If you think your government can protect you from underground monsters, you're wrong. And we've got the soil analysis to prove it. A new study shows that the faster a missile goes, the less well it penetrates the ground.

In other words, it looks as though the god-damn underground monsters are able to move through the dirt much more easily than the projectiles we try to use to stop them.

Ground-penetrating missiles are not performing the way designers, at first, thought they should. We tried making missiles into ground-penetrating weapons — supposedly to destroy bunkers and weapons caches, but we all know the real reason — by making them hit the ground at a higher speed. This did not work. IN fact, often the faster missiles didn't penetrate as deeply as slower missiles.

Duke University took a look at why this happened. They dropped projectiles into beads that were photoelastic, and photographed the entire thing using a polarized filter. What they found were "force chains" — networks of force that sprang up as the energy got transferred from the projectile to the ground.


When the speed of the projectile was low, these chains propagated slowly, meaning that as the projectile moved through the beads, it dealt with mild resistance over a long distance. When the speed of the projectile increased, the chains of stress propagated very quickly. The projectile met massive resistance all at once, and stopped.

In short, we thought that hitting the ground a little faster might cause a little more resistance, but it causes a lot more resistance. Resistance mounts out of proportion with the speed of the projectile, so the faster a missile hits the dirt, the faster it stops.

What do we do now? Well, I'm not going to lie. Those of us who chose to live on loose soil probably will be eaten within a month or two. Those who live in the mountains — Avenge us!


Impact Image: Abram Clark & Physical Review Letters

[Source: Nonlinear Force Propagation During Granular Impact.]