The Caliber Debate, Settled.

November 1st, 2013

We've all endured the various debates about handgun cartridge effectiveness. We're told the venerable .45 ACP is capable of physically unfeasible things, while the 9mm will annoy an assailant at best. While some folks have conjecture and anecdotes, I have physics on my side.

It's all about black holes, specifically the Schwarzschild radius. That's a measurement of how tightly a given object must be compressed in order for it to become a gravitational singularity. For example, the Sun would have to be compressed to a radius of roughly 3 kilometers before it became impossible for light to …