sciencehabit writes "Filling a small swimming pool with cornstarch and water has long been a physicist's party trick. Step onto it slowly and you'll sink, but run across quickly and the oozy mixture will support your weight — almost as though it has turned from liquid to solid. Several reasons have been offered for the phenomenon, but now researchers believe they have the real answer. The key to figuring things out: plunging a 370-gram aluminum rod from a slingshot at around 1 meter per second into a cornstarch suspension." One meter per second doesn't seem very fast for anything launched by a slingshot, but any speed is good as long as it advances important knowledge like this.