travelling at 20km per second. Many previous observations fell into place after that discovery and it is now generally accepted to be the main cause for this extinction event. Though it would not be real science if there was not some room for doubt. 

But a stunning discovery in Arkansas, about 2000 miles from the impact site, threw a chilling light on the very moment of this literally earth-shattering event. While slowly excavating a promising fossil bed, the paleontologists came across fossils of fish which had been peppered with small glass beads as if from a shotgun (the picture at the top). 

These small glass beads are called 'microtektites' and they can sometimes be produced by a volcano but they are certainly produced when trillions of tons of rock are vaporised by an impact and thrown so high into the stratosphere that they eventually cool, solidify, and accelerate towards the ground like avenging angels. So it seems these fish died within minutes of the event that remodelled the world in which they lived and died. 

I LOVE Science.