Multiple freezing-melting pathways of high-density ice through ice XXI phase at room temperature.

Summary: Did you know there are many different types of ice? Usually, scientists have to make water super cold to find weird, new kinds of ice. But recently, scientists did something amazing! They squeezed water really, really hard at normal room temperature. By using a special diamond tool and powerful X-ray lasers, they watched the water freeze and melt in totally new ways. They even discovered a hidden, temporary type of ice called "Ice 21" before it turned into another type called "Ice 6". It shows that water still has many hidden secrets!