Welcome to Michael Stevens living Now last weekend I baked some delicious buttery
rolls for my great grandsons wedding and everyone loved them
But I didn’t I’ve got a problem with rolls
When things roll they aren’t always loyal They roll and roll and they don’t come back
to me And I find unacceptable
How dare you That’s why I created DONG OATS
Dong oats will never leave you.
If you push them away they think better of leaving and decide to come back
Dong oats love you and I love you Today on Michael Stevens living I’m gonna
show you how to make your own
The secret to dong oats is physics There’s no magic here there’s no trick
Except for the fact that I’m using an opaque container so you can’t see what’s happening
inside.
But if I try to pull off the lid Oooo you see that part of what’s going on
involved the power of rubber bands.
What makes rubber bands work?
Well if you haven’t seen Richard Feynman answer that question, you should.
There’s a video link in the description below
But basically rubber bands behave the way they do because they’re made out of polymers.
Long chains of atoms and molecules.
And “chain” is pretty literal in this sense.
If each link on this chain is an atom or a molecule, this is really what that rubber
looks like.
But, it doesn’t form a straight line like this.
And that’s because at a microscopic and sub-microscopic level, our world is constantly
jiggling.
If this is a polymer, if this is a chain of atoms and molecules, and it’s just long
enough to reach down to the table, what happens if I give it some thermal motion, if I give
it a temperature above absolute zero.
well… it’ll start kinking up.
And as you can see it’s no longer reaching down to the table.
It’s shorter in the vertical direction because it’s moving in the horizontal direction
as well.
If you wanted this chain to reach down to the table, you’d have to reach in and pull
it straight down, you’d have to apply a force.
But it would still be jiggling, and as soon as you let go it would go back to jiggling
and being all kinked up nand it would be shorter.
That is exactly what happens in a rubber band.
Now, just like with the chain, thermal motion has the effect of kinking up the polymers
in the rubber band, shortening them.
at this scale the universe really is this busy.
We’re fortunate to see not a chaotic mess of vibration when we look around the universe;
instead, we see the stable general areas of jiggling that we call THINGS.
Ok, anyway, stretching a rubber band requires a force to work AGAINST this thermal bombardment.
When the stretching force ceases, the thermal force — not resisted anymore — kinks the
polymers back up and the band shortens again.
Any action that forces the polymers to unkink against this jiggling and bombardment requires
effort, WORK, but that work can then be done BY THE BAND when the it’s released.
We’re going to take advantage of this behavior of rubber polymers to create a can that rolls
away and then comes back Let’s just start building and as we build
it we’ll see how it works.
To make this really clear i’m going to use a literally clear container.
You could use any kind of bottle you wanted to it just has to be strong enough to withstand
the stretch of a rubber band and hold it in an extended state.
The first thing i need to do is poke some holes in the lid and the bottom of the bottle.
You could do this with hmmm any number of tools.
You could use scissors you could use an ice pick.
But whatever you do please please be careful.
I don’t want anyone getting hurt i just want you to learn, and learning never hurts,
unless you want it to.
K, so here goes the hole in the lid.
Perfect.
It doesn’t have to be exactly in the center that doesn’t matter too much at all.
Now, let’s put a hole in the bottom of the bottle.
Again you don’t need to worry too much about it being perfect, we just need it to be opposite
the lid.
Wonderful.
Beautiful.
Ok, so now that we have a bottle with a hole through both ends ... can you see me there?
Probably not.
I can barely see you, but trust me, this bottle now has a hole through it.
We need to get out these tools i made earlier.
I have a paper clip that I’ve straightened out and then made into a little hook shape.
And i also have this longer piece of stiff wire that I’ve also made a little hook with.
I hope that’s clear.
You don’t need to use theses specific tools, I just find it really easy.
Now if you look up instructions online on how to make a device like this, they often
recommend using a 9 volt battery, but 9 volt batteries are expensive.
That’s ridiculous.
I have a more favoured solution this is actually how i built my first rollback bottle when
i was like 8 or 9 years old.
I hope I’ve been microwaving these long enough.
All right so i’ve got both sides of the rubber band touching each other.
Not on top of each other i think this helps them stick better.
Cause we don’t want them stretching out of the way when we pull both ends of the rubber
band.
K, let’s see, make sure that’s really secure.
Make sure that the pennies don’t move back and forth or up and down on the rubber band.
Good good good.
All right now we’re ready to do some surgery.
I’ve got my two hook tools here and here.
What I’m gonna do is hook one end of the rubber band around this hook.
The only reason I use the hooks is it makes it easier to stretch the rubber band through
the bottle.
So here we go.
The piece of rubber band I have sticking out is really short but using this hooked piece
of stiff wire, I can thread it through the bottle and right into the bottle.
And now I can grab this piece of wire and pull the rubber band.
Now i’m gonna take my other hook and put it through the top look of the rubber band.
This just extends that side so i can drop the penny weight into the bottle.
Perfect.
Now As you can see i’ve got the uh penny i’ve got the pennies taped to the rubber
band.
And i can pull the rubber band through both holes.
Let’s go ahead and put the lid on the top.
Because of this nice paper clip hook I can thread it right through and then I can use
the hook to pull the rubber band out the other end.
Ooh, i need some more paper clips let me go grab some real quick see you soon.
All right i’m back.
I forgot that you need two more paper clips and these are to stop the rubber band from
popping back in.
And here’s how you do that.
If you can see, i’m pulling this rubber band up through the lid just far enough that
i can slip a paper clip through.
Perfect.
Now I can remove the hook and this end of the rubber band won’t fly through the lid
because this paper clip won’t fit through that hole.
Perfect ok now i’m going to pull the other end through the hole in the bottom of the
bottle.
Perfect!
Ok so I’m just gonna hold this.
I hope you can see that little gap there.
It’s through that gap that i’m gonna slip another paper clip and that will stop the
rubber band from going back in through the hole.
The rubber band is in tension right now it really wants to compress back together.
There it is.
Wow the weight isn't really in the middle but that probably won’t make a difference.
So here’s what’s going to happen.
When i push the bottle away, the weight will keep the rubber band from turning with the
bottle, so the band will wind up, become twisted, forcing the polymer it’s made up of to extend
lengthwise down the band against the constant effects of thermal motion.
Now, the force this requires will take momentum away from the rolling bottle, whittling it
away with the help of things like friction and air resistance, until the bottle has zero
forward momentum.
The kinking and shortening effect of thermal motion will continue though.
Now rotating the bottle backward until the band has unwound enough that the torque it
exerts due to thermal motion shortening it’s polymers returns to zero or just becomes too
small to turn the bottle.
It’s a simple thing but i love this.
And it really was one of the first little scientific curiosities i ever built i must
have been single digits old and i loved it.
Um all thanks to the Bill Nye fan club subscription box in a lot of ways I hope the Curiosity
Box can achieve the same excitement in people's minds that that subscription did for me when
i was young.
I don’t know how long it lasted i feel like i only got two or three of them but that’s
all it took.
I still have the rollback bottle that i made when i was younger and it’s at my moms house.
I’m so sad that i didn’t pick it up when i was there uh for the holidays.
Because you could have seen the exact thing that got me so excited about hands-on-science.
So go ahead and make your own.
You can use any device or um bottle or can that you want.
I really like using a uh an opaque cylinder because it’s hard to see how it works.
Also because it’s larger and because the weight i'm using in there is a nine volt battery
i think it’s a little bit slower.
Which is pretty cool . I think it looks more ghostly.
This one also rolls straighter than this one because the weight is more in the middle.
You can youn know, finesse that and fix it however you want.
So there you go.
Rubber bands are fantastic.
And things that roll back because of the behaviour of rubber bands are really fun.
And almost a little bit magic so go build your own, have fun, and as always thanks for
watching.
Dong Oats are the tasty treats that are haunted and wet.
Yum!