Questions tagged [topology]
A puzzle about disentangling knots, folding paper, separating strings and wires, and understanding the connectivity properties of elastic figures. General topology questions are off-topic but can be asked on Mathematics Stack Exchange.
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Metallic Puzzle
I've had this metallic puzzle for a very long time (actually it's a replica since the original was lost). It was bought in a shop were I was told long ago that it must have a solution.
The question is,...
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Remove foldback clips from closed loop string
This is not a trick question. In my hands, I have a closed loop string with two foldback clips:
Is it possible, and if so, how can I remove one or both foldback clips from the closed loop string ...
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Toroidal tic-tac-toe
Part of the Monthly Topic Challenge #10: Möbius Strips, Klein Bottles, and other unusual topological surfaces
Warm-up for topological thinking. You are playing tic-tac-toe with the usual 3x3 grid,...
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It boggles my mind
Part of the Monthly Topic Challenge #10: Möbius Strips, Klein Bottles, and other unusual topological surfaces
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Two arcs equal three arcs
(Gonna answer my own question, as is encouraged.)
To set the stage: an arc (or a Jordan arc) is a non-self-intersecting curve with two distinct endpoints. (For those who are familiar with topology, it'...
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D&D dice for literary people
Put a letter on each face of an icosahedron such that a five-letter word can be read clockwise around each vertex. Specifically, these words:
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rope - knotted or does not knot [closed]
The figure shows the shadow of a piece of rope on the ground, and you can't see which part is on which part; Suppose the rope is placed completely randomly. Now tighten the two ends of the rope to the ...
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Make a topological torus-with-a-hole out of congruent squares that may share an edge or a vertex with other squares
Suppose we arrange, in 3-dimensional space, 8 identical solid cubes in space so they form a square-shaped ring (using a 3x3 arrangement of squares except for the one in the middle).
Its surface will ...
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Topology puzzle: Glueing the edges of a square to itself
It is well known that if you start with a two-dimensional square and could glue — in the most straightforward way — the top and bottom edges to each other, and likewise the left and right edges to ...
user76726
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Are three colors sufficient to color a map with convex regions?
The four color theorem states that no more than four colors are required to color the regions
of any map so that no two adjacent regions have the same color.
If all regions are convex (i.e. the region ...
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Connecting 6 dots with 6 curves
Can you connect 6 dots with 6 curves, such that every pair of curves touch each other exactly once? Curves can touch anywhere at their interior or at the dots, and the whole thing must lie in the ...
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Fair and square island hopping [duplicate]
If amateur fiction is not your thing skip to the bottom.
As IP (Implausible Physics) expert for DREAM, the Department for Reckless Engineering and Advanced Megalomania you have been tasked by sheikh ...
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Dragon summoning spell
The parchment shown below got stained with something. See if you can determine the obscured parts.
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Drawing a complete graph of 5 nodes on a torus
A complete graph of $n$ nodes is a graph where every node is connected to every other node. It is known that one cannot draw a complete graph of 5 nodes on a piece of paper (plane) without any ...
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Is it possible to create a knot that is locked only when the rope is stretched?
Is it possible to create a knot that is stable/locked when the rope is stretched?
When the tension is relived the knot should open.
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wandering knight
Suppose a land with a finite number of castles. Each castle is connected (via roads) with exactly 3 other castles.
One knight leaves from his castle and starts travelling. He moves in the following ...
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Some puzzles just appear while doing diy [closed]
I had fitted a camera above the built-in wardrobe in our children's room. There was a socket behind the drawers. I could just remove the drawer to plug it in, but there was only enough room to slide ...
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The grandest zoo in Appelhaken
In the magnificent country of Appelhaken there is a zoo. Not just any zoo, but a grand zoo, a magnificent zoo, called Appelhaken Grand Magnificent Magnificent Grand Grand Zoo.
In this zoo there are ...
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The grandest bridge in Appelhaken [duplicate]
In the capital of the grand country of Appelhaken there is a plane garden containing four magnificent monuments. So magnificent are they that the country has a Law requiring that there must be a ...
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How to use a Mobius strip for puzzle creation? [closed]
A Mobius strip is one of the basic concepts of topology. There are many interesting tricks using this strip (for example, interesting results of cutting the tape with a different number of turns). ...
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Is the following topology puzzle impossible to solve? [duplicate]
There was a problem I was introduced to in grade school which my teacher claimed that not even his graduate level students could solve, and it went a little like this. You have a set of boxes in a ...
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3D ring/rope wooden puzzle solution?
I have a Eureka 3d "Puzzle G":*
The box lists 3 puzzles:
Remove the ring
Remove the rope
Move the ring to the other side
While I was able to solve shows the first puzzle, I haven't ...
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Changing baby's shirt
Baby needs a change of shirt, but baby is also sucking on a bottle (see this stock photo for a visual). If the bottle leaves baby's mouth, baby will start crying. Also, baby loves holding the ...
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Turning My Pants Inside-Out
A 12-foot long rope has two ends. One end of the rope is tied around a man's left ankle and the other end is tied around the man's right ankle.
If you are not allowed to untie the rope and you're ...
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Teacup geometry
Inspired by the three utilities puzzle from prog_SAHIL I'm now posting a similar puzzle that makes use of the topology of a cup with a handle:
The question is:
How many distinct points can you ...
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The three utilities puzzle
Here is a variant of the three utilities puzzle.
Famously, It is impossible to solve it on a plane paper (Euler's theorem can prove that). But can you solve it on a coffee mug?
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IQ Test Example
I'm reading up on various IQ tests, and a slideshow that I stumbled upon gave the following example:
This doesn't make sense to me, as none of the options duplicate the conditions in the far left ...
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Ant-Man in chains [closed]
"Ant-Man" is a superhero that can change his size. Usually he can get very small, but sometimes he can get large as well. In the movie 'Ant-Man' (minor spoiler here) there is a scene where he is ...
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Pulling strings...not legs?
What happens to the two strings - of the logo of G20 Summit (currently happening in Germany)-if pulled either side (in opposite directions, away from the center) at the same time ?
Your options are:...
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