The Scary Thing About the Universe
Species extinctions are kind of like human deaths—they’re happening constantly, at a mild and steady rate. But a mass extinction event is, for species, like a war or a sweeping epidemic is for humans—an unusual event that kills off a large chunk of the population in one blow. Humans have never experienced a mass extinction event, and if one happened, there’s a reasonable chance it would end the human race—either because the event itself would kill us (like a collision with a large enough asteroid), or the effects of an event would (like something that decimates the food supply or dramatically changes the temperature or atmospheric composition). The extinction graph below shows animal extinction over time (using marine extinction as an indicator). I’ve labeled the five major extinction events and the percentage of total species lost during each one (not included on this graph is what many believe is becoming a new mass extinction, happening right now, caused by the impact of humans):1
…Let’s imagine the Earth is a hard drive, and each species on Earth, including our own, is a Microsoft Excel document on the hard drive filled with trillions of rows of data. Using our shortened timescale, where 50 million years = one month, here’s what we know:
- Right now, it’s August of 2015
- The hard drive (i.e. the Earth) came into existence 7.5 years ago, in early 2008
- A year ago, in August of 2014, the hard drive was loaded up with Excel documents (i.e. the origin of animals). Since then, new Excel docs have been continually created and others have developed an error message and stopped opening (i.e gone extinct).
- Since August 2014, the hard drive has crashed five times—i.e. extinction events—in November 2014, in December 2014, in March 2015, April 2015, and July 2015. Each time the hard drive crashed, it rebooted a few hours later, but after rebooting, about 70% of the Excel docs were no longer there. Except the March 2015 crash, which erased 95% of the documents.
- Now it’s mid-August 2015, and the homo sapiens Excel doc was created about two hours ago.
Now—if you owned a hard drive with an extraordinarily important Excel doc on it, and you knew that the hard drive pretty reliably tended to crash every month or two, with the last crash happening five weeks ago—what’s the very obvious thing you’d do?
You’d copy the document onto a second hard drive.
That’s why Elon Musk wants to put a million people on Mars.
On a related note the latest Planet Money podcast is How to Stop an Asteroid. It’s funny and informative and yours truly makes an appearance. Worth a listen.