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Can You Solve this Ice Diamond Riddle? ft. Vsauce’s Michael Stevens

Can You Solve this Ice Diamond Riddle? ft. Vsauce’s Michael Stevens


Oh yeah. CREW: Oh yeah. Yeah? CREW: Yeah. Do you know what
I’m talking about? CREW: [INAUDIBLE] go
faster and faster. Yeah, I’ve seen
people do this before. But you’ve never
done this before? No. Michael, when did you grow up? The ’90s. We’re, like, pretty close. The 1790s. Hand-clapping hadn’t
been invented yet. Can you tell us– MICHAEL: Robert Clap– –the history? Robert Clap, one day he
was like, that was amazing. And everyone was
like, do that again. He was like– Are you serious right now? I’m totally serious. This is the actual history? Yeah, I tell the
truth at all times. I 80% believed Michael until
I realized, Michael Stevens didn’t grow up in the 1790s. Can’t fool me. But that’s not why you’re here. You’re here because
you want to see me challenge our guest to some
physics, puzzles, and riddles. And I better introduce
him because you might not know who he is, despite the
fact that he has a channel name across his
chest and because he has the most viewed
science YouTube channel on the platform. So better get do it. Hey, I’m Dianna. You’re watching “Physics Girl”. I’m here at the “Vsauce”
warehouse with Michael Stevens, the host of “Vsauce”. You agreed to be asked some
puzzles and riddles, logic, physics, that kind of stuff. I didn’t just agree. I insisted. You did. I love puzzles because
I’m not that great at them, but afterwards I always
feel like a better person because I’ve learned something. Should we get to it? Let’s do it. We’re going to start
with some warm-ups. Then I hope the warm-ups are
easy because you’re calling them warm-ups like I’m
supposed to just squish them. But they’re still riddles
and they’re still puzzles. They’re just the
ones that are like, you either get the
concept or you don’t. OK. OK. I have a ping-pong ball, and I
think that I can throw it such that it will suddenly stop
and turn around and come right back at me. How could I do that? How could you do that? You know the drill. Pause the video here if you want
to think about it for yourself before we continue
on with the answer. So here’s the question again. How could I throw a
ball so that after a bit it stops, turns around,
and comes right back at me. And it’s not bouncing
off of anything. Nope, not bouncing
on anything. Right– right. I’m assuming it has to do with,
like, the spin of the ball. At some point it
will have slowed down enough that its spin
becomes the major component of its motion. That’s a good guess. I’m going to do it such
that no matter my technique, no matter my
skills, I can always get it to come right back at me. Ah, so just throw
it straight up. Yeah. Got it, yeah. See, yeah, that’s one of those
great ones where you’re like, oh, I think of throwing as
been a horizontal action. As being horizontal. The weird thing about
this whole situation is that when you throw a
ball straight up in the air, it’ll stop instantaneously
at the top. But that means that right
before and right after, like a millisecond,
a microsecond before and a microsecond after
it’ll be moving up and then it’ll be moving down. How is it possible that a ball
is only stopped for an instant? Such is the nature
of continuous motion. Is this one of those
situations where I’m like, this is so weird and everybody
else is like, no it’s not. That’s just how the world works. Moving on. Next. DIANNA: Next one. Michael, you’ve got
a glass of water. And over here, imagine
that you have an ice cube. And inside the ice
cube it looks normal because it looks like
everything is clear, but inside of it it’s
got a little diamond frozen in the middle. Got it? MICHAEL: Great, beautiful. DIANNA: Yeah. And then you drop the ice
cube into the glass of water. Now, when the ice cube
melts and the diamond falls to the bottom of the glass– because carbon in diamond form
is more dense than water– does the water level
go down, go up, or stay the same from the
level it was at when the ice cube is first placed in there? Very good question. All right, so let’s
work through this. So– And that’s where
we’re going to cut because I know you love being
on the edge of your seat because it’s so good
for your brain juice to have to wait
just one more day to think about the
answer to the riddle until you get a video with the
answer and maybe a bonus riddle if you guys leave enough
comments with your guesses for the answer to this riddle. Or, in the meantime, here
are three other things I’d love to hear from you. Number one, I’d love
to hear comments about your favorite other
physics riddles or puzzles. Number two, I’d love to
hear your everyday mysteries for the everyday mystery
series using the hashtag #everydaymysteries
in the comments. And number three,
if you have them, tweet me your photos of
the Physics Girl T-shirt. I haven’t gotten any
photos from any ladies yet, but thanks to these
physics-y gentlemen for sending me their photos. And that’s it. Happy physicsing. [MUSIC PLAYING]

100 comments

Hey Dianna, if you wanna get really scientific (so leave that loopy endless plane with infinite answers, but no answer), the "ball-(not-)in-motion-for-an-infinitely-small-part-of-a-second" is the way forward 😉

Oh my stars i over thought too much on that ball riddle for a long time before realizing it was just that simple, these riddles are fun though it's a bit challenging

I had a different guess for the ping pong ball one, but im quite sure its "Wrong". If you throw the ping pong ball at a mirror, it will appear to stop in mid air once it hits the mirror and then come back to you. More of an illusion though, the real answer went right past me.

The water level stays the same because it has the same mass as when the ice cube was frozen. (the diamond was already contributing to the mass of the ice cube)

stays the same, calculation is after cube is dropped. it’s like trying to add something when nothing else is going to happen

#everydayriddle. Think about us travelling in a bus.. now suppose we blind fold ourselves and there are shock and noise absorbers.. we don't feel the motion.. but we are still moving.. now I einstein said that when we drop a ball, it isn't the ball going down but the earth accelerating up..so in the similar sense wouldn't the ground be speeding down the bus rather than the bus moving forward.. ??

#EverydayMystery I live in dubai and you know the temperatures over here.. its scorching!! The situation becomes even bad when you have to park your car in an open place.. but again is there any chance that (by checking out the position of sun) there is some place in a open car lot (when I say open I mean without shades) that recieves less heat and sunlight than the rest of the places in that same parking lot?

How much of a plain ice cube floats above water? ~7%.
How much of an ice cube with diamond floats above water? Depends on the size of the diamond.

The water level doesn't change with just a plain old ice cube. But with the diamond, I estimate the water level shrinks by ~7% of however much ice is displaced by the diamond, compared to just the plain old ice cube.

The water level goes down because density of ice is less than that of water so when it melts it volume reduces and in this case diamond has no role at all.

Please link the answer in the info or comments! The Youtube thingie isn't recommending the answer to me, and this way it'll be easier for other people to find it, too, if they encounter the same problem! 🙂

Objection! The riddle clearly states that the ball stops 'suddenly'. Since gravity is a constant acceleration affecting the ball throughout the event, there is no reasonable sense in which the proposed solution counts as the ball stopping 'suddenly'.

Bouncing the ball off a wall or having someone catch it and throw it back to you are more in line with the riddle as stated.

I was thinking of throwing the ping pong ball at a big fan, was pretty convinced I was clever until the solution was revealed

it would go up, half of the ice and half of the diamond that weren't displacing water would start to. Also some of the ice would melt naturally raising the water level.

I think the level of the water would lower because, although the mass of the water making up the ice cube stays the same even when it melts, the volume decreases. We know that freezing water expands and increases in volume, so as it melts it has to decrease in volume. Right?

The part "turns around" 2:02 is not true when throwing the ball up. It doesn't turn around. The riddle has no right answer!

Attach the ball onto an elastic band throw it away from you. I can guarantee it will stop and come back at you due to its oscillation lol

Late response…but down because ice expands when frozen, so thawing would reduce the overall volume of the glass' contence regardless of the diamond.

1:58 it hits a wall I’m smart because this is the only way and I thought of it I don’t usually do this I’m so happy I have functional brain cells

I was watching this video lying on the bed .

As soon as the ping pong question was asked I got the answer

I think the water level will decrease as the density of ice is a bit less than liquid water and when it will be dropped in the glass it will displace the water equal to its volume but when ice will melt volume of water from the cube will be a bit less than the volume of cube so water level will decrease.

I say the water level rises because you've added an ice cube's worth of more water to the glass. The diamond is irrelevant.

Water level stays the same as it was before ice melting. Because ice cube and diamond will have the same combined volume either in frozen form or liquid form. (ignoring the negligible change in volume of water upon freezing)

I believe the water level should stay the same from the point of putting the ice cube in the water because the volume of the ice cube is not changing

The weight of the diamond on the ice will displace more than it's volume, if it were all ice, it displaces equal to it's volume, and diamonds weigh more than water. So the water level should go down slightly.

I believe that the water level in the glass would go down, because water expands when frozen, and in ice form it takes up more surface area

Dianna: You are wonderfully nieve, (trusting), with friends or people you respect. As a scientist you question everything. Very intriguing dynamic.

the water level will goes up due to melted ice. but the suspension of the diamond will not affect the water level

I have seen many videos of you and i always wait till the end of video to hear “Smelly cat song from FRIEND” by you (Phoebe). If it is possible do it for me. Big fan 😻

it’s a gender thing. boys don’t play clap games… would have been nice to have an honest conv about it, but he’s a nineties guy so he only knows how to pretend to be sensitive not actually be sensitive.

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