 In this study, researchers observed how polycrystalline materials solidify in microgravity conditions aboard the International Space Station. They found that individual crystal cells from one grain could invade another grain of different orientation, creating complex and convoluted boundaries between them. These findings challenged the traditional understanding of grains as discrete regions in three, dimensional space, instead suggesting that they are more like fluid, like entities that can interact with each other. This article was authored by Jungil Song, Fatima El Mota, Damian Tourette, and others.