ruud de rooijFeb 23
The 19 ways to split a 2x2x2 cube into 2 equal tetracubes.
Show threadmeduz'Feb 23

@ruuddotorg Could it be that some of them are the same, but the overall results is rotated?

It looks like the top left one, the one at the rightest right and the one in the center of the bottom line are the same. 👀

Show threadThe Tiller 🌈

@meduz @ruuddotorg
:+1:

If you fully account for mirroring and rotational symmetry, only 3 ways remain I think

Feb 23 at 7:29amWeb
Show threadRobynFeb 23
@swoonie
I would argue that rotational symmetry is the same division - the pieces are identical if rotated in relation to each other. Mirroring creates tetracubes that can't map onto each other. So 4 ways?
@meduz @ruuddotorg
Show threadruud de rooijFeb 24
@RedRobyn @swoonie @meduz That’s correct, considering rotations there are 4 distinct shapes, 2 of which are mirror images of each other.
Show threadPhosphenes5d ago

@ruuddotorg @RedRobyn @swoonie @meduz

I am trying to understand the rules...

The bottom middle one does not seem to have a rotated twin anywhere, but the bottom left one appears 3 times at different rotations. Why is this?

Show threadRobyn5d ago
@Phosphenes
The bottom middle one appears rotated immediately above and to the right of itself, to the far right of the middle row and also top left.
Show threadmeduz'4d ago
@Phosphenes @ruuddotorg @RedRobyn @swoonie It actually appears 3 times, too: https://m.nintendojo.fr/@meduz/116118750335048358
meduz' (@meduz@m.nintendojo.fr)

@ruuddotorg@hachyderm.io Could it be that some of them are the same, but the overall results is rotated? It looks like the top left one, the one at the rightest right and the one in the center of the bottom line are the same. 👀

NintendojoFR
Show threadRobyn4d ago
@meduz
Four times in all.
The fourth is the one diagonally above and to the right of the middle bottom.
Show threadPhosphenes4d ago

@RedRobyn @meduz

D'oh of course. I was seeing it wrong.