Prince Rupert's cube

#1

Post by enhray » Sat, Feb 17, 2018, 4:45 AM UTC

Re: Prince Rupert's cube

#2

Post by mrdmnd » Sat, Feb 17, 2018, 9:43 AM UTC

Interesting that the optimal solution is not "slide it along the space diagonal" but rather "slide it parallel to a face".

Re: Prince Rupert's cube

#3

Post by ThoAppelsin » Sat, Feb 17, 2018, 10:16 AM UTC

mrdmnd wrote: post #2

Interesting that the optimal solution is not "slide it along the space diagonal" but rather "slide it parallel to a face".

I might be wrong about this, but as far as I can see the larger cube slides parallel to an edge and not a face. On top of that, I think the cube passing through would still be sliding parallel to an edge, even if it were to slide along a space diagonal, so those two wouldn't be mutually exclusive. Unless I have failed to visualize it right ok my head.

Re: Prince Rupert's cube

#4

Post by shaded-enmity » Sat, Feb 17, 2018, 10:21 AM UTC

Another interesting thing named after Prince Rupert is the Prince Rupert's drop for anyone interested: https://www.youtube.com/watch?v=k5MORochIDw

Re: Prince Rupert's cube

#5

Post by anvandare » Sat, Feb 17, 2018, 10:43 AM UTC

A video is worth a thousand words of theory:

https://www.youtube.com/watch?v=-2jjgHsxEu4

Re: Prince Rupert's cube

#6

Post by jholman » Sat, Feb 17, 2018, 12:30 PM UTC

anvandare wrote: post #5

A video is worth a thousand words of theory: https://www.youtube.com/watch?v=-2jjgHsxEu4

That was very good (thank you!), but it led me to this, which was even better:

https://www.youtube.com/watch?v=rAHcZGjKVvg

Re: Prince Rupert's cube

#7

Post by mjlee » Sat, Feb 17, 2018, 1:19 PM UTC

I reckon you could stretch this to a 30 minute whiteboard session to answer why (some) manhole covers are round.

Re: Prince Rupert's cube

#8

Post by newman8r » Sat, Feb 17, 2018, 2:01 PM UTC

looks like a fun model to 3d-print

Re: Prince Rupert's cube

#9

Post by newman8r » Sat, Feb 17, 2018, 2:04 PM UTC

shaded-enmity wrote: post #4

Another interesting thing named after Prince Rupert is the Prince Rupert's drop for anyone interested: https://www.youtube.com/watch?v=k5MORochIDw

I recommend trying them with capillary tubes, you can melt them with a cigarette lighter

Re: Prince Rupert's cube

#10

Post by taneq » Sat, Feb 17, 2018, 3:20 PM UTC

anvandare wrote: post #5

A video is worth a thousand words of theory: https://www.youtube.com/watch?v=-2jjgHsxEu4

After watching the video, I feel like this follows intuitively from the fact that sqrt(2) > 1.