[danparsonson]

I submit to you that it's clearly not a thunderbolt but an arrow indicating changing directions; that being overlaid on top of a pair of axes is obviously useful in the study of non-Euclidean geometry to indicate the use of wibbly-wobbly dimensions.

[etothepii]

Particularly useful for timey-whimey relativistic analyses.

[Shorn]

Related to The Whole Sort Of General Mish Mash.