Three parts to this one, which I will click together to make a simple, yet pretty and colourful post.

Firstly, my lucky son, who got an early Christmas gift from his Uncle and family yesterday. They’re away for the festive period, so the cousins took our kids out yesterday and they got to choose their own presents. Scoop chose a cuddly puppy with its own portable kennel, while Alex plumped for a Lego set. He then spent yesterday evening building his 4×4 and trailer and was up and dressed by 6:30 this morning to finish it off.
I always loved Lego as a kid and I still think it’s great, firstly for teaching kids about following instructions and then, as the set gets “integrated” in with the rest of his bricks, for stimulating the imagination as they build ever wilder vehicles and other such fanciful “stuff”. And I haven’t even mention the fine-motor skills bit yet, although now I have.

Secondly, I also came across this story of another kid who has just got a new Lego set as well.

James Groccia has loved LEGO since he was about 4 years old.
But when the little boy told his parents a couple of years ago that he wanted the $100 Emerald Night Train set, which had more than 1,000 pieces, they hesitated before making the big purchase.

The couple, who live in Boylston, Mass., also saw one of those golden parenting opportunities to teach their oldest child about responsibility.
“My wife just basically said, ‘If it’s something you really want, save up for it,” Groccia said.

James, who has a form of autism called Asperger’s syndrome, did just that. It took him about two years to save up the $100.
And then, disaster struck. LEGO had stopped making the train set.

Of course, there were still sets available, but they were on collectors’ websites and – as with all toys that are no longer produced – the prices were through the roof, way beyond the $100 that James had saved up.

James wrote to Lego and explained the situation. Lego sent a letter back saying that they were sorry, but that set was not being produced any more. And that was that.

Until just before James’ birthday, when a package arrived at the Groccia’s home. Here’s what followed:

Well played, Lego. Play well.

But then, in a really tenuous link (and here comes the third bit), what if James had wanted to build a really tall tower out of the Lego set he was sent? I know that you’re asking exactly the same question that I am – Exactly how tall could he build that Lego tower?

It’s a trivial question you might think, but one the Open University’s engineering department has – at the request of the BBC’s More or Less programme – fired up its labs to try to answer.

“It’s an exciting thing to do because it’s an entirely new question and new questions are always interesting,” says Dr Ian Johnston, an applied mathematician and lecturer in engineering.

Looking on the internet, he expected to find the answer, but was surprised to find only a lot of speculation.

Perhaps that’s because not everyone who has pondered the question has ready access to a hydraulic testing machine.

Perhaps that’s the reason, yes. In fact, in a quick poll of my Facebook friends, precisely zero of them had ready access, or indeed, any sort of access to a hydraulic testing machine. Although they had all pondered the question. But yes, 0% that amounts to a fairly robust vote for “not everyone”.

Here’s a 32.5m tall Lego tower in Prague, which is impressive, but could they have made it, say, 33m or even taller?

The problem with doing this experiment “in the flesh” is that there are likely to be a number of difficulties. Finding somewhere big enough to do it, finding enough Lego bricks to build it, finding a way to keep adding the bricks. So the best way is to use a readily accessible  hydraulic testing machine.

Safety glasses on, the engineers begin to nervously edge towards the door.

“We’re setting it up automatically, so that we can all back out of the room, so none of us is in range when the thing goes bang,” Johnston explains – positioned, I notice, slightly behind me.

This basically squeezes the Lego bricks and measures the force they are under to see how many bricks it would take before the bottom bricks fail under the weight of the tower:

…the load on top of the brick gets larger and larger. We reach 3,500 newtons (N) of force – the equivalent of having 350kg (770lbs) sitting on top of the brick – more than a third of a tonne.

The force climbs on, above 4,000N. And then…

Nothing.

Well, not much. There is no big bang. The brick just kind of melts. It looks like a small square of warm Camembert.
This, Ian Johnston explains – noting that the computer also shows the load is no longer increasing – is a “material failure”.

The total force causing that “material failure” was 4,240N. They’ve been doing some rudimentary calculations and that equates to 432kg (950lbs). If you divide that by the mass of a single brick, which is 1.152g, then you get the grand total of bricks a single piece of Lego could support: 375,000.

So, 375,000 bricks towering 3.5km (2.17 miles) high is what it would take to break a Lego brick.

That’s more than 3 Table Mountains piled one on top of the other. So you can see that there would be other issues involved as well, not least the banging SouthEaster which would take it down as soon as it got anywhere above 10cm. Also, we’d have problems with the local Nimbys and their tall-buildings phobia. Incidentally, if you have ready access to a hydraulic press, 4,240N is also quite enough to silence their whining.