I hate to say that but I got frustrated when it came to the part to look for glide reflections. It's like you already know you are missing some symmetries beforehand, and therefore you keep looking for them; the point is, how am I supposed to know whether I have exhausted all possibilites??
This is actually a great question. Hint #1: In reality, there are *only* 17 unique ways in 2D that you can combine the different symmetry elements (these are the 17 plane groups). So technically, you don't need to keep searching and searching - you just need to find enough elements to uniquely identify which plane group you jave, then use that as a map to find other elements. Hint #2: glide planes come from the combination of translation amd reflection. Based on how these elements interact, it's really common to find glide planes halfway between mirror planes or other glide planes. So find the reflection planes that you can, then check halfway in between them.
@@pjshamberger Thanks for your reply. I know the classification result you mentioned above; I just find it hard to look for glide reflection, especially when the wallpaper pattern gets ridiculously complicated. And that is why I googled this and happened to come to your video:)
wow this 12 minute video helped me so much! Thank you for explaining it in a clear way!
This is very helpful.
It helped a lot! Thanks! Could you do some more practice videos for plane groups and how to interpret the notations?
I hate to say that but I got frustrated when it came to the part to look for glide reflections. It's like you already know you are missing some symmetries beforehand, and therefore you keep looking for them; the point is, how am I supposed to know whether I have exhausted all possibilites??
This is actually a great question. Hint #1: In reality, there are *only* 17 unique ways in 2D that you can combine the different symmetry elements (these are the 17 plane groups). So technically, you don't need to keep searching and searching - you just need to find enough elements to uniquely identify which plane group you jave, then use that as a map to find other elements. Hint #2: glide planes come from the combination of translation amd reflection. Based on how these elements interact, it's really common to find glide planes halfway between mirror planes or other glide planes. So find the reflection planes that you can, then check halfway in between them.
@@pjshamberger Thanks for your reply. I know the classification result you mentioned above; I just find it hard to look for glide reflection, especially when the wallpaper pattern gets ridiculously complicated. And that is why I googled this and happened to come to your video:)
@@Ken1208-KF a good way to look at glide axis is to search for unique zigzag shapes
I hope you are having a good day sir.