Every material has a theoretical limit to it's load bearing capacity. Now, scientists have determined what that limit is for Lego, and by extension, how tall a Lego tower could be
Every material has an Ultimate Tensile Strength (UTS), a load limit for the material which, if exceeded, will crush (or tear apart) the material. This can be compensated for, to a degree, by the structure of the material (which is why we have I-beams), but no matter how you look at it, the material will fail at some point. This is true not only for concrete and steel, but for Lego too.
So, bearing this in mind, have you ever wondered how tall you could make a Lego tower? I certainly have, and after a lively debate on Reddit, it seems some scientists at the Open University in the UK have decided to answer that question using science! They placed a standard 2×2 Lego brick made from ABS plastic,in a hydraulic stress testing machine, and applied pressure. The material began deforming slowly once it had passed it's yield point at 430 kg, and shortly thereafter, it became flattened in a process known as plastic failure.
The Lego brick, after being crushed
So, a Lego brick can take around 430 kg before it is crushed by the weight above it. Now, if we know the weight of an individual brick, we can determine how many bricks can be stacked on top of each other, before the bottom one collapses. Each brick weighs in at 1.152 grams. A quick visit to the calculator reveals that we could theoretically stack 373,000 bricks on each other, to a height of 3,591 m.
Size of the Lego tower in perspective
The scientists explain that at such a height, even the smallest deviation in loading could destroy the tower, and factors such as wind would therefore make a real structure of this height impossible. Of course, the scientists also state that if you built the tower tactically, placing gaps in the tower's walls, it could be substantially higher than the limit they've discovered. It is also possible that the 1×2 bricks are stronger than the 2×2 ones, so building with those may result in a better result as well.
Now there's science put to good use!