Sometimes known as the "Levitating Water Trick", surface tension prevents the water flow flowing out of the upturned bottle and even allows small pieces of plastic to be inserted.
Copyright 2016 University of Illinois Board of Trustees. Video of surface tension is made available under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License (international) CC BY-NC-ND 4.0: creativecommons.org/licenses/...