Amazon's supercomputer doesn't exist. Except that it does. Photo: MarkHillary/Flickr

The 42nd fastest supercomputer on earth doesn’t exist.

This fall, Amazon built a virtual supercomputer atop its Elastic Compute Cloud — a web service that spins up virtual servers whenever you want them — and this nonexistent mega-machine outraced all but 41 of the world’s real supercomputers.

Yes, beneath Amazon’s virtual supercomputer, there’s real hardware. When all is said and done, it’s a cluster of machines, like any other supercomputer. But that virtual layer means something. This isn’t a supercomputer tha...