
Tallest Lego building with 4 pieces? - lorenzosnap
https://medium.com/@yolpogists/tallest-lego-building-with-4-pieces-ec99cb520928
======
gerdesj
One commentator here questioned why is this on HN (and was DVd somewhat) There
is the fact that dad teaches stuff to daughter. The lesson is fun and
interactive. The concepts dealt with are pretty profound and can be quite
deep: constraints, maxima and minima.

Well done dad - you've covered some complex stuff in a fun and accessible way.
Good skills.

If anyone else doubts why this is valid Hacker News, they may want to simply
hand in their nerd card and do something else.

~~~
falsedan
Slamming my nerd card down so hard the whole table spins around

It's hacker news, not motivational team building shared insight news. I'd
expect a GA solver which selected the four pieces which could be constructed
into the tallest possible structure (with all the dirty tricks e.g. a boat
hull attached to a wobbly assemblage of Giant Base/wing plates with a 12x24
brick balanced on the top), with a Speculation section positing possible
future pieces which would allow an even taller structure (with plausible
details of the sets & why they would need even longer pieces than those
currently available).

~~~
gerdesj
... and where do you think new hackers come from?

Personally speaking, I have no idea what a GA solver is but my initial
solution would involve putting all the pieces on top of each other with their
longest edges aligned - that's the maximum. Then we look at the constraints:
gravity is a bit of a bugger. etc etc

Keep your card and open your mind. You might be a bright lad but you can still
learn to look at problems from a fresh angle. The OP's daughter is in safe
hands as far as I can see - she'll learn critical thinking and that is a real
gift.

BTW: what is a GA solver?

~~~
vacri
> _with their longest edges aligned_

Longest _axes_ aligned. Longest _edges_ is not the maximum. The article's
final solution uses a long axis rather than an edge.

~~~
gerdesj
Whoops, it is surprisingly easy to think one word and type another.

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jacquesm
Ah, jacquesm bait, ok here is my solution (left), right one is an alternative
to yours.

[http://imgur.com/a/h7HnB](http://imgur.com/a/h7HnB)

just the tops:

[http://imgur.com/a/wsqCw](http://imgur.com/a/wsqCw)

~~~
spydum
I feel like they should be attached and not stacked?

[https://imgur.com/gallery/W13nR](https://imgur.com/gallery/W13nR)

Fwiw: 10.3cm

~~~
spydum
[https://i.imgur.com/zUl5AP8.jpg](https://i.imgur.com/zUl5AP8.jpg)

Measured 10.7cm:
[https://i.imgur.com/I637r2v.jpg](https://i.imgur.com/I637r2v.jpg)

What have you done to me!? Can't stop.

~~~
BatFastard
I never considered that the backplane is the same height as the inter dot
distance. I thing I can think of as a possible improvement would be to put the
single dot side ways, and put a grain of salt on each side. Or find a very
slight indentation to put it in.

------
gene-h
Reminds of a genetic algorithm that was made to optimize lego structures[0].
One of the most notable results of this was optimizing for a structure as long
as possible with a single support. What they got was a 2 meter long organic
looking cantilever that experienced significant brick deformation[1]

[0][http://www.demo.cs.brandeis.edu/pr/buildable/evocad/aid00/](http://www.demo.cs.brandeis.edu/pr/buildable/evocad/aid00/)
[1][http://www.demo.cs.brandeis.edu/pr/buildable/long_bridge/](http://www.demo.cs.brandeis.edu/pr/buildable/long_bridge/)

------
542458
I think you can do ever so slightly better by moving the pink dot to the
highest pip on the 2x2 green cylinder - it extends a little beyond the pip, so
you'd gain about a millimeter that way.

If it's not cheating to have parts not completely attached, you could maybe
even balance the pink dot on top of the green cylinder for an extra 3-4mm.

~~~
fiftyacorn
if you dont have to be attached then place it under the blue brick

~~~
anotheryou
easier to balance on top, but I think it's not a "building" any more than.

~~~
milkytron
Maybe not a building, but still a structure ;)

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jacquesm
Ok, an even better one:

[http://imgur.com/a/FXhbH](http://imgur.com/a/FXhbH)

~~~
ErikHuisman
now do one with the top piece upside down (or put that piece on the bottom)

~~~
jacquesm
I tried, it will not balance (nor at the bottom, because COG is off-center too
far from the center of the round 1x1 plate for it to be able to stand on its
own).

I'd love for someone to beat this one.

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trevyn
>The only rule is “The structure needs to stand on its own.”

Melt it down and recast it, duh. :)

~~~
vacri
Well, taking away the implicit rules, the limit becomes simply "the tallest
structure we can build with current technology".

For example, put the four Lego pieces on top of the Eiffel Tower, and you've
now created a structure that is height "Eiffel Tower + Lego" \- and it's made
with those four pieces (' _with_ ', not ' _only with_ ' :) )

~~~
tdy721
Well yeah... but there's this: [http://www.space.com/12546-lego-figures-
jupiter-juno-spacecr...](http://www.space.com/12546-lego-figures-jupiter-juno-
spacecraft.html)

------
te_platt
Very fun! It reminds me of teaching my son to play tic-tac-toe. He started in
the top-left, I went center, he went top-center, I blocked top-right, he went
in between top-left and top-center and quickly claimed victory. I gave him
that one and said he had to go in an unused square. Next game he started top-
left, I went center, he went top-center and then before I could go he hurried
and went top-right and again claimed victory. I don't remember what we did
after that but I do remember thinking it was more fun pushing the rules than
the actual game.

~~~
jacquesm
Childrens logic: if it isn't said outright before the game then it isn't a
rule. You lost fair & square.

------
tdy721
To entertain myself, I gave this some thought before I clicked. I assumed
exactly what the title says: which 4 lego pieces create the tallest structure
that stands on it's own.

Well, we need the biggest bricks we can find, my mind went to the ship hulls:
[https://www.ebay.com/p/?iid=282223262072&&&dispItem=1&chn=ps](https://www.ebay.com/p/?iid=282223262072&&&dispItem=1&chn=ps)

So how can we connect 2 of these together, and make it stand vertical? Or can
we?

It might be that we need the 3 pieces to make the brick stand... I'm not sure.

And then I clicked on the article...

(I'm not sure if I've even found the largest brick, or if I've found a 3 brick
component; how do we define "brick"? Why do I care? Please comment and
subscribe, it really helps ;)

~~~
tdy721
I need to add, I clicked on the article, and totally enjoyed the content.
(With a small caveat, noted above.)

Envy, I think that's the word for the weird vitriol in this thread.

------
natch
10.9cm free standing, no glue or tricks but top two bricks are just resting,
not attached.

[https://imgur.com/gallery/FEk9l](https://imgur.com/gallery/FEk9l)

~~~
jacquesm
2mm below the tallest, but _how earth do you get the pink piece to balance on
the gray piece_?

I bow to the master.

~~~
natch
There is a taller one? Do tell! Link?

Edit: and as to how to get the pink one to stay, it was just some delicate
balancing. And the pink one is tilted slightly toward the viewer/left, in
other words aside from being (obviously) oriented diagonally, it's also not
oriented straight up and down in the other axis. Managed to do it a few times
for different attempts, as the first time the pip wasn't riding as high as it
could be. The pip just stays on (barely) by friction, btw.

~~~
jacquesm
[http://imgur.com/a/FXhbH](http://imgur.com/a/FXhbH)

That one is 11.1 by my tape measure.

You could put them side-by-side.

Still amazed you got that to balance. I tried it (after seeing your picture)
but gave up :)

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mturmon
It might be interesting to compare the height achieved by a given
configuration, to the upper bound on heights (sum over largest dimension of
all 4 pieces).

------
btbuildem
You can do a bit better if you put the round piece at the base, and make the
blue piece diagonal just like the big flat piece.

You'd need to balance everything on the round piece, but the little pink dot
should assist in that.

Kind of like those balanced rocks thing :)

~~~
martin-adams
yep, that was along the same line of thought I had

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zachrose
Gain an extra 2mm or so by just resting the pink piece on top?

~~~
lorenzosnap
you are right. I will do it and then take another photo

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5ilv3r
Asking questions, challenging assumptions, bending the rules, and just trying
things are all core to the hacker mentality. Well done sir!

------
crazygringo
It's funny, but I feel like this is exactly the kind of skill required in
engineering or business generally -- "How can we creatively maximize 'x' given
what we've got?"

In fact, it wouldn't strike me as an unreasonable interview question, using
the physical pieces. Of course some people are better with spatial reasoning
than others (and experience with Legos is another leg up) -- but using several
simple, general-purpose questions along these lines almost feels like a
FizzBuzz for any job where problem-solving is an important part.

~~~
jacquesm
There's this joke about an Ikea job interview: interviewer tosses a bunch of
parts on the floor in the interview room and says: take a chair.

------
aaron695
Sorry but isn't two or three cheating? These are not valid ways to connect
Lego are they?

~~~
deluvas
Yeah, that's what I thought too.

~~~
RugnirViking
[http://guide.lugnet.com/set/?q=420_1&v=z](http://guide.lugnet.com/set/?q=420_1&v=z)

I think this is an example of a very early set using this technique. But yes,
this is possible and holds rigidly

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gazarullz
Very cool post, in regards to the people clicking on the link and then bashing
the author, it would be nice if you could bring some arguments to your
disliking/bashing.

------
the_unknown
Thank you. I've now had a similar discussion with my two girls (Aged 11 and
4). Was a far better way to spend the evening than a typical night of Netflix.

------
rena-anju
"My daughter asked me"

------
Markoff
kudos to Lego marketing department for great viral

~~~
falsedan
LEGO Group marketing is on another level.

------
xupybd
I have no idea why this post is so popular. I'm equally confused at why I find
it so interesting.

------
asketak
Does this content really belong to hackernews?

~~~
dang
Your comment got treated rather harshly, so let me try to explain. The post is
on topic for HN because, although the question is a whimsical one, it
gratifies intellectual curiosity (please see
[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)).
Whimsical submissions like it have always been welcome here, as long as
they're uncorrelated with anything that's appeared recently. (Sometimes people
start doing the copycat thing of posting follow-up stories on almost the same
topic. Those get old quickly unless they're _really_ interesting, so the bar
gets higher superlinearly.)

It isn't just a question of the community upvoting it. Plenty of stories get
plenty of upvotes yet still don't belong on HN—e.g. most sensational
controversies.

Many HN users value the diversity of the stories that appear here and don't
take well to comments that appear to want to narrow the site down. That might
be why your question got flamed.

~~~
gpderetta
also Lego have the hacker nature.

~~~
dang
Quite.

