World's Longest Straw

Hey Nige, can you get me another coke?

Nah, I'm good, thanks.

It's just downstairs.

Nah, the tennis is on.

You come to my house to watch the tennis and you're not even going to get me another coke?

Yeah, it's the tiebreaker.

Relax.

You know what I wish we had? Like a really long straw so we don't even have to go downstairs to the kitchen.

That would be pretty good.

Yeah.

Yeah.

Right?

How long of a straw could we actually make that you could use?

Downstairs is a bit of a stretch I reckon.

Yeah.

How much is that, like, 3, 4 meters?

Do you think we could?

I reckon we could do it.

We'd need a lot of straws though.

We got a pack here.

Oh, okay.

Now our first test, just to see that Nigel can use a straw properly, we've got about a 1 meter length of straw here.

Think you can suck through that?

I could give it a go.

So we just taped these drinking straws together, and hopefully...

Yeah, that's alright.

But there's a lot of air coming through I think from the...

The joints in the straw, yeah.

We've gotta come up with some better way to test this out.

I happen to have 6 meters of plastic tubing here.

Non-toxic?

Uhh, that's what they said at the hardware store.

We're preparing the preliminary tests.

Nigel is lowering some tubing off the balcony.

He actually thinks he's got a shot at sucking through 6 meters of tubing.

I think he's got no chance and he's going to be nowhere close, but I think this will allow us to establish how much Nigel actually sucks.

(laughing)

He's getting ready up there.

He knows there's a lot riding on it.

When you're ready!

Look at that!

Look at that!

Woah, he shoots up!

He's got 2 meters!

He's got three meters!

Look at that guy go!

He's getting 4 meters, 4 meters!

5!

5 meters!

6!

Yeah!

(Cheering)

Now I'm going to try to do the same thing, but the tube I'm using has a thicker diameter.

Mine is about 5 mil, whereas Nigel's was 3 mil.

So we're going to see if this makes any difference.

(Inspiring music)

Now, I guess the obvious question is, can Nigel do it?

Yes, Nigel thinks that's the obvious answer but I'm pretty sure he's going to fail.

Now, maybe what's worth talking about is how a straw works in the first place.

How does it work?

Yeah, 'cause this is really just a big bendy straw.

If we look at a smaller version of a straw here...

We should all be familiar with how this works.

Or should we?

I don't know.

I think most people think you're just sucking the liquid in and swallowing it.

But, you kind of have to think about air pressure.

Yeah, because actually what's happening is that air pressure is causing the, coke in this case, to go up the straw.

Well, there's a difference in pressure in the atmospheric pressure and the pressure that you create by opening up your lungs and pulling your diaphragm down.

So you reduce the pressure in your mouth, and it's that difference in pressure between the atmospheric pressure and the pressure inside you which gets that liquid flowing into you.

Someone has failed at the 5 mm diameter and you're the next guy to take it on.

You ready for this?

I am ready.

He's been practicing his whole life for this.

Yeah, you can see it's a strong start.

Strong start from Quan.

You've got it.

Oh, he's going big right here.

You can see there's a lot of determination.

He's getting close, getting close.

Look at this.

Look at this.

Can he do it?

Can he do it?

Ohhhhhh, and he's done it!

(cheering)

Agh.

That tastes disgusting.

Yeah, I definitely felt like my tongue, while I was trying to suck it up, was being pulled out into the straw.

(off)

I felt the same thing.

But.

And it was tougher, definitely tougher.

Well done sir.

Thank you.

Means a lot.

For his next challenge, we're going to try to get him to suck through 10.3 meters which is the theoretical maximum size of straw.

How are you feeling?

Well, that theoretical maximum kind of relies on being able to get a perfect vacuum and, although I am perfect in a lot of ways, I don't know that I can create a perfect vacuum.

I have often thought that there is actually a perfect vacuum inside Nigel's head.

Today we're going to really find out, won't we?

Ok, we've got the setup here.

We're down at Tamarama Beach.

And we have 10.5 meters worth of tubing which goes all the way up to Nigel at the very top there.

So I'm going to see if I can relive some of my former glory and get the red liquid up this height.

3!

2!

1!

There you have it.

Nigel is starting to suck on that straw.

There he goes.

Looking strong.

Create that vacuum.

Approaching the edge of the cliff there.

Go, Nigel, Go!

C'mon, Nigel!

Doesn't seem to be going anywhere.

We seem a bit stuck.

At that point right there.

You can see the determination, the focus.

Trying to see how high that is.

He's done well.

But it just doesn't look like it's going to happen.

(Music stops, and breaks down. Signalling failure)

Alright, so Nigel did pretty well there.

We saw that he could get that liquid up the tube about 7 meters.

Not the theoretical maximum of ten meters.

Still more than you.

Just saying.

That's a good point.

That's a good point.

If Nigel could have created a perfect vacuum, then the water would have gone up to 10.3 meters, according to our calculations.

This is kind of similar to how they used to measure atmospheric pressure in the old days, by millimeters of mercury.

So atmospheric pressure would push mercury up a tube with a vacuum at the other end 760 millimeters.

760 millimeters.

So about .76 of a meter.

So you can see why they used mercury and not water because if you were doing this with water, you'd need a cliff.

Yeah, you'd need a ten meter long barometer.

So much better to do it with millimeters of mercury.

And of course now we measure it in kilopascals.

So anyway, well done Nigel.

You really suck.

So how do we work out the maximum length of straw that you could suck through vertically?

Well think about this.

You place the straw into the liquid, and you start sucking from the top.

That decreases the pressure at the top and the difference in pressure between your mouth and atmospheric pressure creates a force that pushes the liquid upwards.

Now that liquid which is in the straw has a weight which is equal to the volume of the liquid, times its density, times the gravitational field strength.

So if we set these two forces equal to each other you can see that the pressure difference must be equal to the density of fluid times its height, times the gravitational field strength.

And if we sub in the numbers, we can see that the maximum height of liquid that anyone could lift, even if they created a perfect vacuum inside their mouth, would be about 10.3 meters.