The New York Times > Science > Beware! Sand in This Physics Lab May Eat You Alive: "Beware of playing in any sandboxes you might find in the laboratory of Dr. Detlef Lohse.
Traditional deathtrap quicksand is a slurry of sand, water and clay. The water keeps the sand from sticking together to support weight, and a person who steps in slowly sinks.
Now Dr. Lohse, a professor of applied physics, and his colleagues at the University of Twente in the Netherlands show that it is possible to vanish into a pile of completely dry sand as well. Worse, their sand looks the same as the normal, weight-supporting variety."
That is intense. The image depicts 4 frames of the video footage. The ping-pong ball gets swallowed up into DRY sand. That is most definitely an amazing scientific discovery!