There is a neat idea called the Murder on the Orient Express Theory, which I’ve been thinking about a lot lately (especially when taking a look at the news). It was first explained to me as being a sort of “ultimate bad day” and has a lot to do with probability.
Prepare yourself for dinosaurs, Agatha Christie, and probability.
Extinction is not a new idea. Over the course of the history of Earth there have been five major extinction events, the most famous being the one that brought about the end of the dinosaurs. To be more precise, this one is called the Permian Triassic (PT) Extinction, and to be less precise it goes by the name of the Great Dying. It is the most catastrophic extinction event Earth has ever had. 96% of marine life died and 70% of terrestrial life. Every creature from dinosaurs to insects suffered.
A lot of people believe an asteroid is a culprit. There is a great deal of evidence to support this, so maybe I should use a stronger word than “believe”. The case has gone pretty cold after 250 million years, but clues have been left behind. Alternative theories have sprouted that it was caused by severe volcanos, sea level changes, global warming, etc.
And then there is the Murder on the Orient Express Theory. Named after the mystery novel by Agatha Christie, and alluding to the surprise ending which I will not spoil, this theory considers what if everything that could go wrong went wrong. What if Earth just had a really bad day? What if the PT Extinction was caused by volcanoes, and then global warming, and then a deep impact? If just one of these events were to happen it would be catastrophic, but certainly something that Earth could recover from. But what if these events just happened back to back? It would be unspeakably horrible on a global scale.
Probability says that it is very unlikely a terrible asteroid will hit the Earth while you are reading this. It is also very unlikely that a tsunami will strike at this time as well. But, given a large enough sample amount of time it becomes more and more likely that these two events will happen, and that they would even overlap. Earth will have a bad day. And when this sample amount of time is over 4 Billion years then it becomes incredibly likely that this overlap would eventually happen. It’s very possible that all of the major extinction events can be attributed to this type of bad day.
And note that as far as bad day goes, it does not mean all of these events happen on the same day. It could be as long of a time period as one million years. In the grand scale of things, a million years is a brief period of time. Earth could be hit with a big disaster, and a second one before it has time to fully recover.
How likely is it that a bad day would happen? Well, it turns out that massive extinctions have in the past occurred almost regularly every 62 million years for over 500 million years as found by a study from Berkeley. In fact, how regular it happens is a bit of a head scratcher, and they have been investigating if there is a direct cause. Where do we fall in that once every 62 million year range? Are we on the chopping block? Well, we’re overdue for a massive extinction apparently by 3 MILLION YEARS, because the last extinction was 65 million years ago. So how much longer before we have ourselves a bad day?