ABSTRACT
Put some small pieces of kitchen foil on the workbench. You can use small pieces of cork, instead. Rub a plastic pen with a dry woollen cloth. Rub hard for ten or twenty seconds. Hold the pen a few millimetres above the pieces of foil. They jump up and stick to the pen. Some of them may jump up and down again several times. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780080959153/a02e7bef-ec09-4853-831d-9795f01199b3/content/fig1_1_OB.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780080959153/a02e7bef-ec09-4853-831d-9795f01199b3/content/fig1_2_OB.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>
