People mind-blown to find out blocks of dry ice can float on sand

You'd think ice would melt the moment it hit hot desert sand, right?

Well, not if it's dry ice.

According to HowStuffWorks, dry ice is 'frozen carbon dioxide', which it says has a surface temperature of -109.3 degrees Fahrenheit, which is about -78.5 degrees C.

A video on the r/Damnthatsinteresting Reddit thread shows just how dry ice can glide across the desert sand.

Posted by Redditor u/kirsion, it explains just why and how it all happens.

The video, which features footage originally made by Huck and his brother Tel Stewart, whose YouTube channel is @TeamStew, starts by asking: "What would happen if you placed dry ice on the desert?".

It goes on to show some blocks of dry ice tumbling out of a protective bag on to the sand and explains: "When gently pushed the dry ice glides smoothly across the sand." Conversely, the video shows a rock being placed on the sand and it doesn't glide at all.

However, as the video points out: "When the rock is put on the dry ice, it moves smoothly over the sand."

So just how is this all happening?

The video explains: "When dry ice touches the sand it causes sublimation at the bottom creating a boiling like effect.

"As the dry ice sits on the sand, the contact area rapidly releases a lot of gas then a layer of carbon dioxide forms between them acting like an air cushion track".

"The dry ice hovers over the sand with almost zero friction so even a light push causes it to slide quickly forward".

According to Britannica.com, sublimation is, in physics, the 'conversion of a substance from the solid to the gaseous state without its becoming liquid'.

The Reddit video has people amazed, with one comment reading: "Now we know how those land speeders worked in Star Wars".

Someone else wondered if there was perhaps a sporting angle to be found as they posted: "Now someone has to make a dry ice snowboard for science".

A discussion on snowboarding in the desert also ensued but as one person pointed out: "You can snowboard on sand. They do this in Qatar (and presumably elsewhere)".

Some scientific explanations also followed on the thread, with one user saying: "Solid phase changing directly to gas is called sublimation which leaves a gas cushion around the block of dry ice, yes".

But another person offered up an entirely more detailed explanation too writing: "But it would be interesting to add that there is some 'dry quicksand' effect at play here. Sand will behave much like a liquid if injected with air.

"In this case, some of the CO2 vapor not only cushions the dry ice block, but partly makes the sand act like a liquid too, would only work if the sand is fine enough, you would notice this effect my 'bubbles' rising up to the sand surface like in the video at 00:13".

So there you have it. But also, take note, when using dry ice you have to wear really thick, protective gloves and appropriate eye wear, because if it touches bare skin, it will cause severe burns given its freezing temperature.