# How does Captain America's shield bounce?

In the first Captain America movie Howard Stark says "Vibranium. It's stronger than steel and a third of the weight. It's completely vibration absorbent."

If the shield completely absorbs vibrations, how does it bounce?

I'm looking for MCU references primarily, with current comics being a close second.

Newtons third law states that every action has an equal and opposite reaction.

Knowing that the shield is made of the strongest material on the planet and that Captain America has super human strength, it is no stretch of the imagination that the resulting force of the throw could potentially bounce back off a HARD surface.

I've not seen a case where he bounces it off a soft surface, like a human... this to me would dampen the kinetic energy... like putting your finger in a newtons cradle and watching it all stop.

In Age of Ultron, Captain America has a much more sophisticated suit that uses magnets to return the shield to him... but in the films prior to that suit... Newtons 3rd law seems to be the answer.

• I could understand that for a normal metal shield. But vibranium absorbs all vibrations, so my understanding is that the kinetic energy is absorbed by the shield. IE, when Thor hits the shield with his hammer, the blow is absorbed by the shield, it's not passed to Steve's arm which would cause it to break (possibly). It seems like the shield should hit the wall and just 'stop'.
– cnim
Jun 2, 2015 at 13:16
• ah... that's true... i forgot about vibraniums vibration dampening property Jun 2, 2015 at 13:19
• perhaps the outer rim of the shield is a different material to the center? I'll look for information. Jun 2, 2015 at 13:23
• I bet it's the old "inconsistent movie magic". Jun 2, 2015 at 16:51
• Down vote because Cap's Shield does not conform to the Laws of Physics as we know it. It can absorb all vibrations with no equal reaction. No Recoil. Except when Cap wants it to. Also, he bounces it off people all the time.
– cde
Mar 4, 2016 at 21:10