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The [[Soma cube]] is a [[mathematical game|mathematical puzzle]] by [[Piet Hein]]. |
The [[Soma cube]] is a [[mathematical game|mathematical puzzle]] by [[Piet Hein]]. |
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:''This text is from the 'Tetromino' article, and is being edited'' |
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Counting rotations in [[2d|two dimensions]] as equivalent, there are seven possible shapes: |
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<ul> |
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<li>[[image:tetris-i.png]] I (also called "stick", "straight"): four blocks in a straight line</li> |
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<li>[[image:tetris-o.png]] Square (also called "O", "package", "block"): four blocks in a 2x2 square</li> |
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<li>[[image:tetris-t.png]] T: a row of three blocks with one added below the center |
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<br>A common move with the T piece is to spin it in place to fill a line.</li> |
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<li>[[image:tetris-l.png]] L: a row of three blocks with one added below the left side</li> |
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<li>[[image:tetris-j.png]] J (also called "inverted L", "[[Gamma]]"): a row of three blocks with one added below the right side |
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<br>This piece is a reflection of L but cannot be rotated into L in two dimensions; this is an example of [[chirality]]. |
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However, in [[3d|three dimensions]], this piece is identical to L.)</li> |
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<li>[[image:tetris-s.png]] S: bent trimino with block placed on outside of clockwise side</li> |
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<li>[[image:tetris-z.png]] Z: bent trimino with block added on outside of anticlockwise side |
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<br>Reflection to S. See "J", above.</li> |
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</ul> |
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When added the third dimension, there are three more patterns, all created by placing a unit cube on the bent trimino: |
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<ul> |
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<li>[[image:tetris-lscrew.png]] Left screw: unit cube placed on top of anticlockwise side. Chiral in 3D.</li> |
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<li>[[image:tetris-rscrew.png]] Right screw: unit cube placed on top of clockwise side. Chiral in 3D.</li> |
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<li>[[image:tetris-branch.png]] Branch: unit cube placed on bend. Not chiral in 3D.</li> |
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</ul> |
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See also: |
See also: |
Revision as of 00:01, 27 January 2002
The Soma cube is a mathematical puzzle by Piet Hein.
- This text is from the 'Tetromino' article, and is being edited
Counting rotations in two dimensions as equivalent, there are seven possible shapes:
- I (also called "stick", "straight"): four blocks in a straight line
- Square (also called "O", "package", "block"): four blocks in a 2x2 square
- T: a row of three blocks with one added below the center
A common move with the T piece is to spin it in place to fill a line. - L: a row of three blocks with one added below the left side
- J (also called "inverted L", "Gamma"): a row of three blocks with one added below the right side
This piece is a reflection of L but cannot be rotated into L in two dimensions; this is an example of chirality. However, in three dimensions, this piece is identical to L.) - S: bent trimino with block placed on outside of clockwise side
- Z: bent trimino with block added on outside of anticlockwise side
Reflection to S. See "J", above.
When added the third dimension, there are three more patterns, all created by placing a unit cube on the bent trimino:
- Left screw: unit cube placed on top of anticlockwise side. Chiral in 3D.
- Right screw: unit cube placed on top of clockwise side. Chiral in 3D.
- Branch: unit cube placed on bend. Not chiral in 3D.
See also: