1. The problem statement, all variables and given/known data In frame S, Herman drops a pizza at the same time that Pavel drops a marker. In frame S', Alice is moving relative to their S frame - What is the space time interval she sees? A. S' > S B. S' < S C. S=S 2. Relevant equations Lorentz transformations is what we've been learning, but there's no calculations here. 3. The attempt at a solution This is my second week learning relativity, so it's a bit difficult to figure out where to start on a problem. First of all, what does "space time interval" mean? I'm still trying to wrap my head around the idea of space and time being essentially one entity. Does it mean I'm trying to figure out the time interval that Alice sees the two events occurring, Herman ordering and Pavel dropping? Or the distance? I'd appreciate a nudge in the right direction.