How to build the impossible
Posted by Huw,
Yesterday Duncan Bramley challenged us to build something that seemingly can't be constructed but can be taken apart.
Here is his solution. Find out how to build it after the break.
Once again, it uses the Technic 5x7 frame. It requires a trick involving a piece of card -- perhaps a cutting from a LEGO box to keep it 'purist' -- to aid construction.
During assembly a strip of stiff cardboard can be inserted through the end spring slot of the central 3M connector peg and arranged to emerge diagonally between the surrounding beams on both sides.
This strip of cardboard can then be used to push the connector peg into engagement with the 5x7 frame. The strip of cardboard can then be pulled out leaving the completed 'impossible' assembly!
It can be disassembled easily by pushing the central pin back in again.
Check out the comments to yesterday's article for discussion about another possible solution.
Did you come up with anything?
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57 comments on this article
I think it's too possible to be "impossible". :P
I wouldnt mind doing it but....
I dont want my lego to be an impossible disassemble :P so ummm i will see haha
I have to say...all those ones they showed yesterday that couldn't be disassembled, actually made me unreasonably anxious. This was all actually really interesting stuff!
Hm. I think I see... So this is the same idea as the "type 1" images from yesterday, where the axle was impossible to pull back out, yeah?
(Those type 1 examples were the Lego equivalent of slashing someone's tires, lol.)
Managed to build a type 1 by accident once already...
https://nplusc.de/lego/gordian_web.jpg
the black gear is connected by a red 2L axle to the middle beam. Only noticed the "aww s??t" when the idea didn't work and i tried to disassemble. Took some thin tweezers to get that axle out
very interesting solution! having an unreacheable pin to insert inside a "box" certainly is a smart idea!
Enjoying this discussion immensely! Seems like a philosophical debate about how you define 'assemble' or 'able to reassemble' as much as anything. I love seeing the actually ideas people are creating, thought the egg concept yesterday was rather brilliant.
Two other more abstract solutions that could be considered:
1. 'Ship of Theseus' solution: Take a new Black Seas Barracuda box, open, build and disassemble. Open 20 other new BSB boxes you have squirreled away on your shelf and mix all the parts together. The exact original first model is statistically impossible to rebuild - able to disassemble but not reassemble.
2. 'Same River Twice' solution: Build a giant mosaic self-portrait. Wait a month. You can disassemble the portrait, but you will have changed so you can't reassemble the portrait exactly the same way.
@CCC, good idea about using string. That should work.
i've gotta say, I found this stuff pretty confusing. Still quite impressive though!
I appreciate the attempt, but the logic here is flawed. Even with the cardboard trick, the pieces were still assembled. The rule was it can’t be assembled
This was assembled
Therefore, it can’t satisfy the requirements to meet the argument, and isn’t a solution
No, the rule was "it can’t (seemingly) be assembled".
More llamas please.
This does not apply to the the rule since nothing that can be dissasembled is seemingly unassembelable...it is simply a logical fallacy...
Really weird article idea but I love it! Super interesting
@Forestman_Bygger said:
"1. 'Ship of Theseus' solution: Take a new Black Seas Barracuda box, open, build and disassemble. Open 20 other new BSB boxes you have squirreled away on your shelf and mix all the parts together. The exact original first model is statistically impossible to rebuild - able to disassemble but not reassemble.
"
I'm somewhat confused about this first one. I agree, chances would be extremely small, but if you spend the rest of this and all your follow-up lives (you do need to believe in reincarnation for this to work I think), at some point in time you will build the exact same BSB model. There is a limited amount of brick configurations possible so a limited amount of possible outcomes ( = constructed BSB sets). I don't know how you can proof that you did build the exact same BSB model as you did the first time though.
I think the egg solution from yesterday nailed it. The same concept- seemingly impossible connections that are only possible with an unseen hand. For instance, if you froze the centre of the egg in water you could assemble it when ordinarily you couldn’t.
I may be mistaken, but I believe this could be made more impossible to build by attaching some SNOT bricks with their tops studs in the sides of the I- beams before attaching those. It would prevent a card or string from sliding in the gap that exists in the current version...
Another way would be to replace each I-beam with 5 length-3 beams lined up in parallel, with more pins.
The pin could still be pulled with a string coming out of the end, past the sides of the -O- piece, but there are ways to make that more difficult, as well.
I keep editing this post with new ideas:
The entire middle section could be brick-built (rather than Technic) as a box with no holes except the technic pin hole at one end. The sides of the box would use brackets.
And further:
The final connection need not be a Technic pin, it could be a sliding section with a stud that is "pushed" into the hole in the frame, so that feeding a thread through that hole doesn't work very well. Then maybe a very thin thread could go through gaps between bricks, and nowhere else.
@graafderk said:
" @Forestman_Bygger said:
"1. 'Ship of Theseus' solution: Take a new Black Seas Barracuda box, open, build and disassemble. Open 20 other new BSB boxes you have squirreled away on your shelf and mix all the parts together. The exact original first model is statistically impossible to rebuild - able to disassemble but not reassemble.
"
I'm somewhat confused about this first one. I agree, chances would be extremely small, but if you spend the rest of this and all your follow-up lives (you do need to believe in reincarnation for this to work I think), at some point in time you will build the exact same BSB model. There is a limited amount of brick configurations possible so a limited amount of possible outcomes ( = constructed BSB sets). I don't know how you can proof that you did build the exact same BSB model as you did the first time though."
True. Even if you increased it to 200 or 2 million BSB sets, the original set would always exist as a potential solution, however vanishingly small. Really gets into the mathematical concept of asymptotic limits, probability and what counts as zero mathematically. If it takes longer than the age of the universe to find, is it impossible? You could conceptually re-find it on the first try even if 0.000000000000000000000000000000000000000001%.
The second solution linked to the passage of time and the self portrait is maybe a more pure philosophical solution, even if a bit of a koan.
@graafderk said:
" @Forestman_Bygger said:
"1. 'Ship of Theseus' solution: Take a new Black Seas Barracuda box, open, build and disassemble. Open 20 other new BSB boxes you have squirreled away on your shelf and mix all the parts together. The exact original first model is statistically impossible to rebuild - able to disassemble but not reassemble.
"
I'm somewhat confused about this first one. I agree, chances would be extremely small, but if you spend the rest of this and all your follow-up lives (you do need to believe in reincarnation for this to work I think), at some point in time you will build the exact same BSB model. There is a limited amount of brick configurations possible so a limited amount of possible outcomes ( = constructed BSB sets). I don't know how you can proof that you did build the exact same BSB model as you did the first time though."
Shuffle a pack or cards and you'll end up with the cards in one of the 52! possible orders. 52! is 80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000.
52! is a hard number to grasp. A word for this number would approximately be 80 unvigintillion. If all the approximately 6 billion people on Earth began shuffling a deck of playing cards one time per second for the next 100 billion years we would not even come close to fulfilling all possible card combinations.
My head hurts!
I actually appreciate the statistics being don here.
My Monday brain says: "stop it, you guys are killing me!"
@aleydita said:
" @graafderk said:
" @Forestman_Bygger said:
"1. 'Ship of Theseus' solution: Take a new Black Seas Barracuda box, open, build and disassemble. Open 20 other new BSB boxes you have squirreled away on your shelf and mix all the parts together. The exact original first model is statistically impossible to rebuild - able to disassemble but not reassemble.
"
I'm somewhat confused about this first one. I agree, chances would be extremely small, but if you spend the rest of this and all your follow-up lives (you do need to believe in reincarnation for this to work I think), at some point in time you will build the exact same BSB model. There is a limited amount of brick configurations possible so a limited amount of possible outcomes ( = constructed BSB sets). I don't know how you can proof that you did build the exact same BSB model as you did the first time though."
Shuffle a pack or cards and you'll end up with the cards in one of the 52! possible orders. 52! is 80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000.
52! is a hard number to grasp. A word for this number would approximately be 80 unvigintillion. If all the approximately 6 billion people on Earth began shuffling a deck of playing cards one time per second for the next 100 billion years we would not even come close to fulfilling all possible card combinations."
If we are in a philosophical mood anyway, is there a difference if the end result is again a complete BSB (and you cannot tell the difference between builds anyway)?
Unfortunately I don't understand. :(
I just see pieces apart and together and no cardboard.
@CCC said:
"A cutting from a LEGO box would not be purist. Purists don't cut genuine LEGO. So maybe instead use (obviously uncut) LEGO string."
Would the plastic pull tab from a light brick be small enough or long enough to use in this situation?
I might be wrong but... It looks perfectly possible to just start by attaching that small piece with the 3M peg, and then build the rest around it. That wouldn't require any unusual techniques at all. Unless I'm missing something...
@davnnh said:
"I might be wrong but... It looks perfectly possible to just start by attaching that small piece with the 3M peg, and then build the rest around it. That wouldn't require any unusual techniques at all. Unless I'm missing something..."
If you mean the piece that looks like -O- , it's not possible to attach the I-shaped beams to it after it's inside the frame. You might be imaging things rotated 90 degrees inside the frame...
Will this same technique work inside of a 6x8 Technic connector beam with studs on the top? That would be interesting and may be more difficult.
@HandPositions said:
"Will this same technique work inside of a 6x8 Technic connector beam with studs on the top? That would be interesting and may be more difficult."
Oh yeah, that opens up more options.
In either case, a stack of frames could be attached from the inside before the inner construction is slid in there, making a thread more difficult to use.
Actually, it should be possible to build a much larger frame than that and brace it from the inside, making it impossible to take apart from the outside. Then there are all kinds of ways to make the inner construction more robust as well.
@davnnh said:
"I might be wrong but... It looks perfectly possible to just start by attaching that small piece with the 3M peg, and then build the rest around it. That wouldn't require any unusual techniques at all. Unless I'm missing something..."
The part you're missing is that that 3M peg is then pushed into the outer frame after the assembly is placed inside it. (The 'impossible' part of the construction, since fingers can't reach the peg once it's enclosed.) (It took me a while to notice that too.)
I found a "cannot be assembled or disassembled" in step 57 of 4504 Millennium Falcon
https://www.lego.com/biassets/bi/4249049.pdf
The other two sets of instructions use a different part, which I found after fighting with the parts for 30 minutes
https://www.lego.com/biassets/bi/4256111.pdf
https://www.lego.com/biassets/bi/4264853.pdf
An official hard to disassemble at the limit of impossible without the help of an iron pair of pincers
or a nervous super powerful AFOL fingers, is the expensive set 42056 Porsche 911 GT3 RS, at the step 362 and 380 where a crazy design is forcing you to take out a black (6) axle which is fixed hard in 2 hard friction pieces and only 1/6 of it is available to catch and pull.
Cool build.
@graafderk said:
" @aleydita said:
" @graafderk said:
" @Forestman_Bygger said:
"1. 'Ship of Theseus' solution: Take a new Black Seas Barracuda box, open, build and disassemble. Open 20 other new BSB boxes you have squirreled away on your shelf and mix all the parts together. The exact original first model is statistically impossible to rebuild - able to disassemble but not reassemble.
"
I'm somewhat confused about this first one. I agree, chances would be extremely small, but if you spend the rest of this and all your follow-up lives (you do need to believe in reincarnation for this to work I think), at some point in time you will build the exact same BSB model. There is a limited amount of brick configurations possible so a limited amount of possible outcomes ( = constructed BSB sets). I don't know how you can proof that you did build the exact same BSB model as you did the first time though."
Shuffle a pack or cards and you'll end up with the cards in one of the 52! possible orders. 52! is 80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000.
52! is a hard number to grasp. A word for this number would approximately be 80 unvigintillion. If all the approximately 6 billion people on Earth began shuffling a deck of playing cards one time per second for the next 100 billion years we would not even come close to fulfilling all possible card combinations."
If we are in a philosophical mood anyway, is there a difference if the end result is again a complete BSB (and you cannot tell the difference between builds anyway)?"
I mean I can't argue with that. Also you'd get 21 brand-new copies of Black Seas Barracuda, enough to start your own naval fleet.
Now just don't make the same mistake as me and put a 1x2 tile inside of the cake suit guy CMF piece-it's stuck in there for good :(
Cannot purchase 21037 in North America, so it cannot be assembled or dis-assembled there.
Schrödinger's Cat quantum solution: Unopened box; set is both assembled and disassembled until observation.
@fulcrumbop said:
"Schrödinger's Cat quantum solution: Unopened box; set is both assembled and disassembled until observation."
Winner. Drop mic.
@fulcrumbop said:
"Schrödinger's Cat quantum solution: Unopened box; set is both assembled and disassembled until observation."
Completely true. Liking the thought process.
How about a Penrose Triangle or a Hypercube for something possible to take apart but not to assemble?
Or an old school stone archway made of plates? Such a thing would be nigh impossible to support when building but a comleted one could be easilly taken apart.
@kingstonjames said:
"How about a Penrose Triangle or a Hypercube for something possible to take apart but not to assemble?
Or an old school stone archway made of plates? Such a thing would be nigh impossible to support when building but a comleted one could be easilly taken apart."
The archway could be built the same way real ones are: with temporary supports that are removed afterwards.
@fulcrumbop said:
"Schrödinger's Cat quantum solution: Unopened box; set is both assembled and disassembled until observation."
Untrue since we know by observation that a completely assembled BSB will not fit inside the box without serious distortion to the container. I think the Schroedinger's argument only holds true if the container can both support and conceal both states of the object within.
@Felix_Mezei said:
"An official hard to disassemble at the limit of impossible without the help of an iron pair of pincers
or a nervous super powerful AFOL fingers, is the expensive set 42056 Porsche 911 GT3 RS, at the step 362 and 380 where a crazy design is forcing you to take out a black (6) axle which is fixed hard in 2 hard friction pieces and only 1/6 of it is available to catch and pull."
Yep, while not impossible, it essentially is as 1/6 of it is too small to get the grip and force required! I’ve dissembled that model a few times, and resorted to wrapping the end of the axle in a tea towel (to stop damage) then using pliers!
Totally being pedantic, but the Ship of Theseus idea is about identity and continuity rather than ability to be made the same again. If you sail across an ocean and replace the pieces one by one, is it still the same ship or not?
@dagsbricks said:
" @fulcrumbop said:
"Schrödinger's Cat quantum solution: Unopened box; set is both assembled and disassembled until observation."
Untrue since we know by observation that a completely assembled BSB will not fit inside the box without serious distortion to the container. I think the Schroedinger's argument only holds true if the container can both support and conceal both states of the object within."
Bionicle sets and the like fit this criteria pretty well...
@Robot99 said:
" @dagsbricks said:
" @fulcrumbop said:
"Schrödinger's Cat quantum solution: Unopened box; set is both assembled and disassembled until observation."
Untrue since we know by observation that a completely assembled BSB will not fit inside the box without serious distortion to the container. I think the Schroedinger's argument only holds true if the container can both support and conceal both states of the object within."
Bionicle sets and the like fit this criteria pretty well..."
Schroedinger's BSB, not so much. Schroedinger's Bionicle, absolutely!
@dagsbricks said:
" @Robot99 said:
" @dagsbricks said:
" @fulcrumbop said:
"Schrödinger's Cat quantum solution: Unopened box; set is both assembled and disassembled until observation."
Untrue since we know by observation that a completely assembled BSB will not fit inside the box without serious distortion to the container. I think the Schroedinger's argument only holds true if the container can both support and conceal both states of the object within."
Bionicle sets and the like fit this criteria pretty well..."
Schroedinger's BSB, not so much. Schroedinger's Bionicle, absolutely!"
To add on the Schrödinger stuff, from a physicist's point of view, it depends on a bunch of things including the boundary conditions, which in this case would be the size of the container.
That being said, the cat dead or alive is just an example of superposition of states. It's overly simplified so that people can grasp it easily, but in reality you don't need 50-50 chances of being dead or alive. It could be 99-1. Or there could be more states in the superposition, like near-dead.
A very realistic approach to Lego would be to guess how built it is inside the box. It could be: in pieces, completely built, or partially built. In pieces is very probable, completely built is highly unlikely, and there's a probability that it randomly assembled some parts, with smaller assemblies more probable than the big ones. And just like the cat, you can only know once you open the box.
@Kynareth said:
"I think the egg solution from yesterday nailed it. The same concept- seemingly impossible connections that are only possible with an unseen hand. For instance, if you froze the centre of the egg in water you could assemble it when ordinarily you couldn’t."
Damn, didn't think of that. :D Now we're back at the beginning.
To pull out pegs like https://brickset.com/parts/4143005/connector-peg-w-knob I usually use a shaft like https://brickset.com/parts/6093525/shaft-3m-%C3%B83-2.
As long as the friction between the shaft and the peg is larger than between the peg and the axle hole, it works.
I believe the same can be done here as well - and it's a 100% Lego solution!
@CCC:
I had the same thought. Technic beams leave just enough gap that string will fit. You might damage the string in the process, but you can feed it through the notch in the end of the pin and it'd definitely work. On the other hand, if you swap that 3L pin out for an axle-pin in a OO+ configuration, string would be a lot harder to work with.
@Forestman_Bygger:
Ship of Theseus isn't _quite_ as hard as you might think. You can weed out a ton of ineligible parts by checking the bottoms of plates to determine which have been assembled onto studs and which clearly have not.
Same River Twice doesn't work. There's nothing to stop you from rebuilding the exact same mosaic. It may no longer look exactly like you, but the same holds true if you never disassembled it.
@Huw:
It took three tries, but we did have a solution presented yesterday that _can't_ be assembled, by means purist nor non-purist. Not until someone invents Star Trek transporter technology, at least.
@aleydita:
And yet all the card manufacturers manage to repeat the exact same shuffle with every new deck! Sneaky cheats...
@shootvolio:
You probably need a bare minimum of three studs length to pull this off (or, rather, in).
@datsunrobbie:
That's...weird. I'm shocked that they let that through. Did the half-cone change at some point? I had to pull it up in MLCad to see why the revised construction actually works while the original does not, but on the sides the offset studs line up perfectly with the same kinds of pins you find on the bottom of 1x bricks and plates, while the centers have reinforcement walls instead. Studs don't fit over those without judicious application of sledgehammer.
@colby_figcustoms:
https://www.bricklink.com/v2/catalog/catalogitem.page?P=35860pb01
That cake suit? Shove a pair of bars up through the holes in the bottom.
@fulcrumbop:
Shaking the box reveals the fallacy of this concept.
@supervir2:
I've got George Washington's axe. I've only had to replace the handle three times and the head twice.
@Robot99:
The Bohrok (probably my favorite Bionicle sets of all time) were even designed to be displayed inside of their pods.
@Paski:
In this case, the 3L pin has a tiny, rectangular hole, so the friction would be insanely higher between the bar and pin than between the pin and hole. Good luck getting the bar into the pin...
"Shaking the box reveals" = observation.
The balance solution: make a tower of tiles, not stuck together in the usual way, but balanced end-on-end. Very difficult to "assemble", but collapses at the lightest breeze.
@darthsutius hey, now, being anxious about not being able to disassemble your Lego? That's perfectly reasonable!
Good solution! that was mindbending!
@Kramii:
Very easy to assemble. All you have to do is build a display case that's just wide and deep enough to fit exactly one tile. Leave the top open, and it's as easy to "build" as playing Connect Four.
But, why no Jeep?
:-P
Couldn't you leave the top "I" technic beam off, as in the second row picture, place the assembly in the 5x7 rectangle, push in the pin with your fingers, than add the top "I" technic beam?
Couldn't you leave the top "I" technic beam off, as in the second row picture, place the assembly in the 5x7 rectangle, push in the pin with your fingers, than add the top "I" technic beam?