I already knew legos were strong without this research.<p>For instance, I know for a fact from legos left on the floor by kids that one lego can hold my entire weight (240 pounds) when I step on it in the middle of the night walking to the bathroom with no signs of damage to said lego.<p>Further, I know that one lego can by itself topple a fully grown man.
>The average maximum force the bricks can stand is 4,240N. That's equivalent to a mass of 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.<p>>So, 375,000 bricks towering 3.5km (2.17 miles) high is what it would take to break a Lego brick.<p>>"That's taller than the highest mountain in Spain. It's significantly higher than Mount Olympus [tallest mountain in Greece], and it's the typical height at which people ski in the Alps," Ian Johnston says (though many skiers also ski at lower altitudes).<p>>"So if the Greek gods wanted to build a new temple on Mount Olympus, and Mount Olympus wasn't available, they could just - but no more - do it with Lego bricks. As long as they don't jump up and down too much."<p>Well, in theory you can go as high as you want, by tapering the tower towards the top. The 3.5 km limit is only valid for straight, constant cross-section structures.<p>Which mountains certainly are not.
> The average maximum force the bricks can stand is 4,240N. That's equivalent to a mass of 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.<p>But the weight it can support will be determined by the weakest link not by the average. If the lowest brick is of below average quality the tower will fall sooner. So if you plan on building a 3.5 km tower I'd advise you to consider the variation of the brick quality. Bonus points for taking into account that each additional brick has to support less weight.
>That's taller than the highest mountain in Spain.<p>Not quite, unless by "Spain" one means "continental Spain." Spain's tallest is Pico del Teide on the Tenerife, measuring 3718 m from the sea level.
I see two issues not addressed by the other comments:<p>1) I would start with a 2x2 plate not a 2x2 brick. They are heavier per height, but I think they will also be much stronger because the weight is not supported by the sidewalls alone.<p>2) They didn't account for compression of the bottom bricks in their height calculation. If anyone is going to take them seriously they need to publish the strain at the yield point. Then we get to use some calculus to figure out the actual height!
As noted building high tower is not feasible in practice. Pyramid though would be much more feasible. It is only 1/3 weight of equivalent tower (polyhedron that is cube) so can be theoretically 3 times higher while simultaneously way more stable. Though if high, curvature of earth has to be considered as well since the lengh of base edge is equal to height.
Good points here. Only many other limitations apply when building an actual tower, so you would probably need a lot of engineering to design a tower even remotely close to that height that can be built before it collapses. If that kind of thing was so easy the carbon nano-tubes fiber cable for the space elevator would be a reality and we would be sending packages to the ISS at almost no cost. But if you take a look at the ideas for the project, you'll find the amazing problems they are trying to solve just to be able to say: Ok, we can do it. Let's build it! <a href="http://en.wikipedia.org/wiki/Space_elevator" rel="nofollow">http://en.wikipedia.org/wiki/Space_elevator</a>
A few commenters here suggested building the base out of flat plates for strength. But as I understood it, the maximum load was determined by the properties of the plastic. The plastic became fluid, rather than the structure of the pieces failing.<p>From TFA:<p>>>The material is just flowing out of the way now and it's not able to take any more. We're getting a plastic failure. It means the brick keeps on deforming, without the load increasing.<p>So, help out the not-a-real-engineer here. Doesn't that mean that changing the shape of the pieces wouldn't help? ie, even if the base were a solid sheet of Lego plastic it would just flow out of the way at that load?
Here's an alternative to the pyramid shape that everyone else is suggesting:<p>Just use different types of blocks.<p>The strongest Lego block is probably one of those thin (1/3-height) 1x1 plates. They are also the heaviest per unit volume. Build the base of the tower using these plates. As you move up the tower, gradually replace them with 1x2 plates, full-height 1x1 blocks, 1x2 blocks, 2x2 blocks, and finally, 2x4 blocks at the top.<p>Strong, heavy blocks go at the bottom. Weak, light blocks go at the top. This strategy will probably let you increase the height of your tower by at least twice, if not more.
I like how the experimental result of 375k bricks with a 2x2 brick is somewhat close (within an order of magnitude) to the 220k bricks someone calculated from FEA simulation in the linked Reddit thread ( <a href="http://www.reddit.com/r/AskReddit/comments/iy0ew/how_many_legos_stacked_one_on_top_of_the_other/" rel="nofollow">http://www.reddit.com/r/AskReddit/comments/iy0ew/how_many_le...</a> )
Did anyone else pedantically think that this phrase<p>> The average maximum force the bricks can stand is 4,240N. That's equivalent to a mass of 432kg (950lbs).<p>Should have instead read...<p>>The average maximum force the bricks can stand is 4,240N (950lbs). That's equivalent to a mass of 432kg.<p>?
If your tower gets exponentially thin towards the top, you can keep going forever as the pressure resting on the each level is independent of the height of the level. At least when the gravity field is approximately constant.