Pub trick -- opening a wine bottle without a corkscrew
Jearl Walker www.flyingcircusofphysics.com
October 2014 Previously, I discussed how you can open a bottle of wine with a shoe. Yes, a shoe. Here is another way to open a bottle without the proper corkscrew opener.
The purpose of the corkscrew is to dig its way into the soft cork so that you have a handle on the cork. You can then pry the cork out of the bottle by pulling upward on the corkscrew. But the friction between the cork and the interior of the neck of the bottle is large. That friction is said to be static friction because there is initially no sliding. The downward frictional force on the cork matches your upward pull on the cork. But if you pull hard enough, you can exceed the maximum value of static friction, and then the cork begins to slide and the friction actually decreases. Thus, getting the cork to slide is the main challenge.
One way is to twist the cork. The rotation itself won’t bring the cork out of the bottle, but once the cork begins to rotate, the friction is reduced and then a moderate upward pull can be enough to remove the cork.
If you lack the corkscrew, any device that can dig into the cork can be used. In the first video here, a common key is used. Once inserted, you can push horizontally on the key start the rotation while also pulling upward on the key once the static friction is overwhelmed.
In the second video, a pair of scissors is used, but notice that the woman could easily have run a blade through her hand. This technique might be OK for the first bottle of wine, but certainly not for the second bottle after the first one has been drunk.
The same danger of puncture lies in the third video in which a knife is used. However, the use of a carpenter’s screw hanger is safe enough, and the use of a bicycle pump to increase the internal pressure is not only safe but inspired. Still, I cannot recommend you use this technique on a first date if you have any hope of a second date.