Today's photo of the day features "Mushroom rock", located off the coast of Muscat, Oman. This deranged sandstone rock formation was weathered by the ocean waves to the point of fungal oblivion. Water erosion is a powerful force that can do more than just chisel away at rock - it change the shape of coastlines. Don't believe it? Here's an experiment you can try at home to explore the erosive effects of ocean waves on shorelines!