Tactical hand signals...on the off chance I find myself with a member of the military during a zombie apocalypse, I'll be glad I repinned this. The time to study up is now!
bear1na:The Many Armors of Iron Man
Infographic: Electricity A visual cheat sheet about electrical physics, containing the most important formulas of current and Ohm’s law expressed through an impossible water circuit analogy. (by Pierluigi Scotolati)