object shrinks whenever I give it rigidbody physics I am trying to make this helmet that you see here below, interact with the ground using rigidbody physics.  However, when I give it an active rigidbody and push play on the animation, the object immediately shrinks really small, and the only way to get it back to its regular size is to undo the rigidbody.
(before )

(After)

Does anyone know why it is doing this?  Any help is appreciated! :)
(PS, I will give the link to my file below)
The helmet shrinks because you have a keyframe on the scale of the helmet. Have a look at the orange block on the first screenshot. It scales down over time (2nd screenshot).
Remove the keyframes, reset the scale to 1 and it should be fine.