Time space diagrams in distributed systems. Very obvious once you see but never before saw some critical problems in distributed systems like fifo ordering, causal ordering and other things explained with such diagrams.

did not have formal education on distributed systems in my country but learned many things in this topic on job.

So then me took course by lindsey kuper on youtube. it is amazing course, super clear instructor even for me with not good english.

i think professor in this class say these diagrams came from leslie lamport who did lot essential thinking in distributed system space