Answer:
A shimmering field that reaches far. Yet it has no tracks, And is crossed without paths.
Turns us on our backs, and open up our stomachs. You will be the wisest of men though at start a lummox.
Always old, sometimes new. Never sad, sometimes blue. Never empty, sometimes full. Never pushes, always pulls.
Once they sailed the sea, now they surf the web
I open wide and tight I shut, Sharp am I and paper-cut fingers too, so do take care, I'm good and bad, so best beware.
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?