We’ve all seen quicksand a dozen times in Hollywood movies. In fact, Slate worked out that around 3 percent of the films made in the 1960s had quicksand in them. The usual cinematic cliché is a hapless hero stumbling into a bubbling pit of quicksand (usually with a half-sunk “Warning: Quicksand” sign) in the middle of the jungle. As time slowly ticks away, they steadily plunge deeper and deeper until all that’s left poking out is their outstretched hand.
But how realistic are these depictions? And the real question is: how do you escape?
"Quicksand" is a term used to describe a mixture of water and fine granular material like sand, silt, or clay. Effectively it’s a bed of waterlogged sand with the viscosity of a super-thick milkshake or, perhaps more accurately, a suspension of corn starch in water. It is a non-Newtonian fluid, meaning any applied stress (like a punch or a stomp) will make its apparent viscosity decrease and effectively turn it solid. This means, in theory, you should be able to run across without sinking.
On the other hand, any attempt to yank a limb out of the quicksand will also cause it to seize up and give it solid-like properties. This is partly where the old mantra of “the more you struggle, the more you’ll sink” comes from. So yep, don’t panic. In most scenarios, you would have to be very unfortunate to be fully sucked under. The main concern is getting jammed near the sea with a fast-approaching tide – being drowned in the quicksand itself shouldn't worry you too much.