What needs strengthening?

So strengthen your drooping hands 

and your weak knees.
 Make straight paths for your feet,
that what is lame may not be 

disjointed but healed. 

--Hebrews 12: 12-13

    This is a picture tracking bullet holes on Allied planes that encountered Nazi anti-aircraft fire in WW2.

    At first, the military wanted to reinforce those areas, because that’s obviously where the ground crews observed the most damage on returning planes… until Hungarian-born Jewish mathematician Abraham Wald pointed out that this was the damage on the planes that made it home, and the Allies should armor the areas where there are no dots at all, because those are the places where the planes won’t survive when hit.

    This phenomenon is called survivorship bias, a logic error where you focus on things that survived when you should really be looking at things that didn’t.

Image & story source: https://www.facebook.com/williamson.orgpsych/photos/a.1293475024130893/2040927782718943/?type=3