SCIENTISTS FIGURED OUT HOW TO WRITE IN WATER

Summary from the TLDR newsletter

A team of German physicists has figured out a method for writing on water. The method involves putting ink directly into water using a microbead made of an ion-exchange material as a pen. The bead writes by altering the local pH value of the water, attracting ink particles to those areas. The method is at a proof of concept stage - future iterations may be able to generate highly complex patterns in fluids. Examples of images drawn in water using the method are available in the article.