This video has gone viral in the past week, and it’s not because of a cute animal doing mischievous things, or someone publicly embarrassing themselves. Simply, it is a video of two friends walking across a frozen lake in the Slovakian HighTatras Mountains. However, the ice is so clear that it appears that the men are walking on water, which is surprisingly unnerving.
So what is the explanation for this clear ice? This happens when the water freezes with no air bubbles, snow or impurities trapped. When these things are present, the light scatters through these impurities, causing it to have a cloudy appearance. It also indicates the depth of a body of water, this one being about 174 feet deep!