Mineralogy Homework: Symmetry in our Lives!
Due: Tuesday!
Rather than have you plot endless stereograms of endless block models, what I want you to do instead is look at some relatively ordinary objects in your lives, and report back to me on their symmetry. Report the symmetry in the proper symbology: that is
m
for mirror plane2,3,4,
etc. for rotational axesi
for inversion2,3,4,6/m
for rotation/mirror plane combinations(bar)2,3, or 4
for rotoinversion combinationsInclude in your description of the symmetry a cursory sketch of each object, showing how the symmetry operator works.
We'll compare notes on these the next session.
A) Here are some objects to examine:
1) your automobile
2) one of your auto's tires (exclude the hubcap)
3) a coffee mug
4) a wooden no. 2 pencil (unsharpened)
5) the light fixture over your dining room table (if you don't have a dining room, check your kitchen!
B) Now that we've got the hang of it, lets go searching! Look around this weekend and find objects with the following symmetry. Be ready to defend your selections to your classmates! (If you have questions about how things with these sorts of symmetry should look, please refer to Chapters 9 and 10 in Perkins, and the various linked websites!
1)
6/m symmetry (that is, a six-fold rotation axis and a perpendicular mirror plane.)2)
3-fold rotoinversion symmetry3)
8-fold rotation with NO mirror plane!