Liquid Sand: This Mind-Blowing Experiment Makes Sand Behave Just Like A Liquid

Watch a box of sand turn into a "fluidized bed". The experimenters run their hands through the sand and it drips just like water.
Jessica Miley

How did I not know about this? What is more fascinating than looking at sand but believing it’s water? You believe what your eyes tell you, right?

Don’t be so fast in thinking the surface you’re walking on can’t start moving all of a sudden. It would be like walking on a waterbed. And when we use scientific methods it’s possible to make this happen.

Imagine if the sand on the beach you’re walking on suddenly becomes liquid. It’s actually physically possible if someone managed to insert a giant air compressor underneath the shoreline.

Does it sound like science fiction more than real science? That’s what I thought. But actually, this phenomenon has been put to good use in the past. I just wish they taught me this in science class.

The process is known as fluidization. It occurs when you place a constant flow of air underneath any fine powder or granulated material. The air forces its way to the surface of the material reducing the friction of the sand and making it appear & behave like a liquid.

Have you ever seen an object sink into sand the moment you place it on top? Yes, during fluidization the liquid sand even allows objects to sink or float on its surface. It’s disconcerting to see because it goes against what you previously knew to be possible.

But enough with the words. Check out this video from Rocky Cheng where you can see the process mimicked in miniature in a bucket of sand. You can watch the experimenters run their hands through the sand and it dripping off just like water. The video images seem to play with your mind and it's an addictive watch.

But earlier I mentioned this being put to good use. I only discovered fluidized sand now but many industries have used it for years.

Fluidization had its heyday in the 40’s and 70’s when it was used extensively in the coal mining industry. You can imagine it’s easier to work with massive amounts of granules when they’re in a more fluid form. They’re easier to transport between two points.

Fluidization also helps keep all particles at the same temperature. Imagine the sun baking down on a certain piece of beach. The moment the sand starts flowing, the particles mix and that heat will travel throughout the area. Science is awesome, isn’t it?

Where can you see liquid sand in action today? The idea of sand like water still has a place in some industrial processes as well as having applications in the shellfish and powder coating industries.

And what about some truly original applications?

This video was posted to Reddit where a few users tried to decide if this process could be used to build a sand moat around a property. The moat would be solid for most of the time, but if enemies approached, an air compressor would be turned on and the intruders would sink down into the sand & be trapped. Sounds possible and terrifying.