A Hot Tub Filled with Liquid Sand | Outrageous Acts of Science

♪♪ Narrator: FRIEND OF THE SHOW MARK ROBER IS BACK WITH A NEW VERSION OF THE JACUZZI. I AM SITTING IN A HOT TUB FILLED TO THE BRIM WITH SOLID SAND. THAT?! Narrator: MARK IS TURNING SOLID SAND INTO LIQUID AND PROTECTING ONLINE WITH OVER 24 MILLION VIEWS. THIS IS JUST AMAZING. I REALLY WANT ONE OF THESE IN MY HOUSE. NO, SERIOUSLY, I WANT ONE OF THESE IN MY HOUSE. Narrator: WE ARE MOVING TOWARDS CALIFORNIA TO DIVE INTO OUR FIRST QUANTUM LEAP. I WANTED TO CAPTURE THE REAL LIKE FIRST REACTION OF WHAT IT FELT WHEN WE TURNED IT ON, AND WHEN I'M SITTING THERE AT THE BEGINNING, IT'S LEGITIMATELY THE FIRST TIME WE TURNED IT ON.

AND THE FEELING OF JUST SITTING ON SOMETHING THAT IS COMPLETELY SOLID AND THEN SUDDENLY IT JUST LIQUATES. IT'S A CRAZY, STRANGE, STRANGE FEELING. THE ENTIRE CONSTRUCTION TOOK US APPROXIMATELY 2 MONTHS. I'd say half of that was just making the prototypes and figuring it all out, like figuring out the general principles, and then the other half was actually building the hot tub. Narrator: NO, IT SURELY WAS NOT QUICKSAND SAND, SO HOW DID MARK IMPROVE THIS HOT SAND PIT? BRAND HAS MADE WHAT IS KNOWN AS A FLUIDIZED BED. Parker: THIS IS WHERE THE AIR IS PUMPED THROUGH THE SAND, MAKING IT BEHAVE LIKE A LIQUID.

WHEN THE AIR IS TURNED OFF... ...IT GOES AGAIN TO BEHAVE MORE LIKE A SOLID. It just stops and you're locked in place. MARK HAS 18 COPPER TUBES RUNNING SIDE SIDE AT THE BOTTOM OF THE JACUZZI. IN THESE, HE HAS DRILLED OVER 2,500 HOLES WHICH ARE REGULARLY SPACED AND ALL POINTING DOWN SO THAT THE SAND DOES NOT GET STUCK IN THEM. THOSE TUBES ARE WELDED TO A LARGE PIPE THAT IS CONNECTED TO THREE NITROGEN GAS CYLINDERS. THEN MARK FILLS THE JACUZZI WITH MORE THAN A TON OF DRY SAND. Narrator: BUT HOW DO YOU MAKE SAND ACT LIKE A LIQUID?

WHEN MARK OPENS A NITROGEN CYLINDER, THE GAS PASSES BETWEEN THE GRAINS OF SAND, REDUCEING THE FRICTION BETWEEN THEM. THE GAS PROVIDES AN UPWARD FORCE ON EACH GRAIN OF SAND THAT COUNTERACTS THE FORCE OF GRAVITY. Elliott: So if those two forces are in balance, the

sand

just floats. THE GAS FLOW HAS TO BE ADEQUATE TO ALLOW THE GRAINS OF SAND TO MOVE FREELY OVER EACH OTHER. IF THE GAS COMES OUT TOO FAST, IT WILL GIVE TOO MUCH FORCE TO THE GRAINS OF SAND AND THEY WILL FLY OUT OF THE JACUZZI. TOO LITTLE GAS AND THE SAND WON'T MOVE AT ALL.

I CAN'T TAKE IT OUT. What's so weird is that when you lift your hand or leave it, it's completely dry. LIKE, THAT'S THE PART THAT'S LIKE, "WHAT'S GOING ON? THIS IS NOT AT ALL CORRECT." CUT IT. AH! THIS LOOKS A LOT OF FUN UNTIL YOU HAVE TO GET SAND OUT OF THE PLACES.