A Swimming Pool of Orbeez Is All Kinds of Scientific Fun
If you could swim in anything, what would it be? We already know that clear putty is not fun and a pool of puppies sounds dangerous. So what about Orbeez? The superabsorbent polymers are tiny balls that grow when placed in water. You can find them in toy stores, peddled in tourist traps, and inside diapers. Thanks to their slippery surface, they look like they'd be great to take a dip in.
YouTube user Mark Rober decided to actually fill a swimming pool with Orbeez (along with some larger generic brand water balls) for science. The former NASA engineer teamed up with The Backyard Scientist who, as the name suggests, had a backyard to conduct the experiment. After filling a giant pool with 25 million liquid polymers, they were ready to test a hypothesis: If you jumped in, how deep would you sink? Rober theorized that he would only sink to about his waist, but ended up sinking all the way to his shoulders.
According to Rober (and your high school science teacher), objects displace their weight in water. That means when a 100 gram item enters the water, it will sink until it has pushed out 100 grams of water. The water line's relation to the object shows how dense it is in comparison; in other words, if the water line is about halfway up the object as it floats, you know said object is about half as dense as the liquid it's in. Orbeez are a little more dense than humans. That, along with the sheer packing efficiency of spheres in water, means that about 85 percent of Rober sank before he displaced his weight and started floating. The YouTuber expected friction to have more of an effect on the experiment but alas, his hypothesis was wrong.
Now that the scientific aspect is out of the way, you can watch the video and try to live vicariously.
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