[gblake]

Originally Posted by Necroterra

I'll admit I don't know much about the topic, but if you used the right density of foam (or maybe layers of scaling density), wouldn't the deformation absorb the impact and send you flying less? Solid steel won't get shredded by a spinner, but instead it just launches you away.

Shock absorber deformation slows/reduces the accelerations, but doesn't decrease the total energy involved. So, yes, shock absorbers tend to attempt to reduce shock magnitudes by spreading energy over longer times and distances, but they don't make the energy disappear (some is turned into heat, the rest shows up in rebounds, etc.).

If a spinning blade does hit a large, inflexible mass, BOTH the item that gets hit AND the device holding the blade experience roughly similar shocks. A difference is that the spinning blade device's designer knew exactly where that shock would hit, and could build in compensation for the shock.

Protecting (in the sense of surviving a head-on hit without being affected) the exterior of anything physical from attacks that can come from any direction an attacker chooses is usually hard to do.

Becoming a more difficult target to hit head-on, or finding a hole in the attacker's strategy is often easier than choosing to be on defense and then going toe-to-toe with them.

Blake