A 2D shape is symmetrical if you can draw a line through the middle of it and either side is a reflection of the other. There is a very famous example of symmetry in nature - the butterfly.

And it's so good to be in all this nature because it's so good for ... but we're going to talk about reflective symmetry. If you draw a line down something and the two sides are a reflection ...

Recent research has delved into the nature of equivalence between theories, the implications of symmetry in physical models, and the philosophical underpinnings of these concepts. This exploration ...