Why when I hit the nozzle of another bottle of beer, it starts to foam?


As the title says. I’m sorry English is not my first language and I’m on a party but the question came to my mind and I remembered this sub.
You know guys you’re with your friends and hit the bottle of your friend and the beer starts to do it’s thing

In: 0

When you hit the top of a beer bottle with another bottle, what happens is the force of the collision forces the impacted bottle to start moving downwards, while the beer inside hasn’t started moving yet. This creates a negative pressure in the beer, and causing cavitation bubbles to form at the bottom of the beer bottle. Cavitation bubbles happen when the pressure is reduced in water, causing a small portion of the water to turn into gas. This cavitation gas bubble quickly collapses, and which can be very energetic and damaging. Boat propellers can create cavitation, and can become [badly damaged by cavitation bubbles](https://images.app.goo.gl/g3G7ZXe64TcTQgMe9). So, when the cavitation bubbles collapse in the beer, they rapidly and violently cause the carbonation to come out of solution,. This caused the beer bottle that was hit to foam tremendously, and allows you to point and laugh at the friend you’ve just done this to at a party.