Glass Bottle Bottom Blown Out

[BrandywineTSD]

You are right that it requires physics to work, but so do all breaks. Wood breaks must break along the grain, speed breaks must break faster than the object is allowed to bend, etc. It still requires good technique and an appropriate amount of force. If the technique is off a little the break fails. It is not intended to be a "power break." No need to apologize for explaining the physics of the break. The bottle size, style, amount of water, position of the hand...all come into play.

[ricktkd69]

i'm sorry to say this, but this is just a trick. The laws of physics come into effect. The water doesn't compress so it travels the force as one. It doesn't take any effort to do this trick. sorry about that.