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  • A while back I was eating lunch with some co-workers and we were debating

  • about just how far you would sink if you jumped into a pool of these orbeez

  • For example would it go up to your calf or to like your waist or all the way

  • above your head

  • Everyone seemed to have a different theory, in fact I asked about

  • a hundred people and you can see how much the guess is varied, so as a firm

  • believer in the scientific method I decided to test our hypotheses

  • So I'm here today in the backyard of the backyard scientist. so for the past six

  • months we've been stockpiling these orbeez in Kevin's backyard and

  • today it's finally the moment of truth

  • all right you ready for this let's do it so take a moment to guess in the

  • comments below of how far you think we'll sink and then we'll see if you're right

  • For the record I think I will sink to about the waist, okay here we go

  • This Feels so crazy

  • This feels like its compressed on all sides but it's so smooth and like slippery

  • So it looks like I was wrong by quite a bit and we have to reject the null hypothesis

  • So now what

  • I decided to call up my nephews you guys want to come

  • swimming at my friend's house in my ongoing quest to be the favorite uncle

  • only I might have forgotten to tell them there'd be no water in the pool

  • also that kevin was right there

  • You guys ready to go swimming in this

  • But before we go swimming in 25 million orbeez let's talk about why I was wrong

  • It has to do with buoyancy so here's a riddle when this ice melts will the water level go

  • up or down as you can see here it actually doesn't change at all

  • Archimedes taught us that you displace your weight in water

  • so this baseball weighs about 135 grams and when I put it in water it will sink

  • until it is pushed out 135 grams worth of water at which point it's in

  • equilibrium and it floats and since the waterline is about halfway up the

  • baseball you know it's about half as dense as water and this is why

  • scooby-doo quicksand is pure lies you sink until you've displaced your weight

  • in quicksand and since it's about twice as dense as a person you Bob like a cork

  • about halfway down and it's impossible to sink so Atreyu

  • relax your horse is going to float

  • So I will keep sinking in Orbeez until I have

  • displaced my weight in Orbeez and since they're a little more dense than me and

  • taking account the packing efficiency of a sphere surrounded by water the fact

  • that about 85 percent of me sank makes sense

  • I thought the friction between the balls would play a bigger role which is why I

  • guessed halfway so I was wrong but a lot of times that's more fun because that

  • means the result was unexpected and you learn something okay back to the pool

  • Guess where my foot is

  • So a huge thanks to Kevin for letting us use his pool he actually also made a

  • video we did eight crazy experiments with a pool full of water balls so go

  • check that out because his footage is amazing as always I also want to thank

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A while back I was eating lunch with some co-workers and we were debating

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